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.