Commit Graph

639 Commits

Author SHA1 Message Date
Sanjay Patel 643d21a62c [InstCombine] use m_APInt to allow icmp (shl X, Y), C folds for splat constant vectors, part 4
This concludes the fixes for icmp+shl in this series:
https://reviews.llvm.org/rL279339
https://reviews.llvm.org/rL279398
https://reviews.llvm.org/rL279399

llvm-svn: 279401
2016-08-21 17:10:07 +00:00
Sanjay Patel 7ffcde7422 [InstCombine] use m_APInt to allow icmp (shl X, Y), C folds for splat constant vectors, part 3
This is a partial enablement (move the ConstantInt guard down).

llvm-svn: 279399
2016-08-21 16:35:34 +00:00
Sanjay Patel 7e09f13fed [InstCombine] use m_APInt to allow icmp (shl X, Y), C folds for splat constant vectors, part 2
This is a partial enablement (move the ConstantInt guard down).

llvm-svn: 279398
2016-08-21 16:28:22 +00:00
Sanjay Patel 792636603f [InstCombine] use APInt instead of ConstantInt in isSignBitCheck(); NFCI
The callers still have ConstantInt guards, so there is no functional change
intended from this change. But relaxing the callers will allow more folds
for vector types.

llvm-svn: 279396
2016-08-21 15:07:45 +00:00
Sanjay Patel fa7de606c4 [InstCombine] use m_APInt to allow icmp (shl X, Y), C folds for splat constant vectors, part 1
This is a partial enablement (move the ConstantInt guard down) because there are many
different folds here and one of the later ones will require reworking 'isSignBitCheck'.

llvm-svn: 279339
2016-08-19 22:33:26 +00:00
Sanjay Patel 7a104615c5 [InstCombine] remove an icmp fold that is already handled by InstSimplify
Specifically, this is done near the end of "SimplifyICmpInst" using 
computeKnownBits() as the broader solution. There are even vector
tests (yay!) for this in test/Transforms/InstSimplify/compare.ll.

I considered putting an assert here instead of just deleting, but
then we could assert every possible fold in InstSimplify in 
InstCombine, so...less is more?

llvm-svn: 279300
2016-08-19 19:03:07 +00:00
Sanjay Patel e38e79c3e6 [InstCombine] use local variables to reduce code in foldICmpShlConstant; NFC
llvm-svn: 279282
2016-08-19 17:34:05 +00:00
Sanjay Patel 38b7506f75 [InstCombine] rename variables in foldICmpShlConstant(); NFC
llvm-svn: 279279
2016-08-19 17:20:37 +00:00
Reid Kleckner a871d3872a Fix regression in InstCombine introduced by r278944
The intended transform is:
  // Simplify icmp eq (or (ptrtoint P), (ptrtoint Q)), 0
  // -> and (icmp eq P, null), (icmp eq Q, null).

P and Q are both pointer types, but may have different types. We need
two calls to getNullValue() to make the icmps.

llvm-svn: 279271
2016-08-19 16:53:18 +00:00
Sanjay Patel a867afe094 [InstCombine] use m_APInt to allow icmp (shl 1, Y), C folds for splat constant vectors
llvm-svn: 279266
2016-08-19 16:12:16 +00:00
Sanjay Patel 57b12d3876 [InstCombine] use m_APInt to allow icmp X, C folds for splat constant vectors
Of course, we really need to refactor and fix all of the cmp predicates, 
but this one is interesting because without it, we later perform an 
information-losing transform of icmp (shl 1, Y), C, and we can't recover
the better fold.

llvm-svn: 279263
2016-08-19 15:40:44 +00:00
Sanjay Patel 98cd99dfc6 [InstCombine] add helper function for folds of icmp (shl 1, Y), C; NFCI
Clean up the existing code by:
1. Renaming variables
2. Adding local variables
3. Making it vector-safe

This is still guarded by a ConstantInt check, so no functional change is intended.
But this should be ready to go: if we move the ConstantInt check down, all of
these folds should do the right thing for vector types.

llvm-svn: 279150
2016-08-18 21:28:30 +00:00
Sanjay Patel 40e8ca46ad [InstCombine] use m_APInt to allow icmp (trunc X, Y), C folds for splat constant vectors
This is a sibling of:
https://reviews.llvm.org/rL278859
https://reviews.llvm.org/rL278935
https://reviews.llvm.org/rL278945
https://reviews.llvm.org/rL279066
https://reviews.llvm.org/rL279077
https://reviews.llvm.org/rL279101

llvm-svn: 279133
2016-08-18 20:28:54 +00:00
Sanjay Patel 5f4ce4e23d [InstCombine] clean up foldICmpTruncConstant(); NFCI
1. Fix variable names
2. Add local variables to reduce code

llvm-svn: 279132
2016-08-18 20:25:16 +00:00
Sanjay Patel fa5ca2bf46 [InstCombine] use m_APInt to allow icmp (udiv X, Y), C folds for splat constant vectors
This is a sibling of:
https://reviews.llvm.org/rL278859
https://reviews.llvm.org/rL278935
https://reviews.llvm.org/rL278945
https://reviews.llvm.org/rL279066
https://reviews.llvm.org/rL279077

llvm-svn: 279101
2016-08-18 17:55:59 +00:00
Sanjay Patel 12a4105647 [InstCombine] clean up foldICmpUDivConstant; NFC
1. Better variable names
2. Remove unnecessary check of ConstantInt

llvm-svn: 279094
2016-08-18 17:37:26 +00:00
Sanjay Patel 6347807f87 [InstCombine] use m_APInt to allow icmp (mul X, Y), C folds for splat constant vectors
This is a sibling of:
https://reviews.llvm.org/rL278859
https://reviews.llvm.org/rL278935
https://reviews.llvm.org/rL278945
https://reviews.llvm.org/rL279066

llvm-svn: 279077
2016-08-18 15:44:44 +00:00
Sanjay Patel 5b112845da [InstCombine] use APInt in isSignTest instead of ConstantInt; NFC
This will enable vector splat folding, but NFC until the callers
have their ConstantInt restrictions removed.

llvm-svn: 279072
2016-08-18 14:59:14 +00:00
Sanjay Patel 4c5e60d95c [InstCombine] use m_APInt to allow icmp (xor X, Y), C folds for splat constant vectors
This is a sibling of:
https://reviews.llvm.org/rL278859
https://reviews.llvm.org/rL278935
https://reviews.llvm.org/rL278945

llvm-svn: 279066
2016-08-18 14:10:48 +00:00
Justin Bogner cd1d5aaf2e Replace a few more "fall through" comments with LLVM_FALLTHROUGH
Follow up to r278902. I had missed "fall through", with a space.

llvm-svn: 278970
2016-08-17 20:30:52 +00:00
Sanjay Patel daffec91ef [InstCombine] more clean up of foldICmpXorConstant(); NFCI
Use m_APInt for the xor constant, but this is all still guarded by the initial
ConstantInt check, so no vector types should make it in here.

llvm-svn: 278957
2016-08-17 19:45:18 +00:00
Sanjay Patel 6d5f448746 [InstCombine] clean up foldICmpXorConstant(); NFCI
1. Change variable names
2. Use local variables to reduce code
3. Early exit to reduce indent

llvm-svn: 278955
2016-08-17 19:23:42 +00:00
Sanjay Patel 63e14a07e8 [InstCombine] use m_APInt to allow icmp (or X, Y), C folds for splat constant vectors
This is a sibling of:
https://reviews.llvm.org/rL278859
https://reviews.llvm.org/rL278935

llvm-svn: 278945
2016-08-17 16:38:57 +00:00
Sanjay Patel 943e92efde [InstCombine] clean up foldICmpOrConstant(); NFCI
1. Change variable names
2. Use local variables to reduce code
3. Use ? instead of if/else
4. Use the APInt variable instead of 'RHS' so the removal of the FIXME code will be direct

llvm-svn: 278944
2016-08-17 16:30:43 +00:00
Sanjay Patel 4f7eb2aa95 [InstCombine] use m_APInt to allow icmp (add X, Y), C folds for splat constant vectors
This is a sibling of:
https://reviews.llvm.org/rL278859

llvm-svn: 278935
2016-08-17 15:24:30 +00:00
Justin Bogner b03fd12cef Replace "fallthrough" comments with LLVM_FALLTHROUGH
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.

llvm-svn: 278902
2016-08-17 05:10:15 +00:00
Sanjay Patel 60ea1b43d6 [InstCombine] clean up foldICmpAddConstant(); NFCI
1. Fix variable names
2. Add local variables to reduce code
3. Fix code comments
4. Add early exit to reduce indentation
5. Remove 'else' after if -> return
6. Hoist common predicate

llvm-svn: 278864
2016-08-16 22:34:42 +00:00
Sanjay Patel e47df1ac62 [InstCombine] use m_APInt to allow icmp (sub X, Y), C folds for splat constant vectors
llvm-svn: 278859
2016-08-16 21:53:19 +00:00
Sanjay Patel b9aa67bfcf [InstCombine] fix variable names to match formula comments; NFC
llvm-svn: 278855
2016-08-16 21:26:10 +00:00
Sanjay Patel a3f4f0828b [InstCombine] add helper functions for foldICmpWithConstant; NFCI
Besides breaking up a 700 line function to improve readability,
this sinks the 'FIXME: ConstantInt' check into each helper. So 
now we can independently break that restriction within any of the
helper functions.

As much as possible, the code was only {cut/paste/clang-format}'ed 
to minimize risk (no functional changes intended), so several more
readability improvements are still possible. 

llvm-svn: 278828
2016-08-16 17:54:36 +00:00
Sanjay Patel 1e5b2d1611 [InstCombine] use m_APInt in foldICmpWithConstant; NFCI
There's some formatting and pointer deref ugliness here that I intend to fix in
subsequent patches. The overall goal is to refactor the obnoxiously long switch
and incrementally remove the restriction to scalar types (allow folds for vector
splats). This patch introduces the use of m_APInt which means the RHSV reference
is now a pointer (and may have matched a vector splat), but the check of 'RHS' 
remains, so vector folds are disallowed and no functional change is intended.

llvm-svn: 278816
2016-08-16 16:08:11 +00:00
Pete Cooper 980a935e27 constify InstCombine::foldAllocaCmp. NFC.
This is part of an effort to constify ValueTracking.cpp.  This change is
to methods which need const Value* instead of Value* to go with the upcoming
changes to ValueTracking.

llvm-svn: 278528
2016-08-12 17:13:28 +00:00
Justin Bogner c7e4fbe11c InstCombine: Clean up some trailing whitespace. NFC
llvm-svn: 277793
2016-08-05 01:09:48 +00:00
Justin Bogner 9979840f59 InstCombine: Replace some never-null pointers with references. NFC
llvm-svn: 277792
2016-08-05 01:06:44 +00:00
Sanjay Patel 3bade138b5 [InstCombine] use m_APInt to allow icmp eq (mul X, C1), C2 folds for splat constant vectors
This concludes the splat vector enhancements for foldICmpEqualityWithConstant().
Other commits in this series:
https://reviews.llvm.org/rL277762
https://reviews.llvm.org/rL277752
https://reviews.llvm.org/rL277738
https://reviews.llvm.org/rL277731
https://reviews.llvm.org/rL277659
https://reviews.llvm.org/rL277638
https://reviews.llvm.org/rL277629

llvm-svn: 277779
2016-08-04 22:19:27 +00:00
Sanjay Patel d938e88e89 [InstCombine] use m_APInt to allow icmp eq (and X, C1), C2 folds for splat constant vectors
llvm-svn: 277762
2016-08-04 20:05:02 +00:00
Sanjay Patel b3de75d3a0 [InstCombine] use m_APInt to allow icmp eq (or X, C1), C2 folds for splat constant vectors
llvm-svn: 277752
2016-08-04 19:12:12 +00:00
Sanjay Patel bcaf6f39dd [InstCombine] use m_APInt to allow icmp eq (op X, Y), C folds for splat constant vectors
I'm removing a misplaced pair of more specific folds from InstCombine in this patch as well,
so we know where those folds are happening in InstSimplify.

llvm-svn: 277738
2016-08-04 17:48:04 +00:00
Sanjay Patel 9d591d15ec [InstCombine] use m_APInt to allow icmp eq (sub C1, X), C2 folds for splat constant vectors
llvm-svn: 277731
2016-08-04 15:19:25 +00:00
Amaury Sechet 6bea674c43 Add popcount(n) == bitsize(n) -> n == -1 transformation.
Summary: As per title.

Reviewers: majnemer, spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23139

llvm-svn: 277694
2016-08-04 05:27:20 +00:00
Sanjay Patel 00a324e893 [InstCombine] use m_APInt to allow icmp eq (add X, C1), C2 folds for splat constant vectors
llvm-svn: 277659
2016-08-03 22:08:44 +00:00
Sanjay Patel 2e9675ff52 [InstCombine] use m_APInt to allow icmp eq (srem X, C1), C2 folds for splat constant vectors
llvm-svn: 277638
2016-08-03 19:48:40 +00:00
Sanjay Patel 43aeb001c9 [InstCombine] use m_APInt to allow icmp (binop X, Y), C folds with constant splat vectors
This removes the restriction for the icmp constant, but as noted by the FIXME comments, 
we still need to change individual checks for binop operand constants.

llvm-svn: 277629
2016-08-03 18:59:03 +00:00
Sanjay Patel 51a767c6b8 use local variables; NFC
llvm-svn: 277612
2016-08-03 17:23:08 +00:00
Sanjay Patel ab50a93888 [InstCombine] replace dyn_casts with matches; NFCI
Clean-up before changing this to allow folds for vectors.

llvm-svn: 277538
2016-08-02 22:38:33 +00:00
Sanjay Patel 1271bf9178 [InstCombine] allow icmp (bit-manipulation-intrinsic(), C) folds for vectors
llvm-svn: 276523
2016-07-23 13:06:49 +00:00
Sanjay Patel 6ebd5857c8 [InstCombine] move udiv+cmp fold over with other BinOp+cmp folds; NFCI
llvm-svn: 276502
2016-07-23 00:28:39 +00:00
Sanjay Patel 18fa9d3ca1 [InstCombine] break up foldICmpEqualityWithConstant(); NFCI
Almost all of these folds require changes to allow vector types. 
Splitting up the logic should make that easier to do incrementally.

llvm-svn: 276360
2016-07-21 23:27:36 +00:00
Sanjay Patel 43395060a1 make InstCombine compare helper functions private; NFC
Also, rename some of them for consistency and to follow current conventions.

llvm-svn: 276312
2016-07-21 18:07:40 +00:00
Sanjay Patel 1710e7cfa7 [InstCombine] break up visitICmpInstWithInstAndIntCst(); NFCI
Making smaller pieces out of some of these ~1000 line functions should make
it easier to incrementally upgrade them to handle vector types.

llvm-svn: 276304
2016-07-21 17:15:49 +00:00
Benjamin Kramer 46e38f3678 Avoid copies of std::strings and APInt/APFloats where we only read from it
As suggested by clang-tidy's performance-unnecessary-copy-initialization.
This can easily hit lifetime issues, so I audited every change and ran the
tests under asan, which came back clean.

llvm-svn: 272126
2016-06-08 10:01:20 +00:00
Sanjay Patel 6a333c3ed9 [InstCombine] limit icmp transform to ConstantInt (PR28011)
In r271810 ( http://reviews.llvm.org/rL271810 ), I loosened the check
above this to work for any Constant rather than ConstantInt. AFAICT, 
that part makes sense if we can determine that the shrunken/extended 
constant remained equal. But it doesn't make sense for this later 
transform where we assume that the constant DID change. 

