[SCEV] Opportunistically interpret unsigned constraints as signed

[oota-llvm.git] / lib / IR / Instructions.cpp

diff --git a/lib/IR/Instructions.cpp b/lib/IR/Instructions.cpp
index 855101b4ac8b593721c50c1eb94dee8dc3735059..59ac99b666628d26efbf7db2b48e8d2ac992739d 100644 (file)
--- a/lib/IR/Instructions.cpp
+++ b/lib/IR/Instructions.cpp
@@ -3558,6 +3558,23 @@ CmpInst::Predicate CmpInst::getSwappedPredicate(Predicate pred) {
   }
 }
 
+CmpInst::Predicate CmpInst::getSignedPredicate(Predicate pred) {
+  assert(CmpInst::isUnsigned(pred) && "Call only with signed predicates!");
+
+  switch (pred) {
+  default:
+    llvm_unreachable("Unknown predicate!");
+  case CmpInst::ICMP_ULT:
+    return CmpInst::ICMP_SLT;
+  case CmpInst::ICMP_ULE:
+    return CmpInst::ICMP_SLE;
+  case CmpInst::ICMP_UGT:
+    return CmpInst::ICMP_SGT;
+  case CmpInst::ICMP_UGE:
+    return CmpInst::ICMP_SGE;
+  }
+}
+
 bool CmpInst::isUnsigned(unsigned short predicate) {
   switch (predicate) {
     default: return false;