/* Original C (for context): * // Declare a real external call so the compiler must respect ABI clobbers. * extern int leaf(int) __attribute__((noinline)); * * __attribute__((noinline)) * int live_across_call(int x) { * volatile int a = x; // a starts in a GPR (from arg) * asm volatile("" :: "r"(a)); // keep 'a' live in a register * int r = leaf(a); // 'a' is live across the call * asm volatile("" :: "r"(a), "r"(r));// still live afterwards * return a + r; * } */ .file "live_across_call.c" .text .globl live_across_call # -- Begin function live_across_call .p2align 4 .type live_across_call,@function live_across_call: # @live_across_call .Lfunc_begin0: .file 0 "." "live_across_call.c" md5 0x351c37295026edf0d468774d35f47e5e .loc 0 5 0 # live_across_call.c:5:0 .cfi_startproc # %bb.0: # %entry #DEBUG_VALUE: live_across_call:x <- $edi pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset %rbp, -16 movq %rsp, %rbp .cfi_def_cfa_register %rbp subq $16, %rsp .Ltmp0: .loc 0 6 16 prologue_end # live_across_call.c:6:16 movl %edi, -4(%rbp) .loc 0 7 26 # live_across_call.c:7:26 movl -4(%rbp), %eax .loc 0 7 3 is_stmt 0 # live_across_call.c:7:3 #APP #NO_APP .loc 0 8 16 is_stmt 1 # live_across_call.c:8:16 movl -4(%rbp), %edi .Ltmp1: #DEBUG_VALUE: live_across_call:x <- [DW_OP_LLVM_entry_value 1] $edi .loc 0 8 11 is_stmt 0 # live_across_call.c:8:11 callq leaf@PLT .Ltmp2: #DEBUG_VALUE: live_across_call:r <- $eax .loc 0 9 26 is_stmt 1 # live_across_call.c:9:26 movl -4(%rbp), %ecx .loc 0 9 3 is_stmt 0 # live_across_call.c:9:3 #APP #NO_APP .loc 0 10 12 is_stmt 1 # live_across_call.c:10:12 addl -4(%rbp), %eax .Ltmp3: .loc 0 10 3 epilogue_begin is_stmt 0 # live_across_call.c:10:3 addq $16, %rsp popq %rbp .cfi_def_cfa %rsp, 8 retq .Ltmp4: .Lfunc_end0: .size live_across_call, .Lfunc_end0-live_across_call .cfi_endproc # -- End function .section .debug_loclists,"",@progbits .long .Ldebug_list_header_end0-.Ldebug_list_header_start0 # Length .Ldebug_list_header_start0: .short 5 # Version .byte 8 # Address size .byte 0 # Segment selector size .long 2 # Offset entry count .Lloclists_table_base0: .long .Ldebug_loc0-.Lloclists_table_base0 .long .Ldebug_loc1-.Lloclists_table_base0 .Ldebug_loc0: .byte 4 # DW_LLE_offset_pair .uleb128 .Lfunc_begin0-.Lfunc_begin0 # starting offset .uleb128 .Ltmp1-.Lfunc_begin0 # ending offset .byte 1 # Loc expr size .byte 85 # super-register DW_OP_reg5 .byte 4 # DW_LLE_offset_pair .uleb128 .Ltmp1-.Lfunc_begin0 # starting offset .uleb128 .Lfunc_end0-.Lfunc_begin0 # ending offset .byte 4 # Loc expr size .byte 163 # DW_OP_entry_value .byte 1 # 1 .byte 85 # super-register DW_OP_reg5 .byte 159 # DW_OP_stack_value .byte 0 # DW_LLE_end_of_list .Ldebug_loc1: .byte 4 # DW_LLE_offset_pair .uleb128 .Ltmp2-.Lfunc_begin0 # starting offset .uleb128 .Ltmp3-.Lfunc_begin0 # ending offset .byte 1 # Loc expr size .byte 80 # super-register DW_OP_reg0 .byte 0 # DW_LLE_end_of_list .Ldebug_list_header_end0: .section .debug_abbrev,"",@progbits .byte 1 # Abbreviation Code .byte 17 # DW_TAG_compile_unit .byte 1 # DW_CHILDREN_yes .byte 37 # DW_AT_producer .byte 37 # DW_FORM_strx1 .byte 19 # DW_AT_language .byte 5 # DW_FORM_data2 .byte 3 # DW_AT_name .byte 37 # DW_FORM_strx1 .byte 114 # DW_AT_str_offsets_base .byte 23 # DW_FORM_sec_offset .byte 16 # DW_AT_stmt_list .byte 23 # DW_FORM_sec_offset .byte 27 # DW_AT_comp_dir .byte 37 # DW_FORM_strx1 .byte 17 # DW_AT_low_pc .byte 27 # DW_FORM_addrx .byte 18 # DW_AT_high_pc .byte 6 # DW_FORM_data4 .byte 115 # DW_AT_addr_base .byte 23 # DW_FORM_sec_offset .ascii "\214\001" # DW_AT_loclists_base .byte 23 # DW_FORM_sec_offset .