[ELF] Implement R_RISCV_TLSDESC for RISC-V #79099
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@llvm/pr-subscribers-backend-risc-v @llvm/pr-subscribers-lld Author: Fangrui Song (MaskRay) ChangesSupport For -no-pie/-pie links, TLSDESC to initial-exec or local-exec
DO NOT SUBMIT: rebase after #66915 lands Patch is 60.16 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/79099.diff 23 Files Affected:
diff --git a/lld/ELF/Arch/RISCV.cpp b/lld/ELF/Arch/RISCV.cpp
index d7d3d3e47814971..8ed4683d721cef7 100644
--- a/lld/ELF/Arch/RISCV.cpp
+++ b/lld/ELF/Arch/RISCV.cpp
@@ -61,6 +61,7 @@ enum Op {
AUIPC = 0x17,
JALR = 0x67,
LD = 0x3003,
+ LUI = 0x37,
LW = 0x2003,
SRLI = 0x5013,
SUB = 0x40000033,
@@ -73,6 +74,7 @@ enum Reg {
X_T0 = 5,
X_T1 = 6,
X_T2 = 7,
+ X_A0 = 10,
X_T3 = 28,
};
@@ -102,6 +104,26 @@ static uint32_t setLO12_S(uint32_t insn, uint32_t imm) {
(extractBits(imm, 4, 0) << 7);
}
+namespace {
+struct SymbolAnchor {
+ uint64_t offset;
+ Defined *d;
+ bool end; // true for the anchor of st_value+st_size
+};
+} // namespace
+
+struct elf::RISCVRelaxAux {
+ // This records symbol start and end offsets which will be adjusted according
+ // to the nearest relocDeltas element.
+ SmallVector<SymbolAnchor, 0> anchors;
+ // For relocations[i], the actual offset is r_offset - (i ? relocDeltas[i-1] :
+ // 0).
+ std::unique_ptr<uint32_t[]> relocDeltas;
+ // For relocations[i], the actual type is relocTypes[i].
+ std::unique_ptr<RelType[]> relocTypes;
+ SmallVector<uint32_t, 0> writes;
+};
+
RISCV::RISCV() {
copyRel = R_RISCV_COPY;
pltRel = R_RISCV_JUMP_SLOT;
@@ -119,6 +141,7 @@ RISCV::RISCV() {
tlsGotRel = R_RISCV_TLS_TPREL32;
}
gotRel = symbolicRel;
+ tlsDescRel = R_RISCV_TLSDESC;
// .got[0] = _DYNAMIC
gotHeaderEntriesNum = 1;
@@ -187,6 +210,8 @@ int64_t RISCV::getImplicitAddend(const uint8_t *buf, RelType type) const {
case R_RISCV_JUMP_SLOT:
// These relocations are defined as not having an implicit addend.
return 0;
+ case R_RISCV_TLSDESC:
+ return config->is64 ? read64le(buf + 8) : read32le(buf + 4);
}
}
@@ -295,6 +320,12 @@ RelExpr RISCV::getRelExpr(const RelType type, const Symbol &s,
case R_RISCV_PCREL_LO12_I:
case R_RISCV_PCREL_LO12_S:
return R_RISCV_PC_INDIRECT;
+ case R_RISCV_TLSDESC_HI20:
+ case R_RISCV_TLSDESC_LOAD_LO12:
+ case R_RISCV_TLSDESC_ADD_LO12:
+ return R_TLSDESC_PC;
+ case R_RISCV_TLSDESC_CALL:
+ return R_TLSDESC_CALL;
case R_RISCV_TLS_GD_HI20:
return R_TLSGD_PC;
case R_RISCV_TLS_GOT_HI20:
@@ -419,6 +450,7 @@ void RISCV::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
case R_RISCV_GOT_HI20:
case R_RISCV_PCREL_HI20:
+ case R_RISCV_TLSDESC_HI20:
case R_RISCV_TLS_GD_HI20:
case R_RISCV_TLS_GOT_HI20:
case R_RISCV_TPREL_HI20:
@@ -430,6 +462,8 @@ void RISCV::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
}
case R_RISCV_PCREL_LO12_I:
+ case R_RISCV_TLSDESC_LOAD_LO12:
+ case R_RISCV_TLSDESC_ADD_LO12:
case R_RISCV_TPREL_LO12_I:
case R_RISCV_LO12_I: {
uint64_t hi = (val + 0x800) >> 12;
@@ -513,29 +547,116 @@ void RISCV::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
break;
case R_RISCV_RELAX:
- return; // Ignored (for now)
-
+ return;
+ case R_RISCV_TLSDESC:
+ // The addend is stored in the second word.
