https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100969
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Keywords| |wrong-debug
Last reconfirmed| |2021-06-09
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
<2><85>: Abbrev Number: 6 (DW_TAG_variable)
<86> DW_AT_name : f
<88> DW_AT_decl_file : 1
<89> DW_AT_decl_line : 8
<8a> DW_AT_decl_column : 12
<8b> DW_AT_type : <0x2d>
<8f> DW_AT_location : 2 byte block: 91 64 (DW_OP_fbreg: -28)
but
(gdb) disassemble
Dump of assembler code for function main:
0x0000000000400497 <+0>: sub $0x18,%rsp
0x000000000040049b <+4>: movl $0x7,0x4(%rsp)
0x00000000004004a3 <+12>: movl $0x8,0x8(%rsp)
=> 0x00000000004004ab <+20>: mov 0x4(%rsp),%rdi
0x00000000004004b0 <+25>: mov $0x9,%esi
0x00000000004004b5 <+30>: call 0x400496 <not_opt>
you see the var on the frame has not been fully initialized but instead
the full variable is in the call argument registers %rdi and %esi only.