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-rw-r--r--llvm/lib/MC/MCExpr.cpp3
-rw-r--r--llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp78
-rw-r--r--llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h9
-rw-r--r--llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h4
-rw-r--r--llvm/test/MC/LoongArch/Misc/subsection.s38
-rw-r--r--llvm/test/MC/LoongArch/Relocations/relax-addsub.s68
6 files changed, 196 insertions, 4 deletions
diff --git a/llvm/lib/MC/MCExpr.cpp b/llvm/lib/MC/MCExpr.cpp
index 73e6569..061f2ad 100644
--- a/llvm/lib/MC/MCExpr.cpp
+++ b/llvm/lib/MC/MCExpr.cpp
@@ -632,7 +632,8 @@ static void AttemptToFoldSymbolOffsetDifference(
// instructions and InSet is false (not expressions in directive like
// .size/.fill), disable the fast path.
if (Layout && (InSet || !SecA.hasInstructions() ||
- !Asm->getContext().getTargetTriple().isRISCV())) {
+ !(Asm->getContext().getTargetTriple().isRISCV() ||
+ Asm->getContext().getTargetTriple().isLoongArch()))) {
// If both symbols are in the same fragment, return the difference of their
// offsets. canGetFragmentOffset(FA) may be false.
if (FA == FB && !SA.isVariable() && !SB.isVariable()) {
diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
index 14bcef7..6d8ef1b 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.cpp
@@ -177,6 +177,34 @@ bool LoongArchAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
}
}
+static inline std::pair<MCFixupKind, MCFixupKind>
+getRelocPairForSize(unsigned Size) {
+ switch (Size) {
+ default:
+ llvm_unreachable("unsupported fixup size");
+ case 6:
+ return std::make_pair(
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD6),
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB6));
+ case 8:
+ return std::make_pair(
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD8),
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB8));
+ case 16:
+ return std::make_pair(
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD16),
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB16));
+ case 32:
+ return std::make_pair(
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD32),
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB32));
+ case 64:
+ return std::make_pair(
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_ADD64),
+ MCFixupKind(FirstLiteralRelocationKind + ELF::R_LARCH_SUB64));
+ }
+}
+
bool LoongArchAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
const MCSubtargetInfo *STI) const {
// We mostly follow binutils' convention here: align to 4-byte boundary with a
@@ -191,6 +219,56 @@ bool LoongArchAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
return true;
}
+bool LoongArchAsmBackend::handleAddSubRelocations(const MCAsmLayout &Layout,
+ const MCFragment &F,
+ const MCFixup &Fixup,
+ const MCValue &Target,
+ uint64_t &FixedValue) const {
+ std::pair<MCFixupKind, MCFixupKind> FK;
+ uint64_t FixedValueA, FixedValueB;
+ const MCSection &SecA = Target.getSymA()->getSymbol().getSection();
+ const MCSection &SecB = Target.getSymB()->getSymbol().getSection();
+
+ // We need record relocation if SecA != SecB. Usually SecB is same as the
+ // section of Fixup, which will be record the relocation as PCRel. If SecB
+ // is not same as the section of Fixup, it will report error. Just return
+ // false and then this work can be finished by handleFixup.
+ if (&SecA != &SecB)
+ return false;
+
+ // In SecA == SecB case. If the linker relaxation is enabled, we need record
+ // the ADD, SUB relocations. Otherwise the FixedValue has already been
+ // calculated out in evaluateFixup, return true and avoid record relocations.
