From e9e16a36d9ff355dab60e4b95673bf7a0cd27e86 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Wed, 15 Sep 2010 04:33:27 +0000
Subject: [PATCH] fix rdar://8431880 - rcl/rcr with no shift amount not
 recognized

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113936 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/AsmParser/X86AsmParser.cpp | 10 +++++++++-
 test/MC/AsmParser/X86/x86_instructions.s  | 11 +++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/Target/X86/AsmParser/X86AsmParser.cpp b/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 7098c58cde9..4856cc9283c 100644
--- a/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -813,7 +813,7 @@ ParseInstruction(StringRef Name, SMLoc NameLoc,
   if (getLexer().is(AsmToken::EndOfStatement))
     Parser.Lex(); // Consume the EndOfStatement
 
-  // FIXME: Hack to handle recognize s{hr,ar,hl} <op>, $1.  Canonicalize to
+  // FIXME: Hack to handle recognize s{hr,ar,hl} $1, <op>.  Canonicalize to
   // "shift <op>".
   if ((Name.startswith("shr") || Name.startswith("sar") ||
        Name.startswith("shl")) &&
@@ -825,6 +825,14 @@ ParseInstruction(StringRef Name, SMLoc NameLoc,
       Operands.erase(Operands.begin() + 1);
     }
   }
+  
+  // FIXME: Hack to handle recognize "rc[lr] <op>" -> "rcl $1, <op>".
+  if ((Name.startswith("rcl") || Name.startswith("rcr")) &&
+      Operands.size() == 2) {
+    const MCExpr *One = MCConstantExpr::Create(1, getParser().getContext());
+    Operands.push_back(X86Operand::CreateImm(One, NameLoc, NameLoc));
+    std::swap(Operands[1], Operands[2]);
+  }
 
   // FIXME: Hack to handle recognize "in[bwl] <op>".  Canonicalize it to
   // "inb <op>, %al".
diff --git a/test/MC/AsmParser/X86/x86_instructions.s b/test/MC/AsmParser/X86/x86_instructions.s
index 4faf2e55fe1..3bd2a305044 100644
--- a/test/MC/AsmParser/X86/x86_instructions.s
+++ b/test/MC/AsmParser/X86/x86_instructions.s
@@ -257,3 +257,14 @@ fnstsw
 fnstsw %ax
 fnstsw %eax
 fnstsw %al
+
+// rdar://8431880
+// CHECK: rclb	$1, %bl
+// CHECK: rcll	$1, 3735928559(%ebx,%ecx,8)
+// CHECK: rcrl	$1, %ecx
+// CHECK: rcrl	$1, 305419896
+
+rcl	%bl
+rcll	0xdeadbeef(%ebx,%ecx,8)
+rcr	%ecx
+rcrl	0x12345678
-- 
2.34.1