Sanjay Patel d8214db086 fold: sqrt(x * x * y) -> fabs(x) * sqrt(y) ...

If a square root call has an FP multiplication argument that can be reassociated,
then we can hoist a repeated factor out of the square root call and into a fabs().

In the simplest case, this:

   y = sqrt(x * x);

becomes this:

   y = fabs(x);

This patch relies on an earlier optimization in instcombine or reassociate to put the
multiplication tree into a canonical form, so we don't have to search over
every permutation of the multiplication tree.

Because there are no IR-level FastMathFlags for intrinsics (PR21290), we have to
use function-level attributes to do this optimization. This needs to be fixed
for both the intrinsics and in the backend.

Differential Revision: http://reviews.llvm.org/D5787



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219944 91177308-0d34-0410-b5e6-96231b3b80d8

2014-10-16 18:48:17 +00:00

..

AddDiscriminators.cpp

Use DILexicalBlockFile, rather than DILexicalBlock, to track discriminator changes to ensure discriminator changes don't introduce new DWARF DW_TAG_lexical_blocks.

2014-08-21 22:45:21 +00:00

ASanStackFrameLayout.cpp

Revert "Introduce a string_ostream string builder facilty"

2014-06-26 22:52:05 +00:00

BasicBlockUtils.cpp

Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."

2014-07-21 17:06:51 +00:00

BreakCriticalEdges.cpp

Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."

2014-07-21 17:06:51 +00:00

BuildLibCalls.cpp

Simplify creation of a bunch of ArrayRefs by using None, makeArrayRef or just letting them be implicitly created.

2014-08-27 05:25:25 +00:00

BypassSlowDivision.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00

CloneFunction.cpp

Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."

2014-07-21 17:06:51 +00:00

CloneModule.cpp

C API: Add LLVMCloneModule()

2014-10-01 17:14:57 +00:00

CMakeLists.txt

Decouple llvm::SpecialCaseList text representation and its LLVM IR semantics.

2014-07-09 19:40:08 +00:00

CmpInstAnalysis.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00

CodeExtractor.cpp

Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."

2014-07-21 17:06:51 +00:00

CtorUtils.cpp

GlobalOpt: Preserve comdats of unoptimized initializers

2014-09-23 22:33:01 +00:00

DemoteRegToStack.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00

FlattenCFG.cpp

utils: Fix segfault in flattencfg

2014-08-13 20:31:53 +00:00

GlobalStatus.cpp

Remove dangling initializers in GlobalDCE

2014-08-25 17:51:14 +00:00

InlineFunction.cpp

Preserve non-byval pointer alignment attributes using @llvm.assume when inlining

2014-10-15 23:44:41 +00:00

InstructionNamer.cpp

[C++11] Add 'override' keyword to virtual methods that override their base class.

2014-03-05 09:10:37 +00:00

IntegerDivision.cpp

[Modules] Fix potential ODR violations by sinking the DEBUG_TYPE

2014-04-22 02:55:47 +00:00

LCSSA.cpp

[Modules] Fix potential ODR violations by sinking the DEBUG_TYPE

2014-04-22 02:55:47 +00:00

LLVMBuild.txt

…

Local.cpp

DIBuilder: Encapsulate DIExpression's element type

2014-10-01 20:26:08 +00:00

LoopSimplify.cpp

Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)

2014-09-07 18:57:58 +00:00

LoopUnroll.cpp

LoopUnroll: Create sub-loops in LoopInfo

2014-10-07 21:19:00 +00:00

LoopUnrollRuntime.cpp

Use a loop to simplify the runtime unrolling prologue.

2014-09-29 11:15:00 +00:00

LowerExpectIntrinsic.cpp

[Modules] Fix potential ODR violations by sinking the DEBUG_TYPE

2014-04-22 02:55:47 +00:00

LowerInvoke.cpp

[Modules] Fix potential ODR violations by sinking the DEBUG_TYPE

2014-04-22 02:55:47 +00:00

LowerSwitch.cpp

Fixup PHIs in LowerSwitch when a Leaf node is not emitted.

2014-07-11 10:34:36 +00:00

Makefile

…

Mem2Reg.cpp

Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)

2014-09-07 18:57:58 +00:00

MetaRenamer.cpp

[C++11] Add 'override' keyword to virtual methods that override their base class.

2014-03-05 09:10:37 +00:00

ModuleUtils.cpp

Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size.

2014-08-21 05:55:13 +00:00

PromoteMemoryToRegister.cpp

Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)

2014-09-07 18:57:58 +00:00

SimplifyCFG.cpp

Switch to select optimization for two-case switches

2014-10-14 01:58:26 +00:00

SimplifyIndVar.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00

SimplifyInstructions.cpp

Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.)

2014-09-07 18:57:58 +00:00

SimplifyLibCalls.cpp

fold: sqrt(x * x * y) -> fabs(x) * sqrt(y)

2014-10-16 18:48:17 +00:00

SSAUpdater.cpp

Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges."

2014-07-21 17:06:51 +00:00

UnifyFunctionExitNodes.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00

Utils.cpp

Pass to emit DWARF path discriminators.

2014-03-03 20:06:11 +00:00

ValueMapper.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00