From: Derek Schuff <dschuff@google.com>
Date: Fri, 26 Oct 2012 19:52:27 +0000 (+0000)
Subject: Stop APInt::shl from generating llvm.trap
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8f5eff7e76491f39c62455d97cf8f704631e54d7;p=platform%2Fupstream%2Fllvm.git

Stop APInt::shl from generating llvm.trap

APInt::shl generated llvm.trap to guard against shifts greater than bit-width.
This was already checked with an assert, and there was a special case for
shifts equal to bit-width. Modify this check to catch shifts greater than or
equal to bit-width, so llvm.trap isn't generated.

Patch contributed by JF Bastien

llvm-svn: 166803
---

diff --git a/llvm/include/llvm/ADT/APInt.h b/llvm/include/llvm/ADT/APInt.h
index 4470534..90114e2 100644
--- a/llvm/include/llvm/ADT/APInt.h
+++ b/llvm/include/llvm/ADT/APInt.h
@@ -760,7 +760,7 @@ public:
   APInt shl(unsigned shiftAmt) const {
     assert(shiftAmt <= BitWidth && "Invalid shift amount");
     if (isSingleWord()) {
-      if (shiftAmt == BitWidth)
+      if (shiftAmt >= BitWidth)
         return APInt(BitWidth, 0); // avoid undefined shift results
       return APInt(BitWidth, VAL << shiftAmt);
     }