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[X86,MC] Add relocation R_X86_64_REX2_GOTPCRELX #106681

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Merged
merged 8 commits into from
Sep 24, 2024
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[X86,MC] Add relocation R_X86_64_REX2_GOTPCRELX #106681

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88cbdf9
[X86,lld] Add relocation R_X86_64_REX2_GOTPCRELX
KanRobert Jun 25, 2024
7329181
add more test
KanRobert Aug 30, 2024
44b828a
clang-format
KanRobert Aug 30, 2024
6e981a0
add more test
KanRobert Aug 30, 2024
338a565
disable clang-format
KanRobert Aug 30, 2024
4bf2ab0
Make test x86-64-gotpc-relax.s pass
KanRobert Sep 1, 2024
62a5da2
Make test x86-64-gotpc-relax-nopic.s pass
KanRobert Sep 1, 2024
42e150f
Revert lld change
KanRobert Sep 24, 2024
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2 changes: 2 additions & 0 deletions clang/test/Driver/relax.s
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Expand Up @@ -8,5 +8,7 @@
// RUN: llvm-readobj -r %t | FileCheck --check-prefix=REL %s

// REL: R_X86_64_REX_GOTPCRELX foo
// REL: R_X86_64_REX2_GOTPCRELX foo

movq foo@GOTPCREL(%rip), %rax
movq foo@GOTPCREL(%rip), %r16
1 change: 1 addition & 0 deletions llvm/include/llvm/BinaryFormat/ELFRelocs/x86_64.def
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Expand Up @@ -43,3 +43,4 @@ ELF_RELOC(R_X86_64_TLSDESC, 36)
ELF_RELOC(R_X86_64_IRELATIVE, 37)
ELF_RELOC(R_X86_64_GOTPCRELX, 41)
ELF_RELOC(R_X86_64_REX_GOTPCRELX, 42)
ELF_RELOC(R_X86_64_REX2_GOTPCRELX, 43)
4 changes: 2 additions & 2 deletions llvm/lib/MC/MCTargetOptionsCommandFlags.cpp
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Expand Up @@ -145,8 +145,8 @@ llvm::mc::RegisterMCTargetOptionsFlags::RegisterMCTargetOptionsFlags() {

static cl::opt<bool> X86RelaxRelocations(
"x86-relax-relocations",
cl::desc(
"Emit GOTPCRELX/REX_GOTPCRELX instead of GOTPCREL on x86-64 ELF"),
cl::desc("Emit GOTPCRELX/REX_GOTPCRELX/REX2_GOTPCRELX instead of "
"GOTPCREL on x86-64 ELF"),
cl::init(true));
MCBINDOPT(X86RelaxRelocations);

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6 changes: 6 additions & 0 deletions llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
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Expand Up @@ -629,15 +629,19 @@ std::optional<MCFixupKind> X86AsmBackend::getFixupKind(StringRef Name) const {

const MCFixupKindInfo &X86AsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
const static MCFixupKindInfo Infos[X86::NumTargetFixupKinds] = {
// clang-format off
{"reloc_riprel_4byte", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
{"reloc_riprel_4byte_movq_load", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
{"reloc_riprel_4byte_movq_load_rex2", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
{"reloc_riprel_4byte_relax", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
{"reloc_riprel_4byte_relax_rex", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
{"reloc_riprel_4byte_relax_rex2", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
{"reloc_signed_4byte", 0, 32, 0},
{"reloc_signed_4byte_relax", 0, 32, 0},
{"reloc_global_offset_table", 0, 32, 0},
{"reloc_global_offset_table8", 0, 64, 0},
{"reloc_branch_4byte_pcrel", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
// clang-format on
};

