Skip to content

[lld][LoongArch] Relax TLSDESC code sequence #123677

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
ylzsx merged 2 commits into from
Mar 31, 2025
Merged

[lld][LoongArch] Relax TLSDESC code sequence #123677

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9d29d9b
Relax TLSDESC code sequence.
ylzsx Dec 31, 2024
49f1b5c
fix typo error
ylzsx Mar 20, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 17 additions & 2 deletions lld/ELF/Arch/LoongArch.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -766,9 +766,12 @@ static bool isPairRelaxable(ArrayRef<Relocation> relocs, size_t i) {
// Relax code sequence.
// From:
// pcalau12i $a0, %pc_hi20(sym) | %ld_pc_hi20(sym) | %gd_pc_hi20(sym)
// | %desc_pc_hi20(sym)
// addi.w/d $a0, $a0, %pc_lo12(sym) | %got_pc_lo12(sym) | %got_pc_lo12(sym)
// | %desc_pc_lo12(sym)
// To:
// pcaddi $a0, %pc_lo12(sym) | %got_pc_lo12(sym) | %got_pc_lo12(sym)
// pcaddi $a0, %pc_lo12(sym) | %got_pc_lo12(sym) | %got_pc_lo12(sym)
// | %desc_pcrel_20(sym)
//
// From:
// pcalau12i $a0, %got_pc_hi20(sym_got)
Expand All @@ -786,7 +789,9 @@ static void relaxPCHi20Lo12(Ctx &ctx, const InputSection &sec, size_t i,
(rHi20.type == R_LARCH_TLS_GD_PC_HI20 &&
rLo12.type == R_LARCH_GOT_PC_LO12) ||
(rHi20.type == R_LARCH_TLS_LD_PC_HI20 &&
rLo12.type == R_LARCH_GOT_PC_LO12)))
rLo12.type == R_LARCH_GOT_PC_LO12) ||
(rHi20.type == R_LARCH_TLS_DESC_PC_HI20 &&
rLo12.type == R_LARCH_TLS_DESC_PC_LO12)))
return;

// GOT references to absolute symbols can't be relaxed to use pcaddi in
Expand All @@ -808,6 +813,8 @@ static void relaxPCHi20Lo12(Ctx &ctx, const InputSection &sec, size_t i,
dest = rHi20.sym->getVA(ctx);
else if (rHi20.expr == RE_LOONGARCH_TLSGD_PAGE_PC)
dest = ctx.in.got->getGlobalDynAddr(*rHi20.sym);
else if (rHi20.expr == RE_LOONGARCH_TLSDESC_PAGE_PC)
dest = ctx.in.got->getTlsDescAddr(*rHi20.sym);
else {
Err(ctx) << getErrorLoc(ctx, (const uint8_t *)loc) << "unknown expr ("
<< rHi20.expr << ") against symbol " << rHi20.sym
Expand Down Expand Up @@ -841,6 +848,8 @@ static void relaxPCHi20Lo12(Ctx &ctx, const InputSection &sec, size_t i,
sec.relaxAux->relocTypes[i + 2] = R_LARCH_TLS_GD_PCREL20_S2;
else if (rHi20.type == R_LARCH_TLS_LD_PC_HI20)
sec.relaxAux->relocTypes[i + 2] = R_LARCH_TLS_LD_PCREL20_S2;
else if (rHi20.type == R_LARCH_TLS_DESC_PC_HI20)
sec.relaxAux->relocTypes[i + 2] = R_LARCH_TLS_DESC_PCREL20_S2;
else
sec.relaxAux->relocTypes[i + 2] = R_LARCH_PCREL20_S2;
sec.relaxAux->writes.push_back(insn(PCADDI, getD5(nextInsn), 0, 0));
Expand Down Expand Up @@ -947,6 +956,7 @@ static bool relax(Ctx &ctx, InputSection &sec) {
case R_LARCH_GOT_PC_HI20:
case R_LARCH_TLS_GD_PC_HI20:
case R_LARCH_TLS_LD_PC_HI20:
case R_LARCH_TLS_DESC_PC_HI20:
// The overflow check for i+2 will be carried out in isPairRelaxable.
if (isPairRelaxable(relocs, i))
relaxPCHi20Lo12(ctx, sec, i, loc, r, relocs[i + 2], remove);
Expand Down Expand Up @@ -1081,6 +1091,11 @@ void LoongArch::finalizeRelax(int passes) const {
write32le(p, aux.writes[writesIdx++]);
r.expr = R_TLSGD_PC;
break;
case R_LARCH_TLS_DESC_PCREL20_S2:
skip = 4;
write32le(p, aux.writes[writesIdx++]);
r.expr = R_TLSDESC_PC;
break;
default:
llvm_unreachable("unsupported type");
}
Expand Down
280 changes: 280 additions & 0 deletions lld/test/ELF/loongarch-relax-tlsdesc.s
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,280 @@
# REQUIRES: loongarch
# RUN: rm -rf %t && split-file %s %t && cd %t
# RUN: llvm-mc -filetype=obj -triple=loongarch64 -mattr=+relax a.s -o a.64.o
# RUN: llvm-mc -filetype=obj -triple=loongarch64 -mattr=+relax c.s -o c.64.o
# RUN: ld.lld --relax -shared -soname=c.64.so c.64.o -o c.64.so