+ if (config->is64)
+ write64le(loc + 8, val);
+ else
+ write32le(loc + 4, val);
+ break;
default:
llvm_unreachable("unknown relocation");
}
}
+static void tlsdescToIe(uint8_t *loc, const Relocation &rel, uint64_t val) {
+ switch (rel.type) {
+ case R_RISCV_TLSDESC_HI20:
+ case R_RISCV_TLSDESC_LOAD_LO12:
+ write32le(loc, 0x00000013); // nop
+ return;
+ case R_RISCV_TLSDESC_ADD_LO12:
+ write32le(loc, utype(AUIPC, X_A0, hi20(val))); // auipc a0,<hi20>
+ return;
+ case R_RISCV_TLSDESC_CALL:
+ if (config->is64)
+ write32le(loc, itype(LD, X_A0, X_A0, lo12(val))); // ld a0,<lo12>(a0)
+ else
+ write32le(loc, itype(LW, X_A0, X_A0, lo12(val))); // lw a0,<lo12>(a0)
+ return;
+ default:
+ llvm_unreachable("unsupported relocation for TLSDESC to IE relaxation");
+ }
+}
+
+static void tlsdescToLe(uint8_t *loc, const Relocation &rel, uint64_t val) {
+ switch (rel.type) {
+ case R_RISCV_TLSDESC_HI20:
+ case R_RISCV_TLSDESC_LOAD_LO12:
+ write32le(loc, 0x00000013); // nop
+ return;
+ case R_RISCV_TLSDESC_ADD_LO12:
+ write32le(loc, utype(LUI, X_A0, hi20(val))); // lui a0,<hi20>
+ return;
+ case R_RISCV_TLSDESC_CALL:
+ if (isInt<12>(val))
+ write32le(loc, itype(ADDI, X_A0, 0, val)); // addi a0,zero,<lo12>
+ else
+ write32le(loc, itype(ADDI, X_A0, X_A0, lo12(val))); // addi a0,a0,<lo12>
+ return;
+ default:
+ llvm_unreachable("unsupported relocation for TLSDESC to LE relaxation");
+ }
+}
+
void RISCV::relocateAlloc(InputSectionBase &sec, uint8_t *buf) const {
uint64_t secAddr = sec.getOutputSection()->addr;
if (auto *s = dyn_cast<InputSection>(&sec))
secAddr += s->outSecOff;
else if (auto *ehIn = dyn_cast<EhInputSection>(&sec))
secAddr += ehIn->getParent()->outSecOff;
- for (size_t i = 0, size = sec.relocs().size(); i != size; ++i) {
- const Relocation &rel = sec.relocs()[i];
+ uint64_t tlsdescVal = 0;
+ bool isToIe = true;
+ MutableArrayRef<Relocation> relocs = sec.relocs();
+ for (size_t i = 0, size = relocs.size(); i != size; ++i) {
+ const Relocation &rel = relocs[i];
uint8_t *loc = buf + rel.offset;
- const uint64_t val =
+ uint64_t val =
sec.getRelocTargetVA(sec.file, rel.type, rel.addend,
secAddr + rel.offset, *rel.sym, rel.expr);
switch (rel.expr) {
case R_RELAX_HINT:
+ continue;
+ case R_TLSDESC_PC:
+ // For R_RISCV_TLSDESC_HI20, store &got(sym)-PC to be used by the
+ // following two instructions L[DW] and ADDI.
