https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108315
Bug ID: 108315
Summary: -mcpu=power10 changes ABI
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Keywords: ABI, wrong-code
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: amonakov at gcc dot gnu.org
Target Milestone: ---
Target: powerpc64le-*-*
Created attachment 54202
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54202&action=edit
testcase
At least the documentation should mention that if intentional.
In the attached example, the function bar is compiled to
bar:
.localentry bar,1
mtctr 3
mr 12,3
bctr
.long 0
.byte 0,0,0,0,0,0,0,0
i.e. it does not preserve r2 (it's compiled with -mcpu=power10). If the caller
is not compiled with -mcpu=power10, it needs r2 preserved (bar has a
localentry, so the nop in the caller stays a nop after linking).
I verified the testcase misbehaves on Compile Farm's gcc135: as it does not use
any power10-specific instructions, it's runnable there.
