maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[InstCombine][ConstantFolding] Make ConstantFoldLoadThroughBitcast TypeSize-aware 

The newly added test previously caused the compiler to fail an
assertion. It looks like a strightforward TypeSize upgrade.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D112142
This commit is contained in:
Peter Waller 2021-10-28 12:14:52 +00:00
parent 0a2708d2ae
commit 98f08752f7
2 changed files with 30 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
llvm/lib/Analysis/ConstantFolding.cpp
View File

@ -352,9 +352,9 @@ Constant *llvm::ConstantFoldLoadThroughBitcast(Constant *C, Type *DestTy,
const DataLayout &DL) {
do {
Type *SrcTy = C->getType();
uint64_t DestSize = DL.getTypeSizeInBits(DestTy);
uint64_t SrcSize = DL.getTypeSizeInBits(SrcTy);
if (SrcSize < DestSize)
TypeSize DestSize = DL.getTypeSizeInBits(DestTy);
TypeSize SrcSize = DL.getTypeSizeInBits(SrcTy);
if (!TypeSize::isKnownGE(SrcSize, DestSize))
return nullptr;
// Catch the obvious splat cases (since all-zeros can coerce non-integral

27
llvm/test/Transforms/InstCombine/vscale_load.ll Normal file
View File

@ -0,0 +1,27 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S -verify | FileCheck %s
define <2 x i8> @constprop_load_bitcast(<vscale x 16 x i1>* %ptr) {
; CHECK-LABEL: @constprop_load_bitcast(
; CHECK-NEXT: store <vscale x 16 x i1> zeroinitializer, <vscale x 16 x i1>* [[PTR:%.*]], align 16
; CHECK-NEXT: ret <2 x i8> zeroinitializer
;
store <vscale x 16 x i1> zeroinitializer, <vscale x 16 x i1>* %ptr, align 16
%cast_to_fixed = bitcast <vscale x 16 x i1>* %ptr to <2 x i8>*
%a = load <2 x i8>, <2 x i8>* %cast_to_fixed, align 16
ret <2 x i8> %a
}
; vscale-sized vec not guaranteed to fill destination.
define <8 x i8> @constprop_load_bitcast_neg(<vscale x 16 x i1>* %ptr) {
; CHECK-LABEL: @constprop_load_bitcast_neg(
; CHECK-NEXT: store <vscale x 16 x i1> zeroinitializer, <vscale x 16 x i1>* [[PTR:%.*]], align 16
; CHECK-NEXT: [[CAST_TO_FIXED:%.*]] = bitcast <vscale x 16 x i1>* [[PTR]] to <8 x i8>*
; CHECK-NEXT: [[A:%.*]] = load <8 x i8>, <8 x i8>* [[CAST_TO_FIXED]], align 16
; CHECK-NEXT: ret <8 x i8> [[A]]
;
store <vscale x 16 x i1> zeroinitializer, <vscale x 16 x i1>* %ptr, align 16
%cast_to_fixed = bitcast <vscale x 16 x i1>* %ptr to <8 x i8>*
%a = load <8 x i8>, <8 x i8>* %cast_to_fixed, align 16
ret <8 x i8> %a
}