From cb559c1270a773de2c97c99700dcd5456f24a732 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Sun, 22 May 2011 18:25:30 +0000
Subject: [PATCH] Teach ValueTracking about x86 crc32 intrinsics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131861 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/ValueTracking.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 8f18dd278aa..7b7e39f6c41 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -670,6 +670,10 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask,
         KnownZero = APInt::getHighBitsSet(BitWidth, BitWidth - LowBits);
         break;
       }
+      case Intrinsic::x86_sse42_crc64_8:
+      case Intrinsic::x86_sse42_crc64_64:
+        KnownZero = APInt::getHighBitsSet(64, 32);
+        break;
       }
     }
     break;