This could assert for a ConstantExpr:
https://llvm.org/bugs/show_bug.cgi?id=28011

And it could be wrong for a vector as shown in the added regression test.

llvm-svn: 271908
2016-06-06 16:56:57 +00:00
Sanjay Patel a6fbc82392 [InstCombine] allow vector icmp bool transforms
llvm-svn: 271843
2016-06-05 17:49:45 +00:00
Sanjay Patel 5f0217f42e fix documentation comments and other clean-ups; NFC
llvm-svn: 271839
2016-06-05 16:46:18 +00:00
Sanjay Patel 6f8f47b358 [InstCombine] less 'CI' confusion; NFC
Change the name of the ICmpInst to 'ICmp' and the Constant (was a ConstantInt) to 'C',
so that it's hopefully clearer that 'CI' refers to CastInst in this context.

While we're scrubbing, fix the documentation comment and use 'auto' with 'dyn_cast'.

llvm-svn: 271817
2016-06-05 00:12:32 +00:00
Sanjay Patel ea8a211169 [InstCombine] allow vector constants for cast+icmp fold
This is step 1 of unknown towards fixing PR28001:
https://llvm.org/bugs/show_bug.cgi?id=28001

llvm-svn: 271810
2016-06-04 22:04:05 +00:00
Sanjay Patel c774f8c265 clean-up; NFC
llvm-svn: 271807
2016-06-04 21:20:44 +00:00
Sanjay Patel 4c204230fc fix formatting, punctuation; NFC
llvm-svn: 271804
2016-06-04 20:39:22 +00:00
Sanjay Patel 22b01febd4 [InstCombine] add another test for wrong icmp constant (PR27792)
It doesn't matter if the comparison is unsigned; the inc/dec is always signed.

llvm-svn: 269831
2016-05-17 20:20:40 +00:00
Sanjay Patel 86564cad06 [InstCombine] fix constant to be signed for signed comparisons
This bug was introduced in r269728 and is the likely cause of many stage 2 ubsan bot failures.
I'll add a test in a follow-up commit assuming this fixes things properly.

llvm-svn: 269797
2016-05-17 18:38:55 +00:00
Benjamin Kramer ca9a0fe2b9 [InstCombine] Don't crash when trying to take an element of a ConstantExpr.
Fixes PR27786.

llvm-svn: 269757
2016-05-17 12:08:55 +00:00
Sanjay Patel 18254935c9 try to avoid unused variable warning in release build; NFCI
llvm-svn: 269729
2016-05-17 01:12:31 +00:00
Sanjay Patel e9b2c32e7f [InstCombine] check vector elements before trying to transform LE/GE vector icmp (PR27756)
Fix a bug introduced with rL269426 :
[InstCombine] canonicalize* LE/GE vector integer comparisons to LT/GT (PR26701, PR26819)

We were assuming that a ConstantDataVector / ConstantVector / ConstantAggregateZero operand of
an ICMP was composed of ConstantInt elements, but it might have ConstantExpr or UndefValue 
elements. Handle those appropriately.

Also, refactor this function to join the scalar and vector paths and eliminate the switches.

Differential Revision: http://reviews.llvm.org/D20289

llvm-svn: 269728
2016-05-17 00:57:57 +00:00
Sanjay Patel 0c8f3f9332 [InstCombine] handle zero constant vectors for LE/GE comparisons too
Enhancement to: http://reviews.llvm.org/rL269426
With discussion in: http://reviews.llvm.org/D17859

This should complete the fixes for: PR26701, PR26819:
https://llvm.org/bugs/show_bug.cgi?id=26701
https://llvm.org/bugs/show_bug.cgi?id=26819
 

llvm-svn: 269439
2016-05-13 17:28:12 +00:00
Sanjay Patel b79ab27853 [InstCombine] canonicalize* LE/GE vector integer comparisons to LT/GT (PR26701, PR26819)
*We don't currently handle the  edge case constants (min/max values), so it's not a complete
canonicalization.

To fully solve the motivating bugs, we need to enhance this to recognize a zero vector
too because that's a ConstantAggregateZero which is a ConstantData, not a ConstantVector
or a ConstantDataVector.

Differential Revision: http://reviews.llvm.org/D17859 

llvm-svn: 269426
2016-05-13 15:10:46 +00:00
Chad Rosier 4e6cda2db5 [InstCombine] Fold icmp ugt/ult (udiv i32 C2, X), C1.
This patch adds support for two optimizations:
icmp ugt (udiv C2, X), C1 -> icmp ule X, C2/(C1+1)
icmp ult (udiv C2, X), C1 -> icmp ugt X, C2/C1

Differential Revision: http://reviews.llvm.org/D20123

llvm-svn: 269109
2016-05-10 20:22:09 +00:00
Chad Rosier 131a42ccdf [InstCombine] Fold icmp eq/ne (udiv i32 A, B), 0 -> icmp ugt/ule B, A.
Differential Revision: http://reviews.llvm.org/D20036

llvm-svn: 268960
2016-05-09 19:30:20 +00:00
Balaram Makam 569eaec5f3 "Reapply r268521 "[InstCombine] Canonicalize icmp instructions based on dominating conditions.""
This reapplies commit r268521, that was reverted in r268530 due to a test failure in select-implied.ll
Modified the test case to reflect the new change.

llvm-svn: 268557
2016-05-04 21:32:14 +00:00
Balaram Makam 31e7e13789 Revert "[InstCombine] Canonicalize icmp instructions based on dominating conditions."
This reverts commit 573a40f79b35cf3e71db331bb00f6a84f03b835d.

llvm-svn: 268530
2016-05-04 18:37:35 +00:00
Balaram Makam cf3bcb2625 [InstCombine] Canonicalize icmp instructions based on dominating conditions.
Summary:
    This patch canonicalizes conditions based on the constant range information
    of the dominating branch condition.
    For example:

      %cmp = icmp slt i64 %a, 0
      br i1 %cmp, label %land.lhs.true, label %lor.rhs
      lor.rhs:
        %cmp2 = icmp sgt i64 %a, 0

    Would now be canonicalized into:

      %cmp = icmp slt i64 %a, 0
      br i1 %cmp, label %land.lhs.true, label %lor.rhs
      lor.rhs:
        %cmp2 = icmp ne i64 %a, 0

Reviewers: mcrosier, gberry, t.p.northover, llvm-commits, reames, hfinkel, sanjoy, majnemer

Subscribers: MatzeB, majnemer, mcrosier

Differential Revision: http://reviews.llvm.org/D18841

llvm-svn: 268521
2016-05-04 17:34:20 +00:00
Sanjay Patel d5b0e54b49 [InstCombine] add helper function for ICmp with constant canonicalization; NFCI
As suggested in http://reviews.llvm.org/D17859 , we should enhance this
to support vectors.

llvm-svn: 268059
2016-04-29 16:22:25 +00:00
David Majnemer b4b27230bf [ValueTracking, VectorUtils] Refactor getIntrinsicIDForCall
The functionality contained within getIntrinsicIDForCall is two-fold: it
checks if a CallInst's callee is a vectorizable intrinsic.  If it isn't
an intrinsic, it attempts to map the call's target to a suitable
intrinsic.

Move the mapping functionality into getIntrinsicForCallSite and rename
getIntrinsicIDForCall to getVectorIntrinsicIDForCall while
reimplementing it in terms of getIntrinsicForCallSite.

llvm-svn: 266801
2016-04-19 19:10:21 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
David Majnemer 2e02ba78d5 [InstCombine] Don't transform compares of calls to functions named fabs{f,l,}
InstCombine wants to optimize compares of calls to fabs with zero.
However, we didn't have the necessary legality checking to verify that
the function call had the same behavior as fabs.

llvm-svn: 266452
2016-04-15 17:21:03 +00:00
Sanjay Patel e998b91d86 [InstCombine] remove constant by inverting compare + logic (PR27105)
https://llvm.org/bugs/show_bug.cgi?id=27105

We can check if all bits outside of a constant mask are set with a 
single constant.

As noted in the bug report, although this form should be considered the
canonical IR, backends may want to transform this into an 'andn' / 'andc' 
comparison against zero because that could be a single machine instruction.

Differential Revision: http://reviews.llvm.org/D18842

llvm-svn: 266362
2016-04-14 20:17:40 +00:00
David Majnemer 3ee5f34469 [InstCombine] We folded an fcmp to an i1 instead of a vector of i1
Remove an ad-hoc transform in InstCombine and replace it with more
general machinery (ValueTracking, InstructionSimplify and VectorUtils).

This fixes PR27332.

llvm-svn: 266175
2016-04-13 06:55:52 +00:00
David Majnemer cdf2873e36 [InstCombine] Don't insert instructions before a catch switch
CatchSwitches are not splittable, we cannot insert casts, etc. before
them.

This fixes PR26992.

llvm-svn: 263874
2016-03-19 04:39:52 +00:00
Philip Reames 8f12eba78d [ValueTracking] Extract isKnownPositive [NFCI]
Extract out a generic interface from a recently landed patch and document a TODO in case compile time becomes a problem.

llvm-svn: 263062
2016-03-09 21:31:47 +00:00
Philip Reames ec8a8b5437 [InstCombine] (icmp sgt smin(PosA, B) 0) -> (icmp sgt B 0)
When checking whether an smin is positive, we can move the comparison to one of the inputs if the other is known positive. If the known positive one is the min, then the other can't be negative. If the other is the min, then we compute the min.

Differential Revision: http://reviews.llvm.org/D17873

llvm-svn: 263059
2016-03-09 21:05:07 +00:00
Richard Trieu 7a08381403 Remove uses of builtin comma operator.
Cleanup for upcoming Clang warning -Wcomma.  No functionality change intended.

llvm-svn: 261270
2016-02-18 22:09:30 +00:00
David Majnemer 0f0abc7bc2 [InstCombine] Don't aggressively replace xor with icmp
For some cases, InstCombine replaces the sequence of xor/sub instruction
followed by cmp instruction into a single cmp instruction.

However, this replacement may result suboptimal result especially when
the xor/sub has more than one use, as discussed in
bug 26465 (https://llvm.org/bugs/show_bug.cgi?id=26465).

This patch make the replacement happen only when xor/sub has only one
use.

Differential Revision: http://reviews.llvm.org/D16915

Patch by Taewook Oh!

llvm-svn: 260695
2016-02-12 18:12:38 +00:00
Sanjay Patel 4b198802b3 function names start with a lowercase letter; NFC
llvm-svn: 259425
2016-02-01 22:23:39 +00:00
David Majnemer f8853ae7b3 [InstCombine] Don't transform (X+INT_MAX)>=(Y+INT_MAX) -> (X<=Y)
This miscompile came about because we tried to use a transform which was
only appropriate for xor operators when addition was present.

This fixes PR26407.

llvm-svn: 259375
2016-02-01 17:37:56 +00:00
Silviu Baranga f29dfd36bb Re-commit r257064, after it was reverted in r257340.
This contains a fix for the issue that caused the revert:
we no longer assume that we can insert instructions after the
instruction that produces the base pointer. We previously
assumed that this would be ok, because the instruction produces
a value and therefore is not a terminator. This is false for invoke
instructions. We will now insert these new instruction directly
at the location of the users.

Original commit message:

[InstCombine] Look through PHIs, GEPs, IntToPtrs and PtrToInts to expose more constants when comparing GEPs

Summary:
When comparing two GEP instructions which have the same base pointer
and one of them has a constant index, it is possible to only compare
indices, transforming it to a compare with a constant. This removes
one use for the GEP instruction with the constant index, can reduce
register pressure and can sometimes lead to removing the comparisson
entirely.

InstCombine was already doing this when comparing two GEPs if the base
pointers were the same. However, in the case where we have complex
pointer arithmetic (GEPs applied to GEPs, PHIs of GEPs, conversions to
or from integers, etc) the value of the original base pointer will be
hidden to the optimizer and this transformation will be disabled.

This change detects when the two sides of the comparison can be
expressed as GEPs with the same base pointer, even if they don't
appear as such in the IR. The transformation will convert all the
pointer arithmetic to arithmetic done on indices and all the relevant
uses of GEPs to GEPs with a common base pointer. The GEP comparison
will be converted to a comparison done on indices.

Reviewers: majnemer, jmolloy

Subscribers: hfinkel, jevinskie, jmolloy, aadg, llvm-commits

Differential Revision: http://reviews.llvm.org/D15146

llvm-svn: 257897
2016-01-15 15:52:05 +00:00
Silviu Baranga 603954ef0e Revert r257164 - it has caused spec2k6 failures in LTO mode
llvm-svn: 257340
2016-01-11 16:19:38 +00:00
NAKAMURA Takumi 134d31e328 InstCombineCompares.cpp: Fix a warning. [-Wbraced-scalar-init]
llvm-svn: 257167
2016-01-08 12:50:03 +00:00
Silviu Baranga 9e007efad2 Re-commit r257064, this time with a fixed assert
In setInsertionPoint if the value is not a PHI, Instruction or
Argument it should be a Constant, not a ConstantExpr.

Original commit message:

[InstCombine] Look through PHIs, GEPs, IntToPtrs and PtrToInts to expose more constants when comparing GEPs

Summary:
When comparing two GEP instructions which have the same base pointer
and one of them has a constant index, it is possible to only compare
indices, transforming it to a compare with a constant. This removes
one use for the GEP instruction with the constant index, can reduce
register pressure and can sometimes lead to removing the comparisson
entirely.

InstCombine was already doing this when comparing two GEPs if the base
pointers were the same. However, in the case where we have complex
pointer arithmetic (GEPs applied to GEPs, PHIs of GEPs, conversions to
or from integers, etc) the value of the original base pointer will be
hidden to the optimizer and this transformation will be disabled.