+ if (!STI.hasFeature(LoongArch::FeatureRelax))
+ return true;
+
+ switch (Fixup.getKind()) {
+ case llvm::FK_Data_1:
+ FK = getRelocPairForSize(8);
+ break;
+ case llvm::FK_Data_2:
+ FK = getRelocPairForSize(16);
+ break;
+ case llvm::FK_Data_4:
+ FK = getRelocPairForSize(32);
+ break;
+ case llvm::FK_Data_8:
+ FK = getRelocPairForSize(64);
+ break;
+ default:
+ llvm_unreachable("unsupported fixup size");
+ }
+ MCValue A = MCValue::get(Target.getSymA(), nullptr, Target.getConstant());
+ MCValue B = MCValue::get(Target.getSymB());
+ auto FA = MCFixup::create(Fixup.getOffset(), nullptr, std::get<0>(FK));
+ auto FB = MCFixup::create(Fixup.getOffset(), nullptr, std::get<1>(FK));
+ auto &Asm = Layout.getAssembler();
+ Asm.getWriter().recordRelocation(Asm, Layout, &F, FA, A, FixedValueA);
+ Asm.getWriter().recordRelocation(Asm, Layout, &F, FB, B, FixedValueB);
+ FixedValue = FixedValueA - FixedValueB;
+ return true;
+}
+
std::unique_ptr<MCObjectTargetWriter>
LoongArchAsmBackend::createObjectTargetWriter() const {
return createLoongArchELFObjectWriter(
diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h
index d1fbf78..fef0e84 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h
@@ -31,10 +31,15 @@ class LoongArchAsmBackend : public MCAsmBackend {
public:
LoongArchAsmBackend(const MCSubtargetInfo &STI, uint8_t OSABI, bool Is64Bit,
const MCTargetOptions &Options)
- : MCAsmBackend(llvm::endianness::little), STI(STI), OSABI(OSABI),
- Is64Bit(Is64Bit), TargetOptions(Options) {}
+ : MCAsmBackend(llvm::endianness::little,
+ LoongArch::fixup_loongarch_relax),
+ STI(STI), OSABI(OSABI), Is64Bit(Is64Bit), TargetOptions(Options) {}
~LoongArchAsmBackend() override {}
+ bool handleAddSubRelocations(const MCAsmLayout &Layout, const MCFragment &F,
+ const MCFixup &Fixup, const MCValue &Target,
+ uint64_t &FixedValue) const override;
+
void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
const MCValue &Target, MutableArrayRef<char> Data,
uint64_t Value, bool IsResolved,
diff --git a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h
index ba2d671..178fa6e 100644
--- a/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h
+++ b/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchFixupKinds.h
@@ -106,7 +106,9 @@ enum Fixups {
// 20-bit fixup corresponding to %gd_pc_hi20(foo) for instruction pcalau12i.
fixup_loongarch_tls_gd_pc_hi20,
// 20-bit fixup corresponding to %gd_hi20(foo) for instruction lu12i.w.
- fixup_loongarch_tls_gd_hi20
+ fixup_loongarch_tls_gd_hi20,
+ // Generate an R_LARCH_RELAX which indicates the linker may relax here.
+ fixup_loongarch_relax = FirstLiteralRelocationKind + ELF::R_LARCH_RELAX
};
} // end namespace LoongArch
} // end namespace llvm
diff --git a/llvm/test/MC/LoongArch/Misc/subsection.s b/llvm/test/MC/LoongArch/Misc/subsection.s
new file mode 100644
index 0000000..0bd22b4
--- /dev/null
+++ b/llvm/test/MC/LoongArch/Misc/subsection.s
@@ -0,0 +1,38 @@
+# RUN: not llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax %s -o /dev/null 2>&1 | FileCheck %s --check-prefixes=ERR,NORELAX --implicit-check-not=error:
+## TODO: not llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s -o /dev/null 2>&1 | FileCheck %s --check-prefixes=ERR,RELAX --implicit-check-not=error:
+
+a:
+ nop
+b:
+ la.pcrel $t0, a
+c:
+ nop
+d:
+
+.data
+## Positive subsection numbers
+## With relaxation, report an error as c-b is not an assemble-time constant.