+ if (rel.type == R_RISCV_TLSDESC_HI20)
+ tlsdescVal = val;
+ else
+ val = tlsdescVal;
break;
+ case R_RELAX_TLS_GD_TO_LE:
+ // See the comment in handleTlsRelocation. For TLSDESC=>IE optimization,
+ // R_RISCV_TLSDESC_{LOAD_LO12,ADD_LO12,CALL} also reach here. If
+ // tlsdescToIe is true, this is actually TLSDESC=>LE optimization.
+ if (rel.type == R_RISCV_TLSDESC_HI20) {
+ tlsdescVal = val;
+ isToIe = false;
+ } else {
+ val = tlsdescVal;
+ }
+ // For the LE optimization, if AUIPC and L[DW] are not removed, tlsdescVal
+ // should be decreased as AUIPC (tlsdescVal is relative to it) is placed
+ // after the current instruction.
+ if (isToIe && rel.type != R_RISCV_TLSDESC_ADD_LO12 && i + 1 < size &&
+ relocs[i + 1].type != R_RISCV_RELAX)
+ tlsdescVal -= 4;
+ if (isToIe)
+ tlsdescToIe(loc, rel, val);
+ else
+ tlsdescToLe(loc, rel, val);
+ continue;
+ case R_RELAX_TLS_GD_TO_IE:
+ // Only R_RISCV_TLSDESC_HI20 reaches here. If the instruction is not
+ // removed, tlsdescVal should be decreased.
+ tlsdescVal = val;
+ isToIe = true;
+ if (i + 1 < size && relocs[i + 1].type != R_RISCV_RELAX)
+ tlsdescVal -= 4;
+ tlsdescToIe(loc, rel, val);
+ continue;
case R_RISCV_LEB128:
if (i + 1 < size) {
const Relocation &rel1 = sec.relocs()[i + 1];
@@ -554,32 +675,12 @@ void RISCV::relocateAlloc(InputSectionBase &sec, uint8_t *buf) const {
": R_RISCV_SET_ULEB128 not paired with R_RISCV_SUB_SET128");
return;
default:
- relocate(loc, rel, val);
break;
}
+ relocate(loc, rel, val);
}
}
-namespace {
-struct SymbolAnchor {
- uint64_t offset;
- Defined *d;
- bool end; // true for the anchor of st_value+st_size
-};
-} // namespace
-
-struct elf::RISCVRelaxAux {
- // This records symbol start and end offsets which will be adjusted according
- // to the nearest relocDeltas element.
- SmallVector<SymbolAnchor, 0> anchors;
- // For relocations[i], the actual offset is r_offset - (i ? relocDeltas[i-1] :
- // 0).
- std::unique_ptr<uint32_t[]> relocDeltas;
- // For relocations[i], the actual type is relocTypes[i].
- std::unique_ptr<RelType[]> relocTypes;
- SmallVector<uint32_t, 0> writes;
-};
-
static void initSymbolAnchors() {
SmallVector<InputSection *, 0> storage;
for (OutputSection *osec : outputSections) {
@@ -762,6 +863,14 @@ static bool relax(InputSection &sec) {
sec.relocs()[i + 1].type == R_RISCV_RELAX)
relaxHi20Lo12(sec, i, loc, r, remove);
break;
+ case R_RISCV_TLSDESC_HI20:
+ case R_RISCV_TLSDESC_LOAD_LO12:
+ // For LE or IE optimization, AUIPC and L[DW] are converted to a removable
+ // NOP.
