commit ef039a3ccdcd39c558c1d1a360b59bbb9bb11af5
author Xing Xue <xingxue@outlook.com> Sun Aug 25 15:17:25 2019 +0000
committer Xing Xue <xingxue@outlook.com> Sun Aug 25 15:17:25 2019 +0000
tree f2823223d2dc5604a4852e70219df5402ff2729e
parent 76f005535addf2ac4817c4f3a1c50330c44a6b57

[PowerPC][AIX] Adds support for writing the .data section in assembly files

Summary:
Adds support for generating the .data section in assembly files for global variables with a non-zero initialization. The support for writing the .data section in XCOFF object files will be added in a follow-on patch. Any relocations are not included in this patch.

Reviewers: hubert.reinterpretcast, sfertile, jasonliu, daltenty, Xiangling_L

Reviewed by: hubert.reinterpretcast

Subscribers: nemanjai, hiraditya, kbarton, MaskRay, jsji, wuzish, shchenz, DiggerLin, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66154

llvm-svn: 369869

llvm/lib/MC/MCAsmInfoXCOFF.cpp

diff --git a/llvm/lib/MC/MCAsmInfoXCOFF.cpp b/llvm/lib/MC/MCAsmInfoXCOFF.cpp
index 92dc505..13939f6 100644
--- a/llvm/lib/MC/MCAsmInfoXCOFF.cpp
+++ b/llvm/lib/MC/MCAsmInfoXCOFF.cpp
@@ -17,4 +17,8 @@
   HasDotTypeDotSizeDirective = false;
   COMMDirectiveAlignmentIsInBytes = false;
   LCOMMDirectiveAlignmentType = LCOMM::Log2Alignment;
+  UseDotAlignForAlignment = true;
+  AsciiDirective = nullptr; // not supported
+  AscizDirective = nullptr; // not supported
+  Data64bitsDirective = "\t.llong\t";
 }

llvm/lib/MC/MCAsmStreamer.cpp

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index e20ba2f..e37bc4a 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -1119,6 +1119,16 @@
 void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
                                          unsigned ValueSize,
                                          unsigned MaxBytesToEmit) {
+  if (MAI->useDotAlignForAlignment()) {
+    if (!isPowerOf2_32(ByteAlignment))
+      report_fatal_error("Only power-of-two alignments are supported "
+                         "with .align.");
+    OS << "\t.align\t";
+    OS << Log2_32(ByteAlignment);
+    EmitEOL();
+    return;
+  }
+
   // Some assemblers don't support non-power of two alignments, so we always
   // emit alignments as a power of two if possible.
   if (isPowerOf2_32(ByteAlignment)) {

llvm/lib/MC/MCObjectFileInfo.cpp

diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp
index d59453a..861e501 100644
--- a/llvm/lib/MC/MCObjectFileInfo.cpp
+++ b/llvm/lib/MC/MCObjectFileInfo.cpp
@@ -770,6 +770,10 @@
   TextSection = Ctx->getXCOFFSection(
       ".text", XCOFF::StorageMappingClass::XMC_PR, XCOFF::XTY_SD,
       XCOFF::C_HIDEXT, SectionKind::getText());
+
+  DataSection = Ctx->getXCOFFSection(
+      ".data", XCOFF::StorageMappingClass::XMC_RW, XCOFF::XTY_SD,
+      XCOFF::C_HIDEXT, SectionKind::getData());
 }
 
 void MCObjectFileInfo::InitMCObjectFileInfo(const Triple &TheTriple, bool PIC,

llvm/lib/MC/MCSectionXCOFF.cpp

diff --git a/llvm/lib/MC/MCSectionXCOFF.cpp b/llvm/lib/MC/MCSectionXCOFF.cpp
index d00a435..db27752 100644
--- a/llvm/lib/MC/MCSectionXCOFF.cpp
+++ b/llvm/lib/MC/MCSectionXCOFF.cpp
@@ -28,6 +28,16 @@
     return;
   }
 
+  if (getKind().isData()) {
+    assert(getMappingClass() == XCOFF::XMC_RW &&
+           "Unhandled storage-mapping class for data section.");
+
+    OS << "\t.csect " << getSectionName() << "["
+       << "RW"
+       << "]" << '\n';
+    return;
+  }
+
   if (getKind().isBSSLocal() || getKind().isCommon()) {
     assert((getMappingClass() == XCOFF::XMC_RW ||
             getMappingClass() == XCOFF::XMC_BS) &&