[PATCH] D54154: [ELF][MIPS] Use MIPS R6 `sigrie` as a trap instruction

[Simon Atanasyan via Phabricator via llvm-commits]

atanasyan created this revision.
atanasyan added reviewers: ruiu, grimar.
Herald added subscribers: jrtc27, arichardson, sdardis, emaste.
Herald added a reviewer: espindola.

Current value using as a trap instruction (0xefefefef) is not a good choice for MIPS because it's a valid MIPS instruction `swc3 $15,-4113(ra)`. This patch replaces 0xefefefef by 0x04170001. For all MIPS ISA revisions before https://reviews.llvm.org/source/compiler-rt/, this value is just invalid instruction. Starting from MIPS https://reviews.llvm.org/source/compiler-rt/ it's a valid instruction `sigrie 1` which signals a Reserved Instruction exception.

mips-got16-relocatable.s test case is changed to test using this trap instruction. Other test cases are modified to remove redundant checking.


Repository:
  rLLD LLVM Linker

https://reviews.llvm.org/D54154

Files:
  ELF/Arch/Mips.cpp
  test/ELF/mips-got16-relocatable.s
  test/ELF/mips-npic-call-pic-os.s
  test/ELF/mips-npic-call-pic-script.s
  test/ELF/mips-npic-call-pic.s

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