+ if (r.expr != R_TLSDESC_PC && i + 1 != sec.relocs().size() &&
+ sec.relocs()[i + 1].type == R_RISCV_RELAX)
+ remove = 4;
+ break;
}
// For all anchors whose offsets are <= r.offset, they are preceded by
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index b6a317bc3b6d697..7e0cfc50605198e 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -1274,26 +1274,31 @@ static unsigned handleTlsRelocation(RelType type, Symbol &sym,
if (config->emachine == EM_MIPS)
return handleMipsTlsRelocation(type, sym, c, offset, addend, expr);
+ bool isRISCV = config->emachine == EM_RISCV;
if (oneof<R_AARCH64_TLSDESC_PAGE, R_TLSDESC, R_TLSDESC_CALL, R_TLSDESC_PC,
R_TLSDESC_GOTPLT>(expr) &&
config->shared) {
+ // R_RISCV_TLSDESC_{LOAD_LO12_I,ADD_LO12_I,CALL} reference a label. Do not
+ // set NEEDS_TLSDESC on the label.
if (expr != R_TLSDESC_CALL) {
- sym.setFlags(NEEDS_TLSDESC);
+ if (!isRISCV || type == R_RISCV_TLSDESC_HI20)
+ sym.setFlags(NEEDS_TLSDESC);
c.addReloc({expr, type, offset, addend, &sym});
}
return 1;
}
// ARM, Hexagon, LoongArch and RISC-V do not support GD/LD to IE/LE
- // relaxation.
+ // optimizations.
+ // RISC-V supports TLSDESC to IE/LE optimizations.
// For PPC64, if the file has missing R_PPC64_TLSGD/R_PPC64_TLSLD, disable
// relaxation as well.
- bool toExecRelax = !config->shared && config->emachine != EM_ARM &&
- config->emachine != EM_HEXAGON &&
- config->emachine != EM_LOONGARCH &&
- config->emachine != EM_RISCV &&
- !c.file->ppc64DisableTLSRelax;
+ bool toExecRelax =
+ !config->shared && config->emachine != EM_ARM &&
+ config->emachine != EM_HEXAGON && config->emachine != EM_LOONGARCH &&
+ !(isRISCV && expr != R_TLSDESC_PC && expr != R_TLSDESC_CALL) &&
+ !c.file->ppc64DisableTLSRelax;
// If we are producing an executable and the symbol is non-preemptable, it
// must be defined and the code sequence can be relaxed to use Local-Exec.
@@ -1347,8 +1352,12 @@ static unsigned handleTlsRelocation(RelType type, Symbol &sym,
return 1;
}
- // Global-Dynamic relocs can be relaxed to Initial-Exec or Local-Exec
+ // Global-Dynamic/TLSDESC can be relaxed to Initial-Exec or Local-Exec
// depending on the symbol being locally defined or not.
+ //
+ // R_RISCV_TLSDESC_{LOAD_LO12_I,ADD_LO12_I,CALL} reference a non-preemptible
+ // label, so the LE transition will be categorized as R_RELAX_TLS_GD_TO_LE.
+ // We fix the categorization in RISCV::relocateAlloc.
