carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-05 22:02:55 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

[SVE] Remove getNumElements() warnings in InstCombiner::visitBitCast

Browse Source 
Whilst trying to compile this test to assembly:

  CodeGen/aarch64-sve-intrinsics/acle_sve_reinterpret.c

I discovered some warnings were firing in InstCombiner::visitBitCast
due to calls to getNumElements() for scalable vector types. These
calls only really made sense for fixed width vectors so I have fixed
up the code appropriately.

Differential Revision: https://reviews.llvm.org/D80559
This commit is contained in:
David Sherwood
2020-05-29 08:00:08 +01:00
parent 9c0ef044be
commit f254f1d94e
2 changed files with 15 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
+2 -2
View File
@@ -2534,7 +2534,7 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
}
}
if (VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
if (FixedVectorType *DestVTy = dyn_cast<FixedVectorType>(DestTy)) {
// Beware: messing with this target-specific oddity may cause trouble.
if (DestVTy->getNumElements() == 1 && SrcTy->isX86_MMXTy()) {
Value *Elem = Builder.CreateBitCast(Src, DestVTy->getElementType());
@@ -2563,7 +2563,7 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
}
}
if (VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
if (FixedVectorType *SrcVTy = dyn_cast<FixedVectorType>(SrcTy)) {
if (SrcVTy->getNumElements() == 1) {
// If our destination is not a vector, then make this a straight
// scalar-scalar cast.
llvm/test/Transforms/InstCombine/AArch64/sve-bitcast.ll
+13
View File
@@ -0,0 +1,13 @@
; RUN: opt -instcombine -mtriple=aarch64-linux-gnu -mattr=+sve -S < %s | FileCheck %s
; We shouldn't fold bitcast(insert <vscale x 1 x iX> .., iX %val, i32 0)
; into bitcast(iX %val) for scalable vectors.
define <vscale x 2 x i8> @bitcast_of_insert_i8_i16(i16 %val) #0 {
; CHECK-LABEL: @bitcast_of_insert_i8_i16(
; CHECK-NOT: bitcast i16 %val to <vscale x 2 x i8>
; CHECK: bitcast <vscale x 1 x i16> %op2 to <vscale x 2 x i8>
entry:
%op2 = insertelement <vscale x 1 x i16> undef, i16 %val, i32 0
%0 = bitcast <vscale x 1 x i16> %op2 to <vscale x 2 x i8>
ret <vscale x 2 x i8> %0
}