Commit Graph

2573 Commits

Author SHA1 Message Date
Sanjay Patel 6e17c00a88 [InstCombine] remove one-use restriction for icmp (shr exact X, C1), C2 --> icmp X, (C2<<C1)
llvm-svn: 314698
2017-10-02 18:26:44 +00:00
Dehao Chen f464627f28 Update getMergedLocation to check the instruction type and merge properly.
Summary: If the merged instruction is call instruction, we need to set the scope to the closes common scope between 2 locations, otherwise it will cause trouble when the call is getting inlined.

Reviewers: dblaikie, aprantl

Reviewed By: dblaikie, aprantl

Subscribers: llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D37877

llvm-svn: 314694
2017-10-02 18:13:14 +00:00
Craig Topper 6e025a3ecc [InstCombine] Use APInt for all the math in foldICmpDivConstant
Summary: This currently uses ConstantExpr to do its math, but as noted in a TODO it can all be done directly on APInt.

Reviewers: spatel, majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38440

llvm-svn: 314640
2017-10-01 23:53:54 +00:00
Daniel Jasper 3c9c60c727 Revert r314579: "Recommi r314561 after fixing over-debug assertion".
And follow-up r314585.
Leads to segfaults. I'll forward reproduction instructions to the patch
author.

Also, for a recommit, still add the original patch description.
Otherwise, it becomes really tedious to find out what a patch actually
does. The fact that it is a recommit with a fix is somewhat secondary.

llvm-svn: 314622
2017-10-01 09:53:53 +00:00
Xinliang David Li b8aac3ac19 Fix buildbot failure -- tighten type check for matching phi
llvm-svn: 314585
2017-09-30 05:27:46 +00:00
Xinliang David Li 3409d9c07f Recommi r314561 after fixing over-debug assertion
llvm-svn: 314579
2017-09-30 00:46:32 +00:00
Xinliang David Li 455dec098b Revert 314561 due to debug build assertion failure
llvm-svn: 314563
2017-09-29 22:30:34 +00:00
Xinliang David Li 5b9d96825b Eliminate PHI (int typed) which has only one use by intptr
This patch will eliminate redundant intptr/ptrtoint that pessimizes
analyses such as SCEV, AA and will make optimization passes such
as auto-vectorization more powerful.

Differential revision: http://reviews.llvm.org/D37832

llvm-svn: 314561
2017-09-29 22:10:15 +00:00
Craig Topper 0cd25942f7 Revert r314017 '[InstCombine] Simplify check for RHS being a splat constant in foldICmpUsingKnownBits by just checking Op1Min==Op1Max rather than going through m_APInt.'
This reverts r314017 and similar code added in later commits. It seems to not work for pointer compares and is causing a bot failure for the last several days.

llvm-svn: 314360
2017-09-27 22:57:18 +00:00
Chad Rosier d8b4b06f5d [InstCombine] Gating select arithmetic optimization.
These changes faciliate positive behavior for arithmetic based select
expressions that match its translation criteria, keeping code size gated to
neutral or improved scenarios.

Patch by Michael Berg <michael_c_berg@apple.com>!

Differential Revision: https://reviews.llvm.org/D38263

llvm-svn: 314320
2017-09-27 17:16:51 +00:00
Craig Topper 8bf622174d [InstCombine] Remove one use restriction on the shift for calls to foldICmpAndShift.
If this transformation succeeds, we're going to remove our dependency on the shift by rewriting the and. So it doesn't matter how many uses the shift has.

This distributes the one use check to other transforms in foldICmpAndConstConst that do need it.

Differential Revision: https://reviews.llvm.org/D38206

llvm-svn: 314233
2017-09-26 18:47:25 +00:00
Craig Topper 30dc9797e9 [InstCombine] Move an optimization from foldICmpAndConstConst to foldICmpUsingKnownBits
All this optimization cares about is knowing how many low bits of LHS is known to be zero and whether that means that the result is 0 or greater than the RHS constant. It doesn't matter where the zeros in the low bits came from. So we don't need to specifically look for an AND. Instead we can use known bits.

Differential Revision: https://reviews.llvm.org/D38195

llvm-svn: 314153
2017-09-25 21:15:00 +00:00
Sanjay Patel ecb175608f [InstCombine] remove extract-of-select vector transform (2nd try)
The 1st attempt at this:
https://reviews.llvm.org/rL314117
was reverted at:
https://reviews.llvm.org/rL314118

because of bot fails for clang tests that were checking optimized IR. That should be fixed with:
https://reviews.llvm.org/rL314144
...so try again. 

