diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp --- a/llvm/lib/MC/ELFObjectWriter.cpp +++ b/llvm/lib/MC/ELFObjectWriter.cpp @@ -1381,6 +1381,17 @@ if (TargetObjectWriter->getEMachine() == ELF::EM_386 && Type == ELF::R_386_GOTOFF) return true; + + // ld.lld handles R_MIPS_HI16/R_MIPS_LO16 separately, not as a whole, so + // it doesn't know that an R_MIPS_HI16 with implicit addend 1 and an + // R_MIPS_LO16 with implicit addend -32768 represents 32768, which is in + // range of a MergeInputSection. We could introduce a new RelExpr member + // (like R_RISCV_PC_INDIRECT for R_RISCV_PCREL_HI20 / R_RISCV_PCREL_LO12) + // but the complexity is unnecessary given that GNU as keeps the original + // symbol for this case as well. + if (TargetObjectWriter->getEMachine() == ELF::EM_MIPS && + !hasRelocationAddend()) + return true; } // Most TLS relocations use a got, so they need the symbol. Even those that diff --git a/llvm/test/MC/Mips/mips_lo16.s b/llvm/test/MC/Mips/mips_lo16.s new file mode 100644 --- /dev/null +++ b/llvm/test/MC/Mips/mips_lo16.s @@ -0,0 +1,22 @@ +# PR49821: Check that R_MIPS_LO16 relocs do not wrap around with large addends. + +# RUN: llvm-mc %s -triple mips-unknown-unknown -filetype=obj | \ +# RUN: llvm-objdump -d -r --no-show-raw-insn - | \ +# RUN: FileCheck -check-prefix=MIPS32 %s + +# RUN: llvm-mc %s -triple mips64-unknown-unknown -filetype=obj | \ +# RUN: llvm-objdump -d -r --no-show-raw-insn - | \ +# RUN: FileCheck -check-prefix=MIPS64 %s + + .text +foo: + lui $2, %hi(bar) +# MIPS32: 00000000: R_MIPS_HI16 bar +# MIPS64: 0000000000000000: R_MIPS_HI16/R_MIPS_NONE/R_MIPS_NONE .rodata.str1.1+0x8000 + addiu $2, $2, %lo(bar) +# MIPS32: 00000004: R_MIPS_LO16 bar +# MIPS64: 0000000000000004: R_MIPS_LO16/R_MIPS_NONE/R_MIPS_NONE .rodata.str1.1+0x8000 + .section .rodata.str1.1,"aMS",@progbits,1 + .zero 0x8000 +bar: + .asciz "hello"