From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 9 Feb 2009 20:54:38 +0000 (+0000)
Subject: Make sure constant subscript is truncated to ptr size if it may not fit.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=b1032a8a2f322e031f7c0947c3fb60fe9e8a10e6;p=oota-llvm.git

Make sure constant subscript is truncated to ptr size if it may not fit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64163 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index 3c90cd767ce..7b613d7f242 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -2699,8 +2699,15 @@ void SelectionDAGLowering::visitGetElementPtr(User &I) {
         if (CI->getZExtValue() == 0) continue;
         uint64_t Offs =
             TD->getTypePaddedSize(Ty)*cast<ConstantInt>(CI)->getSExtValue();
+        SDValue OffsVal = DAG.getConstant(Offs, MVT::i64);
+        unsigned PtrBits = TLI.getPointerTy().getSizeInBits();
+        if (PtrBits < 64)
+          OffsVal = DAG.getNode(ISD::TRUNCATE, getCurDebugLoc(), 
+                                TLI.getPointerTy(), OffsVal);
+        else
+          OffsVal = DAG.getIntPtrConstant(Offs);
         N = DAG.getNode(ISD::ADD, getCurDebugLoc(), N.getValueType(), N,
-                        DAG.getIntPtrConstant(Offs));
+                        OffsVal);
         continue;
       }
 
diff --git a/test/CodeGen/X86/negative-subscript.ll b/test/CodeGen/X86/negative-subscript.ll
new file mode 100644
index 00000000000..f2bd315bd86
--- /dev/null
+++ b/test/CodeGen/X86/negative-subscript.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | llc -march=x86
+; rdar://6559995
+
+@a = external global [255 x i8*], align 32
+
+define i32 @main() nounwind {
+entry:
+	store i8* bitcast (i8** getelementptr ([255 x i8*]* @a, i32 0, i32 -2147483624) to i8*), i8** getelementptr ([255 x i8*]* @a, i32 0, i32 16), align 32
+	ret i32 0
+}