[llvm] [SystemZ][zOS] Override emitGlobalAlias for ADA (PR #84829)
Yusra Syeda via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 13 14:02:48 PDT 2024
https://github.com/ysyeda updated https://github.com/llvm/llvm-project/pull/84829
>From 8418f1498540cf106f1cfefaa7d22f80fba2e329 Mon Sep 17 00:00:00 2001
From: Yusra Syeda <yusra.syeda at ibm.com>
Date: Mon, 11 Mar 2024 16:13:32 -0400
Subject: [PATCH 1/3] update indirect handling
---
llvm/include/llvm/CodeGen/AsmPrinter.h | 4 +-
llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp | 49 ++++++++++++++++---
llvm/lib/Target/SystemZ/SystemZAsmPrinter.h | 1 +
.../CodeGen/SystemZ/zos-ada-relocations.ll | 4 +-
4 files changed, 46 insertions(+), 12 deletions(-)
diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
index a7fbf4aeb74494..857a39a6b71ce6 100644
--- a/llvm/include/llvm/CodeGen/AsmPrinter.h
+++ b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -897,12 +897,14 @@ class AsmPrinter : public MachineFunctionPass {
virtual void emitModuleCommandLines(Module &M);
GCMetadataPrinter *getOrCreateGCPrinter(GCStrategy &S);
+
+protected:
virtual void emitGlobalAlias(const Module &M, const GlobalAlias &GA);
- void emitGlobalIFunc(Module &M, const GlobalIFunc &GI);
private:
/// This method decides whether the specified basic block requires a label.
bool shouldEmitLabelForBasicBlock(const MachineBasicBlock &MBB) const;
+ void emitGlobalIFunc(Module &M, const GlobalIFunc &GI);
protected:
virtual bool shouldEmitWeakSwiftAsyncExtendedFramePointerFlags() const {
diff --git a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
index 5696ae117d69f0..b69dfad5227dc9 100644
--- a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
@@ -26,6 +26,7 @@
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbolGOFF.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/Chrono.h"
#include "llvm/Support/ConvertEBCDIC.h"
@@ -1026,17 +1027,15 @@ void SystemZAsmPrinter::emitADASection() {
EmittedBytes += PointerSize;
break;
case SystemZII::MO_ADA_INDIRECT_FUNC_DESC: {
- MCSymbol *Alias = OutContext.createTempSymbol(
- Twine(Sym->getName()).concat("@indirect"));
- OutStreamer->emitAssignment(Alias,
- MCSymbolRefExpr::create(Sym, OutContext));
- OutStreamer->emitSymbolAttribute(Alias, MCSA_IndirectSymbol);
+ MCSymbolGOFF *IndirectSym =
+ static_cast<MCSymbolGOFF *>(OutContext.getOrCreateSymbol(
+ Twine(Sym->getName()).concat("@indirect")));
EMIT_COMMENT("pointer to function descriptor");
OutStreamer->emitValue(
- SystemZMCExpr::create(SystemZMCExpr::VK_SystemZ_VCon,
- MCSymbolRefExpr::create(Alias, OutContext),
- OutContext),
+ SystemZMCExpr::create(
+ SystemZMCExpr::VK_SystemZ_VCon,
+ MCSymbolRefExpr::create(IndirectSym, OutContext), OutContext),
PointerSize);
EmittedBytes += PointerSize;
break;
@@ -1541,6 +1540,40 @@ void SystemZAsmPrinter::emitPPA2(Module &M) {
OutStreamer->popSection();
}
+void SystemZAsmPrinter::emitGlobalAlias(const Module &M,
+ const GlobalAlias &GA) {
+ if (!TM.getTargetTriple().isOSzOS()) {
+ AsmPrinter::emitGlobalAlias(M, GA);
+ return;
+ }
+
+ MCSymbol *Name = getSymbol(&GA);
+ bool IsFunc = isa<Function>(GA.getAliasee()->stripPointerCasts());
+
+ if (GA.hasExternalLinkage() || !MAI->getWeakRefDirective())
+ OutStreamer->emitSymbolAttribute(Name, MCSA_Global);
+ else if (GA.hasWeakLinkage() || GA.hasLinkOnceLinkage())
+ OutStreamer->emitSymbolAttribute(Name, MCSA_WeakReference);
+ else
+ assert(GA.hasLocalLinkage() && "Invalid alias linkage");
+
+ emitVisibility(Name, GA.getVisibility());
+
+ const MCExpr *Expr;
+
+ // For XPLINK, create a VCON relocation in case of a function, and
+ // a direct reference else.