if (sym.isPreemptible) {
sym.setFlags(NEEDS_TLSGD_TO_IE);
c.addReloc({target->adjustTlsExpr(type, R_RELAX_TLS_GD_TO_IE), type,
diff --git a/lld/test/ELF/riscv-tlsdesc-relax.s b/lld/test/ELF/riscv-tlsdesc-relax.s
new file mode 100644
index 000000000000000..54cfac810990f66
--- /dev/null
+++ b/lld/test/ELF/riscv-tlsdesc-relax.s
@@ -0,0 +1,125 @@
+# REQUIRES: riscv
+# RUN: rm -rf %t && split-file %s %t && cd %t
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+c,+relax a.s -o a.64.o
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+c,+relax c.s -o c.64.o
+# RUN: ld.lld -shared -soname=c.64.so c.64.o -o c.64.so
+
+# RUN: ld.lld -shared -z now a.64.o c.64.o -o a.64.so -z separate-code
+# RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.64.so | FileCheck %s --check-prefix=GD64
+
+# RUN: ld.lld -e 0 -z now a.64.o c.64.o -o a.64.le -z separate-code
+# RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.64.le | FileCheck %s --check-prefix=LE64
+
+# RUN: ld.lld -e 0 -z now a.64.o c.64.so -o a.64.ie -z separate-code
+# RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.64.ie | FileCheck %s --check-prefix=IE64
+
+# GD64: .got 00000018 00000000000020c0
+# GD64-LABEL: <_start>:
+# GD64-NEXT: jal {{.*}} <foo>
+# GD64-LABEL: <foo>:
+## &.got[c]-. = 0x20c0+8 - 0x1004 = 0x10c4
+# GD64: 1004: auipc a2, 0x1
+# GD64-NEXT: ld a3, 0xc4(a2)
+# GD64-NEXT: addi a0, a2, 0xc4
+# GD64-NEXT: jalr t0, 0x0(a3)
+# GD64-NEXT: c.add a0, tp
+# GD64-NEXT: jal {{.*}} <foo>
+# GD64-NEXT: auipc a4, 0x1
+# GD64-NEXT: ld a5, 0xae(a4)
+# GD64-NEXT: addi a0, a4, 0xae
+# GD64-NEXT: jalr t0, 0x0(a5)
+# GD64-NEXT: c.add a0, tp
+
+# LE64-LABEL: <_start>:
+# LE64-NEXT: jal {{.*}} <foo>
+# LE64-LABEL: <foo>:
+# LE64-NEXT: 11004: lui a0, 0x0
+# LE64-NEXT: addi a0, zero, 0xc
+# LE64-NEXT: c.add a0, tp
+# LE64-NEXT: jal {{.*}} <foo>
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: lui a0, 0x0
+# LE64-NEXT: addi a0, zero, 0xc
+# LE64-NEXT: c.add a0, tp
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: lui a0, 0x0
+# LE64-NEXT: addi a0, zero, 0xc
+# LE64-NEXT: c.add a0, tp
+
+# IE64: .got 00000010 00000000000120e0
+# IE64-LABEL: <_start>:
+# IE64-NEXT: jal {{.*}} <foo>
+# IE64-LABEL: <foo>:
+## &.got[c]-. = 0x120e0+8 - 0x11004 = 0x10e4
+# IE64-NEXT: 11004: auipc a0, 0x1
+# IE64-NEXT: ld a0, 0xe4(a0)
+# IE64-NEXT: c.add a0, tp
+# IE64-NEXT: jal {{.*}} <foo>
+# IE64-NEXT: addi zero, zero, 0x0
+## &.got[c]-. = 0x120e0+8 - 0x11016 = 0x10d2
+# IE64-NEXT: 11016: auipc a0, 0x1
+# IE64-NEXT: ld a0, 0xd2(a0)
+# IE64-NEXT: c.add a0, tp
+# IE64-NEXT: addi zero, zero, 0x0
+## &.got[c]-. = 0x120e0+8 - 0x11024 = 0x10c4
+# IE64-NEXT: 11024: auipc a0, 0x1
+# IE64-NEXT: ld a0, 0xc4(a0)
+# IE64-NEXT: c.add a0, tp
+
+#--- a.s
+.globl _start
+_start:
+.balign 16
+ call foo
+
+foo:
+.Ltlsdesc_hi0:
+.option norelax
+## All 4 instructions have an R_RISCV_RELAX.
