| commit | 3fb8c5b43195d6e11ff0557d07e75700343d369f | [log] [tgz] |
|---|---|---|
| author | mconst <mconst@gmail.com> | Wed Jan 22 23:07:07 2025 -0800 |
| committer | GitHub <noreply@github.com> | Thu Jan 23 12:37:07 2025 +0530 |
| tree | f603afa1730cb722d770f1e0c2934015c989766f | |
| parent | 220004d2f8692e3a224dc75f7a7c6001711d3d58 [diff] |
[X86] Fix invalid instructions on x32 with large stack frames (#124041) `X86FrameLowering::emitSPUpdate()` assumes that 64-bit targets use a 64-bit stack pointer, but that's not true on x32. When checking the stack pointer size, we need to look at `Uses64BitFramePtr` rather than `Is64Bit`. This avoids generating invalid instructions like `add esp, rcx`. For impossibly-large stack frames (4 GiB or larger with a 32-bit stack pointer), we were also generating invalid instructions like `mov eax, 5000000000`. The inline stack probe code already had a check for that situation; I've moved the check into `emitSPUpdate()`, so any attempt to allocate a 4 GiB stack frame with a 32-bit stack pointer will now trap rather than adjusting ESP by the wrong amount. This also fixes the "can't have 32-bit 16GB stack frame" assertion, which used to be triggerable by user code but is now correct. To help catch situations like this in the future, I've added `-verify-machineinstrs` to the stack clash tests that generate large stack frames. This fixes the expensive-checks buildbot failure caused by #113219.
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