From 93d5626c135569875bff226aab1391c719f0dcf2 Mon Sep 17 00:00:00 2001
From: Michael Kuperstein <michael.m.kuperstein@intel.com>
Date: Wed, 22 Jul 2015 10:49:44 +0000
Subject: [PATCH] [X86] Add .intel_syntax noprefix directive to intel-syntax
 x86 asm output

Patch by: michael.zuckerman@intel.com
Differential Revision: http://reviews.llvm.org/D11223

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242886 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/MC/MCStreamer.h      |  2 ++
 lib/MC/MCAsmStreamer.cpp          | 11 +++++++++++
 lib/MC/MCStreamer.cpp             |  2 ++
 lib/Target/X86/X86AsmPrinter.cpp  |  1 +
 test/MC/X86/intel-syntax-print.ll |  9 +++++++++
 5 files changed, 25 insertions(+)
 create mode 100644 test/MC/X86/intel-syntax-print.ll

diff --git a/include/llvm/MC/MCStreamer.h b/include/llvm/MC/MCStreamer.h
index 6b9b8a15384..63e30bc3d54 100644
--- a/include/llvm/MC/MCStreamer.h
+++ b/include/llvm/MC/MCStreamer.h
@@ -682,6 +682,8 @@ public:
   virtual void EmitWinEHHandler(const MCSymbol *Sym, bool Unwind, bool Except);
   virtual void EmitWinEHHandlerData();
 
+  virtual void EmitSyntaxDirective();
+
   /// \brief Emit the given \p Instruction into the current section.
   virtual void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI);
 
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 227c937e8d1..ec49058407f 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -78,6 +78,9 @@ public:
     }
     EmitCommentsAndEOL();
   }
+
+  virtual void EmitSyntaxDirective();
+
   void EmitCommentsAndEOL();
 
   /// isVerboseAsm - Return true if this streamer supports verbose assembly at
@@ -480,6 +483,14 @@ void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
   EmitEOL();
 }
 
+void MCAsmStreamer::EmitSyntaxDirective() {
+  if (MAI->getAssemblerDialect() == 1)
+    OS << "\t.intel_syntax noprefix\n";
+  // FIXME: Currently emit unprefix'ed registers.
+  // The intel_syntax directive has one optional argument 
+  // with may have a value of prefix or noprefix.
+}
+
 void MCAsmStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
   OS << "\t.def\t ";
   Symbol->print(OS, MAI);
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index 7fbbbd95b56..a25cdfa971e 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -467,6 +467,8 @@ void MCStreamer::EmitWinEHHandlerData() {
     report_fatal_error("Chained unwind areas can't have handlers!");
 }
 
+void MCStreamer::EmitSyntaxDirective() {}
+
 void MCStreamer::EmitWinCFIPushReg(unsigned Register) {
   EnsureValidWinFrameInfo();
 
diff --git a/lib/Target/X86/X86AsmPrinter.cpp b/lib/Target/X86/X86AsmPrinter.cpp
index 24149e6e9ce..9fe849a04ee 100644
--- a/lib/Target/X86/X86AsmPrinter.cpp
+++ b/lib/Target/X86/X86AsmPrinter.cpp
@@ -535,6 +535,7 @@ void X86AsmPrinter::EmitStartOfAsmFile(Module &M) {
           S, MCConstantExpr::create(int64_t(1), MMI->getContext()));
     }
   }
+  OutStreamer->EmitSyntaxDirective();
 }
 
 static void
diff --git a/test/MC/X86/intel-syntax-print.ll b/test/MC/X86/intel-syntax-print.ll
new file mode 100644
index 00000000000..275e8cd3929
--- /dev/null
+++ b/test/MC/X86/intel-syntax-print.ll
@@ -0,0 +1,9 @@
+; RUN: llc -x86-asm-syntax=intel < %s | FileCheck %s -check-prefix=INTEL
+; RUN: llc -x86-asm-syntax=att < %s | FileCheck %s -check-prefix=ATT
+
+; INTEL: .intel_syntax noprefix
+; ATT-NOT: .intel_syntax noprefix
+define i32 @test() {
+entry:
+  ret i32 0
+}
-- 
2.34.1