+ auipc a2, %tlsdesc_hi(c)
+ .reloc .-4, R_RISCV_RELAX, 0
+ ld a3, %tlsdesc_load_lo(.Ltlsdesc_hi0)(a2)
+ .reloc .-4, R_RISCV_RELAX, 0
+ addi a0, a2, %tlsdesc_add_lo(.Ltlsdesc_hi0)
+ .reloc .-4, R_RISCV_RELAX, 0
+ jalr t0, 0(a3), %tlsdesc_call(.Ltlsdesc_hi0)
+ .reloc .-4, R_RISCV_RELAX, 0
+ add a0, a0, tp
+.option relax
+
+ call foo
+
+.Ltlsdesc_hi1:
+.option norelax
+## LD has an R_RISCV_RELAX.
+ auipc a4, %tlsdesc_hi(c)
+ ld a5, %tlsdesc_load_lo(.Ltlsdesc_hi1)(a4)
+ .reloc .-4, R_RISCV_RELAX, 0
+ addi a0, a4, %tlsdesc_add_lo(.Ltlsdesc_hi1)
+ jalr t0, 0(a5), %tlsdesc_call(.Ltlsdesc_hi1)
+ add a0, a0, tp
+.option relax
+
+.Ltlsdesc_hi2:
+.option norelax
+## AUIPC has an R_RISCV_RELAX.
+ auipc a6, %tlsdesc_hi(c)
+ .reloc .-4, R_RISCV_RELAX, 0
+ ld a7, %tlsdesc_load_lo(.Ltlsdesc_hi2)(a6)
+ addi a0, a6, %tlsdesc_add_lo(.Ltlsdesc_hi2)
+ jalr t0, 0(a7), %tlsdesc_call(.Ltlsdesc_hi2)
+ add a0, a0, tp
+.option relax
+
+.section .tbss
+.globl a
+.zero 8
+a:
+.zero 3
+b:
+.zero 1
+
+#--- c.s
+.tbss
+.globl c
+c: .zero 4
diff --git a/lld/test/ELF/riscv-tlsdesc.s b/lld/test/ELF/riscv-tlsdesc.s
new file mode 100644
index 000000000000000..1759c6cc25583ec
--- /dev/null
+++ b/lld/test/ELF/riscv-tlsdesc.s
@@ -0,0 +1,192 @@
+# REQUIRES: riscv
+# RUN: rm -rf %t && split-file %s %t && cd %t
+# RUN: llvm-mc -filetype=obj -triple=riscv64 a.s -o a.64.o
+# RUN: llvm-mc -filetype=obj -triple=riscv64 c.s -o c.64.o
+# RUN: ld.lld -shared -soname=c.64.so c.64.o -o c.64.so
+# RUN: llvm-mc -filetype=obj -triple=riscv32 --defsym ELF32=1 a.s -o a.32.o
+# RUN: llvm-mc -filetype=obj -triple=riscv32 --defsym ELF32=1 c.s -o c.32.o
+# RUN: ld.lld -shared -soname=c.32.so c.32.o -o c.32.so
+
+# RUN: ld.lld -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 -M no-aliases -h -d a.64.so | FileCheck %s --check-prefix=GD64
+
+# RUN: ld.lld -shared -z now a.64.o c.64.o -o rel.64.so -z rel
+# RUN: llvm-readobj -r -x .got rel.64.so | FileCheck --check-prefix=GD64-REL %s
+
+# RUN: ld.lld -e 0 -z now a.64.o c.64.o -o a.64.le
+# RUN: llvm-readelf -r a.64.le | FileCheck --check-prefix=NOREL %s
+# RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.64.le | FileCheck %s --check-prefix=LE64
+
+# RUN: ld.lld -e 0 -z now a.64.o c.64.so -o a.64.ie
+# RUN: llvm-readobj -r a.64.ie | FileCheck --check-prefix=IE64-RELA %s
+# RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.64.ie | FileCheck %s --check-prefix=IE64
+
+## 32-bit code is mostly the same. We only test a few variants. The IE optimization uses the LW instruction.
