Ian, would you mind looking at this please? A combination of my
-mcall-ms2sysv-xlogues patch with Bernd's patch is causing problems when
ix86_expand_split_stack_prologue() calls ix86_expand_call().
On 05/15/2017 06:46 PM, Daniel Santos wrote:
Rather or not m->call_ms2sysv is set determines which stack layout is
used when ix86_compute_frame_layout() runs. But if we can run
expand_call after the final time ix86_compute_frame_layout() then we
have a problem. It looks like ix86_expand_split_stack_prologue is the
only function that manually calls ix86_expand_call, but maybe it would
be better to modify the test to something like this:
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index a78819d6b3f..c36383f6962 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -29325,7 +29325,7 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx
callarg1,
}
/* Set here, but it may get cleared later. */
- if (TARGET_CALL_MS2SYSV_XLOGUES)
+ if (TARGET_CALL_MS2SYSV_XLOGUES && !reload_completed)
cfun->machine->call_ms2sysv = true;
}
Actually, I think this is wrong. I happened to recall looking at the
morestack code last year and remembered that it was all assembly. I
looked at it again and I don't see that it calls anything outside of
it's implementation file (libgcc/config/i386/morestack.S) except for
_Unwind_Resume and the calling function its self (I think it calls its
caller). It saves and restores rsi and rdi and doesn't use any sse
registers, so it doesn't need to clobber all of the regs in the
x86_64_ms_sysv_extra_clobbered_registers array. I'm guessing that this
should have it's own pattern instead of calling ix86_expand_call in the
first place.
Of course, I'm the new guy here, so please enlighten me if I'm wrong.
Thanks,
Daniel
