[llvm] 04dc969 - [XCOFF][AIX] Enable -ffunction-sections
via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 30 06:30:25 PDT 2020
Author: jasonliu
Date: 2020-07-30T13:30:01Z
New Revision: 04dc9691ebef740cc8dc85e9a5d7a3e1ed595765
URL: https://github.com/llvm/llvm-project/commit/04dc9691ebef740cc8dc85e9a5d7a3e1ed595765
DIFF: https://github.com/llvm/llvm-project/commit/04dc9691ebef740cc8dc85e9a5d7a3e1ed595765.diff
LOG: [XCOFF][AIX] Enable -ffunction-sections
Summary:
This patch implements -ffunction-sections on AIX.
This patch focuses on assembly generation.
Follow-on patch needs to handle:
1. -ffunction-sections implication for jump table.
2. Object file generation path and associated testing.
Differential Revision: https://reviews.llvm.org/D83875
Added:
llvm/test/CodeGen/PowerPC/aix-xcoff-funcsect.ll
Modified:
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index bf3b89e00640..48599199626c 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -2027,8 +2027,8 @@ MCSection *TargetLoweringObjectFileXCOFF::getSectionForExternalReference(
MCSection *TargetLoweringObjectFileXCOFF::SelectSectionForGlobal(
const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
- assert(!TM.getFunctionSections() && !TM.getDataSections() &&
- "XCOFF unique sections not yet implemented.");
+ assert(!TM.getDataSections() &&
+ "XCOFF unique data sections not yet implemented.");
// Common symbols go into a csect with matching name which will get mapped
// into the .bss section.
@@ -2057,8 +2057,13 @@ MCSection *TargetLoweringObjectFileXCOFF::SelectSectionForGlobal(
Kind, /* BeginSymbolName */ nullptr);
}
- if (Kind.isText())
+ if (Kind.isText()) {
+ if (TM.getFunctionSections()) {
+ return cast<MCSymbolXCOFF>(getFunctionEntryPointSymbol(GO, TM))
+ ->getRepresentedCsect();
+ }
return TextSection;
+ }
if (Kind.isData() || Kind.isReadOnlyWithRel())
// TODO: We may put this under option control, because user may want to
@@ -2161,6 +2166,22 @@ MCSymbol *TargetLoweringObjectFileXCOFF::getFunctionEntryPointSymbol(
SmallString<128> NameStr;
NameStr.push_back('.');
getNameWithPrefix(NameStr, Func, TM);
+
+ // When -function-sections is enabled, it's not necessary to emit
+ // function entry point label any more. We will use function entry
+ // point csect instead. For function delcarations, it's okay to continue
+ // using label semantic because undefined symbols gets treated as csect with
+ // XTY_ER property anyway.
+ if (TM.getFunctionSections() && !Func->isDeclaration() &&
+ isa<Function>(Func)) {
+ XCOFF::StorageClass SC =
+ TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(Func);
+ return cast<MCSectionXCOFF>(getContext().getXCOFFSection(
+ NameStr, XCOFF::XMC_PR, XCOFF::XTY_SD, SC,
+ SectionKind::getText()))
+ ->getQualNameSymbol();
+ }
+
return getContext().getOrCreateSymbol(NameStr);
}
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 5affddd8d147..10962df7b872 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -1779,7 +1779,11 @@ void PPCAIXAsmPrinter::emitFunctionDescriptor() {
}
void PPCAIXAsmPrinter::emitFunctionEntryLabel() {
- PPCAsmPrinter::emitFunctionEntryLabel();
+ // It's not necessary to emit the label when we have individual
+ // function in its own csect.
+ if (!TM.getFunctionSections())
+ PPCAsmPrinter::emitFunctionEntryLabel();
+
// Emit aliasing label for function entry point label.
llvm::for_each(
GOAliasMap[&MF->getFunction()], [this](const GlobalAlias *Alias) {
diff --git a/llvm/test/CodeGen/PowerPC/aix-xcoff-funcsect.ll b/llvm/test/CodeGen/PowerPC/aix-xcoff-funcsect.ll
new file mode 100644
index 000000000000..acc521e02885
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/aix-xcoff-funcsect.ll
@@ -0,0 +1,95 @@
+; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff -mcpu=pwr4 \
+; RUN: -mattr=-altivec -function-sections < %s | \
+; RUN: FileCheck --check-prefix=ASM %s
+; RUN: llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff -mcpu=pwr4 \
+; RUN: -mattr=-altivec -function-sections < %s | \
+; RUN: FileCheck --check-prefix=ASM %s
+
+ at alias_foo = alias void (...), bitcast (void ()* @foo to void (...)*)
+
+define void @foo() {
+entry:
+ ret void
+}
+
+define hidden void @hidden_foo() {
+entry:
+ ret void
+}
+
+define void @bar() {
+entry:
+ call void @foo()
+ call void @static_overalign_foo()
+ call void bitcast (void (...)* @alias_foo to void ()*)()
+ call void bitcast (void (...)* @extern_foo to void ()*)()
+ call void @hidden_foo()
+ ret void
+}
+
+declare void @extern_foo(...)
