fold fp div by 0 to inf, the way gcc does. This is legal according to the FP spec

llvm-svn: 21655

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/VMCore/ConstantFolding.cpp b/llvm/lib/VMCore/ConstantFolding.cpp
index 98fcf1a32e4..8cb1c074534 100644
--- a/llvm/lib/VMCore/ConstantFolding.cpp
+++ b/llvm/lib/VMCore/ConstantFolding.cpp
@@ -470,6 +470,13 @@ struct DirectFPRules
                                    (BuiltinType)V2->getValue());
     return ConstantClass::get(*Ty, Result);
   }
+  static Constant *Div(const ConstantClass *V1, const ConstantClass *V2) {
+    if (V2->isExactlyValue(0.0)) return ConstantClass::get(*Ty, INFINITY);
+    if (V2->isExactlyValue(-0.0)) return ConstantClass::get(*Ty, -INFINITY);
+    if (V2->isNullValue()) return 0;
+    BuiltinType R = (BuiltinType)V1->getValue() / (BuiltinType)V2->getValue();
+    return ConstantClass::get(*Ty, R);
+  }
 };