// Fixup kinds from .reloc directive are like R_386_NONE/R_X86_64_NONE. They
Expand Down Expand Up @@ -678,7 +682,9 @@ static unsigned getFixupKindSize(unsigned Kind) {
case X86::reloc_riprel_4byte:
case X86::reloc_riprel_4byte_relax:
case X86::reloc_riprel_4byte_relax_rex:
case X86::reloc_riprel_4byte_relax_rex2:
case X86::reloc_riprel_4byte_movq_load:
case X86::reloc_riprel_4byte_movq_load_rex2:
case X86::reloc_signed_4byte:
case X86::reloc_signed_4byte_relax:
case X86::reloc_global_offset_table:
Expand Down
7 changes: 6 additions & 1 deletion llvm/lib/Target/X86/MCTargetDesc/X86ELFObjectWriter.cpp
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Expand Up @@ -74,7 +74,9 @@ static X86_64RelType getType64(MCFixupKind Kind,
case X86::reloc_riprel_4byte:
case X86::reloc_riprel_4byte_relax:
case X86::reloc_riprel_4byte_relax_rex:
case X86::reloc_riprel_4byte_relax_rex2:
case X86::reloc_riprel_4byte_movq_load:
case X86::reloc_riprel_4byte_movq_load_rex2:
return RT64_32;
case X86::reloc_branch_4byte_pcrel:
Modifier = MCSymbolRefExpr::VK_PLT;
Expand Down Expand Up @@ -205,7 +207,7 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
case MCSymbolRefExpr::VK_GOTPCREL:
checkIs32(Ctx, Loc, Type);
// Older versions of ld.bfd/ld.gold/lld
// do not support GOTPCRELX/REX_GOTPCRELX,
// do not support GOTPCRELX/REX_GOTPCRELX/REX2_GOTPCRELX,
// and we want to keep back-compatibility.
if (!Ctx.getTargetOptions()->X86RelaxRelocations)
return ELF::R_X86_64_GOTPCREL;
Expand All @@ -217,6 +219,9 @@ static unsigned getRelocType64(MCContext &Ctx, SMLoc Loc,
case X86::reloc_riprel_4byte_relax_rex:
case X86::reloc_riprel_4byte_movq_load:
return ELF::R_X86_64_REX_GOTPCRELX;
case X86::reloc_riprel_4byte_relax_rex2:
case X86::reloc_riprel_4byte_movq_load_rex2:
return ELF::R_X86_64_REX2_GOTPCRELX;
}
llvm_unreachable("unexpected relocation type!");
case MCSymbolRefExpr::VK_GOTPCREL_NORELAX:
Expand Down
4 changes: 4 additions & 0 deletions llvm/lib/Target/X86/MCTargetDesc/X86FixupKinds.h
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Expand Up @@ -16,10 +16,14 @@ namespace X86 {
enum Fixups {
reloc_riprel_4byte = FirstTargetFixupKind, // 32-bit rip-relative
reloc_riprel_4byte_movq_load, // 32-bit rip-relative in movq
reloc_riprel_4byte_movq_load_rex2, // 32-bit rip-relative in movq
// with rex2 prefix
reloc_riprel_4byte_relax, // 32-bit rip-relative in relaxable
// instruction
reloc_riprel_4byte_relax_rex, // 32-bit rip-relative in relaxable
// instruction with rex prefix
reloc_riprel_4byte_relax_rex2, // 32-bit rip-relative in relaxable
// instruction with rex2 prefix
reloc_signed_4byte, // 32-bit signed. Unlike FK_Data_4
// this will be sign extended at
// runtime.
Expand Down
19 changes: 9 additions & 10 deletions llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
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Expand Up @@ -568,8 +568,10 @@ void X86MCCodeEmitter::emitImmediate(const MCOperand &DispOp, SMLoc Loc,
if (FixupKind == FK_PCRel_4 ||
FixupKind == MCFixupKind(X86::reloc_riprel_4byte) ||
FixupKind == MCFixupKind(X86::reloc_riprel_4byte_movq_load) ||
FixupKind == MCFixupKind(X86::reloc_riprel_4byte_movq_load_rex2) ||
FixupKind == MCFixupKind(X86::reloc_riprel_4byte_relax) ||
FixupKind == MCFixupKind(X86::reloc_riprel_4byte_relax_rex) ||
FixupKind == MCFixupKind(X86::reloc_riprel_4byte_relax_rex2) ||
FixupKind == MCFixupKind(X86::reloc_branch_4byte_pcrel)) {
ImmOffset -= 4;
// If this is a pc-relative load off _GLOBAL_OFFSET_TABLE_:
Expand Down Expand Up @@ -637,12 +639,11 @@ void X86MCCodeEmitter::emitMemModRMByte(
default:
return X86::reloc_riprel_4byte;
case X86::MOV64rm:
// movq loads is a subset of reloc_riprel_4byte_relax_rex. It is a
// movq loads is a subset of reloc_riprel_4byte_relax_rex/rex2. It is a
// special case because COFF and Mach-O don't support ELF's more
// flexible R_X86_64_REX_GOTPCRELX relaxation.
// TODO: Support new relocation for REX2.
assert(Kind == REX || Kind == REX2);
return X86::reloc_riprel_4byte_movq_load;
// flexible R_X86_64_REX_GOTPCRELX/R_X86_64_REX2_GOTPCRELX relaxation.
return Kind == REX2 ? X86::reloc_riprel_4byte_movq_load_rex2
: X86::reloc_riprel_4byte_movq_load;
case X86::ADC32rm:
case X86::ADD32rm:
case X86::AND32rm:
Expand All @@ -665,11 +666,9 @@ void X86MCCodeEmitter::emitMemModRMByte(
case X86::SBB64rm:
case X86::SUB64rm:
case X86::XOR64rm:
// We haven't support relocation for REX2 prefix, so temporarily use REX
// relocation.
// TODO: Support new relocation for REX2.
return (Kind == REX || Kind == REX2) ? X86::reloc_riprel_4byte_relax_rex
: X86::reloc_riprel_4byte_relax;
return Kind == REX2 ? X86::reloc_riprel_4byte_relax_rex2
: Kind == REX ? X86::reloc_riprel_4byte_relax_rex
: X86::reloc_riprel_4byte_relax;
}
}();

