Fix an issue in SimplifySetCC() specific to vector comparisons.
When folding X == X we need to check getBooleanContents() to determine if the
result is a vector of ones or a vector of negative ones.
I tried creating a test case, but the problem seems to only be exposed on a
much older version of clang (around r144500).
rdar://10923049
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153966 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 792de75..460e284 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2432,8 +2432,16 @@
if (N0 == N1) {
// We can always fold X == X for integer setcc's.
- if (N0.getValueType().isInteger())
- return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
+ if (N0.getValueType().isInteger()) {
+ switch (getBooleanContents(N0.getValueType().isVector())) {
+ default: llvm_unreachable ("Unknown boolean content.");
+ case UndefinedBooleanContent:
+ case ZeroOrOneBooleanContent:
+ return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);
+ case ZeroOrNegativeOneBooleanContent:
+ return DAG.getConstant(ISD::isTrueWhenEqual(Cond) ? -1 : 0, VT);
+ }
+ }
unsigned UOF = ISD::getUnorderedFlavor(Cond);
if (UOF == 2) // FP operators that are undefined on NaNs.
return DAG.getConstant(ISD::isTrueWhenEqual(Cond), VT);