Fix PR409:

Implement the suggested check to ensure that out-of-range float constants
don't get accepted by LLVM accidentally. Adjust the supporting test cases
as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24963 91177308-0d34-0410-b5e6-96231b3b80d8

lib/VMCore/Constants.cpp

@@ -482,6 +482,9 @@ bool ConstantFP::isValueValidForType(const Type *Ty, double Val) {
 
     // TODO: Figure out how to test if a double can be cast to a float!
   case Type::FloatTyID:
+    float FV = float(Val);
+    double DV = double(FV);
+    return  IsNAN(Val) || Val == DV;
   case Type::DoubleTyID:
     return true;          // This is the largest type...
   }

test/Assembler/2004-01-22-FloatNormalization.ll

@@ -1,5 +0,0 @@
-; RUN: llvm-as < %s -o /dev/null -f
-
-; make sure that 'float' values have their value properly truncated.
-
-global float 0x1 

test/Assembler/2004-12-06-ConstantFloatRange.ll

@@ -1,5 +1,4 @@
 ; RUN: llvm-as %s -o /dev/null 2>&1 | grep "constant invalid for type"
-; XFAIL: *
 
 ;; This is a testcase for PR409
 

test/Verifier/2004-01-22-FloatNormalization.ll

@@ -0,0 +1,6 @@
+; RUN: llvm-as < %s -o /dev/null -f
+; XFAIL: *
+
+; make sure that invalid 'float' values are caught.
+
+global float 0x1