Commit Graph

67 Commits

Author SHA1 Message Date
Hal Finkel e2b89118bd [ConstantFold] Don't try to strip fp -> int bitcasts to simplify icmps
ConstantFold has logic to take icmp (bitcast x to y), null and strip the
bitcast. This makes sense in general, but not if x has floating-point type. In
this case, we'd need a fcmp, not an icmp, and the code will assert. We normally
don't see this situation because we constant fold fp -> int bitcasts, however,
we'll see it for bitcasts of ppc_fp128 -> i128. This is because that bitcast is
Endian-dependent, and as a result, we don't simplify it in ConstantFold (we
could, but no one has yet added the necessary logic). Regardless, ConstantFold
should not depend on that canonicalization for correctness.

llvm-svn: 268534
2016-05-04 19:37:08 +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
Sanjay Patel f3bb6c51bc fix documentation comments; NFC
llvm-svn: 265434
2016-04-05 18:23:30 +00:00
Teresa Johnson f4cf1c3eb4 Don't fold double constant to an integer if dest type not integral
Summary:
I encountered this issue when constant folding during inlining tried to
fold away a bitcast of a double to an x86_mmx, which is not an integral
type. The test case exposes the same issue with a smaller code snippet
during early CSE.

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18528

llvm-svn: 265367
2016-04-04 23:50:46 +00:00
Simon Pilgrim b57b002253 [InstCombine] Ensure all undef operands are handled before binary instruction constant folding
As noted in PR18355, this patch makes it clear that all cases with undef operands have been handled before further constant folding is attempted.

Differential Revision: http://reviews.llvm.org/D18305

llvm-svn: 263994
2016-03-21 22:15:50 +00:00
Simon Pilgrim 8c9f00f788 Strip trailing whitespace.
llvm-svn: 263162
2016-03-10 20:58:11 +00:00
Justin Bogner 08154bf3d2 IR: Make the X / undef -> undef fold match the comment
The constant folding for sdiv and udiv has a big discrepancy between the
comments and the code, which looks like a typo. Currently, we're folding
X / undef pretty inconsistently:

  0 / undef -> undef
  C / undef -> 0
  undef / undef -> 0

Whereas the comments state we do X / undef -> undef. The logic that
returns zero is actually commented as doing undef / X -> 0, despite that
the LHS isn't undef in many of the cases that hit it.

llvm-svn: 261813
2016-02-25 01:02:18 +00:00
Benjamin Kramer 8f59adb217 [ConstantFolding] Reduce APInt and APFloat copying.
llvm-svn: 260826
2016-02-13 16:54:14 +00:00
Eduard Burtescu 19eb03106d [opaque pointer types] [NFC] GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.
Summary:
GEPOperator: provide getResultElementType alongside getSourceElementType.
This is made possible by adding a result element type field to GetElementPtrConstantExpr, which GetElementPtrInst already has.

GEP: replace get(Pointer)ElementType uses with get{Source,Result}ElementType.

Reviewers: mjacob, dblaikie

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16275

llvm-svn: 258145
2016-01-19 17:28:00 +00:00
Manuel Jacob c784e6acd9 Fix constant folding of constant vector GEPs with undef or null as pointer argument.
Reviewers: eddyb

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16321

llvm-svn: 258134
2016-01-19 16:34:31 +00:00
Manuel Jacob 6a4761e384 Rename Variable `Ptr` to `PtrTy`. NFC.
llvm-svn: 258130
2016-01-19 15:21:15 +00:00
Craig Topper 1c3f28313e Use CmpInst::Predicate instead of 'unsigned short' in some places. NFC
llvm-svn: 255623
2015-12-15 06:11:33 +00:00
David Majnemer 59be1d653a [ConstantFold] Fix bitcast to gep constant folding transform.
Make sure to check that the destination type is sized.
A check was present but was incorrectly checking the source type
instead.

Patch by Amaury SECHET!

Differential Revision: http://reviews.llvm.org/D15264

llvm-svn: 255536
2015-12-14 19:30:32 +00:00
Stephen Canon b12db0e42c Remove roundingMode argument in APFloat::mod
Because mod is always exact, this function should have never taken a rounding mode argument.  The actual implementation still has issues, which I'll look at resolving in a subsequent patch.

llvm-svn: 248195
2015-09-21 19:29:25 +00:00
Bruce Mitchener e9ffb45b60 Fix typos.
Summary: This fixes a variety of typos in docs, code and headers.

Subscribers: jholewinski, sanjoy, arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D12626

llvm-svn: 247495
2015-09-12 01:17:08 +00:00
David Blaikie 51973e1088 Add comment as follow up to r245712
llvm-svn: 245730
2015-08-21 20:18:39 +00:00
David Blaikie 401bb64b31 Remove an unnecessary use of pointee types introduced in r194220
David Majnemer (the original author) believes this to be an impossible
condition to reach anyway, and no test cases cover this so we'll go with
that.

llvm-svn: 245712
2015-08-21 17:37:41 +00:00
Craig Topper e3dcce9700 De-constify pointers to Type since they can't be modified. NFC
This was already done in most places a while ago. This just fixes the ones that crept in over time.

llvm-svn: 243842
2015-08-01 22:20:21 +00:00
David Blaikie 473b943ea8 Refix a use of explicit pointer types in GEP constant folding
In the glorious future of opaque pointer types, it won't be possible to
retrieve the pointee type of a pointer type which is what's being done
in this GEP loop - but the first iteration is always a pointer type and
the loop doesn't care about that case, except whether or not the index
is a constant.