+ MCSymbol *Sym = getSymbol(GA.getAliaseeObject());
+ if (IsFunc)
+ Expr = SystemZMCExpr::create(SystemZMCExpr::VK_SystemZ_VCon,
+ MCSymbolRefExpr::create(Sym, OutContext),
+ OutContext);
+
+ else
+ Expr = MCSymbolRefExpr::create(Sym, OutContext);
+ OutStreamer->emitAssignment(Name, Expr);
+}
+
void SystemZAsmPrinter::emitFunctionEntryLabel() {
const SystemZSubtarget &Subtarget = MF->getSubtarget<SystemZSubtarget>();
diff --git a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.h b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.h
index 303cce1a1b6581..4d9605725321cd 100644
--- a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.h
+++ b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.h
@@ -118,6 +118,7 @@ class LLVM_LIBRARY_VISIBILITY SystemZAsmPrinter : public AsmPrinter {
void emitFunctionEntryLabel() override;
void emitFunctionBodyEnd() override;
void emitStartOfAsmFile(Module &M) override;
+ void emitGlobalAlias(const Module &M, const GlobalAlias &GA) override;
private:
void emitCallInformation(CallType CT);
diff --git a/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll b/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll
index e25246917ec099..6bdd42a9bd0a58 100644
--- a/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll
+++ b/llvm/test/CodeGen/SystemZ/zos-ada-relocations.ll
@@ -56,9 +56,7 @@ entry:
declare signext i32 @callout(i32 signext)
; CHECK: .section ".ada"
-; CHECK: .set @@DoFunc at indirect0, DoFunc
-; CHECK: .indirect_symbol @@DoFunc at indirect0
-; CHECK: .quad V(@@DoFunc at indirect0) * Offset 0 pointer to function descriptor DoFunc
+; CHECK: .quad V(DoFunc at indirect) * Offset 0 pointer to function descriptor DoFunc
; CHECK: .quad R(Caller) * Offset 8 function descriptor of Caller
; CHECK: .quad V(Caller)
; CHECK: .quad A(i2) * Offset 24 pointer to data symbol i2
>From e1da0442117ce961b380fc3b1c09bf9f91b11a19 Mon Sep 17 00:00:00 2001
From: Yusra Syeda <yusra.syeda at ibm.com>
Date: Tue, 12 Mar 2024 16:45:52 -0400
Subject: [PATCH 2/3] add set/getAliasName & set/getIndirect functions to
MCSymbolGOFF
---
llvm/include/llvm/MC/MCSymbolGOFF.h | 18 +++++++++++++++++-
llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp | 3 +++
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/llvm/include/llvm/MC/MCSymbolGOFF.h b/llvm/include/llvm/MC/MCSymbolGOFF.h
index cc4e2bbe246e2d..2ebb78c97df1da 100644
--- a/llvm/include/llvm/MC/MCSymbolGOFF.h
+++ b/llvm/include/llvm/MC/MCSymbolGOFF.h
@@ -18,10 +18,26 @@
namespace llvm {
class MCSymbolGOFF : public MCSymbol {
+ mutable StringRef AliasName; // ADA indirect
+
+ enum SymbolFlags : uint16_t {
+ SF_Alias = 0x02, // Symbol is alias.
+ SF_Indirect = 0x200, // Symbol referenced indirectly.
+ };
+
public:
MCSymbolGOFF(const StringMapEntry<bool> *Name, bool IsTemporary)
- : MCSymbol(SymbolKindGOFF, Name, IsTemporary) {}
+ : MCSymbol(SymbolKindGOFF, Name, IsTemporary), AliasName() {}
static bool classof(const MCSymbol *S) { return S->isGOFF(); }
+
+ bool hasAliasName() const { return !AliasName.empty(); }
+ void setAliasName(StringRef Name) { AliasName = Name; }
+ StringRef getAliasName() const { return AliasName; }
+
+ void setIndirect(bool Value = true) {
+ modifyFlags(Value ? SF_Indirect : 0, SF_Indirect);
+ }
+ bool isIndirect() const { return getFlags() & SF_Indirect; }
};
} // end namespace llvm
diff --git a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
index b69dfad5227dc9..171aea7808a387 100644
--- a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
@@ -1030,6 +1030,9 @@ void SystemZAsmPrinter::emitADASection() {
MCSymbolGOFF *IndirectSym =
static_cast<MCSymbolGOFF *>(OutContext.getOrCreateSymbol(
Twine(Sym->getName()).concat("@indirect")));
+ IndirectSym->setExternal(Sym->isExternal());
+ IndirectSym->setAliasName(Sym->getName());
+ IndirectSym->setIndirect(true);
EMIT_COMMENT("pointer to function descriptor");
OutStreamer->emitValue(
>From 53d03a490b1f8b7c2a6aa77c79fb50a36896e31e Mon Sep 17 00:00:00 2001
From: Yusra Syeda <yusra.syeda at ibm.com>
Date: Wed, 13 Mar 2024 17:02:08 -0400
Subject: [PATCH 3/3] add test case for global alias
---
.../CodeGen/SystemZ/zos-ada-globalalias.ll | 35 +++++++++++++++++++
1 file changed, 35 insertions(+)
create mode 100644 llvm/test/CodeGen/SystemZ/zos-ada-globalalias.ll
diff --git a/llvm/test/CodeGen/SystemZ/zos-ada-globalalias.ll b/llvm/test/CodeGen/SystemZ/zos-ada-globalalias.ll
new file mode 100644
index 00000000000000..afb3cd2a76b5c7
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/zos-ada-globalalias.ll
@@ -0,0 +1,35 @@
+; RUN: llc -mtriple s390x-ibm-zos < %s | FileCheck %s
+
+; C test case:
+; typedef void (*voidfunc)();
+; void func(){}
+; voidfunc ptr = &func;
+
+; CHECK: ptr:
+; CHECK: .quad func
+
+ at ptr = hidden global void (...)* bitcast (void ()* @func to void (...)*), align 8
+
+define hidden void @func() {
+entry:
+ ret void
+}
+
+; C test case for global alias
+; void __f() {}
+; void f() __attribute__ ((alias ("__f")));
+; void (*fp)() = &f;
+
+; CHECK: .quad f
+
+; CHECK: .globl f
+; CHECK: .hidden f
+; CHECK: .set f, V(__f)
+
+ at fp = hidden global void (...)* @f, align 8
+ at f = hidden alias void (...), bitcast (void ()* @__f to void (...)*)
+
+define hidden void @__f() #0 {
+entry:
+ ret void
+}
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