Sanjay Patel f3436d7dab [DAGCombiner] protect against an infinite loop between shl <--> mul (PR35579) ...

At first, I tried to thread the x86 needle and use a target hook (isVectorShiftByScalarCheap())
to disable the transform only for non-splat pow-of-2 constants, but not AVX2, but only some
element types, but...it's difficult.

Here we just avoid the loop with the x86 vector transform that conflicts with the general DAG
combine and preserve all of the existing behavior AFAICT otherwise.

Some tests that will probably fail if someone does try to restrict this in a more targeted way
for x86-only may be found in:

test/CodeGen/X86/combine-mul.ll
test/CodeGen/X86/vector-mul.ll
test/CodeGen/X86/widen_arith-5.ll

This should prevent the infinite looping seen with:
https://bugs.llvm.org/show_bug.cgi?id=35579

Differential Revision: https://reviews.llvm.org/D41040

llvm-svn: 320374

2017-12-11 15:19:31 +00:00

..

CMakeLists.txt

Remove trailing whitespace to trigger re-cmaking

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

DAGCombiner.cpp

[DAGCombiner] protect against an infinite loop between shl <--> mul (PR35579)

2017-12-11 15:19:31 +00:00

FastISel.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

FunctionLoweringInfo.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

InstrEmitter.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

InstrEmitter.h

…

LegalizeDAG.cpp

DAG: Legalize truncstores to illegal int types

2017-11-28 17:11:30 +00:00

LegalizeFloatTypes.cpp

[legalize-types] Clean up softening machinery.

2017-07-04 01:08:55 +00:00

LegalizeIntegerTypes.cpp

[SelectionDAG] Don't promote the condition operand of VSELECT when promoting the result.

2017-12-05 23:08:32 +00:00

LegalizeTypes.cpp

[SelectionDAG] Don't promote mask operand when widening mstore and mscatter.

2017-12-05 23:08:30 +00:00

LegalizeTypes.h

[SelectionDAG] Don't promote mask operand when widening mstore and mscatter.

2017-12-05 23:08:30 +00:00

LegalizeTypesGeneric.cpp

DAG: Add nuw when splitting loads and stores

2017-11-29 01:25:12 +00:00

LegalizeVectorOps.cpp

[SelectionDAG][X86] Teach promotion legalization for fp_to_sint/fp_to_uint to insert an assertsext/assertzext based on the original type

2017-11-29 22:15:43 +00:00

LegalizeVectorTypes.cpp

[SelectionDAG] In SplitVecOp_EXTRACT_VECTOR_ELT, simplify the code that makes the type byte addressable.

2017-12-07 08:04:34 +00:00

LLVMBuild.txt

…

ResourcePriorityQueue.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

ScheduleDAGFast.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

ScheduleDAGRRList.cpp

[CodeGen] Unify MBB reference format in both MIR and debug output

2017-12-04 17:18:51 +00:00

ScheduleDAGSDNodes.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

ScheduleDAGSDNodes.h

…

ScheduleDAGVLIW.cpp

[CodeGen] Unify MBB reference format in both MIR and debug output

2017-12-04 17:18:51 +00:00

SDNodeDbgValue.h

Doxygenify comments.

2017-10-24 17:23:40 +00:00

SelectionDAG.cpp

Generalize llvm::replaceDbgDeclare and actually support the use-case that

2017-12-08 21:58:18 +00:00

SelectionDAGAddressAnalysis.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

SelectionDAGBuilder.cpp

Relax unaligned access assertion when type is byte aligned

2017-12-09 06:45:36 +00:00

SelectionDAGBuilder.h

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +00:00

SelectionDAGDumper.cpp

[CodeGen] Rename functions PrintReg* to printReg*

2017-11-28 12:42:37 +00:00

SelectionDAGISel.cpp

[RISCV] Support lowering FrameIndex

2017-12-11 11:53:54 +00:00

SelectionDAGPrinter.cpp

Fix a bunch more layering of CodeGen headers that are in Target

2017-11-17 01:07:10 +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

Use getStoreSize() in various places instead of 'BitSize >> 3'.

2017-11-28 14:44:32 +00:00

StatepointLowering.h

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

2017-09-27 23:26:01 +00:00

TargetLowering.cpp

CodeGen: Fix pointer info in SplitVecOp_EXTRACT_VECTOR_ELT/SplitVecRes_INSERT_VECTOR_ELT

2017-12-02 22:13:22 +00:00