Improved fix for abs(val) != 0 to check other similar case. Also fixed style issues and confusing comment
llvm-svn: 145618
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index cebe37b..249de57 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -1796,15 +1796,19 @@
return ReplaceInstUsesWith(I, V);
// comparing -val or val with non-zero is the same as just comparing val
- // ie, (val != 0) == (-val != 0)
+ // ie, abs(val) != 0 -> val != 0
if (I.getPredicate() == ICmpInst::ICMP_NE && match(Op1, m_Zero()))
{
- Value *Cond, *SubSrc, *SelectFalse;
- if (match(Op0, m_Select(m_Value(Cond), m_Sub(m_Zero(), m_Value(SubSrc)),
+ Value *Cond, *SelectTrue, *SelectFalse;
+ if (match(Op0, m_Select(m_Value(Cond), m_Value(SelectTrue),
m_Value(SelectFalse)))) {
- if (SubSrc == SelectFalse) {
- return CmpInst::Create(Instruction::ICmp, I.getPredicate(),
- SubSrc, Op1);
+ if (Value *V = dyn_castNegVal(SelectTrue)) {
+ if (V == SelectFalse)
+ return CmpInst::Create(Instruction::ICmp, I.getPredicate(), V, Op1);
+ }
+ else if (Value *V = dyn_castNegVal(SelectFalse)) {
+ if (V == SelectTrue)
+ return CmpInst::Create(Instruction::ICmp, I.getPredicate(), V, Op1);
}
}
}