Commit Graph

7825 Commits

Author SHA1 Message Date
Benjamin Kramer ac2d5657a6 Fix build.
llvm-svn: 128733
2011-04-01 20:15:16 +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
Benjamin Kramer 398b8c5faf InstCombine: Move (sext icmp) transforms into their own method. No intended functionality change.
llvm-svn: 128731
2011-04-01 20:09:03 +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 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
Jay Foad 52131344a2 Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
PHINode::Create() giving the (known or expected) number of operands.

llvm-svn: 128537
2011-03-30 11:28:46 +00:00
Jay Foad e0938d8a87 (Almost) always call reserveOperandSpace() on newly created PHINodes.
llvm-svn: 128535
2011-03-30 11:19:20 +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
Benjamin Kramer e41395ac24 DSE: Remove an early exit optimization that depended on the ordering of a SmallPtrSet.
Fixes PR9569 and will hopefully make selfhost on ASLR-enabled systems more deterministic.

llvm-svn: 128482
2011-03-29 20:28:57 +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 ebc2f3a68c Remove tabs I accidentally added.
llvm-svn: 128413
2011-03-28 17:48:26 +00:00
Jay Foad 1c83965f5a Make more use of PHINode::getNumIncomingValues().
llvm-svn: 128406
2011-03-28 13:03:10 +00:00
Frits van Bommel d14d991bf7 Add some debug output when -instcombine uses RAUW. This can make debug output for those cases much clearer since without this it only showed that the original instruction was removed, not what it was replaced with.
llvm-svn: 128399
2011-03-27 23:32:31 +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
Benjamin Kramer 1f90da127f Use APInt's umul_ov instead of rolling our own overflow detection.
llvm-svn: 128380
2011-03-27 15:04:38 +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
Bill Wendling b5139920d6 Simplification noticed by Frits.
llvm-svn: 128333
2011-03-26 09:32:07 +00:00
Bill Wendling 19f33b9393 Rework the logic that determines if a store completely overlaps an ealier store.
There are two ways that a later store can comletely overlap a previous store:

1. They both start at the same offset, but the earlier store's size is <= the
   later's size, or
2. The earlier store's offset is > the later's offset, but it's offset + size
   doesn't extend past the later's offset + size.

llvm-svn: 128332
2011-03-26 08:02:59 +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
Nick Lewycky 0e25c8b364 No functionality change, just adjust some whitespace for coding style compliance.
llvm-svn: 128257
2011-03-25 06:05:50 +00:00
Cameron Zwarich 74157ab3e5 Debug intrinsics must be skipped at the beginning and ends of blocks, lest they
affect the generated code.

llvm-svn: 128217
2011-03-24 16:34:59 +00:00
Cameron Zwarich 2edfe778ec It is enough for the CallInst to have no uses to be made a tail call with a ret
void; it doesn't need to have a void type.

llvm-svn: 128212
2011-03-24 15:54:11 +00:00
Devang Patel 8f606d7b9b s/UpdateDT/ModifiedDT/g
llvm-svn: 128211
2011-03-24 15:35:25 +00:00
Cameron Zwarich 4649f17db1 Do early taildup of ret in CodeGenPrepare for potential tail calls that have a
void return type. This fixes PR9487.

llvm-svn: 128197
2011-03-24 04:52:10 +00:00
Cameron Zwarich 0e331c05ae Use an early return instead of a long if block.
llvm-svn: 128196
2011-03-24 04:52:07 +00:00
Cameron Zwarich dd84bcce8f When UpdateDT is set, DT is invalid, which could cause problems when trying to
use it later. I couldn't make a test that hits this with the current code.

