[llvm] 4b19db6 - Revert "AsmPrinter: Remove ELF's special lowerRelativeReference for unnamed_addr function" (#133935)
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llvm-commits at lists.llvm.org
Tue Apr 1 09:39:10 PDT 2025
Author: Petr Hosek
Date: 2025-04-01T09:39:07-07:00
New Revision: 4b19db6db965d95d7259e224f518c5404a7989ba
URL: https://github.com/llvm/llvm-project/commit/4b19db6db965d95d7259e224f518c5404a7989ba
DIFF: https://github.com/llvm/llvm-project/commit/4b19db6db965d95d7259e224f518c5404a7989ba.diff
LOG: Revert "AsmPrinter: Remove ELF's special lowerRelativeReference for unnamed_addr function" (#133935)
Reverts llvm/llvm-project#132684
Added:
llvm/test/CodeGen/ARM/plt-relative-reloc.ll
llvm/test/CodeGen/RISCV/plt-relative-reloc.ll
llvm/test/CodeGen/X86/x86-64-plt-relative-reloc.ll
llvm/test/CodeGen/X86/x86-plt-relative-reloc.ll
Modified:
llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
Removed:
llvm/test/CodeGen/ARM/relative-reloc.ll
llvm/test/CodeGen/RISCV/relative-reloc.ll
llvm/test/CodeGen/X86/relative-reloc-32.ll
llvm/test/CodeGen/X86/relative-reloc-64.ll
################################################################################
diff --git a/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h b/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
index f035d81e85ddb..8b0e5798d1b61 100644
--- a/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
+++ b/llvm/include/llvm/CodeGen/TargetLoweringObjectFileImpl.h
@@ -125,6 +125,10 @@ class TargetLoweringObjectFileELF : public TargetLoweringObjectFile {
lowerSymbolDifference(const MCSymbol *LHS, const MCSymbol *RHS,
int64_t Addend,
std::optional<int64_t> PCRelativeOffset) const;
+ const MCExpr *lowerRelativeReference(const GlobalValue *LHS,
+ const GlobalValue *RHS, int64_t Addend,
+ std::optional<int64_t> PCRelativeOffset,
+ const TargetMachine &TM) const override;
const MCExpr *lowerDSOLocalEquivalent(const MCSymbol *LHS,
const MCSymbol *RHS, int64_t Addend,
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index c9415292e88f7..4c20c5dc74d9a 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -1233,6 +1233,24 @@ const MCExpr *TargetLoweringObjectFileELF::lowerSymbolDifference(
return Res;
}
+const MCExpr *TargetLoweringObjectFileELF::lowerRelativeReference(
+ const GlobalValue *LHS, const GlobalValue *RHS, int64_t Addend,
+ std::optional<int64_t> PCRelativeOffset, const TargetMachine &TM) const {
+ // We may only use a PLT-relative relocation to refer to unnamed_addr
+ // functions.
+ if (!LHS->hasGlobalUnnamedAddr() || !LHS->getValueType()->isFunctionTy())
+ return nullptr;
+
+ // Basic correctness checks.
+ if (LHS->getType()->getPointerAddressSpace() != 0 ||
+ RHS->getType()->getPointerAddressSpace() != 0 || LHS->isThreadLocal() ||
+ RHS->isThreadLocal())
+ return nullptr;
+
+ return lowerSymbolDifference(TM.getSymbol(LHS), TM.getSymbol(RHS), Addend,
+ PCRelativeOffset);
+}
+
// Reference the PLT entry of a function, optionally with a subtrahend (`RHS`).
const MCExpr *TargetLoweringObjectFileELF::lowerDSOLocalEquivalent(
const MCSymbol *LHS, const MCSymbol *RHS, int64_t Addend,
diff --git a/llvm/test/CodeGen/ARM/relative-reloc.ll b/llvm/test/CodeGen/ARM/plt-relative-reloc.ll
similarity index 78%
rename from llvm/test/CodeGen/ARM/relative-reloc.ll
rename to llvm/test/CodeGen/ARM/plt-relative-reloc.ll
index 65053726e66bf..ede891900e6d0 100644
--- a/llvm/test/CodeGen/ARM/relative-reloc.ll
+++ b/llvm/test/CodeGen/ARM/plt-relative-reloc.ll
@@ -10,8 +10,7 @@ declare void @fn1() unnamed_addr
declare void @fn2() unnamed_addr
declare void @fn3()
-;; Create a PC-relative relocation that the linker might decline if the addend symbol is preemptible.
