From dbf5f2557e5daa89e51d59b0da3329b58c84e4cc Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 21 Jan 2009 23:40:54 +0000
Subject: [PATCH] Recognize inline asm for bswap on x86-64 GLIBC. This allows
 it to be supported in the JIT.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62730 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86TargetAsmInfo.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/Target/X86/X86TargetAsmInfo.cpp b/lib/Target/X86/X86TargetAsmInfo.cpp
index e21596cd916..226feb7c1e6 100644
--- a/lib/Target/X86/X86TargetAsmInfo.cpp
+++ b/lib/Target/X86/X86TargetAsmInfo.cpp
@@ -411,11 +411,21 @@ bool X86TargetAsmInfo<BaseTAI>::ExpandInlineAsm(CallInst *CI) const {
 
     // bswap $0
     if (AsmPieces.size() == 2 &&
-        AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
+        AsmPieces[0] == "bswap" && (AsmPieces[1] == "$0" ||
+                                    AsmPieces[1] == "${0:q}")) {
       // No need to check constraints, nothing other than the equivalent of
       // "=r,0" would be valid here.
       return LowerToBSwap(CI);
     }
+    // rorw $$8, ${0:w}  -->  llvm.bswap.i16
+    if (CI->getType() == Type::Int16Ty &&
+        AsmPieces.size() == 3 &&
+        AsmPieces[0] == "rorw" &&
+        AsmPieces[1] == "$$8," &&
+        AsmPieces[2] == "${0:w}" &&
+        IA->getConstraintString() == "=r,0,~{dirflag},~{fpsr},~{flags},~{cc}") {
+      return LowerToBSwap(CI);
+    }
     break;
   case 3:
     if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 &&