## Test the TLSDESC relaxation.
# RUN: ld.lld --relax -shared -z now a.64.o c.64.o -o a.64.so
# RUN: llvm-readobj -r -x .got a.64.so | FileCheck --check-prefix=GD64-RELA %s
# RUN: llvm-objdump --no-show-raw-insn -dr -h a.64.so | FileCheck %s --check-prefix=GD64

## FIXME: The transition frome TLSDESC to IE/LE has not yet been implemented.
## Keep the dynamic relocations and hand them over to dynamic linker.

# RUN: ld.lld --relax -e 0 -z now a.64.o c.64.o -o a.64.le
# RUN: llvm-readobj -r -x .got a.64.le | FileCheck --check-prefix=LE64-RELA %s
# RUN: llvm-objdump --no-show-raw-insn -d -h a.64.le | FileCheck %s --check-prefix=LE64

# RUN: ld.lld --no-relax -e 0 -z now a.64.o c.64.o -o a.64.le.norelax
# RUN: llvm-objdump --no-show-raw-insn -d -h a.64.le.norelax | FileCheck %s --check-prefix=LE64-NORELAX

# RUN: ld.lld --relax -e 0 -z now a.64.o c.64.so -o a.64.ie
# RUN: llvm-readobj -r -x .got a.64.ie | FileCheck --check-prefix=IE64-RELA %s
# RUN: llvm-objdump --no-show-raw-insn -d -h a.64.ie | FileCheck %s --check-prefix=IE64

# RUN: ld.lld --no-relax -e 0 -z now a.64.o c.64.so -o a.64.ie.norelax
# RUN: llvm-objdump --no-show-raw-insn -d -h a.64.ie.norelax | FileCheck %s --check-prefix=IE64-NORELAX

# GD64-RELA: .rela.dyn {
# GD64-RELA-NEXT: 0x20460 R_LARCH_TLS_DESC64 - 0x7FF
# GD64-RELA-NEXT: 0x20430 R_LARCH_TLS_DESC64 a 0x0
# GD64-RELA-NEXT: 0x20440 R_LARCH_TLS_DESC64 c 0x0
# GD64-RELA-NEXT: 0x20450 R_LARCH_TLS_DESC64 d 0x0
# GD64-RELA-NEXT: }
# GD64-RELA: Hex dump of section '.got':
# GD64-RELA-NEXT: 0x00020430 00000000 00000000 00000000 00000000 .
# GD64-RELA-NEXT: 0x00020440 00000000 00000000 00000000 00000000 .
# GD64-RELA-NEXT: 0x00020450 00000000 00000000 00000000 00000000 .
# GD64-RELA-NEXT: 0x00020460 00000000 00000000 00000000 00000000 .

