Constant-fold certain comparisons with infinity and negative infinity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96777 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index b53ac13..1f8053a 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -283,6 +283,32 @@
// True if unordered.
return ConstantInt::getTrue(CFP->getContext());
}
+ // Check whether the constant is an infinity.
+ if (CFP->getValueAPF().isInfinity()) {
+ if (CFP->getValueAPF().isNegative()) {
+ switch (Pred) {
+ case FCmpInst::FCMP_OLT:
+ // No value is ordered and less than negative infinity.
+ return ConstantInt::getFalse(CFP->getContext());
+ case FCmpInst::FCMP_UGE:
+ // All values are unordered with or at least negative infinity.
+ return ConstantInt::getTrue(CFP->getContext());
+ default:
+ break;
+ }
+ } else {
+ switch (Pred) {
+ case FCmpInst::FCMP_OGT:
+ // No value is ordered and greater than infinity.
+ return ConstantInt::getFalse(CFP->getContext());
+ case FCmpInst::FCMP_ULE:
+ // All values are unordered with and at most infinity.
+ return ConstantInt::getTrue(CFP->getContext());
+ default:
+ break;
+ }
+ }
+ }
}
}