+
+# RUN: ld.lld -shared -z now a.32.o c.32.o -o rel.32.so -z rel
+# RUN: llvm-readobj -r -x .got rel.32.so | FileCheck --check-prefix=GD32-REL %s
+# RUN: ld.lld -e 0 -z now a.32.o c.32.so -o a.32.ie
+# RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.32.ie | FileCheck %s --check-prefix=IE32
+
+# GD64-RELA: .rela.dyn {
+# GD64-RELA-NEXT: 0x2408 R_RISCV_TLSDESC - 0x7FF
+# GD64-RELA-NEXT: 0x23E8 R_RISCV_TLSDESC a 0x0
+# GD64-RELA-NEXT: 0x23F8 R_RISCV_TLSDESC c 0x0
+# GD64-RELA-NEXT: }
+# GD64-RELA: Hex dump of section '.got':
+# GD64-RELA-NEXT: 0x000023e0 20230000 00000000 00000000 00000000 #
+# GD64-RELA-NEXT: 0x000023f0 00000000 00000000 00000000 00000000 .
+
+# GD64-REL: .rel.dyn {
+# GD64-REL-NEXT: 0x23F0 R_RISCV_TLSDESC -
+# GD64-REL-NEXT: 0x23D0 R_RISCV_TLSDESC a
+# GD64-REL-NEXT: 0x23E0 R_RISCV_TLSDESC c
+# GD64-REL-NEXT: }
+# GD64-REL: Hex dump of section '.got':
+# GD64-REL-NEXT: 0x000023c8 08230000 00000000 00000000 00000000 .
+# GD64-REL-NEXT: 0x000023d8 00000000 00000000 00000000 00000000 .
+# GD64-REL-NEXT: 0x000023e8 00000000 00000000 00000000 00000000 .
+# GD64-REL-NEXT: 0x000023f8 ff070000 00000000 .
+
+# GD32-REL: .rel.dyn {
+# GD32-REL-NEXT: 0x2274 R_RISCV_TLSDESC -
+# GD32-REL-NEXT: 0x2264 R_RISCV_TLSDESC a
+# GD32-REL-NEXT: 0x226C R_RISCV_TLSDESC c
+# GD32-REL-NEXT: }
+# GD32-REL: Hex dump of section '.got':
+# GD32-REL-NEXT: 0x00002260 00220000 00000000 00000000 00000000 .
+# GD32-REL-NEXT: 0x00002270 00000000 00000000 ff070000 .
+
+# GD64: .got 00000038 00000000000023e0
+
+## &.got[a]-. = 0x23e0+8 - 0x12e0 = 0x1108
+# GD64: 12e0: auipc a0, 0x1
+# GD64-NEXT: ld a1, 0x108(a0)
+# GD64-NEXT: addi a0, a0, 0x108
+# GD64-NEXT: jalr t0, 0x0(a1)
+# GD64-NEXT: add a0, a0, tp
+
+## &.got[b]-. = 0x23e0+40 - 0x12f4 = 0x1114
+# GD64-NEXT: 12f4: auipc a2, 0x1
+# GD64-NEXT: ld a3, 0x114(a2)
+# GD64-NEXT: addi a0, a2, 0x114
+# GD64-NEXT: jalr t0, 0x0(a3)
+# GD64-NEXT: add a0, a0, tp
+
+## &.got[c]-. = 0x23e0+24 - 0x1308 = 0x10f0
+# GD64-NEXT: 1308: auipc a4, 0x1
+# GD64-NEXT: ld a5, 0xf0(a4)
+# GD64-NEXT: addi a0, a4, 0xf0
+# GD64-NEXT: jalr t0, 0x0(a5)
+# GD64-NEXT: add a0, a0, tp
+
+# NOREL: no relocations
+
+## st_value(a) = 8
+# LE64-LABEL: <.text>:
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: lui a0, 0x0
+# LE64-NEXT: addi a0, zero, 0x8
+# LE64-NEXT: add a0, a0, tp
+## st_value(b) = 11
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: lui a0, 0x0
+# LE64-NEXT: addi a0, zero, 0x7ff
+# LE64-NEXT: add a0, a0, tp
+## st_value(c) = 12
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: addi zero, zero, 0x0
+# LE64-NEXT: lui a0, 0x1
+# LE64-NEXT: addi a0, a0, -0x800
+# LE64-NEXT: add a0, a0, tp
+
+# IE64-RELA: .rela.dyn {
+# IE64-RELA-NEXT: 0x123B0 R_RISCV_TLS_TPREL64 c 0x0
+# IE64-RELA-NEXT: }
+
+# IE64: .got 00000010 00000000000123a8
+
+## a and b are optimized to use LE. c is optimized to IE...
