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[SLP]Fix non-determinism in PHI sorting. 

Compare type IDs and DFS numbering for basic block instead of addresses
to fix non-determinism.

Differential Revision: https://reviews.llvm.org/D105031
This commit is contained in:
Alexey Bataev 2021-06-28 07:22:27 -07:00
parent 130ea3ceb4
commit 4e1a0684f1
2 changed files with 23 additions and 18 deletions
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26
llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
View File

@ -8318,7 +8318,7 @@ bool SLPVectorizerPass::vectorizeChainsInBlock(BasicBlock *BB, BoUpSLP &R) {
// No need to analyze deleted, vectorized and non-vectorizable
// instructions.
if (!VisitedInstrs.count(P) && !R.isDeleted(P) &&
!P->getType()->isVectorTy())
isValidElementType(P->getType()))
Incoming.push_back(P);
}
@ -8346,10 +8346,15 @@ bool SLPVectorizerPass::vectorizeChainsInBlock(BasicBlock *BB, BoUpSLP &R) {
}
// Sort by type, parent, operands.
stable_sort(Incoming, [&PHIToOpcodes](Value *V1, Value *V2) {
if (V1->getType() < V2->getType())
stable_sort(Incoming, [this, &PHIToOpcodes](Value *V1, Value *V2) {
assert(isValidElementType(V1->getType()) &&
isValidElementType(V2->getType()) &&
"Expected vectorizable types only.");
// It is fine to compare type IDs here, since we expect only vectorizable
// types, like ints, floats and pointers, we don't care about other type.
if (V1->getType()->getTypeID() < V2->getType()->getTypeID())
return true;
if (V1->getType() > V2->getType())
if (V1->getType()->getTypeID() > V2->getType()->getTypeID())
return false;
ArrayRef<Value *> Opcodes1 = PHIToOpcodes[V1];
ArrayRef<Value *> Opcodes2 = PHIToOpcodes[V2];
@ -8363,10 +8368,15 @@ bool SLPVectorizerPass::vectorizeChainsInBlock(BasicBlock *BB, BoUpSLP &R) {
continue;
if (auto *I1 = dyn_cast<Instruction>(Opcodes1[I]))
if (auto *I2 = dyn_cast<Instruction>(Opcodes2[I])) {
if (I1->getParent() < I2->getParent())
return true;
if (I1->getParent() > I2->getParent())
return false;
DomTreeNodeBase<BasicBlock> *NodeI1 = DT->getNode(I1->getParent());
DomTreeNodeBase<BasicBlock> *NodeI2 = DT->getNode(I2->getParent());
assert(NodeI1 && "Should only process reachable instructions");
assert(NodeI2 && "Should only process reachable instructions");
assert((NodeI1 == NodeI2) ==
(NodeI1->getDFSNumIn() == NodeI2->getDFSNumIn()) &&
"Different nodes should have different DFS numbers");
if (NodeI1 != NodeI2)
return NodeI1->getDFSNumIn() < NodeI2->getDFSNumIn();
InstructionsState S = getSameOpcode({I1, I2});
if (S.getOpcode())
continue;

15
llvm/test/Transforms/SLPVectorizer/X86/remark_unsupported.ll
View File

@ -3,7 +3,7 @@
; RUN: FileCheck --input-file=%t --check-prefix=YAML %s
; This type is not supported by SLP
define void @test(x86_fp80* %i1, x86_fp80* %i2, x86_fp80* %o) {
define i1 @test(x86_fp80* %i1, x86_fp80* %i2) {
; CHECK-LABEL: @test(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[I1_0:%.*]] = load x86_fp80, x86_fp80* [[I1:%.*]], align 16
@ -19,10 +19,8 @@ define void @test(x86_fp80* %i1, x86_fp80* %i2, x86_fp80* %o) {
; CHECK: end:
; CHECK-NEXT: [[PHI0:%.*]] = phi x86_fp80 [ [[I1_0]], [[ENTRY:%.*]] ], [ [[I2_0]], [[THEN]] ]
; CHECK-NEXT: [[PHI1:%.*]] = phi x86_fp80 [ [[I1_1]], [[ENTRY]] ], [ [[I2_1]], [[THEN]] ]
; CHECK-NEXT: store x86_fp80 [[PHI0]], x86_fp80* [[O:%.*]], align 16
; CHECK-NEXT: [[O_GEP1:%.*]] = getelementptr inbounds x86_fp80, x86_fp80* [[O]], i64 1
; CHECK-NEXT: store x86_fp80 [[PHI1]], x86_fp80* [[O_GEP1]], align 16
; CHECK-NEXT: ret void
; CHECK-NEXT: [[RES:%.*]] = fcmp oeq x86_fp80 [[PHI0]], [[PHI1]]
; CHECK-NEXT: ret i1 [[RES]]
;
entry:
%i1.0 = load x86_fp80, x86_fp80* %i1, align 16
@ -37,11 +35,8 @@ then:
br label %end
end:
%phi0 = phi x86_fp80 [ %i1.0, %entry ], [ %i2.0, %then ]
%phi1 = phi x86_fp80 [ %i1.1, %entry ], [ %i2.1, %then ]
store x86_fp80 %phi0, x86_fp80* %o, align 16
%o.gep1 = getelementptr inbounds x86_fp80, x86_fp80* %o, i64 1
store x86_fp80 %phi1, x86_fp80* %o.gep1, align 16
%res = fcmp oeq x86_fp80 %phi0, %phi1
; YAML: Pass: slp-vectorizer
; YAML-NEXT: Name: UnsupportedType
; YAML-NEXT: Function: test
@ -49,5 +44,5 @@ end:
; YAML-NEXT: - String: 'Cannot SLP vectorize list: type '
; YAML-NEXT: - String: x86_fp80 is unsupported by vectorizer
ret void
ret i1 %res
}