Commit Graph

2274 Commits

Author SHA1 Message Date
Nadav Rotem a069c6ce05 InstCombine optimizes gep(bitcast(x)) even when the bitcasts casts away address
space info. We crash with an assert in this case. This change checks that the
address space of the bitcasted pointer is the same as the gep ptr.

llvm-svn: 128884
2011-04-05 14:29:52 +00:00
Eli Friedman 17bf4922c9 PR9446: RecursivelyDeleteTriviallyDeadInstructions can delete the instruction
after the given instruction; make sure to handle that case correctly.
(It's difficult to trigger; the included testcase involves a dead 
block, but I don't think that's a requirement.) 

While I'm here, get rid of the unnecessary warning about
SimplifyInstructionsInBlock, since it should work correctly as far as I know.

llvm-svn: 128782
2011-04-02 22:45:17 +00:00
Benjamin Kramer d121765e64 InstCombine: Turn icmp + sext into bitwise/integer ops when the input has only one unknown bit.
int test1(unsigned x) { return (x&8) ? 0 : -1; }
int test3(unsigned x) { return (x&8) ? -1 : 0; }

before (x86_64):
_test1:
	andl	$8, %edi
	cmpl	$1, %edi
	sbbl	%eax, %eax
	ret
_test3:
	andl	$8, %edi
	cmpl	$1, %edi
	sbbl	%eax, %eax
	notl	%eax
	ret

after:
_test1:
	shrl	$3, %edi
	andl	$1, %edi
	leal	-1(%rdi), %eax
	ret
_test3:
	shll	$28, %edi
	movl	%edi, %eax
	sarl	$31, %eax
	ret

llvm-svn: 128732
2011-04-01 20:09:10 +00:00
Nadav Rotem d74b72b8a9 Instcombile optimization: extractelement(cast) -> cast(extractelement)
llvm-svn: 128683
2011-03-31 22:57:29 +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
Bill Wendling 5034159c5f * The DSE code that tested for overlapping needed to take into account the fact
that one of the numbers is signed while the other is unsigned. This could lead
  to a wrong result when the signed was promoted to an unsigned int.

* Add the data layout line to the testcase so that it will test the appropriate
  thing.

Patch by David Terei!

llvm-svn: 128577
2011-03-30 21:37:19 +00:00
Benjamin Kramer af0ed953c5 Avoid turning a floating point division with a constant power of two into a denormal multiplication.
Some platforms may treat denormals as zero, on other platforms multiplication
with a subnormal is slower than dividing by a normal.

llvm-svn: 128555
2011-03-30 17:02:54 +00:00
Benjamin Kramer 8564e0de96 InstCombine: If the divisor of an fdiv has an exact inverse, turn it into an fmul.
Fixes PR9587.

llvm-svn: 128546
2011-03-30 15:42:35 +00:00
Benjamin Kramer 272f2b0044 InstCombine: Add a few missing combines for ANDs and ORs of sign bit tests.
On x86 we now compile "if (a < 0 && b < 0)" into
	testl	%edi, %esi
	js	IF.THEN

llvm-svn: 128496
2011-03-29 22:06:41 +00:00
Cameron Zwarich ff811cc475 Do some simple copy propagation through integer loads and stores when promoting
vector types. This helps a lot with inlined functions when using the ARM soft
float ABI. Fixes <rdar://problem/9184212>.

llvm-svn: 128453
2011-03-29 05:19:52 +00:00
Nick Lewycky 8544228d5a Teach the transformation that moves binary operators around selects to preserve
the subclass optional data.

llvm-svn: 128388
2011-03-27 19:51:23 +00:00
Frits van Bommel 0bb2ad2cf7 Constant folding support for calls to umul.with.overflow(), basically identical to the smul.with.overflow() code.
llvm-svn: 128379
2011-03-27 14:26:13 +00:00
Nick Lewycky 83167df787 Add a small missed optimization: turn X == C ? X : Y into X == C ? C : Y. This
removes one use of X which helps it pass the many hasOneUse() checks.