llvm-svn: 128195
2011-03-24 04:52:04 +00:00
Cameron Zwarich 47e7175fe9 Check for TLI so that -codegenprepare can be used from opt.
llvm-svn: 128194
2011-03-24 04:51:51 +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 1cc8073bb3 Handle another case that Frits suggested.
llvm-svn: 128068
2011-03-22 03:21:01 +00:00
Devang Patel 17bbd7f495 Simplify.
llvm-svn: 128030
2011-03-21 22:04:45 +00:00
Anders Carlsson 4dd420f193 More cleanups to the OptimizeEmptyGlobalCXXDtors GlobalOpt function.
llvm-svn: 127997
2011-03-21 14:54:40 +00:00
Anders Carlsson 701822a48e As suggested by Nick Lewycky, ignore debugging intrinsics when trying to decide whether a destructor is empty or not.
llvm-svn: 127985
2011-03-21 02:42:27 +00:00
Nick Lewycky d078183725 Fix comments
llvm-svn: 127984
2011-03-21 02:26:01 +00:00
Evan Cheng 0663f23bd8 Re-apply r127953 with fixes: eliminate empty return block if it has no predecessors; update dominator tree if cfg is modified.
llvm-svn: 127981
2011-03-21 01:19:09 +00:00
Anders Carlsson 336fd90f4d Don't try to eliminate invokes to __cxa_atexit.
llvm-svn: 127976
2011-03-20 20:21:33 +00:00
Anders Carlsson fcec2f519a Don't segfault on mutual recursion, as pointed out by Frits.
llvm-svn: 127975
2011-03-20 20:16:43 +00:00
Anders Carlsson 48a44911d3 Address comments from Frits van Bommel.
llvm-svn: 127974
2011-03-20 19:51:13 +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
Daniel Dunbar 327cd36f74 Revert r127953, "SimplifyCFG has stopped duplicating returns into predecessors
to canonicalize IR", it broke a lot of things.

llvm-svn: 127954
2011-03-19 21:47:14 +00:00
Evan Cheng 824a711305 SimplifyCFG has stopped duplicating returns into predecessors to canonicalize IR
to have single return block (at least getting there) for optimizations. This
is general goodness but it would prevent some tailcall optimizations.
One specific case is code like this:
int f1(void);
int f2(void);
int f3(void);
int f4(void);
int f5(void);
int f6(void);
int foo(int x) {
  switch(x) {
  case 1: return f1();
  case 2: return f2();
  case 3: return f3();
  case 4: return f4();
  case 5: return f5();
  case 6: return f6();
  }
}

=>
LBB0_2:                                 ## %sw.bb
  callq   _f1
  popq    %rbp
  ret
LBB0_3:                                 ## %sw.bb1
  callq   _f2
  popq    %rbp
  ret
LBB0_4:                                 ## %sw.bb3
  callq   _f3
  popq    %rbp
  ret

This patch teaches codegenprep to duplicate returns when the return value
is a phi and where the phi operands are produced by tail calls followed by
an unconditional branch:

sw.bb7:                                           ; preds = %entry
  %call8 = tail call i32 @f5() nounwind
  br label %return
sw.bb9:                                           ; preds = %entry
  %call10 = tail call i32 @f6() nounwind
  br label %return
return:
  %retval.0 = phi i32 [ %call10, %sw.bb9 ], [ %call8, %sw.bb7 ], ... [ 0, %entry ]
  ret i32 %retval.0

This allows codegen to generate better code like this:

LBB0_2:                                 ## %sw.bb
        jmp     _f1                     ## TAILCALL
LBB0_3:                                 ## %sw.bb1
        jmp     _f2                     ## TAILCALL
LBB0_4:                                 ## %sw.bb3
        jmp     _f3                     ## TAILCALL

rdar://9147433

llvm-svn: 127953
2011-03-19 17:17:39 +00:00
Devang Patel 2c7ee2700c If an AllocaInst referred by DbgDeclareInst is used by a LoadInst then the LoadInst should also get a corresponding llvm.dbg.value intrinsic.
llvm-svn: 127924
2011-03-18 23:45:43 +00:00
Devang Patel 3ac171d49a Remove dead code.
llvm-svn: 127923
2011-03-18 23:33:58 +00:00