[PATCH] D158169: [X86] Fix i128 argument passing under SysV ABI

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added reviewers: pengfei, craig.topper, efriedma.
Herald added subscribers: StephenFan, hiraditya.
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The x86_64 SysV ABI specifies that `__int128` is passed either in two registers (if available) or in a 16 byte aligned stack slot. GCC implements this behavior. However, if only one free register is available, LLVM will instead pass one half of the i128 in a register, and the other on the stack.

Make sure that either both are passed in registers or both on the stack.

Fixes https://github.com/llvm/llvm-project/issues/41784. The patch is basically what @craig.topper proposed to do there.


https://reviews.llvm.org/D158169

Files:
  llvm/lib/Target/X86/X86CallingConv.td
  llvm/test/CodeGen/X86/addcarry.ll
  llvm/test/CodeGen/X86/i128-abi.ll
  llvm/test/CodeGen/X86/sadd_sat_vec.ll
  llvm/test/CodeGen/X86/ssub_sat_vec.ll
  llvm/test/CodeGen/X86/subcarry.ll
  llvm/test/CodeGen/X86/uadd_sat_vec.ll
  llvm/test/CodeGen/X86/usub_sat_vec.ll

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