So pull that special case out before the loop and start at the second
iteration (index 1) instead.

Originally committed in r236670 and reverted with a test case in
r239015. This change keeps the test case working while also avoiding
depending on pointee types.

llvm-svn: 239629
2015-06-12 18:22:03 +00:00
David Majnemer 38eb9f46db [ConstantFold] Don't skip the first gep index when folding geps
We neglected to check if the first index made the GEP ineligible for
'inbounds'.

This fixes PR23753.

llvm-svn: 239015
2015-06-04 07:01:56 +00:00
David Blaikie f87cc6d3ab [opaque pointer type] Pass explicit pointee type in another case of GEP constant folding
llvm-svn: 237860
2015-05-21 00:06:38 +00:00
Yaron Keren 004756d366 As r237678 was reverted, this is no longer needed.
llvm-svn: 237687
2015-05-19 11:46:27 +00:00
Yaron Keren d90d6fb53a Fix Visual C++ errors C2784, C2780, C2782 after r237678.
It does not like std::min(unsigned, uint32_t).

llvm-svn: 237683
2015-05-19 11:18:10 +00:00
David Blaikie e7107060f8 [opaque pointer type] Use GlobalVariable::getValueType rather than accessing it through the GV's pointee type
llvm-svn: 237311
2015-05-13 22:54:54 +00:00
David Blaikie 4c2814e5d6 [opaque pointer type] Constant Folding: Use GEPOperator to access the pointee source type rather than going through the first operand's pointer type
llvm-svn: 237274
2015-05-13 18:35:29 +00:00
David Blaikie d9d900c05b Recommit r236670: [opaque pointer type] Pass explicit pointer type through GEP constant folding""
Clang regressions were caused by more stringent assertion checking
introduced by this change. Small fix needed to clang has been committed
in r236751.

llvm-svn: 236752
2015-05-07 17:28:58 +00:00
David Blaikie 567d0e5a90 Revert "[opaque pointer type] Pass explicit pointer type through GEP constant folding"
Causes regressions in Clang. Reverting while I investigate.

This reverts commit r236670.

llvm-svn: 236678
2015-05-06 23:56:21 +00:00
David Blaikie e66a45fdb4 [opaque pointer type] Pass explicit pointer type through GEP constant folding
llvm-svn: 236670
2015-05-06 23:49:14 +00:00
Pawel Bylica c25918a043 Constfold insertelement to undef when index is out-of-bounds
Summary:
This patch adds constant folding of insertelement instruction to undef value when index operand is constant and is not less than vector size or is undef.

InstCombine does not support this case, but I'm happy to add it there also if this change is accepted.

Test Plan: Unittests and regression tests for ConstProp pass.

Reviewers: majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9287

llvm-svn: 235854
2015-04-27 09:30:49 +00:00
Pawel Bylica bce9c2e263 Correct extractelement constant folding
Summary: Constant folding of extractelement with out-of-bound index produces undef also for indexes bigger than 64bit (instead of crash assert failure as before)

Test Plan: Unit tests included.

Reviewers: majnemer

Reviewed By: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9225

llvm-svn: 235700
2015-04-24 07:42:35 +00:00
David Blaikie 4a2e73b066 [opaque pointer type] API migration for GEP constant factories
Require the pointee type to be passed explicitly and assert that it is
correct. For now it's possible to pass nullptr here (and I've done so in
a few places in this patch) but eventually that will be disallowed once
all clients have been updated or removed. It'll be a long road to get
all the way there... but if you have the cahnce to update your callers
to pass the type explicitly without depending on a pointer's element
type, that would be a good thing to do soon and a necessary thing to do
eventually.

llvm-svn: 233938
2015-04-02 18:55:32 +00:00
David Blaikie d288fb8681 [opaque pointer type] Change GetElementPtrInst::getIndexedType to take the pointee type
This pushes the use of PointerType::getElementType up into several
callers - I'll essentially just have to keep pushing that up the stack
until I can eliminate every call to it...

llvm-svn: 233604
2015-03-30 21:41:43 +00:00
Hal Finkel cd5553ed39 [ConstantFold] Don't fold ppc_fp128 <-> int bitcasts
PPC_FP128 is really the sum of two consecutive doubles, where the first double
is always stored first in memory, regardless of the target endianness. The
memory layout of i128, however, depends on the target endianness, and so we
can't fold this without target endianness information. As a result, we must not
do this folding in lib/IR/ConstantFold.cpp (it could be done instead in
Analysis/ConstantFolding.cpp, but that's not done now).