+
+define internal void @static_overalign_foo() align 64 {
+entry:
+ ret void
+}
+
+; ASM: .csect .foo[PR],2
+; ASM-NEXT: .globl foo[DS] # -- Begin function foo
+; ASM-NEXT: .globl .foo[PR]
+; ASM-NEXT: .align 4
+; ASM-NEXT: .csect foo[DS]
+; ASM-NEXT: alias_foo: # @foo
+; ASM-NEXT: .vbyte {{[0-9]+}}, .foo[PR]
+; ASM-NEXT: .vbyte {{[0-9]+}}, TOC[TC0]
+; ASM-NEXT: .vbyte {{[0-9]+}}, 0
+; ASM-NEXT: .csect .foo[PR],2
+; ASM-NEXT: .alias_foo:
+; ASM-NEXT: # %bb.0: # %entry
+; ASM-NEXT: blr
+; ASM: .csect .hidden_foo[PR],2
+; ASM-NEXT: .globl hidden_foo[DS],hidden # -- Begin function hidden_foo
+; ASM-NEXT: .globl .hidden_foo[PR],hidden
+; ASM-NEXT: .align 4
+; ASM-NEXT: .csect hidden_foo[DS]
+; ASM-NEXT: .vbyte {{[0-9]+}}, .hidden_foo[PR] # @hidden_foo
+; ASM-NEXT: .vbyte {{[0-9]+}}, TOC[TC0]
+; ASM-NEXT: .vbyte {{[0-9]+}}, 0
+; ASM-NEXT: .csect .hidden_foo[PR]
+; ASM-NEXT: # %bb.0: # %entry
+; ASM-NEXT: blr
+; ASM: .csect .bar[PR],2
+; ASM-NEXT: .globl bar[DS] # -- Begin function bar
+; ASM-NEXT: .globl .bar[PR]
+; ASM-NEXT: .align 4
+; ASM-NEXT: .csect bar[DS]
+; ASM-NEXT: .vbyte {{[0-9]+}}, .bar[PR] # @bar
+; ASM-NEXT: .vbyte {{[0-9]+}}, TOC[TC0]
+; ASM-NEXT: .vbyte {{[0-9]+}}, 0
+; ASM-NEXT: .csect .bar[PR],2
+; ASM-NEXT: # %bb.0: # %entry
+; ASM: bl .foo[PR]
+; ASM-NEXT: nop
+; ASM-NEXT: bl .static_overalign_foo[PR]
+; ASM-NEXT: nop
+; ASM-NEXT: bl .alias_foo
+; ASM-NEXT: nop
+; ASM-NEXT: bl .extern_foo
+; ASM-NEXT: nop
+; ASM-NEXT: bl .hidden_foo[PR]
+; ASM-NEXT: nop
+; ASM: .csect .static_overalign_foo[PR],6
+; ASM-NEXT: .lglobl static_overalign_foo[DS] # -- Begin function static_overalign_foo
+; ASM-NEXT: .lglobl .static_overalign_foo[PR]
+; ASM-NEXT: .align 6
+; ASM-NEXT: .csect static_overalign_foo[DS]
+; ASM-NEXT: .vbyte {{[0-9]+}}, .static_overalign_foo[PR] # @static_overalign_foo
+; ASM-NEXT: .vbyte {{[0-9]+}}, TOC[TC0]
+; ASM-NEXT: .vbyte {{[0-9]+}}, 0
+; ASM-NEXT: .csect .static_overalign_foo[PR],6
+; ASM-NEXT: # %bb.0: # %entry
+; ASM-NEXT: blr
+; ASM: .extern .extern_foo
+; ASM-NEXT: .extern extern_foo[DS]
+; ASM-NEXT: .globl alias_foo
+; ASM-NEXT: .globl .alias_foo
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