From 9057466943aa7743f823b8a3e8e66600ef1c285d Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Tue, 27 Oct 2015 17:32:48 +0000
Subject: [PATCH] [ms-inline-asm] Leave alignment in bytes if the native
 assembler uses bytes

The existing behavior was correct on Darwin, which is probably the
platform it was written for.

Before this change, we would rewrite "align 8" to ".align 3" and then
fail to make it through the integrated assembler because 3 is not a
power of 2.

Differential Revision: http://reviews.llvm.org/D14120

llvm-svn: 251418
---
 lib/MC/MCParser/AsmParser.cpp | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 0c5100c07f5..ad2e1fd5809 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -4792,10 +4792,16 @@ bool AsmParser::parseMSInlineAsm(
       OS << ".byte";
       break;
     case AOK_Align: {
-      unsigned Val = AR.Val;
-      OS << ".align " << Val;
+      // MS alignment directives are measured in bytes. If the native assembler
+      // measures alignment in bytes, we can pass it straight through.
+      OS << ".align";
+      if (getContext().getAsmInfo()->getAlignmentIsInBytes())
+        break;
 
-      // Skip the original immediate.
+      // Alignment is in log2 form, so print that instead and skip the original
+      // immediate.
+      unsigned Val = AR.Val;
+      OS << ' ' << Val;
       assert(Val < 10 && "Expected alignment less then 2^10.");
       AdditionalSkip = (Val < 4) ? 2 : Val < 7 ? 3 : 4;
       break;