[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251418 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 0c5100c..ad2e1fd 100644 (file)
--- 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;