[ARM] Negative constants mishandled in ARM CGP
During type promotion, sometimes we convert negative an add with a
negative constant into a sub with a positive constant. The loop that
performs this transformation has two issues:
- it iterates over a set, causing non-determinism.
- it breaks, instead of continuing, when it finds the first
non-negative operand.
Differential Revision: https://reviews.llvm.org/D58452
llvm-svn: 354557
diff --git a/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp b/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp
index e9f5e6a..b59f05d 100644
--- a/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp
+++ b/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp
@@ -119,7 +119,7 @@
// This defines the max range of the values that we allow in the promoted
// tree.
IntegerType *OrigTy = nullptr;
- SmallPtrSetImpl<Value*> *Visited;
+ SetVector<Value*> *Visited;
SmallPtrSetImpl<Value*> *Sources;
SmallPtrSetImpl<Instruction*> *Sinks;
SmallPtrSetImpl<Instruction*> *SafeToPromote;
@@ -138,7 +138,7 @@
void Mutate(Type *OrigTy,
- SmallPtrSetImpl<Value*> &Visited,
+ SetVector<Value*> &Visited,
SmallPtrSetImpl<Value*> &Sources,
SmallPtrSetImpl<Instruction*> &Sinks,
SmallPtrSetImpl<Instruction*> &SafeToPromote);
@@ -498,7 +498,7 @@
if (auto *Const = dyn_cast<ConstantInt>(I->getOperand(1))) {
if (!Const->isNegative())
- break;
+ continue;
unsigned Opc = I->getOpcode();
if (Opc != Instruction::Add && Opc != Instruction::Sub)
@@ -755,7 +755,7 @@
}
void IRPromoter::Mutate(Type *OrigTy,
- SmallPtrSetImpl<Value*> &Visited,
+ SetVector<Value*> &Visited,
SmallPtrSetImpl<Value*> &Sources,
SmallPtrSetImpl<Instruction*> &Sinks,
SmallPtrSetImpl<Instruction*> &SafeToPromote) {
@@ -935,7 +935,7 @@
SetVector<Value*> WorkList;
SmallPtrSet<Value*, 8> Sources;
SmallPtrSet<Instruction*, 4> Sinks;
- SmallPtrSet<Value*, 16> CurrentVisited;
+ SetVector<Value*> CurrentVisited;
WorkList.insert(V);
// Return true if V was added to the worklist as a supported instruction,