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 2 # Abbreviation Code .byte 46 # DW_TAG_subprogram .byte 1 # DW_CHILDREN_yes .byte 17 # DW_AT_low_pc .byte 27 # DW_FORM_addrx .byte 18 # DW_AT_high_pc .byte 6 # DW_FORM_data4 .byte 64 # DW_AT_frame_base .byte 24 # DW_FORM_exprloc .byte 122 # DW_AT_call_all_calls .byte 25 # DW_FORM_flag_present .byte 3 # DW_AT_name .byte 37 # DW_FORM_strx1 .byte 58 # DW_AT_decl_file .byte 11 # DW_FORM_data1 .byte 59 # DW_AT_decl_line .byte 11 # DW_FORM_data1 .byte 39 # DW_AT_prototyped .byte 25 # DW_FORM_flag_present .byte 73 # DW_AT_type .byte 19 # DW_FORM_ref4 .byte 63 # DW_AT_external .byte 25 # DW_FORM_flag_present .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 3 # Abbreviation Code .byte 5 # DW_TAG_formal_parameter .byte 0 # DW_CHILDREN_no .byte 2 # DW_AT_location .byte 34 # DW_FORM_loclistx .byte 3 # DW_AT_name .byte 37 # DW_FORM_strx1 .byte 58 # DW_AT_decl_file .byte 11 # DW_FORM_data1 .byte 59 # DW_AT_decl_line .byte 11 # DW_FORM_data1 .byte 73 # DW_AT_type .byte 19 # DW_FORM_ref4 .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 4 # Abbreviation Code .byte 52 # DW_TAG_variable .byte 0 # DW_CHILDREN_no .byte 2 # DW_AT_location .byte 24 # DW_FORM_exprloc .byte 3 # DW_AT_name .byte 37 # DW_FORM_strx1 .byte 58 # DW_AT_decl_file .byte 11 # DW_FORM_data1 .byte 59 # DW_AT_decl_line .byte 11 # DW_FORM_data1 .byte 73 # DW_AT_type .byte 19 # DW_FORM_ref4 .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 5 # Abbreviation Code .byte 52 # DW_TAG_variable .byte 0 # DW_CHILDREN_no .byte 2 # DW_AT_location .byte 34 # DW_FORM_loclistx .byte 3 # DW_AT_name .byte 37 # DW_FORM_strx1 .byte 58 # DW_AT_decl_file .byte 11 # DW_FORM_data1 .byte 59 # DW_AT_decl_line .byte 11 # DW_FORM_data1 .byte 73 # DW_AT_type .byte 19 # DW_FORM_ref4 .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 6 # Abbreviation Code .byte 72 # DW_TAG_call_site .byte 0 # DW_CHILDREN_no .byte 127 # DW_AT_call_origin .byte 19 # DW_FORM_ref4 .byte 125 # DW_AT_call_return_pc .byte 27 # DW_FORM_addrx .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 7 # Abbreviation Code .byte 46 # DW_TAG_subprogram .byte 1 # DW_CHILDREN_yes .byte 3 # DW_AT_name .byte 37 # DW_FORM_strx1 .byte 58 # DW_AT_decl_file .byte 11 # DW_FORM_data1 .byte 59 # DW_AT_decl_line .byte 11 # DW_FORM_data1 .byte 39 # DW_AT_prototyped .byte 25 # DW_FORM_flag_present .byte 73 # DW_AT_type .byte 19 # DW_FORM_ref4 .byte 60 # DW_AT_declaration .byte 25 # DW_FORM_flag_present .byte 63 # DW_AT_external .byte 25 # DW_FORM_flag_present .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 8 # Abbreviation Code .byte 5 # DW_TAG_formal_parameter .byte 0 # DW_CHILDREN_no .byte 73 # DW_AT_type .byte 19 # DW_FORM_ref4 .