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

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp b/llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
index 754143bea7f..99675b3cb35 100644
--- a/llvm/lib/Transforms/IPO/SimplifyLibCalls.cpp
+++ b/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;
   }