In my analysis, this turns up very often where X = A >>exact B and that can't be
simplified unless X has one use (except by increasing the lifetime of A which is
generally a performance loss).

llvm-svn: 128373
2011-03-27 07:30:57 +00:00
Cameron Zwarich d4174ee43e Fix a typo and add a test.
llvm-svn: 128331
2011-03-26 04:58:50 +00:00
Bill Wendling db40b5c899 PR9561: A store with a negative offset (via GEP) could erroniously say that it
completely overlaps a previous store, thus mistakenly deleting that store. Check
for this condition.

llvm-svn: 128319
2011-03-26 01:20:37 +00:00
Cameron Zwarich 10ebc189ee Fix PR9464 by correcting some math that just happened to be right in most cases
that were hit in practice.

llvm-svn: 128146
2011-03-23 05:25:55 +00:00
Anders Carlsson ee6bc70d2f Add an optimization to GlobalOpt that eliminates calls to __cxa_atexit, if the function passed is empty.
llvm-svn: 127970
2011-03-20 17:59:11 +00:00
Andrew Trick 1c4b42d00f Avoid creating canonical induction variables for non-native types.
For example, on 32-bit architecture, don't promote all uses of the IV
to 64-bits just because one use is a 64-bit cast.
Alternate implementation of the patch by Arnaud de Grandmaison.

llvm-svn: 127884
2011-03-18 16:50:32 +00:00
Eli Friedman c17c9a78aa FileCheck-ize and update test.
llvm-svn: 127845
2011-03-18 01:10:31 +00:00
Devang Patel aad34d882d Try to not lose variable's debug info during instcombine.
This is done by lowering dbg.declare intrinsic into dbg.value intrinsic.
Radar 9143931.

llvm-svn: 127834
2011-03-17 22:18:16 +00:00
Cameron Zwarich 0454253d7a Only convert allocas to scalars if it is profitable. The profitability metric I
chose is having a non-memcpy/memset use and being larger than any native integer
type. Originally I chose having an access of a size smaller than the total size
of the alloca, but this caused some minor issues on the spirit benchmark where
SRoA runs again after some inlining.

This fixes <rdar://problem/8613163>.

llvm-svn: 127718
2011-03-16 00:13:44 +00:00
Cameron Zwarich 7b0f3c6a1a Add native integer type TargetData to some existing tests.
llvm-svn: 127717
2011-03-16 00:13:40 +00:00
Cameron Zwarich 0b8cdfb6ec Do not add PHIs with no users when creating LCSSA form. Patch by Andrew Clinton.
llvm-svn: 127674
2011-03-15 07:41:25 +00:00
Eli Friedman c4414c6e92 PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
of pointers in an std::map.

llvm-svn: 127650
2011-03-15 02:23:35 +00:00
Eric Christopher 2139d3148f If we don't know how long a string is we can't fold an _chk version to the
normal version.

Fixes rdar://9123638

llvm-svn: 127636
2011-03-15 00:25:41 +00:00
Benjamin Kramer 5acc751b6f Teach ComputeMaskedBits about sub nsw.
llvm-svn: 127548
2011-03-12 17:18:11 +00:00
Cameron Zwarich 338d362200 Roll r127459 back in:
Optimize trivial branches in CodeGenPrepare, which often get created from the
lowering of objectsize intrinsics. Unfortunately, a number of tests were relying
on llc not optimizing trivial branches, so I had to add an option to allow them
to continue to test what they originally tested.

This fixes <rdar://problem/8785296> and <rdar://problem/9112893>.

llvm-svn: 127498
2011-03-11 21:52:04 +00:00
Daniel Dunbar 94ccb27b43 Revert r127459, "Optimize trivial branches in CodeGenPrepare, which often get
created from the", it broke some GCC test suite tests.

llvm-svn: 127477
2011-03-11 19:30:30 +00:00
Benjamin Kramer 391a946fa9 ComputeMaskedBits: sub falls through to add, and sub doesn't have the same overflow semantics as add.
Should fix the selfhost failures that started with r127463.

llvm-svn: 127465
2011-03-11 14:46:49 +00:00
Benjamin Kramer 51897bcd3e InstCombine: Fix a thinko where transform an icmp under the assumption that it's a zero comparison when it's not.
Fixes PR9454.

llvm-svn: 127464
2011-03-11 11:37:40 +00:00
Nick Lewycky cc79973856 Teach ComputeMaskedBits about nsw on add. I don't think there's anything we can
do with nuw here, but sub and mul should be given similar treatment.
Fixes PR9343 #15!

llvm-svn: 127463
2011-03-11 09:00:19 +00:00
Cameron Zwarich cc27b3acc4 Optimize trivial branches in CodeGenPrepare, which often get created from the
lowering of objectsize intrinsics. Unfortunately, a number of tests were relying
on llc not optimizing trivial branches, so I had to add an option to allow them
to continue to test what they originally tested.

