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[ARM/AArch64] Fix cost model for interleaved accesses 

Summary:
Fix the cost of interleaved accesses for ARM/AArch64.
We were calling getTypeAllocSize and using it to check
the number of bits, when we should have called
getTypeAllocSizeInBits instead.

This would pottentially cause the vectorizer to
generate loads/stores and shuffles which cannot
be matched with an interleaved access instruction.

No performance changes are expected for now since
matching/generating interleaved accesses is still
disabled by default.

Reviewers: rengolin

Subscribers: aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D11524

llvm-svn: 243270
This commit is contained in:
Silviu Baranga 2015-07-27 14:39:34 +00:00
parent 6db02dd8f0
commit 7581d22512
4 changed files with 80 additions and 2 deletions
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2
llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
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@ -416,7 +416,7 @@ unsigned AArch64TTIImpl::getInterleavedMemoryOpCost(
if (Factor <= TLI->getMaxSupportedInterleaveFactor()) {
unsigned NumElts = VecTy->getVectorNumElements();
Type *SubVecTy = VectorType::get(VecTy->getScalarType(), NumElts / Factor);
unsigned SubVecSize = DL.getTypeAllocSize(SubVecTy);
unsigned SubVecSize = DL.getTypeAllocSizeInBits(SubVecTy);
// ldN/stN only support legal vector types of size 64 or 128 in bits.
if (NumElts % Factor == 0 && (SubVecSize == 64 || SubVecSize == 128))

2
llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
View File

@ -493,7 +493,7 @@ unsigned ARMTTIImpl::getInterleavedMemoryOpCost(unsigned Opcode, Type *VecTy,
if (Factor <= TLI->getMaxSupportedInterleaveFactor() && !EltIs64Bits) {
unsigned NumElts = VecTy->getVectorNumElements();
Type *SubVecTy = VectorType::get(VecTy->getScalarType(), NumElts / Factor);
unsigned SubVecSize = DL.getTypeAllocSize(SubVecTy);
unsigned SubVecSize = DL.getTypeAllocSizeInBits(SubVecTy);
// vldN/vstN only support legal vector types of size 64 or 128 in bits.
if (NumElts % Factor == 0 && (SubVecSize == 64 || SubVecSize == 128))

39
llvm/test/Transforms/LoopVectorize/AArch64/interleaved_cost.ll Normal file
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@ -0,0 +1,39 @@
; RUN: opt -S -debug-only=loop-vectorize -loop-vectorize -instcombine -enable-interleaved-mem-accesses=true < %s |& FileCheck %s
target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
target triple = "aarch64--linux-gnueabi"
@AB = common global [1024 x i8] zeroinitializer, align 4
@CD = common global [1024 x i8] zeroinitializer, align 4
define void @test_byte_interleaved_cost(i8 %C, i8 %D) {
entry:
br label %for.body
; 8xi8 and 16xi8 are valid i8 vector types, so the cost of the interleaved
; access group is 2.
; CHECK: LV: Found an estimated cost of 2 for VF 8 For instruction: %tmp = load i8, i8* %arrayidx0, align 4
; CHECK: LV: Found an estimated cost of 2 for VF 16 For instruction: %tmp = load i8, i8* %arrayidx0, align 4
for.body: ; preds = %for.body, %entry
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx0 = getelementptr inbounds [1024 x i8], [1024 x i8]* @AB, i64 0, i64 %indvars.iv
%tmp = load i8, i8* %arrayidx0, align 4
%tmp1 = or i64 %indvars.iv, 1
%arrayidx1 = getelementptr inbounds [1024 x i8], [1024 x i8]* @AB, i64 0, i64 %tmp1
%tmp2 = load i8, i8* %arrayidx1, align 4
%add = add nsw i8 %tmp, %C
%mul = mul nsw i8 %tmp2, %D
%arrayidx2 = getelementptr inbounds [1024 x i8], [1024 x i8]* @CD, i64 0, i64 %indvars.iv
store i8 %add, i8* %arrayidx2, align 4
%arrayidx3 = getelementptr inbounds [1024 x i8], [1024 x i8]* @CD, i64 0, i64 %tmp1
store i8 %mul, i8* %arrayidx3, align 4
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 2
%cmp = icmp slt i64 %indvars.iv.next, 1024
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}

39
llvm/test/Transforms/LoopVectorize/ARM/interleaved_cost.ll Normal file
View File

@ -0,0 +1,39 @@
; RUN: opt -S -debug-only=loop-vectorize -loop-vectorize -instcombine -enable-interleaved-mem-accesses=true < %s |& FileCheck %s
target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128"
target triple = "armv8--linux-gnueabihf"
@AB = common global [1024 x i8] zeroinitializer, align 4
@CD = common global [1024 x i8] zeroinitializer, align 4
define void @test_byte_interleaved_cost(i8 %C, i8 %D) {
entry:
br label %for.body
; 8xi8 and 16xi8 are valid i8 vector types, so the cost of the interleaved
; access group is 2.
; CHECK: LV: Found an estimated cost of 2 for VF 8 For instruction: %tmp = load i8, i8* %arrayidx0, align 4
; CHECK: LV: Found an estimated cost of 2 for VF 16 For instruction: %tmp = load i8, i8* %arrayidx0, align 4
for.body: ; preds = %for.body, %entry
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx0 = getelementptr inbounds [1024 x i8], [1024 x i8]* @AB, i64 0, i64 %indvars.iv
%tmp = load i8, i8* %arrayidx0, align 4
%tmp1 = or i64 %indvars.iv, 1
%arrayidx1 = getelementptr inbounds [1024 x i8], [1024 x i8]* @AB, i64 0, i64 %tmp1
%tmp2 = load i8, i8* %arrayidx1, align 4
%add = add nsw i8 %tmp, %C
%mul = mul nsw i8 %tmp2, %D
%arrayidx2 = getelementptr inbounds [1024 x i8], [1024 x i8]* @CD, i64 0, i64 %indvars.iv
store i8 %add, i8* %arrayidx2, align 4
%arrayidx3 = getelementptr inbounds [1024 x i8], [1024 x i8]* @CD, i64 0, i64 %tmp1
store i8 %mul, i8* %arrayidx3, align 4
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 2
%cmp = icmp slt i64 %indvars.iv.next, 1024
br i1 %cmp, label %for.body, label %for.end
for.end: ; preds = %for.body
ret void
}