Original commit message:

The transform to convert an extract-of-a-select-of-vectors was added at:
https://reviews.llvm.org/rL194013

And a question about the validity of this transform was raised in the review:
https://reviews.llvm.org/D1539:
...but not answered AFAICT>

Most of the motivating cases in that patch are now handled by other combines. These are the tests that were added with
the original commit, but they are not regressing even after we remove the transform in this patch.

The diffs we see after removing this transform cause us to avoid increasing the instruction count, so we don't want to do
those transforms as canonicalizations.

The motivation for not turning a vector-select-of-vectors into a scalar operation is shown in PR33301:
https://bugs.llvm.org/show_bug.cgi?id=33301
...in those cases, we'll get vector ops with this patch rather than the vector/scalar mix that we currently see.

Differential Revision: https://reviews.llvm.org/D38006

llvm-svn: 314147
2017-09-25 20:30:53 +00:00
Sanjay Patel aa7f750bec revert r314117 because there are bogus clang tests that depend on the optimizer
llvm-svn: 314118
2017-09-25 17:00:04 +00:00
Sanjay Patel 9639897d77 [InstCombine] remove extract-of-select vector transform
The transform to convert an extract-of-a-select-of-vectors was added at:
rL194013

And a question about the validity of this transform was raised in the review:
https://reviews.llvm.org/D1539:
...but not answered AFAICT>

Most of the motivating cases in that patch are now handled by other combines. These are the tests that were added with
the original commit, but they are not regressing even after we remove the transform in this patch.

The diffs we see after removing this transform cause us to avoid increasing the instruction count, so we don't want to do
those transforms as canonicalizations.

The motivation for not turning a vector-select-of-vectors into a scalar operation is shown in PR33301:
https://bugs.llvm.org/show_bug.cgi?id=33301
...in those cases, we'll get vector ops with this patch rather than the vector/scalar mix that we currently see.

Differential Revision: https://reviews.llvm.org/D38006

llvm-svn: 314117
2017-09-25 16:41:34 +00:00
Craig Topper ea927baee2 [InstCombine] Teach foldICmpUsingKnownBits to simplify SLE/SGE/ULE/UGE to equality comparisons when the min/max ranges intersect in a single value.
This is the inverse of what we do for SGT/SLT/UGT/ULT.

llvm-svn: 314032
2017-09-22 21:47:22 +00:00
Craig Topper 3f364aa908 [InstCombine] Add constant splat handling to one of the ICMP_SLT/SGT cases in foldICmpUsingKnownBits.
llvm-svn: 314025
2017-09-22 19:54:15 +00:00
Craig Topper 3edda87c42 [InstCombine] Move the call to isSignBitCheck into getDemandedBitsLHSMask instead of calling it outside and passing its result through a flag. NFCI
The result of the isSignBitCheck isn't used anywhere else and this allows us to share the m_APInt call in the likely case that it isn't a sign bit check.

llvm-svn: 314018
2017-09-22 18:57:23 +00:00
Craig Topper 5b35b68785 [InstCombine] Simplify check for RHS being a splat constant in foldICmpUsingKnownBits by just checking Op1Min==Op1Max rather than going through m_APInt.
llvm-svn: 314017
2017-09-22 18:57:22 +00:00
Craig Topper 2c9b7d7894 [InstCombine] Make cases for ICMP_UGT/ICMP_ULT use similar formatting since they use similar code. NFC
llvm-svn: 314016
2017-09-22 18:57:20 +00:00
Reid Kleckner 0fe506bc5e Re-land r313825: "[IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare"
The fix is to avoid invalidating our insertion point in
replaceDbgDeclare:
     Builder.insertDeclare(NewAddress, DIVar, DIExpr, Loc, InsertBefore);
+    if (DII == InsertBefore)
+      InsertBefore = &*std::next(InsertBefore->getIterator());
     DII->eraseFromParent();

I had to write a unit tests for this instead of a lit test because the
use list order matters in order to trigger the bug.

The reduced C test case for this was:
  void useit(int*);
  static inline void inlineme() {
    int x[2];
    useit(x);
  }
  void f() {
    inlineme();
    inlineme();
  }

llvm-svn: 313905
2017-09-21 19:52:03 +00:00
Daniel Jasper 7d2f38d600 Revert r313825: "[IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare"
.. as well as the two subsequent changes r313826 and r313875.