This fixes <rdar://problem/8785296> and <rdar://problem/9112893>.

llvm-svn: 127459
2011-03-11 04:54:27 +00:00
Dan Gohman 154ed49784 Fix reassociate to postpone certain instruction deletions until
after it has finished all of its reassociations, because its
habit of unlinking operands and holding them in a datastructure
while working means that it's not easy to determine when an
instruction is really dead until after all its regular work is
done. rdar://9096268.

llvm-svn: 127424
2011-03-10 19:51:54 +00:00
Benjamin Kramer b49b964b98 InstCombine: Turn umul_with_overflow into mul nuw if we can prove that it cannot overflow.
This happens a lot in clang-compiled C++ code because it adds overflow checks to operator new[]:
  unsigned *foo(unsigned n) { return new unsigned[n]; }
We can optimize away the overflow check on 64 bit targets because (uint64_t)n*4 cannot overflow.

llvm-svn: 127418
2011-03-10 18:40:14 +00:00
Benjamin Kramer 1885d21700 Fix mistyped CHECK lines.
llvm-svn: 127366
2011-03-09 22:07:31 +00:00
Devang Patel 13f8c7d48e Preserve line number information while simplifying libcalls.
llvm-svn: 127362
2011-03-09 21:27:52 +00:00
Cameron Zwarich 718918b07a Add a test case for r127320.
llvm-svn: 127321
2011-03-09 08:11:02 +00:00
Nick Lewycky 980104d1d6 Add another micro-optimization. Apologies for the lack of refactoring, but I
gave up when I realized I couldn't come up with a good name for what the
refactored function would be, to describe what it does.

This is PR9343 test12, which is test3 with arguments reordered. Whoops!

llvm-svn: 127318
2011-03-09 06:26:03 +00:00
Cameron Zwarich 3b649f4d01 Add support to scalar replacement for partial vector accesses of an alloca, e.g.
a union of a float, <2 x float>, and <4 x float>. This mostly comes up with the
use of vector intrinsics, especially in NEON when programmers know the layout of
the register file. This enables codegen to eliminate a lot of the subregister
traffic it would otherwise generate.

This commit only enables this for a small number of floating-point cases, but a
lot more integer cases. I assume this is okay for all ports, but I did not do
extensive testing of the quality of code involving i512 vectors and the like. If
there is a use case where this generates worse code than before, let me know and
we can scale it back.

This fixes <rdar://problem/9036264>.

llvm-svn: 127317
2011-03-09 05:43:05 +00:00
Eli Friedman a81a82dcaf PR9346: Prevent SimplifyDemandedBits from incorrectly introducing
INT_MIN % -1.

llvm-svn: 127306
2011-03-09 01:28:35 +00:00
Eli Friedman aac35b3fbb PR9420; an instruction before an unreachable is guaranteed not to have any
reachable uses, but there still might be uses in dead blocks.  Use the
standard solution of replacing all the uses with undef.  This is
a rare case because it's very sensitive to phase ordering in SimplifyCFG.

llvm-svn: 127299
2011-03-09 00:48:33 +00:00
Duncan Sands 7dc3d47c34 Fix PR9331. Simplified version of a patch by Jakub Staszak.
llvm-svn: 127243
2011-03-08 12:39:03 +00:00
Devang Patel 97d0be8ee1 While sinking an instruction, do not lose llvm.dbg.value intrinsic.
llvm-svn: 127214
2011-03-08 03:06:19 +00:00
Devang Patel d00c628f8f Preserve line no. info.
Radar 9097659

llvm-svn: 127182
2011-03-07 22:43:45 +00:00
Rafael Espindola 15a29867ed Add test for r127138.
llvm-svn: 127172
2011-03-07 21:28:14 +00:00