# GD64: .got 00000040 0000000000020430

## &.got[a]-. = 0x20430 - 0x10318 = 16454<<2
# GD64: 10318: pcaddi $a0, 16454
# GD64-NEXT: ld.d $ra, $a0, 0
# GD64-NEXT: jirl $ra, $ra, 0
# GD64-NEXT: add.d $a1, $a0, $tp

## &.got[b]-. = 0x20430+48 - 0x10328: 0x10 pages, page offset 0x460
## R_LARCH_RELAX does not appear in pairs. No relaxation.
# GD64: 10328: pcalau12i $a0, 16
# GD64-NEXT: addi.d $a0, $a0, 1120
# GD64-NEXT: ld.d $ra, $a0, 0
# GD64-NEXT: jirl $ra, $ra, 0
# GD64-NEXT: add.d $a2, $a0, $tp

## &.got[c]-. = 0x20430+16 - 0x1033c: 0x10 pages, page offset 0x440
## Without R_LARCH_RELAX relocation. No relaxation.
# GD64: 1033c: pcalau12i $a0, 16
# GD64-NEXT: addi.d $t0, $zero, 0
# GD64-NEXT: addi.d $a0, $a0, 1088
# GD64-NEXT: addi.d $t0, $t0, 1
# GD64-NEXT: ld.d $ra, $a0, 0
# GD64-NEXT: addi.d $t0, $t0, 1
# GD64-NEXT: jirl $ra, $ra, 0
# GD64-NEXT: add.d $a3, $a0, $tp

## &.got[d]-. = 0x20430+32 - 0x1035c = 16445<<2
# GD64: 1035c: pcaddi $a0, 16445
# GD64-NEXT: ld.d $ra, $a0, 0
# GD64-NEXT: jirl $ra, $ra, 0
# GD64-NEXT: add.d $a4, $a0, $tp

# LE64-RELA: .rela.dyn {
# LE64-RELA-NEXT: 0x30280 R_LARCH_TLS_DESC64 - 0x8
# LE64-RELA-NEXT: 0x30290 R_LARCH_TLS_DESC64 - 0x800
# LE64-RELA-NEXT: 0x302A0 R_LARCH_TLS_DESC64 - 0x1000
# LE64-RELA-NEXT: 0x302B0 R_LARCH_TLS_DESC64 - 0x7FF
# LE64-RELA-NEXT: }
# LE64-RELA: Hex dump of section '.got':
# LE64-RELA-NEXT: 0x00030280 00000000 00000000 00000000 00000000 .
# LE64-RELA-NEXT: 0x00030290 00000000 00000000 00000000 00000000 .
# LE64-RELA-NEXT: 0x000302a0 00000000 00000000 00000000 00000000 .
# LE64-RELA-NEXT: 0x000302b0 00000000 00000000 00000000 00000000 .

# LE64: .got 00000040 0000000000030280

## &.got[a]-. = 0x30280 - 0x20228 = 16406<<2
# LE64: 20228: pcaddi $a0, 16406
# LE64-NEXT: ld.d $ra, $a0, 0
# LE64-NEXT: jirl $ra, $ra, 0
# LE64-NEXT: add.d $a1, $a0, $tp

## &.got[b]-. = 0x30280+48 - 0x20238: 0x10 pages, page offset 0x2b0
## R_LARCH_RELAX does not appear in pairs. No relaxation.
# LE64: 20238: pcalau12i $a0, 16
# LE64-NEXT: addi.d $a0, $a0, 688
# LE64-NEXT: ld.d $ra, $a0, 0
# LE64-NEXT: jirl $ra, $ra, 0
# LE64-NEXT: add.d $a2, $a0, $tp

## &.got[c]-. = 0x30280+16 - 0x2024c: 0x10 pages, page offset 0x290
## Without R_LARCH_RELAX relocation. No relaxation.
# LE64: 2024c: pcalau12i $a0, 16
# LE64-NEXT: addi.d $t0, $zero, 0
# LE64-NEXT: addi.d $a0, $a0, 656
# LE64-NEXT: addi.d $t0, $t0, 1
# LE64-NEXT: ld.d $ra, $a0, 0
# LE64-NEXT: addi.d $t0, $t0, 1
# LE64-NEXT: jirl $ra, $ra, 0
# LE64-NEXT: add.d $a3, $a0, $tp

## &.got[d]-. = 0x30280+32 - 0x2026c = 16397<<2
# LE64: 2026c: pcaddi $a0, 16397
# LE64-NEXT: ld.d $ra, $a0, 0
# LE64-NEXT: jirl $ra, $ra, 0
# LE64-NEXT: add.d $a4, $a0, $tp

