[all-commits] [llvm/llvm-project] cc8872: [CodeGen] Ensure callers of CreateStackTemporary u...

[david-arm via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: cc8872400c3c0960e2673ea67ab6bcfcc9b3966b
      https://github.com/llvm/llvm-project/commit/cc8872400c3c0960e2673ea67ab6bcfcc9b3966b
  Author: David Sherwood <david.sherwood at arm.com>
  Date:   2020-06-09 (Tue, 09 Jun 2020)

  Changed paths:
    M llvm/include/llvm/CodeGen/SelectionDAG.h
    M llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
    M llvm/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp
    M llvm/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/test/CodeGen/AArch64/build-one-lane.ll
    M llvm/test/CodeGen/AMDGPU/scratch-simple.ll
    M llvm/test/CodeGen/AMDGPU/vgpr-spill-emergency-stack-slot.ll
    M llvm/test/CodeGen/X86/avx512-insert-extract.ll
    M llvm/test/CodeGen/X86/extractelement-index.ll
    M llvm/test/CodeGen/X86/half.ll
    M llvm/test/CodeGen/X86/i64-mem-copy.ll
    M llvm/test/CodeGen/X86/insertelement-var-index.ll
    M llvm/test/CodeGen/X86/pr31088.ll
    M llvm/test/CodeGen/X86/var-permute-128.ll
    M llvm/test/CodeGen/X86/vec_fneg.ll
    M llvm/test/CodeGen/X86/vec_insert-4.ll
    M llvm/test/CodeGen/X86/vector-extend-inreg.ll

  Log Message:
  -----------
  [CodeGen] Ensure callers of CreateStackTemporary use sensible alignments

In two instances of CreateStackTemporary we are sometimes promoting
alignments beyond the stack alignment. I have introduced a new function
called getReducedAlign that will return the alignment for the broken
down parts of illegal vector types. For example, on NEON a <32 x i8>
type is made up of two <16 x i8> types - in this case the sensible
alignment is 16 bytes, not 32.

In the legalization code wherever we create stack temporaries I have
started using the reduced alignments instead for illegal vector types.

I added a test to

  CodeGen/AArch64/build-one-lane.ll

that tries to insert an element into an illegal fixed vector type
that involves creating a temporary stack object.

Differential Revision: https://reviews.llvm.org/D80370