Sanjay Patel 9d4952d6a5 [DAGCombiner] try to convert pow(x, 1/3) to cbrt(x) ...

This is a follow-up suggested in D51630 and originally proposed as an IR transform in D49040.

Copying the motivational statement by @evandro from that patch:
"This transformation helps some benchmarks in SPEC CPU2000 and CPU2006, such as 188.ammp, 
447.dealII, 453.povray, and especially 300.twolf, as well as some proprietary benchmarks. 
Otherwise, no regressions on x86-64 or A64."

I'm proposing to add only the minimum support for a DAG node here. Since we don't have an 
LLVM IR intrinsic for cbrt, and there are no other DAG ways to create a FCBRT node yet, I 
don't think we need to worry about DAG builder, legalization, a strict variant, etc. We 
should be able to expand as needed when adding more functionality/transforms. For reference, 
these are transform suggestions currently listed in SimplifyLibCalls.cpp:

//   * cbrt(expN(X))  -> expN(x/3)
//   * cbrt(sqrt(x))  -> pow(x,1/6)
//   * cbrt(cbrt(x))  -> pow(x,1/9)

Also, given that we bail out on long double for now, there should not be any logical 
differences between platforms (unless there's some platform out there that has pow()
but not cbrt()).

Differential Revision: https://reviews.llvm.org/D51753


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342348 91177308-0d34-0410-b5e6-96231b3b80d8

2018-09-16 16:50:26 +00:00

..

CMakeLists.txt

Remove trailing whitespace to trigger re-cmaking

2017-10-02 21:54:38 +00:00

DAGCombiner.cpp

[DAGCombiner] try to convert pow(x, 1/3) to cbrt(x)

2018-09-16 16:50:26 +00:00

FastISel.cpp

[IR] Replace isa<TerminatorInst> with isTerminator().

2018-08-26 09:51:22 +00:00

FunctionLoweringInfo.cpp

DAG: Add calling convention argument to calling convention funcs

2018-07-28 13:25:19 +00:00

InstrEmitter.cpp

[MI] Change the array of MachineMemOperand pointers to be

2018-08-16 21:30:05 +00:00

InstrEmitter.h

[DebugInfo] Convert intrinsic llvm.dbg.label to MachineInstr.

2018-05-09 02:41:08 +00:00

LegalizeDAG.cpp

[DAGCombiner] try to convert pow(x, 1/3) to cbrt(x)

2018-09-16 16:50:26 +00:00

LegalizeFloatTypes.cpp

DAG: Try to custom lower when promoting float operands

2018-08-15 20:34:54 +00:00

LegalizeIntegerTypes.cpp

[SelectionDAG] Remove some code from PromoteIntOp_MGATHER that handles UpdateNodeOperands returning an existing node instead of updating.

2018-09-12 05:25:41 +00:00

LegalizeTypes.cpp

[DAG] Don't map a TableId to itself in the ReplacedValues map

2018-06-20 16:06:09 +00:00

LegalizeTypes.h

[X86] Support v2i32 gather/scatter indices with -x86-experimental-vector-widening-legalization

2018-08-29 02:12:49 +00:00

LegalizeTypesGeneric.cpp

Avoid losing Hi part when expanding VAARG nodes on big endian machines

2018-07-16 12:14:17 +00:00

LegalizeVectorOps.cpp

[FPEnv] Support constrained FREM intrinsic

2018-08-20 19:28:56 +00:00

LegalizeVectorTypes.cpp

[X86] Support v2i32 gather/scatter indices with -x86-experimental-vector-widening-legalization

2018-08-29 02:12:49 +00:00

LLVMBuild.txt

…

ResourcePriorityQueue.cpp

Silence a bunch of implicit fallthrough warnings

2017-12-19 22:05:25 +00:00

ScheduleDAGFast.cpp

Rename DEBUG macro to LLVM_DEBUG.

2018-05-14 12:53:11 +00:00

ScheduleDAGRRList.cpp

[ScheduleDAG] Fix unfolding of SUnits to already existent nodes.

2018-07-18 18:01:03 +00:00

ScheduleDAGSDNodes.cpp

[SDAG] Remove the reliance on MI's allocation strategy for

2018-08-14 23:30:32 +00:00

ScheduleDAGSDNodes.h

[CodeGen] Fix inconsistent declaration parameter name

2018-07-16 18:51:40 +00:00

ScheduleDAGVLIW.cpp

Rename DEBUG macro to LLVM_DEBUG.

2018-05-14 12:53:11 +00:00

SDNodeDbgValue.h

SelectionDAG: Add compact SDDbgValue representation to -dag-dump-verbose output

2018-09-14 17:08:02 +00:00

SelectionDAG.cpp

Fix debug info for SelectionDAG legalization of DAG nodes with two results.

2018-09-14 19:38:45 +00:00

SelectionDAGAddressAnalysis.cpp

[DAG] Teach findBaseOffset to interpret indexes of indexed memory operations

2018-01-26 16:51:27 +00:00

SelectionDAGBuilder.cpp

DAG: Handle odd vector sizes in calling conv splitting

2018-09-10 11:49:23 +00:00

SelectionDAGBuilder.h

DAG: Add calling convention argument to calling convention funcs

2018-07-28 13:25:19 +00:00

SelectionDAGDumper.cpp

[DAGCombiner] try to convert pow(x, 1/3) to cbrt(x)

2018-09-16 16:50:26 +00:00

SelectionDAGISel.cpp

[NFC] Rename the DivergenceAnalysis to LegacyDivergenceAnalysis

2018-08-30 14:21:36 +00:00

SelectionDAGPrinter.cpp

Rename DEBUG macro to LLVM_DEBUG.

2018-05-14 12:53:11 +00:00

SelectionDAGTargetInfo.cpp

[CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

2017-09-13 21:15:20 +00:00

StatepointLowering.cpp

Remove trailing space

2018-07-30 19:41:25 +00:00

StatepointLowering.h

[IR][CodeGen] Remove dependency on EVT from IR/Function.cpp. Move EVT to CodeGen layer.

2018-03-29 17:21:10 +00:00

TargetLowering.cpp

DAG: Fix expansion of unaligned FP loads and stores

2018-09-13 12:14:23 +00:00