https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91515
Bug ID: 91515
Summary: missed optimization: no tailcall for types of class
MEMORY
Product: gcc
Version: 9.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: no...@turm-lahnstein.de
Target Milestone: ---
Produced assembler (-O2) for
struct Vec3{
double x, y, z;
};
struct Vec3 create(void);
struct Vec3 use(){
return create();
}
looks as follows (live: https://godbolt.org/z/v-HjX0):
use:
pushq %r12
movq %rdi, %r12
call create
movq %r12, %rax
popq %r12
ret
Hower, I think that under System V AMD64 - ABI, the tailcall optimization:
use:
jmp create
as create will move %rdi-value to %rax anyway.
