ConstantInt::get only works for arguments < 128.

SimplifyLibCalls probably has to be audited to make sure it does not make
this mistake elsewhere.  Also, if this code knows that the type will be
unsigned, obviously one arm of this is dead.

Reid, can you take a look into this further?

llvm-svn: 22566

llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp

@@ -962,8 +962,12 @@ struct StrLenOptimization : public LibCallOptimization
       return false;
 
     // strlen("xyz") -> 3 (for example)
-    ci->replaceAllUsesWith(
-        ConstantInt::get(SLC.getTargetData()->getIntPtrType(),len));
+    const Type *Ty = SLC.getTargetData()->getIntPtrType();
+    if (Ty->isSigned())
+      ci->replaceAllUsesWith(ConstantSInt::get(Ty, len));
+    else
+      ci->replaceAllUsesWith(ConstantUInt::get(Ty, len));
+     
     ci->eraseFromParent();
     return true;
   }