https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108996
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
What is done on other arches? I mean the situation is basically the same on
x86_64,
where the artificial return value pointer argument is spilled early, then
clobbered
on calls and again b debug info is correct after the spill:
pushq %rbp
movq %rsp, %rbp
subq $16, %rsp
movq %rdi, -8(%rbp)
movl %esi, -12(%rbp)
movl %edx, -16(%rbp)
movq -8(%rbp), %rax
movq %rax, %rdi
call _ZN1BC1Ev
movl -12(%rbp), %edx
movl -16(%rbp), %eax
addl %eax, %edx
movq -8(%rbp), %rax
movl %edx, (%rax)
nop
movq -8(%rbp), %rax
leave
ret
...
.byte 0x1 # uleb128 0x1; (DIE (0xcc) DW_TAG_variable)
.ascii "b\0" # DW_AT_name
# DW_AT_decl_file (1, pr108996.C)
.byte 0x1f # DW_AT_decl_line
.byte 0x8 # DW_AT_decl_column
.long 0x2a # DW_AT_type
.byte 0x2 # uleb128 0x2; DW_AT_location
.byte 0x91 # DW_OP_fbreg
.byte 0x64 # sleb128 -28