This change detects when the two sides of the comparison can be
expressed as GEPs with the same base pointer, even if they don't
appear as such in the IR. The transformation will convert all the
pointer arithmetic to arithmetic done on indices and all the relevant
uses of GEPs to GEPs with a common base pointer. The GEP comparison
will be converted to a comparison done on indices.

Reviewers: majnemer, jmolloy

Subscribers: hfinkel, jevinskie, jmolloy, aadg, llvm-commits

Differential Revision: http://reviews.llvm.org/D15146

llvm-svn: 257164
2016-01-08 11:11:04 +00:00
Silviu Baranga dd68d46ec1 Revert r257064. It caused failures in some sanitizer tests.
llvm-svn: 257069
2016-01-07 15:46:43 +00:00
Silviu Baranga c67ec3f716 Fix build after r257064: we should be returning false, not nullptr
llvm-svn: 257067
2016-01-07 15:09:22 +00:00
Silviu Baranga 57b1b90996 [InstCombine] Look through PHIs, GEPs, IntToPtrs and PtrToInts to expose more constants when comparing GEPs
Summary:
When comparing two GEP instructions which have the same base pointer
and one of them has a constant index, it is possible to only compare
indices, transforming it to a compare with a constant. This removes
one use for the GEP instruction with the constant index, can reduce
register pressure and can sometimes lead to removing the comparisson
entirely.

InstCombine was already doing this when comparing two GEPs if the
base pointers were the same. However, in the case where we have
complex pointer arithmetic (GEPs applied to GEPs, PHIs of GEPs,
conversions to or from integers, etc) the value of the original
base pointer will be hidden to the optimizer and this transformation
will be disabled.

This change detects when the two sides of the comparison can be
expressed as GEPs with the same base pointer, even if they don't
appear as such in the IR. The transformation will convert all the
pointer arithmetic to arithmetic done on indices and all the
relevant uses of GEPs to GEPs with a common base pointer. The
GEP comparison will be converted to a comparison done on indices.

Reviewers: majnemer, jmolloy

Subscribers: hfinkel, jevinskie, jmolloy, aadg, llvm-commits

Differential Revision: http://reviews.llvm.org/D15146

llvm-svn: 257064
2016-01-07 14:56:08 +00:00
Sanjay Patel af674fbfd9 getParent() ^ 3 == getModule() ; NFCI
llvm-svn: 255511
2015-12-14 17:24:23 +00:00
Michael Liao c65d386b81 [InstCombine] Optimize icmp of inc/dec at RHS
Allow LLVM to optimize the sequence like the following:

  %inc = add nsw i32 %i, 1
  %cmp = icmp slt %n, %inc

into:

  %cmp = icmp sle i32 %n, %i

The case is not handled previously due to the complexity of compuation of %n.
Hence, LLVM cannot swap operands of icmp accordingly.

llvm-svn: 250746
2015-10-19 22:08:14 +00:00
Hans Wennborg f1f36517b7 InstCombine: Fold comparisons between unguessable allocas and other pointers
This will allow us to optimize code such as:

  int f(int *p) {
    int x;
    return p == &x;
  }

as well as:

  int *allocate(void);
  int f() {
    int x;
    int *p = allocate();
    return p == &x;
  }

The folding can only be done under certain circumstances. Even though p and &x
cannot alias, the comparison must still return true if the pointer
representations are equal. If a user successfully generates a p that's a
correct guess for &x, comparison should return true even though p is an invalid
pointer.

This patch argues that if the address of the alloca isn't observable outside the
function, the function can act as-if the address is impossible to guess from the
outside. The tricky part is keeping the act consistent: if we fold p == &x to
false in one place, we must make sure to fold any other comparisons based on
those pointers similarly. To ensure that, we only fold when &x is involved
exactly once in comparison instructions.

Differential Revision: http://reviews.llvm.org/D13358

llvm-svn: 249490
2015-10-07 00:20:07 +00:00
Hans Wennborg 083ca9bb32 Fix Clang-tidy modernize-use-nullptr warnings in source directories and generated files; other minor cleanups.
Patch by Eugene Zelenko!

Differential Revision: http://reviews.llvm.org/D13321

llvm-svn: 249482
2015-10-06 23:24:35 +00:00
David Majnemer 47ce0b81b0 [InstCombine] FoldICmpCstShrCst failed for ashr when comparing against -1
(icmp eq (ashr C1, %V) -1) may have multiple answers if C1 is not a
power of two and has the sign bit set.

This fixes PR24873.

llvm-svn: 248074
2015-09-19 00:48:31 +00:00
David Majnemer e5977ebecc [InstCombine] FoldICmpCstShrCst didn't handle icmps of -1 in the ashr case correctly
llvm-svn: 248073
2015-09-19 00:48:26 +00:00
Sanjoy Das e5f4889ba9 [InstCombine] Optimize icmp slt signum(x), 1 --> icmp slt x, 1
Summary:
`signum(x)` is sometimes implemented as `(x >> 63) | (-x >>> 63)` (for
an `i64` `x`).  This change adds a matcher for that pattern, and an
instcombine rule to optimize `signum(x) s< 1`.

Later, we can also consider optimizing:

  icmp slt signum(x), 0 --> icmp slt x, 0
  icmp sle signum(x), 1 --> true

etc.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12703

llvm-svn: 247846
2015-09-16 20:41:29 +00:00
Arch D. Robison 8ed0854f55 Broaden optimization of fcmp ([us]itofp x, constant) by instcombine.
The patch extends the optimization to cases where the constant's
magnitude is so small or large that the rounding of the conversion
is irrelevant.  The "so small" case includes negative zero.

Differential review: http://reviews.llvm.org/D11210

llvm-svn: 247708
2015-09-15 17:51:59 +00:00
David Majnemer daa24b9789 [InstCombine] Don't assume m_Mul gives back an Instruction
This fixes PR24713.

llvm-svn: 246933
2015-09-05 20:44:56 +00:00
Sanjoy Das 6f5dca70ed [InstCombine] Fix PR24605.
PR24605 is caused due to an incorrect insert point in instcombine's IR
builder.  When simplifying

  %t = add X Y
  ...
  %m = icmp ... %t

the replacement for %t should be placed before %t, not before %m, as
there could be a use of %t between %t and %m.

llvm-svn: 246315
2015-08-28 19:09:31 +00:00
Sanjoy Das c86c162a58 Re-apply r245635, "[InstCombine] Transform A & (L - 1) u< L --> L != 0"
The original checkin was buggy, this change has a fix.

Original commit message:

[InstCombine] Transform A & (L - 1) u< L --> L != 0

Summary:

This transform is never a pessimization at the IR level (since it
replaces an `icmp` with another), and has potentiall payoffs:

 1. It may make the `icmp` fold away or become loop invariant.
 2. It may make the `A & (L - 1)` computation dead.

This shows up in Java, in range checks generated by array accesses of
the form `a[i & (a.length - 1)]`.

Reviewers: reames, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12210

llvm-svn: 245753
2015-08-21 22:22:37 +00:00
NAKAMURA Takumi 6a6232818d Revert r245635, "[InstCombine] Transform A & (L - 1) u< L --> L != 0"
It caused miscompilation in clang.

llvm-svn: 245678
2015-08-21 07:46:07 +00:00
Sanjoy Das e472d8a57a [InstCombine] Transform A & (L - 1) u< L --> L != 0
Summary:
This transform is never a pessimization at the IR level (since it
replaces an `icmp` with another), and has potentiall payoffs:

 1. It may make the `icmp` fold away or become loop invariant.
 2. It may make the `A & (L - 1)` computation dead.

This shows up in Java, in range checks generated by array accesses of
the form `a[i & (a.length - 1)]`.

Reviewers: reames, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12210

llvm-svn: 245635
2015-08-20 22:31:55 +00:00
David Majnemer dfa3b09541 [InstCombine] Replace an and+icmp with a trunc+icmp
Bitwise arithmetic can obscure a simple sign-test.  If replacing the
mask with a truncate is preferable if the type is legal because it
permits us to rephrase the comparison more explicitly.

llvm-svn: 245171
2015-08-16 07:09:17 +00:00
Sanjoy Das 827529e7a0 Fix PR24354.
`InstCombiner::OptimizeOverflowCheck` was asserting an
invariant (operands to binary operations are ordered by decreasing
complexity) that wasn't really an invariant.  Fix this by instead having
`InstCombiner::OptimizeOverflowCheck` establish the invariant if it does
not hold.

llvm-svn: 244676
2015-08-11 21:33:55 +00:00
Benjamin Kramer f4ebfa3ae1 [InstSimplify] Fold away ord/uno fcmps when nnan is present.
This is important to fold away the slow case of complex multiplies
emitted by clang.

llvm-svn: 241911
2015-07-10 14:02:02 +00:00
Jingyue Wu 5e34ce33f5 [InstCombine] call SimplifyICmpInst with correct context
Summary:
Fixes PR23809. Without passing the context to SimplifyICmpInst, we would
use the assume to prove that the condition feeding the assume is
trivially true (see isValidAssumeForContext in ValueTracking.cpp),
causing the removal of the assume which may be useful for later
optimizations.

Test Plan: pr23800.ll

Reviewers: hfinkel, majnemer

Reviewed By: hfinkel

Subscribers: henryhu, llvm-commits, wengxt, broune, meheff, eliben

Differential Revision: http://reviews.llvm.org/D10695

llvm-svn: 240683
2015-06-25 20:14:47 +00:00
Sanjoy Das c80dad6f18 [InstCombine][NFC] Add a ``break;`` statement.
This change is NFC because both the ``break;`` and the fall through end
up returning immediately. However, this helps clarify intent and also
ensures correctness in case more ``case`` blocks are added later.

llvm-svn: 239172
2015-06-05 18:04:46 +00:00
Sanjoy Das 72cb5e1087 [InstCombine] Fix PR23751.
PR23751 was caused by a missing ``break;`` in r234388.

llvm-svn: 239171
2015-06-05 18:04:42 +00:00
David Majnemer 1503258157 [InstSimplify] Handle some overflow intrinsics in InstSimplify
This change does a few things:
- Move some InstCombine transforms to InstSimplify
- Run SimplifyCall from within InstCombine::visitCallInst
- Teach InstSimplify to fold [us]mul_with_overflow(X, undef) to 0.

llvm-svn: 237995
2015-05-22 03:56:46 +00:00
David Majnemer 27e89ba24c [InstCombine] X - 0 is equal to X, not undef
A refactoring made @llvm.ssub.with.overflow.i32(i32 %X, i32 0) transform
into undef instead of %X.

This fixes PR23624.

llvm-svn: 237968
2015-05-21 23:04:21 +00:00
James Molloy 2b21a7cf36 Reapply r237539 with a fix for the Chromium build.
Make sure if we're truncating a constant that would then be sign extended
that the sign extension of the truncated constant is the same as the
original constant.

> Canonicalize min/max expressions correctly.
>
> This patch introduces a canonical form for min/max idioms where one operand
> is extended or truncated. This often happens when the other operand is a
> constant. For example:
>
> %1 = icmp slt i32 %a, i32 0
> %2 = sext i32 %a to i64
> %3 = select i1 %1, i64 %2, i64 0
>
> Would now be canonicalized into:
>
> %1 = icmp slt i32 %a, i32 0
> %2 = select i1 %1, i32 %a, i32 0
> %3 = sext i32 %2 to i64
>
> This builds upon a patch posted by David Majenemer
> (https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
> passively stopped instcombine from ruining canonical patterns. This
> patch additionally actively makes instcombine canonicalize too.
>
> Canonicalization of expressions involving a change in type from int->fp
> or fp->int are not yet implemented.

llvm-svn: 237821
2015-05-20 18:41:25 +00:00
Hans Wennborg 2f21b8760e Revert r237539: "Reapply r237520 with another fix for infinite looping"
This caused PR23583.

llvm-svn: 237739
2015-05-19 23:06:30 +00:00
David Blaikie ff6409d096 Simplify IRBuilder::CreateCall* by using ArrayRef+initializer_list/braced init only
llvm-svn: 237624
2015-05-18 22:13:54 +00:00
James Molloy 53958e187a Reapply r237520 with another fix for infinite looping
SimplifyDemandedBits was "simplifying" a constant by removing just sign bits.
This caused a canonicalization race between different parts of instcombine.

Fix and regression test added - third time lucky?

llvm-svn: 237539
2015-05-17 08:27:27 +00:00
James Molloy e8698ae3e1 Revert commits r237521 and r237520.
The AArch64 LNT bot is unhappy - I've found that the problem is in
SimpliftDemandedBits, but that's going to require another code review
so reverting in the meantime.

llvm-svn: 237528
2015-05-16 21:27:14 +00:00
James Molloy b5aa200a33 Reapply r237453 with a fix for the test timeouts.
The test timeouts were due to instcombine fighting itself. Regression test added.
Original log message:

Canonicalize min/max expressions correctly.

This patch introduces a canonical form for min/max idioms where one operand
is extended or truncated. This often happens when the other operand is a
constant. For example:

  %1 = icmp slt i32 %a, i32 0
    %2 = sext i32 %a to i64
      %3 = select i1 %1, i64 %2, i64 0

Would now be canonicalized into:

  %1 = icmp slt i32 %a, i32 0
    %2 = select i1 %1, i32 %a, i32 0
      %3 = sext i32 %2 to i64

This builds upon a patch posted by David Majenemer
(https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
passively stopped instcombine from ruining canonical patterns. This
patch additionally actively makes instcombine canonicalize too.

Canonicalization of expressions involving a change in type from int->fp
or fp->int are not yet implemented.

llvm-svn: 237520
2015-05-16 13:10:45 +00:00
James Molloy 1675b4a57f Revert "Canonicalize min/max expressions correctly."
This reverts r237453 - it was causing timeouts on some bots. Reverting
while I investigate (it's probably InstCombine fighting itself...)

llvm-svn: 237458
2015-05-15 17:45:09 +00:00
James Molloy 6edf0b4cd4 Canonicalize min/max expressions correctly.
This patch introduces a canonical form for min/max idioms where one operand
is extended or truncated. This often happens when the other operand is a
constant. For example:

  %1 = icmp slt i32 %a, i32 0
  %2 = sext i32 %a to i64
  %3 = select i1 %1, i64 %2, i64 0

Would now be canonicalized into:

  %1 = icmp slt i32 %a, i32 0
  %2 = select i1 %1, i32 %a, i32 0
  %3 = sext i32 %2 to i64

This builds upon a patch posted by David Majenemer
(https://www.marc.info/?l=llvm-commits&m=143008038714141&w=2). That pass
passively stopped instcombine from ruining canonical patterns. This
patch additionally actively makes instcombine canonicalize too.

