[LoongArch] Add relax relocations for tls_le code sequence

This commit add relax relocations for tls_le code sequence.
Handwritten assembly and generating source code by clang are
both affected.

Scheduled tls_le code sequence can be relaxed normally. So we
can add relax relocations when code emitting according to their
relocs. Other relaxable macros' code sequence cannot be
scheduled when relaxation enabled. Attaching relax relocations
for them will be implemented in later commit.

Author: zhaoqi5

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCCodeEmitter.cpp

@@ -282,9 +282,11 @@ LoongArchMCCodeEmitter::getExprOpValue(const MCInst &MI, const MCOperand &MO,
       break;
     case LoongArchMCExpr::VK_LoongArch_TLS_LE_HI20_R:
       FixupKind = LoongArch::fixup_loongarch_tls_le_hi20_r;
+      RelaxCandidate = true;
       break;
     case LoongArchMCExpr::VK_LoongArch_TLS_LE_LO12_R:
       FixupKind = LoongArch::fixup_loongarch_tls_le_lo12_r;
+      RelaxCandidate = true;
       break;
     case LoongArchMCExpr::VK_LoongArch_PCREL20_S2:
       FixupKind = LoongArch::fixup_loongarch_pcrel20_s2;
@@ -387,11 +389,18 @@ void LoongArchMCCodeEmitter::expandAddTPRel(const MCInst &MI,
          "Expected %le_add_r relocation on TP-relative symbol");
 
   // Emit the correct %le_add_r relocation for the symbol.
-  // TODO: Emit R_LARCH_RELAX for %le_add_r where the relax feature is enabled.
   Fixups.push_back(MCFixup::create(
       0, Expr, MCFixupKind(LoongArch::fixup_loongarch_tls_le_add_r),
       MI.getLoc()));
 
+  // Emit R_LARCH_RELAX for %le_add_r when the relax feature is enabled.
+  bool EnableRelax = STI.hasFeature(LoongArch::FeatureRelax);
+  if (EnableRelax) {
+    const MCConstantExpr *Dummy = MCConstantExpr::create(0, Ctx);
+    Fixups.push_back(MCFixup::create(
+        0, Dummy, MCFixupKind(LoongArch::fixup_loongarch_relax), MI.getLoc()));
+  }
+
   // Emit a normal ADD instruction with the given operands.
   unsigned ADD = MI.getOpcode() == LoongArch::PseudoAddTPRel_D
                      ? LoongArch::ADD_D