This leads to segfaults in combination with ASAN. Will forward repro
instructions to the original author (rnk).

llvm-svn: 313876
2017-09-21 12:07:33 +00:00
Craig Topper 18887bf179 [InstCombine] Teach getDemandedBitsLHSMask to handle constant splat vectors
This replaces a ConstantInt dyn_cast with m_APInt

Differential Revision: https://reviews.llvm.org/D38100

llvm-svn: 313840
2017-09-20 23:48:58 +00:00
Reid Kleckner 3f547e87b2 [IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare
Summary:
This implements the design discussed on llvm-dev for better tracking of
variables that live in memory through optimizations:
  http://lists.llvm.org/pipermail/llvm-dev/2017-September/117222.html

This is tracked as PR34136

llvm.dbg.addr is intended to be produced and used in almost precisely
the same way as llvm.dbg.declare is today, with the exception that it is
control-dependent. That means that dbg.addr should always have a
position in the instruction stream, and it will allow passes that
optimize memory operations on local variables to insert llvm.dbg.value
calls to reflect deleted stores. See SourceLevelDebugging.rst for more
details.

The main drawback to generating DBG_VALUE machine instrs is that they
usually cause LLVM to emit a location list for DW_AT_location. The next
step will be to teach DwarfDebug.cpp how to recognize more DBG_VALUE
ranges as not needing a location list, and possibly start setting
DW_AT_start_offset for variables whose lifetimes begin mid-scope.

Reviewers: aprantl, dblaikie, probinson

Subscribers: eraman, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D37768

llvm-svn: 313825
2017-09-20 21:52:33 +00:00
Craig Topper 562bf99ee6 [InstCombine] Handle (X & C2) < C1 --> (X & C2) == 0
We already did (X & C2) > C1 --> (X & C2) != 0, if any bit set in (X & C2) will produce a result greater than C1. But there is an equivalent inverse condition with <= C1 (which will be canonicalized to < C1+1)

Differential Revision: https://reviews.llvm.org/D38065

llvm-svn: 313819
2017-09-20 21:18:17 +00:00
Craig Topper a0c897f634 [InstCombine] Use APInt::getActiveBits() to avoid creating an APInt from a trailing zero count to do a comparison. NFCI
llvm-svn: 313792
2017-09-20 18:49:29 +00:00
Quentin Colombet aa103b3d86 [InstCombine] Add select simplifications
In these cases, two selects have constant selectable operands for
both the true and false components and have the same conditional
expression.
We then create two arithmetic operations of the same type and feed a
final select operation using the result of the true arithmetic for the true
operand and the result of the false arithmetic for the false operand and reuse
the original conditionl expression.
The arithmetic operations are naturally folded as a consequence, leaving
only the newly formed select to replace the old arithmetic operation.

Patch by: Michael Berg <michael_c_berg@apple.com>
Differential Revision: https://reviews.llvm.org/D37019

llvm-svn: 313774
2017-09-20 17:32:16 +00:00
Craig Topper f264fcc704 [X86] Remove VPERM2F128/VPERM2I128 intrinsics and autoupgrade to native shuffles.
I've moved the test cases from the InstCombine optimizations to the backend to keep the coverage we had there. It covered every possible immediate so I've preserved the resulting shuffle mask for each of those immediates.

llvm-svn: 313450
2017-09-16 07:36:14 +00:00
Reid Kleckner 8a1cd91016 [InstCombine] Add a flag to disable LowerDbgDeclare
Summary:
This should improve optimized debug info for address-taken variables at
the cost of inaccurate debug info in some situations.

We patched this into clang and deployed this change to Chromium
developers, and this significantly improved debuggability of optimized
code. The long-term solution to PR34136 seems more and more like it's
going to take a while, so I would like to commit this change under a
flag so that it can be used as a stop-gap measure.

This flag should really help so for C++ aggregates like std::string and
std::vector, which are typically address-taken, even after inlining, and
cannot be SROA-ed.

