caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[InstCombine][foldPHIArgGEPIntoPHI] Early return for const vector index for gep inst (#138661)

Browse Source
This commit is contained in:
haonan
2025-05-08 16:00:49 +08:00
committed by GitHub
parent 01761a73e4
commit 5b8664fcb2
2 changed files with 41 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
View File

@@ -574,8 +574,8 @@ Instruction *InstCombinerImpl::foldPHIArgGEPIntoPHI(PHINode &PN) {
// substantially cheaper to compute for the constants, so making it a
// variable index could pessimize the path. This also handles the case
// for struct indices, which must always be constant.
if (isa<ConstantInt>(FirstInst->getOperand(Op)) ||
isa<ConstantInt>(GEP->getOperand(Op)))
if (isa<Constant>(FirstInst->getOperand(Op)) ||
isa<Constant>(GEP->getOperand(Op)))
return nullptr;
if (FirstInst->getOperand(Op)->getType() !=

39
llvm/test/Transforms/InstCombine/fold-phi-arg-gep-to-phi-negative.ll Normal file
View File

@@ -0,0 +1,39 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
%foo = type { i16, i16, i16 }
define <16 x ptr> @test(i1 %tobool) {
; CHECK-LABEL: define <16 x ptr> @test(
; CHECK-SAME: i1 [[TOBOOL:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[LANE_0:%.*]] = alloca [[FOO:%.*]], align 16
; CHECK-NEXT: [[LANE_15:%.*]] = insertelement <16 x ptr> poison, ptr [[LANE_0]], i64 0
; CHECK-NEXT: br i1 [[TOBOOL]], label %[[F1:.*]], label %[[F0:.*]]
; CHECK: [[F0]]:
; CHECK-NEXT: [[MM_VECTORGEP:%.*]] = getelementptr inbounds [[FOO]], <16 x ptr> [[LANE_15]], <16 x i64> zeroinitializer, <16 x i32> splat (i32 1)
; CHECK-NEXT: br label %[[MERGE:.*]]
; CHECK: [[F1]]:
; CHECK-NEXT: [[MM_VECTORGEP2:%.*]] = getelementptr inbounds [[FOO]], <16 x ptr> [[LANE_15]], <16 x i64> zeroinitializer, <16 x i32> splat (i32 2)
; CHECK-NEXT: br label %[[MERGE]]
; CHECK: [[MERGE]]:
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <16 x ptr> [ [[MM_VECTORGEP]], %[[F0]] ], [ [[MM_VECTORGEP2]], %[[F1]] ]
; CHECK-NEXT: ret <16 x ptr> [[VEC_PHI]]
;
entry:
%lane.0 = alloca %foo, align 16
%lane.15 = insertelement <16 x ptr> poison, ptr %lane.0, i64 0
%mm_vectorGEP = getelementptr inbounds %foo, <16 x ptr> %lane.15, <16 x i64> zeroinitializer, <16 x i32> splat (i32 1)
%mm_vectorGEP2 = getelementptr inbounds %foo, <16 x ptr> %lane.15, <16 x i64> zeroinitializer, <16 x i32> splat (i32 2)
br i1 %tobool, label %f1, label %f0
f0:
br label %merge
f1:
br label %merge
merge:
%vec.phi = phi <16 x ptr> [ %mm_vectorGEP, %f0], [ %mm_vectorGEP2, %f1 ]
ret <16 x ptr> %vec.phi
}