llvm/test/MC/LoongArch/Relocations/relax-tls-le.s

@@ -0,0 +1,70 @@
+# RUN: llvm-mc --filetype=obj --triple=loongarch32 --mattr=+relax < %s \
+# RUN:     | llvm-readobj -r - | FileCheck --check-prefix=LA32-RELAX-RELOC %s
+# RUN: llvm-mc --filetype=obj --triple=loongarch32 --mattr=-relax < %s \
+# RUN:     | llvm-readobj -r - | FileCheck --check-prefix=LA32-NORELAX-RELOC %s
+# RUN: llvm-mc --triple=loongarch32 --mattr=+relax < %s --show-encoding \
+# RUN:     | FileCheck --check-prefix=LA32-RELAX-FIXUP %s
+
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=+relax --defsym=LA64=1 < %s \
+# RUN:     | llvm-readobj -r - | FileCheck --check-prefix=LA64-RELAX-RELOC %s
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax --defsym=LA64=1 < %s \
+# RUN:     | llvm-readobj -r - | FileCheck --check-prefix=LA64-NORELAX-RELOC %s
+# RUN: llvm-mc --triple=loongarch64 --mattr=+relax --defsym=LA64=1 < %s --show-encoding \
+# RUN:     | FileCheck --check-prefix=LA64-RELAX-FIXUP %s
+
+.long foo
+
+.ifndef LA64
+
+lu12i.w $a0, %le_hi20_r(foo)
+# LA32-NORELAX-RELOC: R_LARCH_TLS_LE_HI20_R foo 0x0
+# LA32-NORELAX-RELOC-NOT: R_LARCH_RELAX - 0x0
+# LA32-RELAX-RELOC: R_LARCH_TLS_LE_HI20_R foo 0x0
+# LA32-RELAX-RELOC: R_LARCH_RELAX - 0x0
+# LA32-RELAX-FIXUP: fixup A - offset: 0, value: %le_hi20_r(foo), kind: FK_NONE
+# LA32-RELAX-FIXUP: fixup B - offset: 0, value: 0, kind: FK_NONE
+
+add.w $a0, $a0, $tp, %le_add_r(foo)
+# LA32-NORELAX-RELOC: R_LARCH_TLS_LE_ADD_R foo 0x0
+# LA32-NORELAX-RELOC-NOT: R_LARCH_RELAX - 0x0
+# LA32-RELAX-RELOC: R_LARCH_TLS_LE_ADD_R foo 0x0
+# LA32-RELAX-RELOC: R_LARCH_RELAX - 0x0
+# LA32-RELAX-FIXUP: fixup A - offset: 0, value: %le_add_r(foo), kind: FK_NONE
+# LA32-RELAX-FIXUP: fixup B - offset: 0, value: 0, kind: FK_NONE
+
+addi.w $a0, $a0, %le_lo12_r(foo)
+# LA32-NORELAX-RELOC: R_LARCH_TLS_LE_LO12_R foo 0x0
+# LA32-NORELAX-RELOC-NOT: R_LARCH_RELAX - 0x0
+# LA32-RELAX-RELOC: R_LARCH_TLS_LE_LO12_R foo 0x0
+# LA32-RELAX-RELOC: R_LARCH_RELAX - 0x0
+# LA32-RELAX-FIXUP: fixup A - offset: 0, value: %le_lo12_r(foo), kind: FK_NONE
+# LA32-RELAX-FIXUP: fixup B - offset: 0, value: 0, kind: FK_NONE
+
+.else
+
+lu12i.w $a0, %le_hi20_r(foo)
+# LA64-NORELAX-RELOC: R_LARCH_TLS_LE_HI20_R foo 0x0
+# LA64-NORELAX-RELOC-NOT: R_LARCH_RELAX - 0x0
+# LA64-RELAX-RELOC: R_LARCH_TLS_LE_HI20_R foo 0x0
+# LA64-RELAX-RELOC: R_LARCH_RELAX - 0x0
+# LA64-RELAX-FIXUP: fixup A - offset: 0, value: %le_hi20_r(foo), kind: FK_NONE
+# LA64-RELAX-FIXUP: fixup B - offset: 0, value: 0, kind: FK_NONE
+
+add.d $a0, $a0, $tp, %le_add_r(foo)
+# LA64-NORELAX-RELOC: R_LARCH_TLS_LE_ADD_R foo 0x0
+# LA64-NORELAX-RELOC-NOT: R_LARCH_RELAX - 0x0
+# LA64-RELAX-RELOC: R_LARCH_TLS_LE_ADD_R foo 0x0
+# LA64-RELAX-RELOC: R_LARCH_RELAX - 0x0
+# LA64-RELAX-FIXUP: fixup A - offset: 0, value: %le_add_r(foo), kind: FK_NONE
+# LA64-RELAX-FIXUP: fixup B - offset: 0, value: 0, kind: FK_NONE
+
+addi.d $a0, $a0, %le_lo12_r(foo)
+# LA64-NORELAX-RELOC: R_LARCH_TLS_LE_LO12_R foo 0x0
+# LA64-NORELAX-RELOC-NOT: R_LARCH_RELAX - 0x0
+# LA64-RELAX-RELOC: R_LARCH_TLS_LE_LO12_R foo 0x0
+# LA64-RELAX-RELOC: R_LARCH_RELAX - 0x0
+# LA64-RELAX-FIXUP: fixup A - offset: 0, value: %le_lo12_r(foo), kind: FK_NONE
+# LA64-RELAX-FIXUP: fixup B - offset: 0, value: 0, kind: FK_NONE
+
+.endif
+