Canonicalization of expressions involving a change in type from int->fp
or fp->int are not yet implemented.

llvm-svn: 237453
2015-05-15 16:10:59 +00:00
Nick Lewycky abe2cc17da Subtraction is not commutative. Fixes PR23212!
llvm-svn: 234780
2015-04-13 19:17:37 +00:00
Sanjoy Das b6c5914308 [InstCombine][CodeGenPrep] Create llvm.uadd.with.overflow in CGP.
Summary:
This change moves creating calls to `llvm.uadd.with.overflow` from
InstCombine to CodeGenPrep.  Combining overflow check patterns into
calls to the said intrinsic in InstCombine inhibits optimization because
it introduces an intrinsic call that not all other transforms and
analyses understand.

Depends on D8888.

Reviewers: majnemer, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8889

llvm-svn: 234638
2015-04-10 21:07:09 +00:00
Sanjoy Das b098447128 [InstCombine] Refactor out OptimizeOverflowCheck. NFCI.
Summary:
This patch adds an enum `OverflowCheckFlavor` and a function
`OptimizeOverflowCheck`.  This will allow InstCombine to optimize
overflow checks without directly introducing an intermediate call to the
`llvm.$op.with.overflow` instrinsics.

This specific change is a refactoring and does not intend to change
behavior.

Reviewers: majnemer, atrick

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8888

llvm-svn: 234388
2015-04-08 04:27:22 +00:00
Benjamin Kramer 7fa8c430f7 InstCombine: fold (A << C) == (B << C) --> ((A^B) & (~0U >> C)) == 0
Anding and comparing with zero can be done in a single instruction on
most archs so this is a bit cheaper.

llvm-svn: 233291
2015-03-26 17:12:06 +00:00
Mehdi Amini a28d91d81b DataLayout is mandatory, update the API to reflect it with references.
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
2015-03-10 02:37:25 +00:00
Michael Liao d266b928ae [InstCombine] Fix a bug when combining `icmp` from `ptrtoint`
- First, there's a crash when we try to combine that pointers into `icmp`
  directly by creating a `bitcast`, which is invalid if that two pointers are
  from different address spaces.

- It's not always appropriate to cast one pointer to another if they are from
  different address spaces as that is not no-op cast. Instead, we only combine
  `icmp` from `ptrtoint` if that two pointers are of the same address space.

llvm-svn: 229063
2015-02-13 04:51:26 +00:00
Chandler Carruth a917458203 [PM] Rename InstCombine.h to InstCombineInternal.h in preparation for
creating a non-internal header file for the InstCombine pass.

I thought about calling this InstCombiner.h or in some way more clearly
associating it with the InstCombiner clas that it is primarily defining,
but there are several other utility interfaces defined within this for
InstCombine. If, in the course of refactoring, those end up moving
elsewhere or going away, it might make more sense to make this the
combiner's header alone.

Naturally, this is a bikeshed to a certain degree, so feel free to lobby
for a different shade of paint if this name just doesn't suit you.

llvm-svn: 226783
2015-01-22 05:25:13 +00:00
Chandler Carruth 62d4215baa [PM] Move TargetLibraryInfo into the Analysis library.
While the term "Target" is in the name, it doesn't really have to do
with the LLVM Target library -- this isn't an abstraction which LLVM
targets generally need to implement or extend. It has much more to do
with modeling the various runtime libraries on different OSes and with
different runtime environments. The "target" in this sense is the more
general sense of a target of cross compilation.

This is in preparation for porting this analysis to the new pass
manager.

No functionality changed, and updates inbound for Clang and Polly.

llvm-svn: 226078
2015-01-15 02:16:27 +00:00
David Majnemer a0afb55ff9 InstCombine: Don't take A-B<0 into A<B if A-B has other uses
This fixes PR22226.

llvm-svn: 226023
2015-01-14 19:26:56 +00:00
Matt Arsenault b935d9df4c Fix fcmp + fabs instcombines when using the intrinsic
This was only handling the libcall. This is another example
of why only the intrinsic should ever be used when it exists.

llvm-svn: 225465
2015-01-08 20:09:34 +00:00
Matt Arsenault 55e7312cd8 Convert fcmp with 0.0 from casted integers to icmp
This is already handled in general when it is known the
conversion can't lose bits with smaller integer types
casted into wider floating point types.

This pattern happens somewhat often in GPU programs that cast
workitem intrinsics to float, which are often compared with 0.

Specifically handle the special case of compares with zero which
should also be known to not lose information. I had a more general
version of this which allows equality compares if the casted float is
exactly representable in the integer, but I'm not 100% confident that
is always correct.

Also fold cases that aren't integers to true / false.

llvm-svn: 225265
2015-01-06 15:50:59 +00:00
Chandler Carruth 66b3130cda [PM] Split the AssumptionTracker immutable pass into two separate APIs:
a cache of assumptions for a single function, and an immutable pass that
manages those caches.

The motivation for this change is two fold. Immutable analyses are
really hacks around the current pass manager design and don't exist in
the new design. This is usually OK, but it requires that the core logic
of an immutable pass be reasonably partitioned off from the pass logic.
This change does precisely that. As a consequence it also paves the way
for the *many* utility functions that deal in the assumptions to live in
both pass manager worlds by creating an separate non-pass object with
its own independent API that they all rely on. Now, the only bits of the
system that deal with the actual pass mechanics are those that actually
need to deal with the pass mechanics.

Once this separation is made, several simplifications become pretty
obvious in the assumption cache itself. Rather than using a set and
callback value handles, it can just be a vector of weak value handles.
The callers can easily skip the handles that are null, and eventually we
can wrap all of this up behind a filter iterator.

For now, this adds boiler plate to the various passes, but this kind of
boiler plate will end up making it possible to port these passes to the
new pass manager, and so it will end up factored away pretty reasonably.

llvm-svn: 225131
2015-01-04 12:03:27 +00:00
David Majnemer f89dc3edc9 InstCombine: try to transform A-B < 0 into A < B
We are allowed to move the 'B' to the right hand side if we an prove
there is no signed overflow and if the comparison itself is signed.

llvm-svn: 225034
2014-12-31 04:21:41 +00:00
Ankur Garg 876b891d51 Removed extra line from a comment to test first commit. NFC.
llvm-svn: 222916
2014-11-28 10:38:18 +00:00
David Majnemer 83484fdb8b InstCombine: Silence a parenthesis warning
llvm-svn: 222609
2014-11-22 06:09:28 +00:00
Gerolf Hoflehner ec6217c929 [InstCombine] Re-commit of r218721 (Optimize icmp-select-icmp sequence)
Fixes the self-host fail. Note that this commit activates dominator
analysis in the combiner by default (like the original commit did).

llvm-svn: 222590
2014-11-21 23:36:44 +00:00
David Majnemer c1eca5ad7c InstCombine: Rely on cmpxchg's return code when it's strong
Comparing the result of a cmpxchg instruction can be replaced with an
extractvalue of the cmpxchg success indicator.

llvm-svn: 221498
2014-11-06 23:23:30 +00:00
David Majnemer 634ca236dc InstCombine: Don't assume that m_ZExt matches an Instruction
m_ZExt might bind against a ConstantExpr instead of an Instruction.
Assuming this, using cast<Instruction>, results in InstCombine crashing.

Instead, introduce ZExtOperator to bridge both Instruction and
ConstantExpr ZExts.

This fixes PR21445.

llvm-svn: 221069
2014-11-01 23:46:05 +00:00
David Majnemer 549f4f2510 InstCombine: Combine (X+cst) < 0 --> X < -cst
This can happen pretty often in code that looks like:
int foo = bar - 1;
if (foo < 0)
  do stuff

In this case, bar < 1 is an equivalent condition.

This transform requires that the add instruction be annotated with nsw.

llvm-svn: 221045
2014-11-01 09:09:51 +00:00
David Majnemer 2abb8183b5 InstCombine: Remove overzealous asserts
These asserts can trigger if the worklist iteration order is
sufficiently unlucky.  Instead of adding special case logic to handle
these edge conditions, just bail out on trying to transform them:
InstSimplify will get them when it reaches them on the worklist.

This fixes PR21378.

N.B.  No test case is included because any test would rely on the
fragile worklist iteration order.

llvm-svn: 220612
2014-10-25 07:13:13 +00:00
David Majnemer d205602a0b InstCombine: Simplify FoldICmpCstShrCst
This function was complicated by the fact that it tried to perform
canonicalizations that were already preformed by InstSimplify.  Remove
this extra code and move the tests over to InstSimplify.  Add asserts to
make sure our preconditions hold before we make any assumptions.

llvm-svn: 220314
2014-10-21 19:51:55 +00:00
David Majnemer 59939acd26 InstCombine: Optimize icmp eq/ne (shl Const2, A), Const1
The following implements the optimization for sequences of the form:
icmp eq/ne (shl Const2, A), Const1

Such sequences can be transformed to:
icmp eq/ne A, (TrailingZeros(Const1) - TrailingZeros(Const2))

This handles only the equality operators for now. Other operators need
to be handled.

Patch by Ankur Garg!

llvm-svn: 220162
2014-10-19 08:23:08 +00:00
Andrea Di Biagio 458a669f49 [InstCombine] Fix wrong folding of constant comparisons involving ashr and negative values.
This patch fixes a bug in method InstCombiner::FoldCmpCstShrCst where we
wrongly computed the distance between the highest bits set of two negative
values.

This fixes PR21222.

Differential Revision: http://reviews.llvm.org/D5700

llvm-svn: 219406
2014-10-09 12:41:49 +00:00
Justin Bogner 894eff7a9f Revert "[InstCombine] re-commit r218721 with fix for pr21199"
This seems to cause a miscompile when building clang, which causes a
bootstrapped clang to fail or crash in several of its tests.

See:
  http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-RA/builds/1184
  http://bb.pgr.jp/builders/clang-3stage-x86_64-linux/builds/7813

This reverts commit r219282.

llvm-svn: 219317
2014-10-08 16:30:22 +00:00
Gerolf Hoflehner e2ff5b9223 [InstCombine] re-commit r218721 with fix for pr21199
The icmp-select-icmp optimization targets select-icmp.eq
only. This is now ensured by testing the branch predicate
explictly. This commit also includes the test case for pr21199.

llvm-svn: 219282
2014-10-08 06:42:19 +00:00
Hans Wennborg 1256198bbc Revert r219175 - [InstCombine] re-commit r218721 icmp-select-icmp optimization
This seems to have caused PR21199.

llvm-svn: 219264
2014-10-08 01:05:57 +00:00
Gerolf Hoflehner c0b4c20e5e [InstCombine] re-commit r218721 icmp-select-icmp optimization
Takes care of the assert that caused build fails.
Rather than asserting the code checks now that the definition
and use are in the same block, and does not attempt
to optimize when that is not the case.

llvm-svn: 219175
2014-10-07 00:16:12 +00:00
Evgeniy Stepanov 815f2869ad Revert r218721, r218735.
Failing bootstrap on Linux (arm, x86).

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/13139/steps/bootstrap%20clang/logs/stdio
http://lab.llvm.org:8011/builders/clang-cmake-armv7-a15-selfhost/builds/470
http://lab.llvm.org:8011/builders/clang-native-arm-lnt/builds/8518

llvm-svn: 218752
2014-10-01 10:07:28 +00:00
Gerolf Hoflehner 19fc3dafc8 [InstCombine] Fix for assert build failures caused by r218721
The icmp-select-icmp optimization made the implicit assumption
that the select-icmp instructions are in the same block and asserted on it.
The fix explicitly checks for that condition and conservatively suppresses
the optimization when it is violated.

llvm-svn: 218735
2014-10-01 03:24:39 +00:00
Gerolf Hoflehner 08cc4b950c [InstCombine] Optimize icmp-select-icmp
In special cases select instructions can be eliminated by
replacing them with a cheaper bitwise operation even when the
select result is used outside its home block. The instances implemented
are patterns like
    %x=icmp.eq
    %y=select %x,%r, null
    %z=icmp.eq|neq %y, null
    br %z,true, false
==> %x=icmp.ne
    %y=icmp.eq %r,null
    %z=or %x,%y
    br %z,true,false
The optimization is integrated into the instruction
combiner and performed only when all uses of the select result can
be replaced by the select operand proper. For this dominator information
is used and dominance is now a required analysis pass in the combiner.
The optimization itself is iterative. The critical step is to replace the
select result with the non-constant select operand. So the select becomes
local and the combiner iteratively works out simpler code pattern and
eventually eliminates the select.

rdar://17853760

llvm-svn: 218721
2014-10-01 00:13:22 +00:00
Andrea Di Biagio 5b92b4971a [InstCombine] Fix wrong folding of constant comparison involving ahsr and negative quantities (PR20945).
Example:
define i1 @foo(i32 %a) {
  %shr = ashr i32 -9, %a
  %cmp = icmp ne i32 %shr, -5
  ret i1 %cmp
}

Before this fix, the instruction combiner wrongly thought that %shr
could have never been equal to -5. Therefore, %cmp was always folded to 'true'.
However, when %a is equal to 1, then %cmp evaluates to 'false'. Therefore,
in this example, it is not valid to fold %cmp to 'true'.
The problem was only affecting the case where the comparison was between
negative quantities where one of the quantities was obtained from arithmetic
shift of a negative constant.

This patch fixes the problem with the wrong folding (fixes PR20945).
With this patch, the 'icmp' from the example is now simplified to a
comparison between %a and 1. This still allows us to get rid of the arithmetic
shift (%shr).

llvm-svn: 217950
2014-09-17 11:32:31 +00:00
Hal Finkel 60db05896a Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)
This change, which allows @llvm.assume to be used from within computeKnownBits
(and other associated functions in ValueTracking), adds some (optional)
parameters to computeKnownBits and friends. These functions now (optionally)
take a "context" instruction pointer, an AssumptionTracker pointer, and also a
DomTree pointer, and most of the changes are just to pass this new information
when it is easily available from InstSimplify, InstCombine, etc.

As explained below, the significant conceptual change is that known properties
of a value might depend on the control-flow location of the use (because we
care that the @llvm.assume dominates the use because assumptions have
control-flow dependencies). This means that, when we ask if bits are known in a
value, we might get different answers for different uses.

The significant changes are all in ValueTracking. Two main changes: First, as
with the rest of the code, new parameters need to be passed around. To make
this easier, I grouped them into a structure, and I made internal static
versions of the relevant functions that take this structure as a parameter. The
new code does as you might expect, it looks for @llvm.assume calls that make
use of the value we're trying to learn something about (often indirectly),
attempts to pattern match that expression, and uses the result if successful.
By making use of the AssumptionTracker, the process of finding @llvm.assume
calls is not expensive.

