The fact that both options accept negative forms suggests that maybe they aren't negative forms of each other. They are, but that isn't clear even by examining common.opt. Use NegativeAlias to make it abundantly clear.
The 'Optimization' keyword next to freg-struct-return was the only thing that caused flag_pcc_struct_return to be a per-function flag, and ipa-inline relied on that. After making it an alias, the Optimization keyword was no longer operational. I'm not sure it was sensible or desirable for flag_pcc_struct_return to be a per-function setting, but this patch does not intend to change behavior. Regstrapped on x86_64-linux-gnu and ppc64le-linux-gnu. Ok to install? for gcc/ChangeLog * common.opt (freg-struct-return): Make it explicitly fpcc-struct-return's NegativeAlias. Copy Optimization... (freg-struct-return): ... here. --- gcc/common.opt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/gcc/common.opt b/gcc/common.opt index ad3488447752b..12d93c76a1e63 100644 --- a/gcc/common.opt +++ b/gcc/common.opt @@ -2406,7 +2406,7 @@ Common RejectNegative Joined UInteger Optimization -fpack-struct=<number> Set initial maximum structure member alignment. fpcc-struct-return -Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN) +Common Var(flag_pcc_struct_return,1) Init(DEFAULT_PCC_STRUCT_RETURN) Optimization Return small aggregates in memory, not registers. fpeel-loops @@ -2596,7 +2596,7 @@ Common Var(flag_record_gcc_switches) Record gcc command line switches in the object file. freg-struct-return -Common Var(flag_pcc_struct_return,0) Optimization +Common NegativeAlias Alias(fpcc_struct_return) Optimization Return small aggregates in registers. fregmove -- Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/ Free Software Activist GNU Toolchain Engineer More tolerance and less prejudice are key for inclusion and diversity Excluding neuro-others for not behaving ""normal"" is *not* inclusive