[cfe-commits] r162766 - in /cfe/trunk: lib/CodeGen/CGExprScalar.cpp test/CodeGen/pr13704.c

[Michael Liao]

Author: hliao
Date: Tue Aug 28 11:55:13 2012
New Revision: 162766

URL: http://llvm.org/viewvc/llvm-project?rev=162766&view=rev
Log:
Fix PR13704

- The increment needs to be signed value to preserve the original value when
  its data type is larger than 64-bit integer.


Added:
    cfe/trunk/test/CodeGen/pr13704.c
Modified:
    cfe/trunk/lib/CodeGen/CGExprScalar.cpp

Modified: cfe/trunk/lib/CodeGen/CGExprScalar.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprScalar.cpp?rev=162766&r1=162765&r2=162766&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprScalar.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprScalar.cpp Tue Aug 28 11:55:13 2012
@@ -1306,7 +1306,7 @@
   // Most common case by far: integer increment.
   } else if (type->isIntegerType()) {
 
-    llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount);
+    llvm::Value *amt = llvm::ConstantInt::get(value->getType(), amount, true);
 
     // Note that signed integer inc/dec with width less than int can't
     // overflow because of promotion rules; we're just eliding a few steps here.

Added: cfe/trunk/test/CodeGen/pr13704.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/pr13704.c?rev=162766&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/pr13704.c (added)
+++ cfe/trunk/test/CodeGen/pr13704.c Tue Aug 28 11:55:13 2012
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s
+extern void foo(__int128);
+
+void bar() {
+  __int128 x = 2;
+  x--;
+  foo(x);
+// CHECK: add nsw i128 %0, -1
+}