Fixes PR23026.

llvm-svn: 233481
2015-03-28 16:44:57 +00:00
David Majnemer e2a4b856d8 ConstantFold: Fix big shift constant folding
Constant folding for shift IR instructions ignores all bits above 32 of
second argument (shift amount).
Because of that, some undef results are not recognized and APInt can
raise an assert failure if second argument has more than 64 bits.

Patch by Paweł Bylica!

Differential Revision: http://reviews.llvm.org/D7701

llvm-svn: 232176
2015-03-13 16:39:46 +00:00
Mehdi Amini eb242a5041 InstCombine: fix fold "fcmp x, undef" to account for NaN
Summary:
See the two test cases.

; Can fold fcmp with undef on one side by choosing NaN for the undef

; Can fold fcmp with undef on both side
;   fcmp u_pred undef, undef -> true
;   fcmp o_pred undef, undef -> false
; because whatever you choose for the first undef
; you can choose NaN for the other undef

Reviewers: hfinkel, chandlerc, majnemer

Reviewed By: majnemer

Subscribers: majnemer, llvm-commits

Differential Revision: http://reviews.llvm.org/D7617

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231626
2015-03-09 03:20:25 +00:00
Benjamin Kramer 6cd780ff21 Prefer SmallVector::append/insert over push_back loops.
Same functionality, but hoists the vector growth out of the loop.

llvm-svn: 229500
2015-02-17 15:29:18 +00:00
David Majnemer 8b77454dff ConstantFold: Properly fold GEP indices wider than i64
llvm-svn: 229420
2015-02-16 19:10:02 +00:00
David Majnemer 824e011ad7 ConstantFold: Shifting undef by zero results in undef
llvm-svn: 224553
2014-12-18 23:54:43 +00:00
David Majnemer 3729668056 ConstantFold: Clean up X * undef code
No functional change intended.

llvm-svn: 223970
2014-12-10 21:58:17 +00:00
David Majnemer 5a7717e498 ConstantFold, InstSimplify: undef >>a x can be either -1 or 0, choose 0
Zero is usually a nicer constant to have than -1.

llvm-svn: 223969
2014-12-10 21:58:15 +00:00
David Majnemer 89cf6d79eb ConstantFold: an undef shift amount results in undef
X shifted by undef results in undef because the undef value can
represent values greater than the width of the operands.

llvm-svn: 223968
2014-12-10 21:38:05 +00:00
David Majnemer 7b86b77248 ConstantFold: div undef, 0 should fold to undef, not zero
Dividing by zero yields an undefined value.

llvm-svn: 223924
2014-12-10 09:14:55 +00:00
David Majnemer 770fd82f39 ConstantFold: Zero-sized globals might land on top of another global
A zero sized array is zero sized and might share its address with
another global.

llvm-svn: 223684
2014-12-08 19:35:31 +00:00
David Majnemer 64ba326b1e ConstantFold: Don't optimize comparisons with weak linkage objects
Consider:
void f() {}
void __attribute__((weak)) g() {}
bool b = &f != &g;

It's possble for g to resolve to f if --defsym=g=f is passed on to the
linker.

llvm-svn: 223585
2014-12-06 11:58:33 +00:00
David Majnemer ed00cd20ad I didn't intend to commit this change.
llvm-svn: 223584
2014-12-06 10:52:32 +00:00
David Majnemer 1af36e5baf InstSimplify: Optimize away useless unsigned comparisons
Code like X < Y && Y == 0 should always be folded away to false.

llvm-svn: 223583
2014-12-06 10:51:40 +00:00
Sanjay Patel ad8b666624 Return undef on FP <-> Int conversions that overflow (PR21330).
The LLVM Lang Ref states for signed/unsigned int to float conversions:
"If the value cannot fit in the floating point value, the results are undefined."

And for FP to signed/unsigned int:
"If the value cannot fit in ty2, the results are undefined."

This matches the C definitions.

The existing behavior pins to infinity or a max int value, but that may just
lead to more confusion as seen in:
http://llvm.org/bugs/show_bug.cgi?id=21130

Returning undef will hopefully lead to a less silent failure.

Differential Revision: http://reviews.llvm.org/D5603

llvm-svn: 219542
2014-10-10 23:00:21 +00:00
Jiangning Liu 950844fadb Fix a bug around truncating vector in const prop.
In constant folding stage, "TRUNC" can't handle vector data type.

llvm-svn: 216149
2014-08-21 02:12:35 +00:00
Duncan P. N. Exon Smith 0c39d40c8b IR: Don't add inbounds to GEPs of extern_weak variables
Global variables that have `extern_weak` linkage may be null, so it's
incorrect to add `inbounds` when constant folding.

This also fixes a bug when parsing global aliases, whose forward
reference placeholders are global variables with `extern_weak` linkage.
If GEPs to these aliases are encountered before the alias itself, the
GEPs would incorrectly gain the `inbounds` keyword as well.

llvm-svn: 215803
2014-08-16 01:54:32 +00:00
David Majnemer d1bea693e2 IR: Fold away compares between GV GEPs and GVs
A GEP of a non-weak global variable will not be equivalent to another
non-weak global variable or a GEP of such a variable.

Differential Revision: http://reviews.llvm.org/D4238

llvm-svn: 212360
2014-07-04 22:05:26 +00:00