Part of the structure being passed around inside ValueTracking is a set of
already-considered @llvm.assume calls. This is to prevent a query using, for
example, the assume(a == b), to recurse on itself. The context and DT params
are used to find applicable assumptions. An assumption needs to dominate the
context instruction, or come after it deterministically. In this latter case we
only handle the specific case where both the assumption and the context
instruction are in the same block, and we need to exclude assumptions from
being used to simplify their own ephemeral values (those which contribute only
to the assumption) because otherwise the assumption would prove its feeding
comparison trivial and would be removed.

This commit adds the plumbing and the logic for a simple masked-bit propagation
(just enough to write a regression test). Future commits add more patterns
(and, correspondingly, more regression tests).

llvm-svn: 217342
2014-09-07 18:57:58 +00:00
David Majnemer 074052b623 InstCombine: Remove redundant combines
InstSimplify already handles icmp (X+Y), X (and things like it)
appropriately.  The first thing that InstCombine does is run
InstSimplify on the instruction.

llvm-svn: 216659
2014-08-28 10:08:37 +00:00
David Majnemer 76d06bc613 InstSimplify: Move a transform from InstCombine to InstSimplify
Several combines involving icmp (shl C2, %X) C1 can be simplified
without introducing any new instructions.  Move them to InstSimplify;
while we are at it, make them more powerful.

llvm-svn: 216642
2014-08-28 03:34:28 +00:00
David Majnemer 0ffccf7fb5 InstCombine: Properly optimize or'ing bittests together
CFE, with -03, would turn:
bool f(unsigned x) {
  bool a = x & 1;
  bool b = x & 2;
  return a | b;
}

into:
  %1 = lshr i32 %x, 1
  %2 = or i32 %1, %x
  %3 = and i32 %2, 1
  %4 = icmp ne i32 %3, 0

This sort of thing exposes a nasty pathology in GCC, ICC and LLVM.

Instead, we would rather want:
  %1 = and i32 %x, 3
  %2 = icmp ne i32 %1, 0

Things get a bit more interesting in the following case:
  %1 = lshr i32 %x, %y
  %2 = or i32 %1, %x
  %3 = and i32 %2, 1
  %4 = icmp ne i32 %3, 0

Replacing it with the following sequence is better:
  %1 = shl nuw i32 1, %y
  %2 = or i32 %1, 1
  %3 = and i32 %2, %x
  %4 = icmp ne i32 %3, 0

This sequence is preferable because %1 doesn't involve %x and could
potentially be hoisted out of loops if it is invariant; only perform
this transform in the non-constant case if we know we won't increase
register pressure.

llvm-svn: 216343
2014-08-24 09:10:57 +00:00
Suyog Sarda 3a8c2c1e6c This patch implements optimization as mentioned in PR19753: Optimize comparisons with "ashr/lshr exact" of a constanst.
It handles the errors which were seen in PR19958 where wrong code was being emitted due to earlier patch.
Added code for lshr as well as non-exact right shifts.

It implements : 
(icmp eq/ne (ashr/lshr const2, A), const1)" ->
(icmp eq/ne A, Log2(const2/const1)) ->
(icmp eq/ne A, Log2(const2) - Log2(const1))

Differential Revision: http://reviews.llvm.org/D4068
 

llvm-svn: 213678
2014-07-22 19:19:36 +00:00
Benjamin Kramer d0993e0077 InstCombine: Simplify code, no functionality change.
llvm-svn: 212449
2014-07-07 11:01:16 +00:00
Benjamin Kramer c96a7f88b9 InstCombine: Disable umul.with.overflow recognition for vectors.
It doesn't make a lot on most targets and the code isn't ready for it. PR20113.

llvm-svn: 211583
2014-06-24 10:47:52 +00:00
Matt Arsenault 44f60d0a60 Look through addrspacecasts when turning ptr comparisons into
index comparisons.

llvm-svn: 210488
2014-06-09 19:20:29 +00:00
Rafael Espindola 4ba22f0813 Revert 209903 and 210040.
The messages were

 "PR19753: Optimize comparisons with "ashr exact" of a constanst."
 "Added support to optimize comparisons with "lshr exact" of a constant."

They were not correctly handling signed/unsigned operation differences,
causing pr19958.

llvm-svn: 210393
2014-06-07 04:12:35 +00:00
Rafael Espindola 6b04ef785e Added support to optimize comparisons with "lshr exact" of a constant.
Patch by Rahul Jain.

llvm-svn: 210040
2014-06-02 19:19:04 +00:00
Dinesh Dwivedi ce5d35a9d0 Added inst combine tarnsform for (1 << X) & C pattrens where C is (some PowerOf2 - 1)
This patch can handles following cases from http://nondot.org/sabre/LLVMNotes/InstCombine.txt
  "((1 << X) & 7) == 0" ==> "X > 2"
  "((1 << X) & 7) != 0" ==> "X < 3".

Differential Revision: http://reviews.llvm.org/D3678

llvm-svn: 210007
2014-06-02 07:57:24 +00:00
Rafael Espindola c323952cb4 PR19753: Optimize comparisons with "ashr exact" of a constanst.
Patch by suyog sarda.

llvm-svn: 209903
2014-05-30 15:54:32 +00:00
David Majnemer 186c94244c InstCombine: Optimize -x s< cst
Summary:
This gets rid of a sub instruction by moving the negation to the
constant when valid.

Reviewers: nicholas

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D3773

llvm-svn: 208827
2014-05-15 00:02:20 +00:00
Jay Foad a0653a3e6c Rename ComputeMaskedBits to computeKnownBits. "Masked" has been
inappropriate since it lost its Mask parameter in r154011.

llvm-svn: 208811
2014-05-14 21:14:37 +00:00
Craig Topper f40110f4d8 [C++] Use 'nullptr'. Transforms edition.
llvm-svn: 207196
2014-04-25 05:29:35 +00:00
Chandler Carruth 964daaaf19 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Transforms/...
edition.

This one is tricky for two reasons. We again have a couple of passes
that define something else before the includes as well. I've sunk their
name macros with the DEBUG_TYPE.

Also, InstCombine contains headers that need DEBUG_TYPE, so now those
headers #define and #undef DEBUG_TYPE around their code, leaving them
well formed modular headers. Fixing these headers was a large motivation
for all of these changes, as "leaky" macros of this form are hard on the
modules implementation.

llvm-svn: 206844
2014-04-22 02:55:47 +00:00
Chandler Carruth 5f1f26e891 [Modules] Sink all the DEBUG_TYPE defines for InstCombine out of the
header files and into the cpp files.

These files will require more touches as the header files actually use
DEBUG(). Eventually, I'll have to introduce a matched #define and #undef
of DEBUG_TYPE for the header files, but that comes as step N of many to
clean all of this up.

llvm-svn: 206777
2014-04-21 19:51:41 +00:00
Serge Pavlov b5f3ddc7a1 Use APInt arithmetic, fixed typo. Thanks to Benjamin Kramer for noticing that.
llvm-svn: 206144
2014-04-14 02:20:19 +00:00
Serge Pavlov 4bb54d51c8 Recognize test for overflow in integer multiplication.
If multiplication involves zero-extended arguments and the result is
compared as in the patterns:

    %mul32 = trunc i64 %mul64 to i32
    %zext = zext i32 %mul32 to i64
    %overflow = icmp ne i64 %mul64, %zext
or
    %overflow = icmp ugt i64 %mul64 , 0xffffffff

then the multiplication may be replaced by call to umul.with.overflow.
This change fixes PR4917 and PR4918.

Differential Revision: http://llvm-reviews.chandlerc.com/D2814

llvm-svn: 206137
2014-04-13 18:23:41 +00:00
Erik Verbruggen 5e1bac3a38 Revert "InstCombine: merge constants in both operands of icmp."
This reverts commit r204912, and follow-up commit r204948.

This introduced a performance regression, and the fix is not completely
clear yet.

llvm-svn: 205010
2014-03-28 14:50:57 +00:00
Reid Kleckner 3bdf9bc48b InstCombine: Don't combine constants on unsigned icmps
Fixes a miscompile introduced in r204912.  It would miscompile code like
(unsigned)(a + -49) <= 5U.  The transform would turn this into
(unsigned)a < 55U, which would return true for values in [0, 49], when
it should not.

llvm-svn: 204948
2014-03-27 17:49:27 +00:00
Erik Verbruggen 59a1219846 InstCombine: merge constants in both operands of icmp.
Transform:
    icmp X+Cst2, Cst
into:
    icmp X, Cst-Cst2
when Cst-Cst2 does not overflow, and the add has nsw.

llvm-svn: 204912
2014-03-27 11:16:05 +00:00
Chandler Carruth cdf4788401 [C++11] Add range based accessors for the Use-Def chain of a Value.
This requires a number of steps.
1) Move value_use_iterator into the Value class as an implementation
   detail
2) Change it to actually be a *Use* iterator rather than a *User*
   iterator.
3) Add an adaptor which is a User iterator that always looks through the
   Use to the User.
4) Wrap these in Value::use_iterator and Value::user_iterator typedefs.
5) Add the range adaptors as Value::uses() and Value::users().
6) Update *all* of the callers to correctly distinguish between whether
   they wanted a use_iterator (and to explicitly dig out the User when
   needed), or a user_iterator which makes the Use itself totally
   opaque.

Because #6 requires churning essentially everything that walked the
Use-Def chains, I went ahead and added all of the range adaptors and
switched them to range-based loops where appropriate. Also because the
renaming requires at least churning every line of code, it didn't make
any sense to split these up into multiple commits -- all of which would
touch all of the same lies of code.

The result is still not quite optimal. The Value::use_iterator is a nice
regular iterator, but Value::user_iterator is an iterator over User*s
rather than over the User objects themselves. As a consequence, it fits
a bit awkwardly into the range-based world and it has the weird
extra-dereferencing 'operator->' that so many of our iterators have.
I think this could be fixed by providing something which transforms
a range of T&s into a range of T*s, but that *can* be separated into
another patch, and it isn't yet 100% clear whether this is the right
move.

However, this change gets us most of the benefit and cleans up
a substantial amount of code around Use and User. =]

llvm-svn: 203364
2014-03-09 03:16:01 +00:00
Chandler Carruth 8cd041ef19 [Modules] Move the ConstantRange class into the IR library. This is
a bit surprising, as the class is almost entirely abstracted away from
any particular IR, however it encodes the comparsion predicates which
mutate ranges as ICmp predicate codes. This is reasonable as they're
used for both instructions and constants. Thus, it belongs in the IR
library with instructions and constants.

llvm-svn: 202838
2014-03-04 12:24:34 +00:00
Chandler Carruth 820a908df7 [Modules] Move the LLVM IR pattern match header into the IR library, it
obviously is coupled to the IR.

llvm-svn: 202818
2014-03-04 11:08:18 +00:00
Chandler Carruth 03eb0de93d [Modules] Move GetElementPtrTypeIterator into the IR library. As its
name might indicate, it is an iterator over the types in an instruction
in the IR.... You see where this is going.

Another step of modularizing the support library.

llvm-svn: 202815
2014-03-04 10:40:04 +00:00
Rafael Espindola aeff8a9c05 Make some DataLayout pointers const.
No functionality change. Just reduces the noise of an upcoming patch.

llvm-svn: 202087
2014-02-24 23:12:18 +00:00
Rafael Espindola 37dc9e19f5 Rename many DataLayout variables from TD to DL.
I am really sorry for the noise, but the current state where some parts of the
code use TD (from the old name: TargetData) and other parts use DL makes it
hard to write a patch that changes where those variables come from and how
they are passed along.

llvm-svn: 201827
2014-02-21 00:06:31 +00:00
Owen Anderson 883b5add8e Remove a very old instcombine where we would turn sequences of selects into
logical operations on the i1's driving them.  This is a bad idea for every
target I can think of (confirmed with micro tests on all of: x86-64, ARM,
AArch64, Mips, and PowerPC) because it forces the i1 to be materialized into
a general purpose register, whereas consuming it directly into a select generally
allows it to exist only transiently in a predicate or flags register.

Chandler ran a set of performance tests with this change, and reported no
measurable change on x86-64.

llvm-svn: 201275
2014-02-12 23:54:07 +00:00
Alp Toker cb40291100 Fix known typos
Sweep the codebase for common typos. Includes some changes to visible function
names that were misspelt.

llvm-svn: 200018
2014-01-24 17:20:08 +00:00
Benjamin Kramer 970f4959d4 InstCombine: Hoist 3 copies of AddOne/SubOne into a header.
llvm-svn: 199605
2014-01-19 16:56:10 +00:00
Kay Tiong Khoo e37d52095e Stay classy (and legal) LLVM. Remove links to 3rd party SMT solver whose links may not be permanent.
llvm-svn: 197713
2013-12-19 18:35:54 +00:00
Kay Tiong Khoo a570b5adb5 Improved fix for PR17827 (instcombine of shift/and/compare).
This change fixes the case of arithmetic shift right - do not attempt to fold that case.
This change also relaxes the conditions when attempting to fold the logical shift right and shift left cases.

No additional IR-level test cases included at this time. See http://llvm.org/bugs/show_bug.cgi?id=17827 for proofs that these are correct transformations.

llvm-svn: 197705
2013-12-19 18:07:17 +00:00
Kay Tiong Khoo d7b00cac10 Use local variable for repeated use rather than 'get' method. No functional change intended.
llvm-svn: 196164
2013-12-02 22:23:32 +00:00
Kay Tiong Khoo 64b732005f Move variables to where they are used and give them better names. No functional change intended.
llvm-svn: 196163
2013-12-02 22:20:40 +00:00
Kay Tiong Khoo 564560f911 Rename variables to be consistent (CST -> Cst). No functional change intended.
llvm-svn: 196161
2013-12-02 22:11:56 +00:00
Kay Tiong Khoo 5389f74655 Conservative fix for PR17827 - don't optimize a shift + and + compare sequence where the shift is logical unless the comparison is unsigned
llvm-svn: 196129
2013-12-02 18:43:59 +00:00
Benjamin Kramer 03f3e248eb InstCombine: fold (A >> C) == (B >> C) --> (A^B) < (1 << C) for constant Cs.
This is common in bitfield code.

llvm-svn: 194925
2013-11-16 16:00:48 +00:00
Matt Arsenault 8468062c6e Use right address space size in InstCombineCompares
The test's output doesn't change, but this ensures
this is actually hit with a different address space.

llvm-svn: 191701
2013-09-30 21:11:01 +00:00
Matt Arsenault 06adecabe7 Constant fold ptrtoint + compare with address spaces
llvm-svn: 191699
2013-09-30 21:06:18 +00:00
Matt Arsenault fa25272db9 Use type helper functions
llvm-svn: 191574
2013-09-27 22:18:51 +00:00
Benjamin Kramer 0e2d162d1e InstCombine: Remove unused argument. No functionality change.
llvm-svn: 191112
2013-09-20 22:12:42 +00:00
Quentin Colombet 5ab555532b [InstCombiner] Expose opportunities to merge subtract and comparison.
Several architectures use the same instruction to perform both a comparison and
a subtract. The instruction selection framework does not allow to consider
different basic blocks to expose such fusion opportunities.