Reviewers: aprantl, dblaikie, probinson, dberlin

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D36596

llvm-svn: 313108
2017-09-13 01:43:25 +00:00
Uriel Korach 18972237a2 Test commit
llvm-svn: 312878
2017-09-10 08:31:22 +00:00
Nuno Lopes 404f106d71 Merge isKnownNonNull into isKnownNonZero
It now knows the tricks of both functions.
Also, fix a bug that considered allocas of non-zero address space to be always non null

Differential Revision: https://reviews.llvm.org/D37628

llvm-svn: 312869
2017-09-09 18:23:11 +00:00
Sanjay Patel 6840c5ff75 [ValueTracking, InstCombine] canonicalize fcmp ord/uno with non-NAN ops to null constants
This is a preliminary step towards solving the remaining part of PR27145 - IR for isfinite():
https://bugs.llvm.org/show_bug.cgi?id=27145

In order to solve that one more generally, we need to add matching for and/or of fcmp ord/uno
with a constant operand.

But while looking at those patterns, I realized we were missing a canonicalization for nonzero
constants. Rather than limiting to just folds for constants, we're adding a general value
tracking method for this based on an existing DAG helper.

By transforming everything to 0.0, we can simplify the existing code in foldLogicOfFCmps()
and pick up missing vector folds.

Differential Revision: https://reviews.llvm.org/D37427

llvm-svn: 312591
2017-09-05 23:13:13 +00:00
Craig Topper 28d6d962d5 [InstCombine] Move foldSelectICmpAnd helper function earlier in the file to enable reuse in a future patch.
llvm-svn: 312518
2017-09-05 05:26:37 +00:00
Craig Topper 4c766a0559 [InstCombine] In foldSelectIntoOp, avoid creating a Constant before we know for sure we're going to use it and avoid an unnecessary call to m_APInt.
Instead of creating a Constant and then calling m_APInt with it (which will always return true). Just create an APInt initially, and use that for the checks in isSelect01 function. If it turns out we do need the Constant, create it from the APInt.

This is a refactor for a future patch that will do some more checks of the constant values here.

llvm-svn: 312517
2017-09-05 05:26:36 +00:00
Sanjay Patel bc6da4e40f [InstCombine] replace unnecessary fcmp fold with assert
See https://reviews.llvm.org/rL312411 for related InstSimplify tests.

llvm-svn: 312421
2017-09-02 18:10:29 +00:00
Sanjay Patel 64fc5daf42 [InstCombine] combine foldAndOfFCmps and foldOrOfFcmps; NFCI
In addition to removing chunks of duplicated code, we don't
want these to diverge. If there's a fold for one, there
should be a fold of the other via DeMorgan's Laws.

llvm-svn: 312420
2017-09-02 17:53:33 +00:00
Sanjay Patel 275bb5a14e [InstCombine] fix misnamed locals and use them to reduce code; NFCI
We had these locals:
Value *Op0RHS = LHS->getOperand(1);
Value *Op1LHS = RHS->getOperand(0);
...so we confusingly transposed the meaning of left/right and op0/op1.

llvm-svn: 312418
2017-09-02 17:17:17 +00:00
Sanjay Patel da6f9b2fee [InstCombine] remove unnecessary code; NFC
llvm-svn: 312416
2017-09-02 16:32:37 +00:00
Sanjay Patel 4c52f765a5 [InstCombine] move related functions next to each other; NFC
This makes it easier to see that they're almost duplicates.
As with the similar icmp functions, there should be identical 
folds for both logic ops because those are DeMorganized variants.

llvm-svn: 312415
2017-09-02 16:30:27 +00:00
Sanjay Patel 6b139464ca [InstCombine] use local variable to reduce code duplication; NFCI
llvm-svn: 312414
2017-09-02 15:11:55 +00:00
Craig Topper 924f20262b [InstCombine][InstSimplify] Teach decomposeBitTestICmp to look through truncate instructions
This patch teaches decomposeBitTestICmp to look through truncate instructions on the input to the compare. If a truncate is found it will now return the pre-truncated Value and appropriately extend the APInt mask.

This allows some code to be removed from InstSimplify that was doing this functionality.

This allows InstCombine's bit test combining code to match a pre-truncate Value with the same Value appear with an 'and' on another icmp. Or it allows us to combine a truncate to i16 and a truncate to i8. This also required removing the type check from the beginning of getMaskedTypeForICmpPair, but I believe that's ok because we still have to find two values from the input to each icmp that are equal before we'll do any transformation. So the type check was really just serving as an early out.