# LE64-NORELAX: .got 00000040 0000000000030288

## &.got[a]-. = 0x30288 - 0x20228 = 0x10 pages, page offset 0x288
# LE64-NORELAX: 20228: pcalau12i $a0, 16
# LE64-NORELAX-NEXT: addi.d $a0, $a0, 648
# LE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# LE64-NORELAX-NEXT: jirl $ra, $ra, 0
# LE64-NORELAX-NEXT: add.d $a1, $a0, $tp

## &.got[b]-. = 0x30288+48 - 0x2023c: 0x10 pages, page offset 0x2b8
## R_LARCH_RELAX does not appear in pairs. No relaxation.
# LE64-NORELAX: 2023c: pcalau12i $a0, 16
# LE64-NORELAX-NEXT: addi.d $a0, $a0, 696
# LE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# LE64-NORELAX-NEXT: jirl $ra, $ra, 0
# LE64-NORELAX-NEXT: add.d $a2, $a0, $tp

## &.got[c]-. = 0x30288+16 - 0x20250: 0x10 pages, page offset 0x298
## Without R_LARCH_RELAX relocation. No relaxation.
# LE64-NORELAX: 20250: pcalau12i $a0, 16
# LE64-NORELAX-NEXT: addi.d $t0, $zero, 0
# LE64-NORELAX-NEXT: addi.d $a0, $a0, 664
# LE64-NORELAX-NEXT: addi.d $t0, $t0, 1
# LE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# LE64-NORELAX-NEXT: addi.d $t0, $t0, 1
# LE64-NORELAX-NEXT: jirl $ra, $ra, 0
# LE64-NORELAX-NEXT: add.d $a3, $a0, $tp

## &.got[d]-. = 0x30288+32 - 0x20270: 0x10 pages, page offset 0x2a8
# LE64-NORELAX: 20270: pcalau12i $a0, 16
# LE64-NORELAX-NEXT: addi.d $a0, $a0, 680
# LE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# LE64-NORELAX-NEXT: jirl $ra, $ra, 0
# LE64-NORELAX-NEXT: add.d $a4, $a0, $tp

# IE64-RELA: .rela.dyn {
# IE64-RELA-NEXT: 0x30430 R_LARCH_TLS_DESC64 - 0x8
# IE64-RELA-NEXT: 0x30460 R_LARCH_TLS_DESC64 - 0x7FF
# IE64-RELA-NEXT: 0x30440 R_LARCH_TLS_DESC64 c 0x0
# IE64-RELA-NEXT: 0x30450 R_LARCH_TLS_DESC64 d 0x0
# IE64-RELA-NEXT: }
# IE64-RELA: Hex dump of section '.got':
# IE64-RELA-NEXT: 0x00030430 00000000 00000000 00000000 00000000 .
# IE64-RELA-NEXT: 0x00030440 00000000 00000000 00000000 00000000 .
# IE64-RELA-NEXT: 0x00030450 00000000 00000000 00000000 00000000 .
# IE64-RELA-NEXT: 0x00030460 00000000 00000000 00000000 00000000 .

# IE64: .got 00000040 0000000000030430

## a and b are optimized to use LE. c and d are optimized to IE.
## &.got[a]-. = 0x30430 - 0x202f8 = 16462<<2
# IE64: 202f8: pcaddi $a0, 16462
# IE64-NEXT: ld.d $ra, $a0, 0
# IE64-NEXT: jirl $ra, $ra, 0
# IE64-NEXT: add.d $a1, $a0, $tp

## &.got[b]-. = 0x30430+48 - 0x20308: 0x10 pages, page offset 0x460
## R_LARCH_RELAX does not appear in pairs. No relaxation.
# IE64: 20308: pcalau12i $a0, 16
# IE64-NEXT: addi.d $a0, $a0, 1120
# IE64-NEXT: ld.d $ra, $a0, 0
# IE64-NEXT: jirl $ra, $ra, 0
# IE64-NEXT: add.d $a2, $a0, $tp

## &.got[c]-. = 0x30430+16 - 0x2031c: 0x10 pages, page offset 0x440
## Without R_LARCH_RELAX relocation. No relaxation.
# IE64: 2031c: pcalau12i $a0, 16
# IE64-NEXT: addi.d $t0, $zero, 0
# IE64-NEXT: addi.d $a0, $a0, 1088
# IE64-NEXT: addi.d $t0, $t0, 1
# IE64-NEXT: ld.d $ra, $a0, 0
# IE64-NEXT: addi.d $t0, $t0, 1
# IE64-NEXT: jirl $ra, $ra, 0
# IE64-NEXT: add.d $a3, $a0, $tp