Therefore, these instructions are “merged” by CSE at MI IR level.

To increase the likelihood of CSE to apply in such situation, we reorder the
operands of the comparison, when they have the same complexity, so that they
matches the order of the most frequent subtract.
E.g.,

icmp A, B
...
sub B, A

<rdar://problem/14514580>

llvm-svn: 190352
2013-09-09 20:56:48 +00:00
Matt Arsenault 745101d666 Teach InstCombine about address spaces
llvm-svn: 188926
2013-08-21 19:53:10 +00:00
Matt Arsenault 5aeae18e9d Revert non-test parts of r188507
Re-add the inboundsless tests I didn't add originally

llvm-svn: 188710
2013-08-19 21:40:31 +00:00
Matt Arsenault 1de76773bc Don't do FoldCmpLoadFromIndexedGlobal for non inbounds GEPs
This path wasn't tested before without a datalayout,
so add some more tests and re-run with and without one.

llvm-svn: 188507
2013-08-15 23:11:07 +00:00
David Majnemer eeed73b981 InstCombine: Fix typo in comment for visitICmpInstWithInstAndIntCst
llvm-svn: 185916
2013-07-09 09:24:35 +00:00
David Majnemer 72d76275ac InstCombine: variations on 0xffffffff - x >= 4
The following transforms are valid if -C is a power of 2:
(icmp ugt (xor X, C), ~C) -> (icmp ult X, C)
(icmp ult (xor X, C), -C) -> (icmp uge X, C)

These are nice, they get rid of the xor.

llvm-svn: 185915
2013-07-09 09:20:58 +00:00
David Majnemer 414d4e58aa InstCombine: X & -C != -C -> X <= u ~C
Tests were added in r185910 somehow.

llvm-svn: 185912
2013-07-09 08:09:32 +00:00
David Majnemer bafa537eb7 Commit r185909 was a misapplied patch, fix it
llvm-svn: 185910
2013-07-09 07:58:32 +00:00
David Majnemer f2a9a513c7 InstCombine: add more transforms
C1-X <u C2 -> (X|(C2-1)) == C1
C1-X >u C2 -> (X|C2) == C1
X-C1 <u C2 -> (X & -C2) == C1
X-C1 >u C2 -> (X & ~C2) == C1

llvm-svn: 185909
2013-07-09 07:50:59 +00:00
David Majnemer fa90a0b325 InstCombine: Fold X-C1 <u 2 -> (X & -2) == C1
Back in r179493 we determined that two transforms collided with each
other.  The fix back then was to reorder the transforms so that the
preferred transform would give it a try and then we would try the
secondary transform.  However, it was noted that the best approach would
canonicalize one transform into the other, removing the collision and
allowing us to optimize IR given to us in that form.

llvm-svn: 185808
2013-07-08 11:53:08 +00:00
David Majnemer 5953d3712a InstCombine: FoldGEPICmp shouldn't change sign of base pointer comparison
Changing the sign when comparing the base pointer would introduce all
sorts of unexpected things like:
  %gep.i = getelementptr inbounds [1 x i8]* %a, i32 0, i32 0
  %gep2.i = getelementptr inbounds [1 x i8]* %b, i32 0, i32 0
  %cmp.i = icmp ult i8* %gep.i, %gep2.i
  %cmp.i1 = icmp ult [1 x i8]* %a, %b
  %cmp = icmp ne i1 %cmp.i, %cmp.i1
  ret i1 %cmp

into:
  %cmp.i = icmp slt [1 x i8]* %a, %b
  %cmp.i1 = icmp ult [1 x i8]* %a, %b
  %cmp = xor i1 %cmp.i, %cmp.i1
  ret i1 %cmp

By preserving the original sign, we now get:
  ret i1 false

This fixes PR16483.

llvm-svn: 185259
2013-06-29 10:28:04 +00:00
David Majnemer 92a8a7d45a InstCombine: Small whitespace cleanup in FoldGEPICmp
llvm-svn: 185258
2013-06-29 09:45:35 +00:00
David Majnemer b889e405eb InstCombine: Optimize (1 << X) Pred CstP2 to X Pred Log2(CstP2)
We may, after other optimizations, find ourselves with IR that looks
like:

  %shl = shl i32 1, %y
  %cmp = icmp ult i32 %shl, 32

Instead, we should just compare the shift count:

  %cmp = icmp ult i32 %y, 5

llvm-svn: 185242
2013-06-28 23:42:03 +00:00
Michael Gottesman 79b0967548 Revert "Revert "[APFloat] Removed APFloat constructor which initialized to either zero/NaN but allowed you to arbitrarily set the category of the float.""
This reverts commit r185099.

Looks like both the ppc-64 and mips bots are still failing after I reverted this
change.

Since:

1. The mips bot always performs a clean build,
2. The ppc64-bot failed again after a clean build (I asked the ppc-64
maintainers to clean the bot which they did... Thanks Will!),

I think it is safe to assume that this change was not the cause of the failures
that said builders were seeing. Thus I am recomitting.

llvm-svn: 185111
2013-06-27 21:58:19 +00:00
Michael Gottesman ccaf3321f1 Revert "[APFloat] Removed APFloat constructor which initialized to either zero/NaN but allowed you to arbitrarily set the category of the float."
This reverts commit r185095. This is causing a FileCheck failure on
the 3dnow intrinsics on at least the mips/ppc bots but not on the x86
bots.

Reverting while I figure out what is going on.

llvm-svn: 185099
2013-06-27 20:40:11 +00:00
Michael Gottesman 03255a1675 [APFloat] Removed APFloat constructor which initialized to either zero/NaN but allowed you to arbitrarily set the category of the float.
The category which an APFloat belongs to should be dependent on the
actual value that the APFloat has, not be arbitrarily passed in by the
user. This will prevent inconsistency bugs where the category and the
actual value in APFloat differ.

I also fixed up all of the references to this constructor (which were
only in LLVM).

llvm-svn: 185095
2013-06-27 19:50:52 +00:00
Jakub Staszak bddea11bc5 Re-apply "Use IRBuilder instead of ConstantInt methods." with the fixed issues.
llvm-svn: 183439
2013-06-06 20:18:46 +00:00
Rafael Espindola a7bbc0b740 Revert "Use IRBuilder instead of ConstantInt methods. It simplifies code a little bit."
This reverts commit 183328. It caused pr16244 and broke the bots.

llvm-svn: 183422
2013-06-06 17:03:05 +00:00
Jakub Staszak 2f390b755a Use IRBuilder instead of ConstantInt methods. It simplifies code a little bit.
llvm-svn: 183328
2013-06-05 18:27:02 +00:00
David Majnemer 1a08accbb7 Simplify (A & ~B) in icmp if A is a power of 2
The transform will execute like so:
(A & ~B) == 0 --> (A & B) != 0
(A & ~B) != 0 --> (A & B) == 0

llvm-svn: 179386
2013-04-12 17:25:07 +00:00
David Majnemer b81cd63c4b Optimize icmp involving addition better
Allows LLVM to optimize sequences like the following:

%add = add nsw i32 %x, 1
%cmp = icmp sgt i32 %add, %y

into:

%cmp = icmp sge i32 %x, %y

as well as:

%add1 = add nsw i32 %x, 20
%add2 = add nsw i32 %y, 57
%cmp = icmp sge i32 %add1, %add2

into:

%add = add nsw i32 %y, 37
%cmp = icmp sle i32 %cmp, %x

llvm-svn: 179316
2013-04-11 20:05:46 +00:00
Jim Grosbach bdbd73460c Tidy up a bit. No functional change.
llvm-svn: 178915
2013-04-05 21:20:12 +00:00
Arnaud A. de Grandmaison 3ee88e8a77 Address issues found by Duncan during post-commit review of r177856.
llvm-svn: 177863
2013-03-25 11:47:38 +00:00
Arnaud A. de Grandmaison 9c383d68cf InstCombine: simplify comparisons to zero of (shl %x, Cst) or (mul %x, Cst)
This simplification happens at 2 places :
 - using the nsw attribute when the shl / mul is used by a sign test
 - when the shl / mul is compared for (in)equality to zero

llvm-svn: 177856
2013-03-25 09:48:49 +00:00
Arnaud A. de Grandmaison f364bc63e7 InstCombine: Improve the result bitvect type when folding (cmp pred (load (gep GV, i)) C) to a bit test.
The original code used i32, and i64 if legal. This introduced unneeded
casts when they aren't legal, or when the index variable i has another
type. In order of preference: try to use i's type; use the smallest
fitting legal type (using an added DataLayout method); default to i32.
A testcase checks that this works when the index gep operand is i16.

Patch by : Ahmed Bougacha <ahmed.bougacha@gmail.com>
Reviewed by : Duncan

llvm-svn: 177712
2013-03-22 08:25:01 +00:00
Arnaud A. de Grandmaison 7153305b92 Fix a performance regression when combining to smaller types in icmp (shl %v, C1), C2 :
Only combine when the shl is only used by the icmp

llvm-svn: 176950
2013-03-13 14:40:37 +00:00
Arnaud A. de Grandmaison 1fd843eee7 Fix refactoring mistake in "Teach InstCombine to work with smaller legal types..."
llvm-svn: 175273
2013-02-15 15:18:17 +00:00
Arnaud A. de Grandmaison 61c167c62b Teach InstCombine to work with smaller legal types in icmp (shl %v, C1), C2
It enables to work with a smaller constant, which is target friendly for those which can compare to immediates.
It also avoids inserting a shift in favor of a trunc, which can be free on some targets.

This used to work until LLVM-3.1, but regressed with the 3.2 release.

llvm-svn: 175270
2013-02-15 14:35:47 +00:00
Chandler Carruth 9fb823bbd4 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

llvm-svn: 171366
2013-01-02 11:36:10 +00:00
Paul Redmond 5917f4c715 Transform (x&C)>V into (x&C)!=0 where possible
When the least bit of C is greater than V, (x&C) must be greater than V
if it is not zero, so the comparison can be simplified.

Although this was suggested in Target/X86/README.txt, it benefits any
architecture with a directly testable form of AND.

Patch by Kevin Schoedel

llvm-svn: 170576
2012-12-19 19:47:13 +00:00
NAKAMURA Takumi 38d2b2442f Revert r170020, "Simplify negated bit test", for now.
This assumes (1 << n) is always not zero. Consider n is greater than word size.
Although I know it is undefined, this transforms undefined behavior hidden.

This led clang unexpected behavior with some failures. I will investigate to fix undefined shl in clang.

llvm-svn: 170128
2012-12-13 14:28:16 +00:00
Rafael Espindola a2c107e661 Missed these calls from the previous rename somehow.
llvm-svn: 170094
2012-12-13 03:42:31 +00:00
David Majnemer 5226aa94ce Simplify negated bit test
llvm-svn: 170020
2012-12-12 20:48:54 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Duncan Sands d7d8c09b93 Make this easier to understand, as suggested by Chandler.
llvm-svn: 168196
2012-11-16 20:53:08 +00:00
Duncan Sands 1d3acddf0e Fix PR14361: wrong simplification of A+B==B+A. You may think that the old logic
replaced by this patch is equivalent to the new logic, but you'd be wrong, and
that's exactly where the bug was.  There's a similar bug in instsimplify which
manifests itself as instsimplify failing to simplify this, rather than doing it
wrong, see next commit.

llvm-svn: 168181
2012-11-16 18:55:49 +00:00
Chandler Carruth 5da3f0512e Revert the majority of the next patch in the address space series:
r165941: Resubmit the changes to llvm core to update the functions to
         support different pointer sizes on a per address space basis.

Despite this commit log, this change primarily changed stuff outside of
VMCore, and those changes do not carry any tests for correctness (or
even plausibility), and we have consistently found questionable or flat
out incorrect cases in these changes. Most of them are probably correct,
but we need to devise a system that makes it more clear when we have
handled the address space concerns correctly, and ideally each pass that
gets updated would receive an accompanying test case that exercises that
pass specificaly w.r.t. alternate address spaces.

However, from this commit, I have retained the new C API entry points.
Those were an orthogonal change that probably should have been split
apart, but they seem entirely good.

In several places the changes were very obvious cleanups with no actual
multiple address space code added; these I have not reverted when
I spotted them.

In a few other places there were merge conflicts due to a cleaner
solution being implemented later, often not using address spaces at all.
In those cases, I've preserved the new code which isn't address space
dependent.

This is part of my ongoing effort to clean out the partial address space
code which carries high risk and low test coverage, and not likely to be
finished before the 3.2 release looms closer. Duncan and I would both
like to see the above issues addressed before we return to these
changes.

llvm-svn: 167222
2012-11-01 09:14:31 +00:00
Chandler Carruth 7ec5085e01 Revert the series of commits starting with r166578 which introduced the
getIntPtrType support for multiple address spaces via a pointer type,
and also introduced a crasher bug in the constant folder reported in
PR14233.

These commits also contained several problems that should really be
addressed before they are re-committed. I have avoided reverting various
cleanups to the DataLayout APIs that are reasonable to have moving
forward in order to reduce the amount of churn, and minimize the number
of commits that were reverted. I've also manually updated merge
conflicts and manually arranged for the getIntPtrType function to stay
in DataLayout and to be defined in a plausible way after this revert.

Thanks to Duncan for working through this exact strategy with me, and
Nick Lewycky for tracking down the really annoying crasher this
triggered. (Test case to follow in its own commit.)

After discussing with Duncan extensively, and based on a note from
Micah, I'm going to continue to back out some more of the more
problematic patches in this series in order to ensure we go into the
LLVM 3.2 branch with a reasonable story here. I'll send a note to
llvmdev explaining what's going on and why.