+# RELAX: :[[#@LINE+1]]:14: error: cannot evaluate subsection number
+.subsection c-b
+# RELAX: :[[#@LINE+1]]:14: error: cannot evaluate subsection number
+.subsection d-b
+# RELAX: :[[#@LINE+1]]:14: error: cannot evaluate subsection number
+.subsection c-a
+
+.subsection b-a
+.subsection d-c
+
+## Negative subsection numbers
+# NORELAX: :[[#@LINE+2]]:14: error: subsection number -8 is not within [0,2147483647]
+# RELAX: :[[#@LINE+1]]:14: error: cannot evaluate subsection number
+.subsection b-c
+# NORELAX: :[[#@LINE+2]]:14: error: subsection number -12 is not within [0,2147483647]
+# RELAX: :[[#@LINE+1]]:14: error: cannot evaluate subsection number
+.subsection b-d
+# NORELAX: :[[#@LINE+2]]:14: error: subsection number -12 is not within [0,2147483647]
+# RELAX: :[[#@LINE+1]]:14: error: cannot evaluate subsection number
+.subsection a-c
+# ERR: :[[#@LINE+1]]:14: error: subsection number -4 is not within [0,2147483647]
+.subsection a-b
+# ERR: :[[#@LINE+1]]:14: error: subsection number -4 is not within [0,2147483647]
+.subsection c-d
diff --git a/llvm/test/MC/LoongArch/Relocations/relax-addsub.s b/llvm/test/MC/LoongArch/Relocations/relax-addsub.s
new file mode 100644
index 0000000..532eb4e
--- /dev/null
+++ b/llvm/test/MC/LoongArch/Relocations/relax-addsub.s
@@ -0,0 +1,68 @@
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax %s \
+# RUN: | llvm-readobj -r -x .data - | FileCheck %s --check-prefix=NORELAX
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax %s \
+# RUN: | llvm-readobj -r -x .data - | FileCheck %s --check-prefix=RELAX
+
+# NORELAX: Relocations [
+# NORELAX-NEXT: Section ({{.*}}) .rela.text {
+# NORELAX-NEXT: 0x10 R_LARCH_PCALA_HI20 .text 0x0
+# NORELAX-NEXT: 0x14 R_LARCH_PCALA_LO12 .text 0x0
+# NORELAX-NEXT: }
+# NORELAX-NEXT: ]
+
+# NORELAX: Hex dump of section '.data':
+# NORELAX-NEXT: 0x00000000 04040004 00000004 00000000 0000000c
+# NORELAX-NEXT: 0x00000010 0c000c00 00000c00 00000000 00000808
+# NORELAX-NEXT: 0x00000020 00080000 00080000 00000000 00
+
+# RELAX: Relocations [
+# RELAX-NEXT: Section ({{.*}}) .rela.text {
+# RELAX-NEXT: 0x10 R_LARCH_PCALA_HI20 .L1 0x0
+# RELAX-NEXT: 0x14 R_LARCH_PCALA_LO12 .L1 0x0
+# RELAX-NEXT: }
+# RELAX-NEXT: Section ({{.*}}) .rela.data {
+# RELAX-NEXT: 0xF R_LARCH_ADD8 .L3 0x0
+# RELAX-NEXT: 0xF R_LARCH_SUB8 .L2 0x0
+# RELAX-NEXT: 0x10 R_LARCH_ADD16 .L3 0x0
+# RELAX-NEXT: 0x10 R_LARCH_SUB16 .L2 0x0
+# RELAX-NEXT: 0x12 R_LARCH_ADD32 .L3 0x0
+# RELAX-NEXT: 0x12 R_LARCH_SUB32 .L2 0x0
+# RELAX-NEXT: 0x16 R_LARCH_ADD64 .L3 0x0
+# RELAX-NEXT: 0x16 R_LARCH_SUB64 .L2 0x0
+# RELAX-NEXT: }
+# RELAX-NEXT: ]
+
+# RELAX: Hex dump of section '.data':
+# RELAX-NEXT: 0x00000000 04040004 00000004 00000000 00000000
+# RELAX-NEXT: 0x00000010 00000000 00000000 00000000 00000808
+# RELAX-NEXT: 0x00000020 00080000 00080000 00000000 00
+
+.text
+.L1:
+ nop
+.L2:
+ .align 4
+.L3:
+ la.pcrel $t0, .L1
+.L4:
+ ret
+
+.data
+## Not emit relocs
+.byte .L2 - .L1
+.short .L2 - .L1
+.word .L2 - .L1
+.dword .L2 - .L1
+## With relaxation, emit relocs because of the .align making the diff variable.
+## TODO Handle alignment directive. Why they emit relocs now? They returns
+## without folding symbols offset in AttemptToFoldSymbolOffsetDifference().
+.byte .L3 - .L2
+.short .L3 - .L2
+.word .L3 - .L2
+.dword .L3 - .L2
+## TODO
+## With relaxation, emit relocs because la.pcrel is a linker-relaxable inst.
+.byte .L4 - .L3
+.short .L4 - .L3
+.word .L4 - .L3
+.dword .L4 - .L3
generated by cgit v1.1 at 2025-10-17 10:42:19 +0000