Expand Down
6 changes: 5 additions & 1 deletion llvm/lib/Target/X86/MCTargetDesc/X86MachObjectWriter.cpp
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Expand Up @@ -66,8 +66,10 @@ class X86MachObjectWriter : public MCMachObjectTargetWriter {
static bool isFixupKindRIPRel(unsigned Kind) {
return Kind == X86::reloc_riprel_4byte ||
Kind == X86::reloc_riprel_4byte_movq_load ||
Kind == X86::reloc_riprel_4byte_movq_load_rex2 ||
Kind == X86::reloc_riprel_4byte_relax ||
Kind == X86::reloc_riprel_4byte_relax_rex;
Kind == X86::reloc_riprel_4byte_relax_rex ||
Kind == X86::reloc_riprel_4byte_relax_rex2;
}

static unsigned getFixupKindLog2Size(unsigned Kind) {
Expand All @@ -83,7 +85,9 @@ static unsigned getFixupKindLog2Size(unsigned Kind) {
case X86::reloc_riprel_4byte:
case X86::reloc_riprel_4byte_relax:
case X86::reloc_riprel_4byte_relax_rex:
case X86::reloc_riprel_4byte_relax_rex2:
case X86::reloc_riprel_4byte_movq_load:
case X86::reloc_riprel_4byte_movq_load_rex2:
case X86::reloc_signed_4byte:
case X86::reloc_signed_4byte_relax:
case X86::reloc_branch_4byte_pcrel:
Expand Down
2 changes: 2 additions & 0 deletions llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
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Expand Up @@ -66,8 +66,10 @@ unsigned X86WinCOFFObjectWriter::getRelocType(MCContext &Ctx,
case FK_PCRel_4:
case X86::reloc_riprel_4byte:
case X86::reloc_riprel_4byte_movq_load:
case X86::reloc_riprel_4byte_movq_load_rex2:
case X86::reloc_riprel_4byte_relax:
case X86::reloc_riprel_4byte_relax_rex:
case X86::reloc_riprel_4byte_relax_rex2:
case X86::reloc_branch_4byte_pcrel:
return COFF::IMAGE_REL_AMD64_REL32;
case FK_Data_4:
Expand Down
3 changes: 3 additions & 0 deletions llvm/test/MC/ELF/relocation-alias.s
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Expand Up @@ -16,7 +16,10 @@ movabsq $memcpy+2, %rax

# CHECK: movq (%rip), %rax
# CHECK-NEXT: R_X86_64_REX_GOTPCRELX abs-0x4
# CHECK: movq (%rip), %r16
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX abs-0x4
movq abs@GOTPCREL(%rip), %rax
movq abs@GOTPCREL(%rip), %r16
abs = 42

# CHECK: movabsq $0, %rbx
Expand Down
34 changes: 34 additions & 0 deletions llvm/test/MC/X86/gotpcrelx.s
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Expand Up @@ -37,6 +37,16 @@
# CHECK-NEXT: R_X86_64_REX_GOTPCRELX sbb
# CHECK-NEXT: R_X86_64_REX_GOTPCRELX sub
# CHECK-NEXT: R_X86_64_REX_GOTPCRELX xor
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX mov
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX test
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX adc
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX add
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX and
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX cmp
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX or
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX sbb
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX sub
# CHECK-NEXT: R_X86_64_REX2_GOTPCRELX xor
# CHECK-NEXT: }