## &.got[d]-. = 0x30430+32 - 0x2033c = 16453<<2
# IE64: 2033c: pcaddi $a0, 16453
# IE64-NEXT: ld.d $ra, $a0, 0
# IE64-NEXT: jirl $ra, $ra, 0
# IE64-NEXT: add.d $a4, $a0, $tp

# IE64-NORELAX: .got 00000040 0000000000030438

## &.got[a]-. = 0x30438 - 0x202f8 = 0x10 pages, page offset 0x438
# IE64-NORELAX: 202f8: pcalau12i $a0, 16
# IE64-NORELAX-NEXT: addi.d $a0, $a0, 1080
# IE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# IE64-NORELAX-NEXT: jirl $ra, $ra, 0
# IE64-NORELAX-NEXT: add.d $a1, $a0, $tp

## &.got[b]-. = 0x30438+48 - 0x2030c: 0x10 pages, page offset 0x468
## R_LARCH_RELAX does not appear in pairs. No relaxation.
# IE64-NORELAX: 2030c: pcalau12i $a0, 16
# IE64-NORELAX-NEXT: addi.d $a0, $a0, 1128
# IE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# IE64-NORELAX-NEXT: jirl $ra, $ra, 0
# IE64-NORELAX-NEXT: add.d $a2, $a0, $tp

## &.got[c]-. = 0x30438+16 - 0x20320: 0x10 pages, page offset 0x448
## Without R_LARCH_RELAX relocation. No relaxation.
# IE64-NORELAX: 20320: pcalau12i $a0, 16
# IE64-NORELAX-NEXT: addi.d $t0, $zero, 0
# IE64-NORELAX-NEXT: addi.d $a0, $a0, 1096
# IE64-NORELAX-NEXT: addi.d $t0, $t0, 1
# IE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# IE64-NORELAX-NEXT: addi.d $t0, $t0, 1
# IE64-NORELAX-NEXT: jirl $ra, $ra, 0
# IE64-NORELAX-NEXT: add.d $a3, $a0, $tp

## &.got[d]-. = 0x30438+32 - 0x20340: 0x10 pages, page offset 0x458
# IE64-NORELAX: 20340: pcalau12i $a0, 16
# IE64-NORELAX-NEXT: addi.d $a0, $a0, 1112
# IE64-NORELAX-NEXT: ld.d $ra, $a0, 0
# IE64-NORELAX-NEXT: jirl $ra, $ra, 0
# IE64-NORELAX-NEXT: add.d $a4, $a0, $tp

#--- a.s
la.tls.desc $a0, a
add.d $a1, $a0, $tp

# ADDI.D does not have R_LARCH_RELAX. No relaxation.
pcalau12i $a0, %desc_pc_hi20(b)
.reloc .-4, R_LARCH_RELAX, 0
addi.d $a0, $a0, %desc_pc_lo12(b)
ld.d $ra, $a0, %desc_ld(b)
jirl $ra, $ra, %desc_call(b)
add.d $a2, $a0, $tp

# TLSDESC to LE. No relaxation.
pcalau12i $a0, %desc_pc_hi20(c)
addi.d $t0, $zero, 0
addi.d $a0, $a0, %desc_pc_lo12(c)
addi.d $t0, $t0, 1
ld.d $ra, $a0, %desc_ld(c)
addi.d $t0, $t0, 1
jirl $ra, $ra, %desc_call(c)
add.d $a3, $a0, $tp

# PCALAU12I and ADDI.D have R_LARCH_RELAX. We preform relaxation.
pcalau12i $a0, %desc_pc_hi20(d)
.reloc .-4, R_LARCH_RELAX, 0
addi.d $a0, $a0, %desc_pc_lo12(d)
.reloc .-4, R_LARCH_RELAX, 0
ld.d $ra, $a0, %desc_ld(d)
jirl $ra, $ra, %desc_call(d)
add.d $a4, $a0, $tp

.section .tbss,"awT",@nobits
.globl a
.zero 8
a:
.zero 2039 ## Place b at 0x7ff
b:
.zero 1

#--- c.s
.section .tbss,"awT",@nobits
.globl c, d
c:
.zero 2048 ## Place d at 0x1000
d:
.zero 4