[truncated]
|
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This needs a rebase after #66915 lands. I have verified that a runtime test on musl works using this patch I used the same test to find issues for my x86-32 TLSDESC patch https://reviews.llvm.org/D112582 |
Support R_RISCV_TLSDESC_HI20/R_RISCV_TLSDESC_LOAD_LO12_I/R_RISCV_TLSDESC_ADD_LO12_I/R_RISCV_TLSDESC_CALL. LOAD_LO12_I/ADD_LO12_I/CALL relocations reference a label at the HI20 location, which requires special handling. We save the value of HI20 to be reused. For -no-pie/-pie links, TLSDESC to initial-exec or local-exec optimizations are eligible. Implement the relevant hooks (R_RELAX_TLS_GD_TO_LE, R_RELAX_TLS_GD_TO_IE). AUIPC/L[DW] for initial-exec uses GOT offsets, which may be adjusted in the presence of linker relaxation. ``` // TLSDESC to LE/IE optimization .Ltlsdesc_hi2: auipc a4, %tlsdesc_hi(c) # if R_RISCV_RELAX: remove; otherwise, NOP load a5, %tlsdesc_load_lo(.Ltlsdesc_hi2)(a4) # if R_RISCV_RELAX: remove; otherwise, NOP addi a0, a4, %tlsdesc_add_lo(.Ltlsdesc_hi2) jalr t0, 0(a5), %tlsdesc_call(.Ltlsdesc_hi2) add a0, a0, tp ``` * `riscv64-tlsdesc.s` is inspired by `i386-tlsdesc-gd.s` (https://reviews.llvm.org/D112582). * `riscv64-tlsdesc-relax.s` tests linker relaxation. * `riscv-tlsdesc-gd-mixed.s` is inspired by `x86-64-tlsdesc-gd-mixed.s` (https://reviews.llvm.org/D116900). DO NOT SUBMIT: rebase after llvm#66915 lands
|
The base LLVM patch has landed. Recreate #79239 using spr for a proper review. |
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Support
R_RISCV_TLSDESC_HI20/R_RISCV_TLSDESC_LOAD_LO12_I/R_RISCV_TLSDESC_ADD_LO12_I/R_RISCV_TLSDESC_CALL.
LOAD_LO12_I/ADD_LO12_I/CALL relocations reference a label at the HI20
location, which requires special handling. We save the value of HI20 to
be reused.
For -no-pie/-pie links, TLSDESC to initial-exec or local-exec
optimizations are eligible. Implement the relevant hooks
(R_RELAX_TLS_GD_TO_LE, R_RELAX_TLS_GD_TO_IE). AUIPC/L[DW] for
initial-exec uses GOT offsets, which may be adjusted in the presence of
linker relaxation.
riscv64-tlsdesc.sis inspired byi386-tlsdesc-gd.s(https://reviews.llvm.org/D112582).riscv64-tlsdesc-relax.stests linker relaxation.riscv-tlsdesc-gd-mixed.sis inspired byx86-64-tlsdesc-gd-mixed.s(https://reviews.llvm.org/D116900).DO NOT SUBMIT: rebase after #66915 lands