[AIX] Update data directives for AIX assembly
Summary:
The standard data emission directives (e.g. .short, .long) in the AIX assembler
have the unintended consequence of aligning their output to the natural byte
boundary. This cause problems because we aren't expecting behavior from the
Data*bitsDirectives, so the final alignment of data isn't correct in some cases
on AIX.
This patch updated the Data*bitsDirectives to use .vbyte pseudo-ops instead to emit the
data, since we will emit the .align directives as needed. We update the existing
testcases and add a test for emission of struct data.
Reviewers: hubert.reinterpretcast, Xiangling_L, jasonliu
Reviewed By: hubert.reinterpretcast, jasonliu
Subscribers: wuzish, nemanjai, hiraditya, kbarton, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80934
diff --git a/llvm/lib/MC/MCAsmInfoXCOFF.cpp b/llvm/lib/MC/MCAsmInfoXCOFF.cpp
index 479578f..1d4d4ad 100644
--- a/llvm/lib/MC/MCAsmInfoXCOFF.cpp
+++ b/llvm/lib/MC/MCAsmInfoXCOFF.cpp
@@ -20,7 +20,12 @@
ZeroDirectiveSupportsNonZeroValue = false;
AsciiDirective = nullptr; // not supported
AscizDirective = nullptr; // not supported
- Data64bitsDirective = "\t.llong\t";
+
+ // Use .vbyte for data definition to avoid directives that apply an implicit
+ // alignment.
+ Data16bitsDirective = "\t.vbyte\t2, ";
+ Data32bitsDirective = "\t.vbyte\t4, ";
+
COMMDirectiveAlignmentIsInBytes = false;
LCOMMDirectiveAlignmentType = LCOMM::Log2Alignment;
HasDotTypeDotSizeDirective = false;