; CHECK: .long 0
-; CHECK-NEXT: .long fn1-vtable-4
-; CHECK-NEXT: .long fn2-vtable-4
+; CHECK-NEXT: .long fn1(prel31)-vtable-4
+; CHECK-NEXT: .long fn2(prel31)-vtable-4
; CHECK-NEXT: .long fn3-vtable-4
diff --git a/llvm/test/CodeGen/RISCV/relative-reloc.ll b/llvm/test/CodeGen/RISCV/plt-relative-reloc.ll
similarity index 84%
rename from llvm/test/CodeGen/RISCV/relative-reloc.ll
rename to llvm/test/CodeGen/RISCV/plt-relative-reloc.ll
index 6c94b9fce9308..d2dceb773b2e9 100644
--- a/llvm/test/CodeGen/RISCV/relative-reloc.ll
+++ b/llvm/test/CodeGen/RISCV/plt-relative-reloc.ll
@@ -12,11 +12,10 @@ declare void @fn2() unnamed_addr
declare void @fn3()
@global4 = external unnamed_addr global i8
-;; Create a PC-relative relocation that the linker might decline if the addend symbol is preemptible.
; CHECK: vtable:
; CHECK-NEXT: .word 0 # 0x0
-; CHECK-NEXT: .word fn1-vtable-4
-; CHECK-NEXT: .word fn2-vtable-4
+; CHECK-NEXT: .word %pltpcrel(fn1)
+; CHECK-NEXT: .word %pltpcrel(fn2+4)
; CHECK-NEXT: .word fn3-vtable-4
; CHECK-NEXT: .word global4-vtable-4
; CHECK-NEXT: .size vtable, 20
diff --git a/llvm/test/CodeGen/X86/relative-reloc-64.ll b/llvm/test/CodeGen/X86/x86-64-plt-relative-reloc.ll
similarity index 84%
rename from llvm/test/CodeGen/X86/relative-reloc-64.ll
rename to llvm/test/CodeGen/X86/x86-64-plt-relative-reloc.ll
index 6f88edfa075b8..54736c94af248 100644
--- a/llvm/test/CodeGen/X86/relative-reloc-64.ll
+++ b/llvm/test/CodeGen/X86/x86-64-plt-relative-reloc.ll
@@ -12,9 +12,8 @@ declare void @fn2() unnamed_addr
declare void @fn3()
@global4 = external unnamed_addr global i8
-;; Create a PC-relative relocation that the linker might decline if the addend symbol is preemptible.
; CHECK: .long 0
-; CHECK-NEXT: .long fn1-vtable-4
-; CHECK-NEXT: .long fn2-vtable-4
+; CHECK-NEXT: .long fn1 at PLT-vtable-4
+; CHECK-NEXT: .long fn2 at PLT-vtable-4
; CHECK-NEXT: .long fn3-vtable-4
; CHECK-NEXT: .long global4-vtable-4
diff --git a/llvm/test/CodeGen/X86/relative-reloc-32.ll b/llvm/test/CodeGen/X86/x86-plt-relative-reloc.ll
similarity index 89%
rename from llvm/test/CodeGen/X86/relative-reloc-32.ll
rename to llvm/test/CodeGen/X86/x86-plt-relative-reloc.ll
index 7d0b1fd546a00..d5e80285b160d 100644
--- a/llvm/test/CodeGen/X86/relative-reloc-32.ll
+++ b/llvm/test/CodeGen/X86/x86-plt-relative-reloc.ll
@@ -11,6 +11,6 @@ declare void @fn2() unnamed_addr
declare void @fn3()
; CHECK: .long 0
-; CHECK-NEXT: .long fn1-vtable-4
-; CHECK-NEXT: .long fn2-vtable-4
+; CHECK-NEXT: .long fn1 at PLT-vtable-4
+; CHECK-NEXT: .long fn2 at PLT-vtable-4
; CHECK-NEXT: .long fn3-vtable-4
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