There was one user of decomposeBitTestICmp that didn't want to look through truncates, so I've added a flag to prevent that behavior when necessary.

Differential Revision: https://reviews.llvm.org/D37158

llvm-svn: 312382
2017-09-01 21:27:34 +00:00
Craig Topper d3b465606a [InstCombine] Don't require the compare types to be the same in getMaskedTypeForICmpPair.
A future patch will make the code look through truncates feeding the compare. So the compares might be different types but the pretruncated types might be the same.

This should be safe because we still require the same Value* to be used truncated or not in both compares. So that serves to ensure the types are the same.

llvm-svn: 312381
2017-09-01 21:27:31 +00:00
Craig Topper 085c1f4dea [InstCombine] When converting decomposeBitTestICmp's APInt return to ConstantInt, make sure we use the type from the Value* that was also returned from decomposeBitTestICmp.
Previously we used the type from the LHS of the compare, but a future patch will change decomposeBitTestICmp to look through truncates so it will return a pretruncated Value* and the type needs to match that.

llvm-svn: 312380
2017-09-01 21:27:29 +00:00
Sanjay Patel e6b48a1b02 [InstCombine] improve demanded vector elements analysis of insertelement
Recurse instead of returning on the first found optimization. Also, return early in the caller
instead of continuing because that allows another round of simplification before we might
potentially lose undef information from a shuffle mask by eliminating the shuffle.

As noted in the review, we could probably do better and be more efficient by moving all of
demanded elements into a separate pass, but this is yet another quick fix to instcombine.

Differential Revision: https://reviews.llvm.org/D37236

llvm-svn: 312248
2017-08-31 15:57:17 +00:00
Sanjay Patel 6f7ac7e402 [InstCombine] remove unnecessary vector select fold; NFCI
This code is double-dead:
1. We simplify all selects with constant true/false condition in InstSimplify.
   I've minimized/moved the tests to show that works as expected.
2. All remaining vector selects with a constant condition are canonicalized to
   shufflevector, so we really can't see this pattern.

llvm-svn: 312123
2017-08-30 14:04:57 +00:00
Florian Hahn b992feee13 [InstCombine] Fold insert sequence if first ins has multiple users.
Summary:
If the first insertelement instruction has multiple users and inserts at
position 0, we can re-use this instruction when folding a chain of
insertelement instructions. As we need to generate the first
insertelement instruction anyways, this should be a strict improvement.

We could get rid of the restriction of inserting at position 0 by
creating a different shufflemask, but it is probably worth to keep the
first insertelement instruction with position 0, as this is easier to do
efficiently than at other positions I think.

Reviewers: grosser, mkuper, fpetrogalli, efriedma

Reviewed By: fpetrogalli

Subscribers: gareevroman, llvm-commits

Differential Revision: https://reviews.llvm.org/D37064

llvm-svn: 312110
2017-08-30 10:54:21 +00:00
Craig Topper 4431bfe88c [InstCombine] Support vector splats in transformZExtICmp
This patch adds splat support to transformZExtICmp. The test cases are vector versions of tests that failed when commenting out parts of the existing scalar code.

One test didn't vectorize optimize properly due to another bug so a TODO has been added.

Differential Revision: https://reviews.llvm.org/D37253

llvm-svn: 312023
2017-08-29 18:58:13 +00:00
Craig Topper 5d6ddda92d [InstCombine] Teach foldSelectICmpAndOr to handle vector splats
This was pretty close to working already. While I was here I went ahead and passed the ICmpInst pointer from the caller instead of doing a dyn_cast that can never fail.

Differential Revision: https://reviews.llvm.org/D37237

llvm-svn: 311960
2017-08-29 00:13:49 +00:00
Craig Topper 516e39cd38 [InstCombine] Teach select01 helper of foldSelectIntoOp to handle vector splats
We were handling some vectors in foldSelectIntoOp, but not if the operand of the bin op was any kind of vector constant. This patch fixes it to treat vector splats the same as scalars.

Differential Revision: https://reviews.llvm.org/D37232

llvm-svn: 311940
2017-08-28 22:00:27 +00:00
Craig Topper 3763f0e00d [InstCombine] Call hasNoSignedWrap instead of hasNoUnsignedWrap to get the NSW flag when handling Add in SimplifyDemandedUseBits.
This is a typo from r311789.

This should fix PR34349.

llvm-svn: 311902
2017-08-28 18:44:28 +00:00