[AMDGPU] Change section name with metadata access

[piotr]

Summary

The commit rL348922 introduced a means to set Metadata
section kind for a global variable, if its explicit section
name was prefixed with ".AMDGPU.metadata.".

This patch changes that prefix to ".AMDGPU.comment.",
as "metadata" in the section name might lead to
ambiguity with metadata used by AMD PAL runtime.

Change-Id: Idd4748800d6fe801441d91595fc21e5a4171e668

[kzhuravl]

LGTM

llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetObjectFile.cpp

MCSection *AMDGPUTargetObjectFile::SelectSectionForGlobal(
 
   return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, Kind, TM);
 }
 
 MCSection *AMDGPUTargetObjectFile::getExplicitSectionGlobal(
     const GlobalObject *GO, SectionKind SK, const TargetMachine &TM) const {
   // Set metadata access for the explicit section
   StringRef SectionName = GO->getSection();
-  if (SectionName.startswith(".AMDGPU.metadata."))
+  if (SectionName.startswith(".AMDGPU.comment."))
     SK = SectionKind::getMetadata();
 
   return TargetLoweringObjectFileELF::getExplicitSectionGlobal(GO, SK, TM);
 }

llvm/trunk/test/CodeGen/AMDGPU/elf.metadata.ll

 ; RUN: llc < %s -march=amdgcn -mcpu=fiji -filetype=obj | llvm-readobj -symbols -s -sd - | FileCheck %s
 
 ; CHECK: Section {
-; CHECK: Name: .AMDGPU.metadata.info_1
+; CHECK: Name: .AMDGPU.comment.info_1
 ; CHECK: Type: SHT_PROGBITS (0x1)
 ; CHECK: Flags [ (0x0)
 ; CHECK: Size: 16
 ; CHECK: SectionData (
 ; CHECK: 0000: 414D4431 414D4431 414D4431 414D4431  |AMD1AMD1AMD1AMD1|
 ; CHECK: )
 ; CHECK: }
 
 ; CHECK: Section {
-; CHECK: Name: .AMDGPU.metadata.info_2
+; CHECK: Name: .AMDGPU.comment.info_2
 ; CHECK: Type: SHT_PROGBITS (0x1)
 ; CHECK: Flags [ (0x0)
 ; CHECK: Size: 16
 ; CHECK: SectionData (
 ; CHECK: 0000: 414D4432 414D4432 414D4432 414D4432  |AMD2AMD2AMD2AMD2|
 ; CHECK: )
 ; CHECK: }
 
 ; CHECK: Section {
-; CHECK: Name: .AMDGPU.metadata.info_3
+; CHECK: Name: .AMDGPU.comment.info_3
 ; CHECK: Type: SHT_PROGBITS (0x1)
 ; CHECK: Flags [ (0x0)
 ; CHECK: Size: 16
 ; CHECK: SectionData (
 ; CHECK: 0000: 414D4433 414D4433 414D4433 414D4433  |AMD3AMD3AMD3AMD3|
 ; CHECK: )
 ; CHECK: }
 
 ; CHECK: Symbol {
-; CHECK: Name: metadata_info_var_1
+; CHECK: Name: comment_info_var_1
 ; CHECK: Size: 16
 ; CHECK: Binding: Local
-; CHECK: Section: .AMDGPU.metadata.info_1
+; CHECK: Section: .AMDGPU.comment.info_1
 ; CHECK: }
 
 ; CHECK: Symbol {
-; CHECK: Name: metadata_info_var_2
+; CHECK: Name: comment_info_var_2
 ; CHECK: Size: 16
 ; CHECK: Binding: Global
-; CHECK: Section: .AMDGPU.metadata.info_2
+; CHECK: Section: .AMDGPU.comment.info_2
 ; CHECK: }
 
 ; CHECK: Symbol {
-; CHECK: Name: metadata_info_var_3
+; CHECK: Name: comment_info_var_3
 ; CHECK: Size: 16
 ; CHECK: Binding: Global
-; CHECK: Section: .AMDGPU.metadata.info_3
+; CHECK: Section: .AMDGPU.comment.info_3
 ; CHECK: }
 
-@metadata_info_var_1 = internal global [4 x i32][i32 826559809, i32 826559809, i32 826559809, i32 826559809], align 1, section ".AMDGPU.metadata.info_1"
-@metadata_info_var_2 = constant [4 x i32][i32 843337025, i32 843337025, i32 843337025, i32 843337025], align 1, section ".AMDGPU.metadata.info_2"
-@metadata_info_var_3 = global [4 x i32][i32 860114241, i32 860114241, i32 860114241, i32 860114241], align 1, section ".AMDGPU.metadata.info_3"
+@comment_info_var_1 = internal global [4 x i32][i32 826559809, i32 826559809, i32 826559809, i32 826559809], align 1, section ".AMDGPU.comment.info_1"
+@comment_info_var_2 = constant [4 x i32][i32 843337025, i32 843337025, i32 843337025, i32 843337025], align 1, section ".AMDGPU.comment.info_2"
+@comment_info_var_3 = global [4 x i32][i32 860114241, i32 860114241, i32 860114241, i32 860114241], align 1, section ".AMDGPU.comment.info_3"