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

[LV] Pass compare predicate to getCmpSelInstrCost. 

If the condition of a select is a compare, pass its predicate to
TTI::getCmpSelInstrCost to get a more accurate cost value instead
of passing BAD_ICMP_PREDICATE.

I noticed that the commit message from D90070 had a comment about the
vectorized select predicate possibly being composed of other compares with
different predicate values, but I wasn't able to construct an example
where this was an actual issue. If this is an issue, I guess we could
add another check that the block isn't predicated for any reason.

Reviewed By: dmgreen, fhahn

Differential Revision: https://reviews.llvm.org/D114646
This commit is contained in:
Sander de Smalen 2021-12-06 11:14:27 +00:00
parent ab31d003e1
commit 3d549dddf7
2 changed files with 15 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
View File

@ -7570,8 +7570,12 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, ElementCount VF,
Type *CondTy = SI->getCondition()->getType();
if (!ScalarCond)
CondTy = VectorType::get(CondTy, VF);
return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, CondTy,
CmpInst::BAD_ICMP_PREDICATE, CostKind, I);
CmpInst::Predicate Pred = CmpInst::BAD_ICMP_PREDICATE;
if (auto *Cmp = dyn_cast<CmpInst>(SI->getCondition()))
Pred = Cmp->getPredicate();
return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, CondTy, Pred,
CostKind, I);
}
case Instruction::ICmp:
case Instruction::FCmp: {
@ -7581,7 +7585,8 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, ElementCount VF,
ValTy = IntegerType::get(ValTy->getContext(), MinBWs[Op0AsInstruction]);
VectorTy = ToVectorTy(ValTy, VF);
return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, nullptr,
CmpInst::BAD_ICMP_PREDICATE, CostKind, I);
cast<CmpInst>(I)->getPredicate(), CostKind,
I);
}
case Instruction::Store:
case Instruction::Load: {

14
llvm/test/Transforms/LoopVectorize/AArch64/select-costs.ll
View File

@ -5,17 +5,17 @@ target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
target triple = "arm64-apple-ios5.0.0"
define void @selects_1(i32* nocapture %dst, i32 %A, i32 %B, i32 %C, i32 %N) {
; CHECK: LV: Found an estimated cost of 5 for VF 2 For instruction: %cond = select i1 %cmp1, i32 10, i32 %and
; CHECK: LV: Found an estimated cost of 5 for VF 2 For instruction: %cond6 = select i1 %cmp2, i32 30, i32 %and
; CHECK: LV: Found an estimated cost of 5 for VF 2 For instruction: %cond11 = select i1 %cmp7, i32 %cond, i32 %cond6
; CHECK: LV: Found an estimated cost of 1 for VF 2 For instruction: %cond = select i1 %cmp1, i32 10, i32 %and
; CHECK: LV: Found an estimated cost of 1 for VF 2 For instruction: %cond6 = select i1 %cmp2, i32 30, i32 %and
; CHECK: LV: Found an estimated cost of 1 for VF 2 For instruction: %cond11 = select i1 %cmp7, i32 %cond, i32 %cond6
; CHECK: LV: Found an estimated cost of 13 for VF 4 For instruction: %cond = select i1 %cmp1, i32 10, i32 %and
; CHECK: LV: Found an estimated cost of 13 for VF 4 For instruction: %cond6 = select i1 %cmp2, i32 30, i32 %and
; CHECK: LV: Found an estimated cost of 13 for VF 4 For instruction: %cond11 = select i1 %cmp7, i32 %cond, i32 %cond6
; CHECK: LV: Found an estimated cost of 1 for VF 4 For instruction: %cond = select i1 %cmp1, i32 10, i32 %and
; CHECK: LV: Found an estimated cost of 1 for VF 4 For instruction: %cond6 = select i1 %cmp2, i32 30, i32 %and
; CHECK: LV: Found an estimated cost of 1 for VF 4 For instruction: %cond11 = select i1 %cmp7, i32 %cond, i32 %cond6
; CHECK-LABEL: define void @selects_1(
; CHECK: vector.body:
; CHECK: select <2 x i1>
; CHECK: select <4 x i1>
entry:
%cmp26 = icmp sgt i32 %N, 0