Enable assembly output of local commons for AIX
Summary:
This patch enable assembly output of local commons for AIX using .lcomm
directives. Adds a EmitXCOFFLocalCommonSymbol to MCStreamer so we can emit the
AIX version of .lcomm assembly directives which include a csect name. Handle the
case of BSS locals in PPCAIXAsmPrinter by using EmitXCOFFLocalCommonSymbol. Adds
a test for generating .lcomm on AIX Targets.
Reviewers: cebowleratibm, hubert.reinterpretcast, Xiangling_L, jasonliu, sfertile
Reviewed By: sfertile
Subscribers: wuzish, nemanjai, hiraditya, kbarton, MaskRay, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64825
llvm-svn: 368306
diff --git a/llvm/lib/MC/MCAsmInfoXCOFF.cpp b/llvm/lib/MC/MCAsmInfoXCOFF.cpp
index 6a9bef6..92dc505 100644
--- a/llvm/lib/MC/MCAsmInfoXCOFF.cpp
+++ b/llvm/lib/MC/MCAsmInfoXCOFF.cpp
@@ -16,4 +16,5 @@
IsLittleEndian = false;
HasDotTypeDotSizeDirective = false;
COMMDirectiveAlignmentIsInBytes = false;
+ LCOMMDirectiveAlignmentType = LCOMM::Log2Alignment;
}
diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index c0890b59..967ee8b 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -162,6 +162,8 @@
void EmitCOFFSectionIndex(MCSymbol const *Symbol) override;
void EmitCOFFSecRel32(MCSymbol const *Symbol, uint64_t Offset) override;
void EmitCOFFImgRel32(MCSymbol const *Symbol, int64_t Offset) override;
+ void EmitXCOFFLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlign) override;
void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) override;
@@ -757,6 +759,24 @@
EmitEOL();
}
+// We need an XCOFF specific version of this directive as the AIX syntax
+// requires a QualName argument identifying the csect name and storage mapping
+// class to appear before the alignment if we are specifying it.
+void MCAsmStreamer::EmitXCOFFLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlignment) {
+ assert(MAI->getLCOMMDirectiveAlignmentType() == LCOMM::Log2Alignment &&
+ "We only support writing log base-2 alignment format with XCOFF");
+ assert(isPowerOf2_32(ByteAlignment) && "alignment must be a power of 2");
+
+ OS << "\t.lcomm\t";
+ Symbol->print(OS, MAI);
+ OS << ',' << Size;
+ OS << ',' << Symbol->getName();
+ OS << ',' << Log2_32(ByteAlignment);
+
+ EmitEOL();
+}
+
void MCAsmStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
assert(MAI->hasDotTypeDotSizeDirective());
OS << "\t.size\t";
diff --git a/llvm/lib/MC/MCSectionXCOFF.cpp b/llvm/lib/MC/MCSectionXCOFF.cpp
index 9cee1cc..a3f79c3 100644
--- a/llvm/lib/MC/MCSectionXCOFF.cpp
+++ b/llvm/lib/MC/MCSectionXCOFF.cpp
@@ -28,9 +28,11 @@
return;
}
- if (getKind().isCommon()) {
- if (getMappingClass() != XCOFF::XMC_RW)
- llvm_unreachable("Unsupported storage-mapping class for common csect");
+ if (getKind().isBSSLocal() || getKind().isCommon()) {
+ if (getMappingClass() != XCOFF::XMC_RW &&
+ getMappingClass() != XCOFF::XMC_BS)
+ llvm_unreachable("Generated a storage-mapping class for a common/bss "
+ "csect we don't understand how to switch to.");
if (getCSectType() != XCOFF::XTY_CM)
llvm_unreachable("wrong csect type for .bss csect");
// Don't have to print a directive for switching to section for commons.
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 254eb2c..2e36fe7 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -1055,6 +1055,10 @@
void MCStreamer::EmitCOFFSymbolType(int Type) {
llvm_unreachable("this directive only supported on COFF targets");
}
+void MCStreamer::EmitXCOFFLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlign) {
+ llvm_unreachable("this directive only supported on XCOFF targets");
+}
void MCStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
void MCStreamer::emitELFSymverDirective(StringRef AliasName,
const MCSymbol *Aliasee) {}
diff --git a/llvm/lib/MC/MCXCOFFStreamer.cpp b/llvm/lib/MC/MCXCOFFStreamer.cpp
index 071de02..7d526cc 100644
--- a/llvm/lib/MC/MCXCOFFStreamer.cpp
+++ b/llvm/lib/MC/MCXCOFFStreamer.cpp
@@ -57,3 +57,8 @@
S->getAssembler().setRelaxAll(true);
return S;
}
+
+void MCXCOFFStreamer::EmitXCOFFLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlign) {
+ llvm_unreachable("Not implemented yet.");
+}
\ No newline at end of file