Summary of reverted revisions:

r166634: Fix a compiler warning with an unused variable.
r166607: Add some cleanup to the DataLayout changes requested by
         Chandler.
r166596: Revert "Back out r166591, not sure why this made it through
         since I cancelled the command. Bleh, sorry about this!
r166591: Delete a directory that wasn't supposed to be checked in yet.
r166578: Add in support for getIntPtrType to get the pointer type based
         on the address space.
llvm-svn: 167221
2012-11-01 08:07:29 +00:00
Ulrich Weigand 6a9bb51a8d Enable some additional constant folding for PPCDoubleDouble.
This fixes Clang :: CodeGen/complex-builtints.c on PowerPC.

llvm-svn: 167013
2012-10-30 12:33:18 +00:00
Micah Villmow bf3eeb2dfc Add some cleanup to the DataLayout changes requested by Chandler.
llvm-svn: 166607
2012-10-24 18:36:13 +00:00
Micah Villmow 12d9127833 Add in support for getIntPtrType to get the pointer type based on the address space.
This checkin also adds in some tests that utilize these paths and updates some of the
clients.

llvm-svn: 166578
2012-10-24 15:52:52 +00:00
Micah Villmow 4bb926d91d Resubmit the changes to llvm core to update the functions to support different pointer sizes on a per address space basis.
llvm-svn: 165941
2012-10-15 16:24:29 +00:00
Micah Villmow 0c61134d8d Revert 165732 for further review.
llvm-svn: 165747
2012-10-11 21:27:41 +00:00
Micah Villmow 083189730e Add in the first iteration of support for llvm/clang/lldb to allow variable per address space pointer sizes to be optimized correctly.
llvm-svn: 165726
2012-10-11 17:21:41 +00:00
Micah Villmow cdfe20b97f Move TargetData to DataLayout.
llvm-svn: 165402
2012-10-08 16:38:25 +00:00
Benjamin Kramer 9d03242fcf InstCombine: Fix a crasher when encountering a function pointer.
llvm-svn: 162180
2012-08-18 22:04:34 +00:00
Benjamin Kramer 9282aef86d Remove overly conservative hasOneUse check, this always expands into a single IR instruction.
llvm-svn: 162175
2012-08-18 20:24:19 +00:00
Benjamin Kramer 8c2a733c55 InstCombine: Add a couple of fabs identities for comparing with 0.0.
llvm-svn: 162174
2012-08-18 20:06:47 +00:00
Bob Wilson 61f3ad5759 Fix a serious typo in InstCombine's optimization of comparisons.
An unsigned value converted to floating-point will always be greater than
a negative constant.  Unfortunately InstCombine reversed the check so that
unsigned values were being optimized to always be greater than all positive
floating-point constants.  <rdar://problem/12029145>

llvm-svn: 161452
2012-08-07 22:35:16 +00:00
Benjamin Kramer 2150145ae4 InstCombine: factor code better.
No functionality change.

llvm-svn: 158301
2012-06-11 08:01:25 +00:00
Benjamin Kramer 8b8a76974f InstCombine: Turn (zext A) == (B & (1<<X)-1) into A == (trunc B), narrowing the compare.
This saves a cast, and zext is more expensive on platforms with subreg support
than trunc is. This occurs in the BSD implementation of memchr(3), see PR12750.
On the synthetic benchmark from that bug stupid_memchr and bsd_memchr have the
same performance now when not inlining either function.

stupid_memchr: 323.0us
bsd_memchr: 321.0us
memchr: 479.0us

where memchr is the llvm-gcc compiled bsd_memchr from osx lion's libc. When
inlining is enabled bsd_memchr still regresses down to llvm-gcc memchr time,
I haven't fully understood the issue yet, something is grossly mangling the
loop after inlining.

llvm-svn: 158297
2012-06-10 20:35:00 +00:00
Eli Friedman e0a64d83fc Fix a minor logic mistake transforming compares in instcombine. PR12514.
llvm-svn: 156600
2012-05-11 01:32:59 +00:00
Rafael Espindola ba0a6cabb8 Always compute all the bits in ComputeMaskedBits.
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.

llvm-svn: 154011
2012-04-04 12:51:34 +00:00
Benjamin Kramer c7a22fe76b Fix unsigned off-by-one in comment.
llvm-svn: 151056
2012-02-21 13:40:06 +00:00
Benjamin Kramer 6ee8690aa5 InstCombine: Don't transform a signed icmp of two GEPs into a signed compare of the indices.
This transformation is not safe in some pathological cases (signed icmp of pointers should be an
extremely rare thing, but it's valid IR!). Add an explanatory comment.

Kudos to Duncan for pointing out this edge case (and not giving up explaining it until I finally got it).

llvm-svn: 151055
2012-02-21 13:31:09 +00:00
Benjamin Kramer ac8ecc4e7e InstCombine: Removing the base from the address calculation is only safe when the GEPs are inbounds.
llvm-svn: 150978
2012-02-20 18:45:10 +00:00
Benjamin Kramer 7adb189538 InstCombine: When comparing two GEPs that were derived from the same base pointer but use different types, expand the offset calculation and to the compare on the offset if profitable.
This came up in SmallVector code.

llvm-svn: 150962
2012-02-20 15:07:47 +00:00
Devang Patel 698452bc7e Check against umin while converting fcmp into an icmp.
llvm-svn: 150425
2012-02-13 23:05:18 +00:00
Chris Lattner fe741769dd enhance logic to support ConstantDataArray.
llvm-svn: 149340
2012-01-31 02:55:06 +00:00
Dan Gohman 518cda42b9 The powers that be have decided that LLVM IR should now support 16-bit
"half precision" floating-point with a first-class type.

This patch adds basic IR support (but not codegen support).

llvm-svn: 146786
2011-12-17 00:04:22 +00:00
Chad Rosier 43a33066b4 Fix a few more places where TargetData/TargetLibraryInfo is not being passed.
Add FIXMEs to places that are non-trivial to fix.

llvm-svn: 145661
2011-12-02 01:26:24 +00:00
Pete Cooper fdddc27143 Improved fix for abs(val) != 0 to check other similar case. Also fixed style issues and confusing comment
llvm-svn: 145618
2011-12-01 19:13:26 +00:00
Pete Cooper bc5c524b71 Added instcombine pattern to spot comparing -val or val against 0.
(val != 0) == (-val != 0) so "abs(val) != 0" becomes "val != 0"

Fixes <rdar://problem/10482509>

llvm-svn: 145563
2011-12-01 03:58:40 +00:00
Eli Friedman b3f9b0676a Add a missing safety check to ProcessUGT_ADDCST_ADD. Fixes PR11438.
llvm-svn: 145316
2011-11-28 23:32:19 +00:00
Jim Grosbach 011dafba61 Don't modify constant in-place.
llvm-svn: 140875
2011-09-30 19:58:46 +00:00
Jim Grosbach 24ff834671 float comparison to double 'zero' constant can just be a float 'zero.'
InstCombine was incorrectly considering the conversion of the constant
zero to be unsafe.

We want to transform:
define float @bar(float %x) nounwind readnone optsize ssp {
  %conv = fpext float %x to double
  %cmp = fcmp olt double %conv, 0.000000e+00
  %conv1 = zext i1 %cmp to i32
  %conv2 = sitofp i32 %conv1 to float
  ret float %conv2
}

Into:
define float @bar(float %x) nounwind readnone optsize ssp {
  %cmp = fcmp olt float %x, 0.000000e+00   ; <---- This
  %conv1 = zext i1 %cmp to i32
  %conv2 = sitofp i32 %conv1 to float
  ret float %conv2
}


rdar://10215914

llvm-svn: 140869
2011-09-30 18:45:50 +00:00
Jim Grosbach 129c52af18 Tidy up. Trailing whitespace.
llvm-svn: 140865
2011-09-30 18:09:53 +00:00
Benjamin Kramer 547b6c5ecd Stop emitting instructions with the name "tmp" they eat up memory and have to be uniqued, without any benefit.
If someone prefers %tmp42 to %42, run instnamer.

llvm-svn: 140634
2011-09-27 20:39:19 +00:00
Eli Friedman 911e12f505 Clean up includes of llvm/Analysis/ConstantFolding.h so it's included where it's used and not included where it isn't.
llvm-svn: 135628
2011-07-20 21:57:23 +00:00
Chris Lattner 229907cd11 land David Blaikie's patch to de-constify Type, with a few tweaks.
llvm-svn: 135375
2011-07-18 04:54:35 +00:00
Chris Lattner b1a1512119 start using the new helper methods a bit.
llvm-svn: 135251
2011-07-15 06:08:15 +00:00
Benjamin Kramer e6e1933f31 Change Intrinsic::getDeclaration and friends to take an ArrayRef.
llvm-svn: 135154
2011-07-14 17:45:39 +00:00
Jay Foad 57aa636794 Convert InsertValueInst and ExtractValueInst APIs to use ArrayRef.
llvm-svn: 135040
2011-07-13 10:26:04 +00:00
Jay Foad b804a2b751 Second attempt at de-constifying LLVM Types in FunctionType::get(),
StructType::get() and TargetData::getIntPtrType().

llvm-svn: 134982
2011-07-12 14:06:48 +00:00
Bill Wendling a78cd228c2 Revert r134893 and r134888 (and related patches in other trees). It was causing
an assert on Darwin llvm-gcc builds.

Assertion failed: (castIsValid(op, S, Ty) && "Invalid cast!"), function Create, file /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.llvm-gcc-i386-darwin9-RA/llvm.src/lib/VMCore/Instructions.cpp, li\
ne 2067.
etc.

http://smooshlab.apple.com:8013/builders/llvm-gcc-i386-darwin9-RA/builds/2354

--- Reverse-merging r134893 into '.':
U    include/llvm/Target/TargetData.h
U    include/llvm/DerivedTypes.h
U    tools/bugpoint/ExtractFunction.cpp
U    unittests/Support/TypeBuilderTest.cpp
U    lib/Target/ARM/ARMGlobalMerge.cpp
U    lib/Target/TargetData.cpp
U    lib/VMCore/Constants.cpp
U    lib/VMCore/Type.cpp
U    lib/VMCore/Core.cpp
U    lib/Transforms/Utils/CodeExtractor.cpp
U    lib/Transforms/Instrumentation/ProfilingUtils.cpp
U    lib/Transforms/IPO/DeadArgumentElimination.cpp
U    lib/CodeGen/SjLjEHPrepare.cpp
--- Reverse-merging r134888 into '.':
G    include/llvm/DerivedTypes.h
U    include/llvm/Support/TypeBuilder.h
U    include/llvm/Intrinsics.h
U    unittests/Analysis/ScalarEvolutionTest.cpp
U    unittests/ExecutionEngine/JIT/JITTest.cpp
U    unittests/ExecutionEngine/JIT/JITMemoryManagerTest.cpp
U    unittests/VMCore/PassManagerTest.cpp
G    unittests/Support/TypeBuilderTest.cpp
U    lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
U    lib/Target/Blackfin/BlackfinIntrinsicInfo.cpp
U    lib/VMCore/IRBuilder.cpp
G    lib/VMCore/Type.cpp
U    lib/VMCore/Function.cpp
G    lib/VMCore/Core.cpp
U    lib/VMCore/Module.cpp
U    lib/AsmParser/LLParser.cpp
U    lib/Transforms/Utils/CloneFunction.cpp
G    lib/Transforms/Utils/CodeExtractor.cpp
U    lib/Transforms/Utils/InlineFunction.cpp
U    lib/Transforms/Instrumentation/GCOVProfiling.cpp
U    lib/Transforms/Scalar/ObjCARC.cpp
U    lib/Transforms/Scalar/SimplifyLibCalls.cpp
U    lib/Transforms/Scalar/MemCpyOptimizer.cpp
G    lib/Transforms/IPO/DeadArgumentElimination.cpp
U    lib/Transforms/IPO/ArgumentPromotion.cpp
U    lib/Transforms/InstCombine/InstCombineCompares.cpp
U    lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
U    lib/Transforms/InstCombine/InstCombineCalls.cpp
U    lib/CodeGen/DwarfEHPrepare.cpp
U    lib/CodeGen/IntrinsicLowering.cpp
U    lib/Bitcode/Reader/BitcodeReader.cpp

llvm-svn: 134949
2011-07-12 01:15:52 +00:00
Jay Foad 56cc1530ee De-constify Types in FunctionType::get().
llvm-svn: 134888
2011-07-11 07:56:41 +00:00
Benjamin Kramer 9eca5feff1 PR10267: Don't combine an equality compare with an AND into an inequality compare when the AND has more than one use.
This can pessimize code, inequalities are generally more expensive.

llvm-svn: 134379
2011-07-04 20:16:36 +00:00
Benjamin Kramer c970849ea0 InstCombine: Fold A-b == C --> b == A-C if A and C are constants.
The backend already knew this trick.

llvm-svn: 132915
2011-06-13 15:24:24 +00:00
Benjamin Kramer 91f914ce21 InstCombine: Shrink ((zext X) & C1) == C2 to fold away the cast if the "zext" and the "and" have one use.
llvm-svn: 132897
2011-06-12 22:48:00 +00:00
Benjamin Kramer 35159c114c Simplify code. No functionality changes, name changes aside.
llvm-svn: 132896
2011-06-12 22:47:53 +00:00
Eli Friedman 865866e7fe PR9998: ashr exact %x, 31 is not equivalent to sdiv exact %x, -2147483648.
llvm-svn: 132097
2011-05-25 23:26:20 +00:00
Eli Friedman 1754a25977 More instcombine simplifications towards better debug locations.
llvm-svn: 131596
2011-05-18 23:11:30 +00:00
Stuart Hastings 66a82b966e Avoid combining GEPs that might overflow at runtime.
rdar://problem/9267970

Patch by Julien Lerouge!

llvm-svn: 131339
2011-05-14 05:55:10 +00:00
Eli Friedman 8a20e66926 PR9838: Fix transform introduced in r127064 to not trigger when only one side of the icmp is an exact shift.
llvm-svn: 130954
2011-05-05 21:59:18 +00:00
Chris Lattner 1b06c71668 Transform: "icmp eq (trunc (lshr(X, cst1)), cst" to "icmp (and X, mask), cst"
when X has multiple uses.  This is useful for exposing secondary optimizations,
but the X86 backend isn't ready for this when X has a single use.  For example,
this can disable load folding.