# NORELAX-NEXT: R_X86_64_GOTPCREL mov
Expand Down Expand Up @@ -71,6 +81,16 @@
# NORELAX-NEXT: R_X86_64_GOTPCREL sbb
# NORELAX-NEXT: R_X86_64_GOTPCREL sub
# NORELAX-NEXT: R_X86_64_GOTPCREL xor
# NORELAX-NEXT: R_X86_64_GOTPCREL mov
# NORELAX-NEXT: R_X86_64_GOTPCREL test
# NORELAX-NEXT: R_X86_64_GOTPCREL adc
# NORELAX-NEXT: R_X86_64_GOTPCREL add
# NORELAX-NEXT: R_X86_64_GOTPCREL and
# NORELAX-NEXT: R_X86_64_GOTPCREL cmp
# NORELAX-NEXT: R_X86_64_GOTPCREL or
# NORELAX-NEXT: R_X86_64_GOTPCREL sbb
# NORELAX-NEXT: R_X86_64_GOTPCREL sub
# NORELAX-NEXT: R_X86_64_GOTPCREL xor
# NORELAX-NEXT: }

movl mov@GOTPCREL(%rip), %eax
Expand Down Expand Up @@ -108,10 +128,22 @@ sbb sbb@GOTPCREL(%rip), %rax
sub sub@GOTPCREL(%rip), %rax
xor xor@GOTPCREL(%rip), %rax

movq mov@GOTPCREL(%rip), %r16
test %r16, test@GOTPCREL(%rip)
adc adc@GOTPCREL(%rip), %r16
add add@GOTPCREL(%rip), %r16
and and@GOTPCREL(%rip), %r16
cmp cmp@GOTPCREL(%rip), %r16
or or@GOTPCREL(%rip), %r16
sbb sbb@GOTPCREL(%rip), %r16
sub sub@GOTPCREL(%rip), %r16
xor xor@GOTPCREL(%rip), %r16

# COMMON-NEXT: Section ({{.*}}) .rela.norelax {
# COMMON-NEXT: R_X86_64_GOTPCREL mov 0x0
# COMMON-NEXT: R_X86_64_GOTPCREL mov 0xFFFFFFFFFFFFFFFD
# COMMON-NEXT: R_X86_64_GOTPCREL mov 0xFFFFFFFFFFFFFFFC
# COMMON-NEXT: R_X86_64_GOTPCREL mov 0xFFFFFFFFFFFFFFFD
# COMMON-NEXT: }
# COMMON-NEXT: ]

Expand All @@ -123,3 +155,5 @@ movl mov@GOTPCREL+4(%rip), %eax
movq mov@GOTPCREL+1(%rip), %rax
## We could emit R_X86_64_GOTPCRELX, but it is probably unnecessary.
movl mov@GOTPCREL+0(%rip), %eax
## Don't emit R_X86_64_GOTPCRELX.
movq mov@GOTPCREL+1(%rip), %r16
3 changes: 3 additions & 0 deletions llvm/test/MC/X86/reloc-directive-elf-64.s
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Expand Up @@ -9,6 +9,7 @@
# PRINT-NEXT: .reloc 0, R_X86_64_64, .data+2
# PRINT-NEXT: .reloc 0, R_X86_64_GOTPCRELX, foo+3
# PRINT-NEXT: .reloc 0, R_X86_64_REX_GOTPCRELX, 5
# PRINT-NEXT: .reloc 0, R_X86_64_REX2_GOTPCRELX, 7
# PRINT: .reloc 0, BFD_RELOC_NONE, 9
# PRINT-NEXT: .reloc 0, BFD_RELOC_8, 9
# PRINT-NEXT: .reloc 0, BFD_RELOC_16, 9
Expand All @@ -21,6 +22,7 @@
# CHECK-NEXT: 0x0 R_X86_64_64 .data 0x2
# CHECK-NEXT: 0x0 R_X86_64_GOTPCRELX foo 0x3
# CHECK-NEXT: 0x0 R_X86_64_REX_GOTPCRELX - 0x5
# CHECK-NEXT: 0x0 R_X86_64_REX2_GOTPCRELX - 0x7
# CHECK-NEXT: 0x0 R_X86_64_NONE - 0x9
# CHECK-NEXT: 0x0 R_X86_64_8 - 0x9
# CHECK-NEXT: 0x0 R_X86_64_16 - 0x9
Expand All @@ -37,6 +39,7 @@
.reloc 0, R_X86_64_64, .data+2
.reloc 0, R_X86_64_GOTPCRELX, foo+3
.reloc 0, R_X86_64_REX_GOTPCRELX, 5
.reloc 0, R_X86_64_REX2_GOTPCRELX, 7

.reloc 0, BFD_RELOC_NONE, 9
.reloc 0, BFD_RELOC_8, 9
Expand Down