This is inching towards resolving PR6627.

llvm-svn: 130238
2011-04-26 20:18:20 +00:00
Chris Lattner 31b106d7dd some random cleanups, no functionality change.
llvm-svn: 130237
2011-04-26 20:02:45 +00:00
Chris Lattner 0ab5e2cded Fix a ton of comment typos found by codespell. Patch by
Luis Felipe Strano Moraes!

llvm-svn: 129558
2011-04-15 05:18:47 +00:00
Benjamin Kramer 5291054ef1 InstCombine: APFloat can't perform arithmetic on PPC double doubles, don't even try.
Thanks Eli!

llvm-svn: 128676
2011-03-31 21:35:49 +00:00
Benjamin Kramer be209ab8a2 InstCombine: Fix transform to use the swapped predicate.
Thanks Frits!

llvm-svn: 128628
2011-03-31 10:46:03 +00:00
Benjamin Kramer d159d94644 InstCombine: fold fcmp (fneg x), (fneg y) -> fcmp x, y
llvm-svn: 128627
2011-03-31 10:12:22 +00:00
Benjamin Kramer a8c5d0872d InstCombine: fold fcmp pred (fneg x), C -> fcmp swap(pred) x, -C
llvm-svn: 128626
2011-03-31 10:12:15 +00:00
Benjamin Kramer cbb18e91a8 InstCombine: Shrink "fcmp (fpext x), C" to "fcmp x, C" if C can be losslessly converted to the type of x.
Fixes PR9592.

llvm-svn: 128625
2011-03-31 10:12:07 +00:00
Benjamin Kramer 2ccfbc8b71 InstCombine: fold fcmp (fpext x), (fpext y) -> fcmp x, y.
llvm-svn: 128624
2011-03-31 10:11:58 +00:00
Nick Lewycky afc8098c9e Reorder comments to put them the right way around.
llvm-svn: 127220
2011-03-08 06:29:47 +00:00
Nick Lewycky 92db8e8e39 ConstantInt has some getters which return ConstantInt's or ConstantVector's of
the value splatted into every element. Extend this to getTrue and getFalse which
by providing new overloads that take Types that are either i1 or <N x i1>. Use
it in InstCombine to add vector support to some code, fixing PR8469!

llvm-svn: 127116
2011-03-06 03:36:19 +00:00
Nick Lewycky 9719a719c7 Thread comparisons over udiv/sdiv/ashr/lshr exact and lshr nuw/nsw whenever
possible. This goes into instcombine and instsimplify because instsimplify
doesn't need to check hasOneUse since it returns (almost exclusively) constants.

This fixes PR9343 #4 #5 and #8!

llvm-svn: 127064
2011-03-05 05:19:11 +00:00
Nick Lewycky 25cc338d88 Try once again to optimize "icmp (srem X, Y), Y" by turning the comparison into
true/false or "icmp slt/sge Y, 0".

llvm-svn: 127063
2011-03-05 04:28:48 +00:00
Nick Lewycky 66f4f22f7b srem doesn't actually have the same resulting sign as its numerator, you could
also have a zero when numerator = denominator. Reverts parts of r126635 and
r126637.

llvm-svn: 126644
2011-02-28 09:17:39 +00:00
Nick Lewycky 174a705497 Teach InstCombine to fold "(shr exact X, Y) == 0" --> X == 0, fixing #1 from
PR9343.

llvm-svn: 126643
2011-02-28 08:31:40 +00:00
Nick Lewycky 6b445419b0 The sign of an srem instruction is the sign of its dividend (the first
argument), regardless of the divisor. Teach instcombine about this and fix
test7 in PR9343!

llvm-svn: 126635
2011-02-28 06:20:05 +00:00
Duncan Sands 84653b3674 Add some transforms of the kind X-Y>X -> 0>Y which are valid when there is no
overflow.  These subsume some existing equality transforms, so zap those.

llvm-svn: 125843
2011-02-18 16:25:37 +00:00
Duncan Sands e522001171 Transform "A + B >= A + C" into "B >= C" if the adds do not wrap. Likewise for some
variations (some of these were already present so I unified the code).  Spotted by my
auto-simplifier as occurring a lot.

llvm-svn: 125734
2011-02-17 07:46:37 +00:00
Chris Lattner 9bd7fdff58 remove a now-unneccesary cast.
llvm-svn: 125464
2011-02-13 18:30:09 +00:00
Chris Lattner 43273affb9 implement instcombine folding for things like (x >> c) < 42.
We were previously simplifying divisions, but not right shifts!

llvm-svn: 125454
2011-02-13 08:07:21 +00:00
Chris Lattner d369f575d7 refactor some code out into a helper method.
llvm-svn: 125451
2011-02-13 07:43:07 +00:00
Benjamin Kramer 1800d823de Also fold (A+B) == A -> B == 0 when the add is commuted.
llvm-svn: 125411
2011-02-11 21:46:48 +00:00
Chris Lattner 98457101fc Enhance the "compare with shift" and "compare with div"
optimizations to be much more aggressive in the face of
exact/nsw/nuw div and shifts.  For example, these (which
are the same except the first is 'exact' sdiv:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %A = sdiv exact i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %A = sdiv i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

compile down to:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %1 = icmp eq i64 %X, 0
  ret i1 %1
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %X.off = add i64 %X, 4
  %1 = icmp ult i64 %X.off, 9
  ret i1 %1
}

This happens when you do something like:
  (ptr1-ptr2) == 42

where the pointers are pointers to non-unit types.

llvm-svn: 125266
2011-02-10 05:23:05 +00:00
Anders Carlsson f23a6da271 Recognize and simplify
(A+B) == A  ->  B == 0
A == (A+B)  ->  B == 0

llvm-svn: 124567
2011-01-30 22:01:13 +00:00
Duncan Sands 8fb2c3827c At -O123 the early-cse pass is run before instcombine has run. According to my
auto-simplier the transform most missed by early-cse is (zext X) != 0 -> X != 0.
This patch adds this transform and some related logic to InstructionSimplify
and removes some of the logic from instcombine (unfortunately not all because
there are several situations in which instcombine can improve things by making
new instructions, whereas instsimplify is not allowed to do this).  At -O2 this
often results in more than 15% more simplifications by early-cse, and results in
hundreds of lines of bitcode being eliminated from the testsuite.  I did see some
small negative effects in the testsuite, for example a few additional instructions
in three programs.  One program, 483.xalancbmk, got an additional 35 instructions,
which seems to be due to a function getting an additional instruction and then
being inlined all over the place.

llvm-svn: 123911
2011-01-20 13:21:55 +00:00
Chris Lattner ea7131a062 remove the AllowAggressive argument to FoldOpIntoPhi. It is forced to false in the
first line of the function because it isn't a good idea, even for compares.

llvm-svn: 123566
2011-01-16 05:14:26 +00:00
Chris Lattner 497459d5fd fix typo
llvm-svn: 123516
2011-01-15 05:42:47 +00:00
Chris Lattner f3c4eefff8 Catch ~x < cst just like ~x < ~y, we currently handle this through
means that are about to disappear.

llvm-svn: 123515
2011-01-15 05:41:33 +00:00
Owen Anderson 0022a4b417 Remove dead variable, const-ref-ize an APInt.
llvm-svn: 123248
2011-01-11 18:26:37 +00:00
Owen Anderson d490c2d2ae Fix a random missed optimization by making InstCombine more aggressive when determining which bits are demanded by
a comparison against a constant.

llvm-svn: 123203
2011-01-11 00:36:45 +00:00
Chris Lattner 5e0c0c72e9 recognize an unsigned add with overflow idiom into uadd.
This resolves a README entry and technically resolves PR4916,
but we still get poor code for the testcase in that PR because
GVN isn't CSE'ing uadd with add, filed as PR8817.

Previously we got:

_test7:                                 ## @test7
	addq	%rsi, %rdi
	cmpq	%rdi, %rsi
	movl	$42, %eax
	cmovaq	%rsi, %rax
	ret

Now we get:

_test7:                                 ## @test7
	addq	%rsi, %rdi
	movl	$42, %eax
	cmovbq	%rsi, %rax
	ret

llvm-svn: 122182
2010-12-19 19:37:52 +00:00
Chris Lattner ce2995ae58 use IC.ReplaceInstUsesWith instead of a raw RAUW so that uses of
the old thing end up on the instcombine worklist.  Not doing this
can cause an extra top-level iteration of instcombine, burning
compile time.

llvm-svn: 122179
2010-12-19 18:38:44 +00:00
Chris Lattner 79874566ce generalize the sadd creation code to not require that the
sadd formed is half the size of the original type. We can
now compile this into a sadd.i8:

unsigned char X(char a, char b) {
  int res = a+b;
  if ((unsigned )(res+128) > 255U)
    abort();
  return res;
}

llvm-svn: 122178
2010-12-19 18:35:09 +00:00
Chris Lattner c56c845377 fix another miscompile in the llvm.sadd formation logic: it wasn't
checking to see if the high bits of the original add result were dead.
Inserting a smaller add and zexting back to that size is not good enough.

This is likely to be the fix for 8816.

llvm-svn: 122177
2010-12-19 18:22:06 +00:00
Chris Lattner f29562db25 fix a bug (possibly 8816) in the sadd forming xform: it isn't
profitable (or safe) to promote code when the add-with-constant
has other uses.

llvm-svn: 122175
2010-12-19 17:59:02 +00:00
Chris Lattner ee61c1d820 rework the code added in r122072 to pull it out to its own
helper function, clean up comments, and reduce indentation.
No functionality change.

llvm-svn: 122174
2010-12-19 17:52:50 +00:00
Owen Anderson 1294ea7d53 Reapply r121905 (automatic synthesis of @llvm.sadd.with.overflow) with a fix for a bug that manifested itself
on the DragonEgg self-host bot.  Unfortunately, the testcase is pretty messy and doesn't reduce well due to
interactions with other parts of InstCombine.

llvm-svn: 122072
2010-12-17 18:08:00 +00:00
Duncan Sands 8d1ab6f6e1 Speculatively revert commit 121905 since it looks like it might have broken the
dragonegg self-host buildbot.  Original commit message:

Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics.  This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.

llvm-svn: 121965
2010-12-16 09:40:54 +00:00
Owen Anderson 1cf8881299 Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics.  This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.

Fixes <rdar://problem/8558713>.

llvm-svn: 121905
2010-12-15 22:32:38 +00:00
Jay Foad 583abbc4df PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

llvm-svn: 121120
2010-12-07 08:25:19 +00:00
Jay Foad 25a5e4ca1f PR5207: Rename overloaded APInt methods set(), clear(), flip() to
setAllBits(), setBit(unsigned), etc.

llvm-svn: 120564
2010-12-01 08:53:58 +00:00
Chris Lattner e5afa15b77 duncan's spider sense was right, I completely reversed the condition
on this instcombine xform.  This fixes a miscompilation of 403.gcc.

llvm-svn: 119988
2010-11-23 02:42:04 +00:00
Chris Lattner f7e896138e optimize:
void a(int x) { if (((1<<x)&8)==0) b(); }

into "x != 3", which occurs over 100 times in 403.gcc but in no
other program in llvm-test.

llvm-svn: 119922
2010-11-21 06:44:42 +00:00
Eli Friedman 0428a61e45 PR7750: !CExpr->isNullValue() only properly computes whether CExpr is nonnull
if CExpr is a ConstantInt.

llvm-svn: 109773
2010-07-29 18:03:33 +00:00
Duncan Sands 41b4a6b36a Convert some tab stops into spaces.
llvm-svn: 108130
2010-07-12 08:16:59 +00:00
Gabor Greif 7ccec09252 use ArgOperand API
llvm-svn: 106752
2010-06-24 16:11:44 +00:00
Duncan Sands f162eace49 Teach instCombine to remove malloc+free if malloc's only uses are comparisons
to null.  Patch by Matti Niemenmaa.

llvm-svn: 104871
2010-05-27 19:09:06 +00:00
Eric Christopher 7258dcd77f Revert 101465, it broke internal OpenGL testing.
Probably the best way to know that all getOperand() calls have been handled
is to replace that API instead of updating.

llvm-svn: 101579
2010-04-16 23:37:20 +00:00
Gabor Greif f375520f7b reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101465
2010-04-16 15:33:14 +00:00
Gabor Greif 403e9694f9 back out r101423 and r101397, they break llvm-gcc self-host on darwin10
llvm-svn: 101434
2010-04-16 01:16:20 +00:00
Gabor Greif 33ae80bff7 reapply r101364, which has been backed out in r101368
with a fix

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101397
2010-04-15 20:51:13 +00:00
Gabor Greif 9fd00c7d25 back out r101364, as it trips the linux nightlybot on some clang C++ tests
llvm-svn: 101368
2010-04-15 12:46:56 +00:00
Gabor Greif aafd209632 rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101364
2010-04-15 10:49:53 +00:00
Dan Gohman 4ce1fb1448 Add variants of ult, ule, etc. which take a uint64_t RHS, for convenience.
llvm-svn: 100824
2010-04-08 23:03:40 +00:00
Chris Lattner 067459c62b Fix PR6503. This turned into a much more interesting and nasty bug. Various
parts of the cmp|cmp and cmp&cmp folding logic wasn't prepared for vectors
(unrelated to the bug but noticed while in the code) and the code was 
*definitely* not safe to use by the (cast icmp)|(cast icmp) handling logic
that I added in r95855.  Fix all this up by changing the various routines
to more consistently use IRBuilder and not pass in the I which had the wrong 
type.

llvm-svn: 97801
2010-03-05 08:46:26 +00:00
Dan Gohman 94732024eb Fix indentation.
llvm-svn: 97024
2010-02-24 06:46:09 +00:00
Duncan Sands 19d0b47b1f There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.

llvm-svn: 96344
2010-02-16 11:11:14 +00:00
Duncan Sands 9dff9bec31 Uniformize the names of type predicates: rather than having isFloatTy and
isInteger, we now have isFloatTy and isIntegerTy.  Requested by Chris!

llvm-svn: 96223
2010-02-15 16:12:20 +00:00
Chris Lattner 9306ffa05a cleanups.
llvm-svn: 94995
2010-02-01 19:54:45 +00:00
Chris Lattner 8c92b57df9 tidy up some stuff duncan pointed out.
llvm-svn: 93007
2010-01-08 17:48:19 +00:00
Chris Lattner 54f4e39956 optimize comparisons against cttz/ctlz/ctpop, patch by Alastair Lynn!
llvm-svn: 92745
2010-01-05 18:09:56 +00:00
Chris Lattner a751d09c08 Truncate GEP indexes larger than the pointer size down to pointer size
when doing this transform if the GEP is not inbounds.  No testcase because
it is very difficult to trigger this: instcombine already canonicalizes
GEP indices to pointer size, so it relies specific permutations of the
instcombine worklist.

Thanks to Duncan for pointing this possible problem out.

llvm-svn: 92495
2010-01-04 18:57:15 +00:00
Chris Lattner 2188e40e4c split instcombine of compares (visit[FI]Cmp) out to
a new InstCombineCompares.cpp file.

llvm-svn: 92467
2010-01-04 07:37:31 +00:00