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 9 # Abbreviation Code .byte 36 # DW_TAG_base_type .byte 0 # DW_CHILDREN_no .byte 3 # DW_AT_name .byte 37 # DW_FORM_strx1 .byte 62 # DW_AT_encoding .byte 11 # DW_FORM_data1 .byte 11 # DW_AT_byte_size .byte 11 # DW_FORM_data1 .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 10 # Abbreviation Code .byte 53 # DW_TAG_volatile_type .byte 0 # DW_CHILDREN_no .byte 73 # DW_AT_type .byte 19 # DW_FORM_ref4 .byte 0 # EOM(1) .byte 0 # EOM(2) .byte 0 # EOM(3) .section .debug_info,"",@progbits .Lcu_begin0: .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit .Ldebug_info_start0: .short 5 # DWARF version number .byte 1 # DWARF Unit Type .byte 8 # Address Size (in bytes) .long .debug_abbrev # Offset Into Abbrev. Section .byte 1 # Abbrev [1] 0xc:0x66 DW_TAG_compile_unit .byte 0 # DW_AT_producer .short 29 # DW_AT_language .byte 1 # DW_AT_name .long .Lstr_offsets_base0 # DW_AT_str_offsets_base .long .Lline_table_start0 # DW_AT_stmt_list .byte 2 # DW_AT_comp_dir .byte 0 # DW_AT_low_pc .long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc .long .Laddr_table_base0 # DW_AT_addr_base .long .Lloclists_table_base0 # DW_AT_loclists_base .byte 2 # Abbrev [2] 0x27:0x33 DW_TAG_subprogram .byte 0 # DW_AT_low_pc .long .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc .byte 1 # DW_AT_frame_base .byte 86 # DW_AT_call_all_calls .byte 5 # DW_AT_name .byte 0 # DW_AT_decl_file .byte 5 # DW_AT_decl_line # DW_AT_prototyped .long 104 # DW_AT_type # DW_AT_external .byte 3 # Abbrev [3] 0x36:0x9 DW_TAG_formal_parameter .byte 0 # DW_AT_location .byte 7 # DW_AT_name .byte 0 # DW_AT_decl_file .byte 5 # DW_AT_decl_line .long 104 # DW_AT_type .byte 4 # Abbrev [4] 0x3f:0xb DW_TAG_variable .byte 2 # DW_AT_location .byte 145 .byte 124 .byte 6 # DW_AT_name .byte 0 # DW_AT_decl_file .byte 6 # DW_AT_decl_line .long 108 # DW_AT_type .byte 5 # Abbrev [5] 0x4a:0x9 DW_TAG_variable .byte 1 # DW_AT_location .byte 8 # DW_AT_name .byte 0 # DW_AT_decl_file .byte 8 # DW_AT_decl_line .long 104 # DW_AT_type .byte 6 # Abbrev [6] 0x53:0x6 DW_TAG_call_site .long 90 # DW_AT_call_origin .byte 1 # DW_AT_call_return_pc .byte 0 # End Of Children Mark .byte 7 # Abbrev [7] 0x5a:0xe DW_TAG_subprogram .byte 3 # DW_AT_name .byte 0 # DW_AT_decl_file .byte 2 # DW_AT_decl_line # DW_AT_prototyped .long 104 # DW_AT_type # DW_AT_declaration # DW_AT_external .byte 8 # Abbrev [8] 0x62:0x5 DW_TAG_formal_parameter .long 104 # DW_AT_type .byte 0 # End Of Children Mark .byte 9 # Abbrev [9] 0x68:0x4 DW_TAG_base_type .byte 4 # DW_AT_name .byte 5 # DW_AT_encoding .byte 4 # DW_AT_byte_size .byte 10 # Abbrev [10] 0x6c:0x5 DW_TAG_volatile_type .long 104 # DW_AT_type .byte 0 # End Of Children Mark .Ldebug_info_end0: .section .debug_str_offsets,"",@progbits .long 40 # Length of String Offsets Set .short 5 .short 0 .Lstr_offsets_base0: .section .debug_str,"MS",@progbits,1 .Linfo_string0: .asciz "clang version 22.0.0git (https://github.com/UltimateForce21/llvm-project.git 79c0a9e1e7da0f727c41d27c9c6ff8a28bb7d06f)" # string offset=0 .Linfo_string1: .asciz "live_across_call.c" # string offset=119 .Linfo_string2: .asciz "." # string offset=138 .Linfo_string3: .asciz "leaf" # string offset=140 .Linfo_string4: .asciz "int" # string offset=145 .Linfo_string5: .asciz "live_across_call" # string offset=149 .Linfo_string6: .asciz "a" # string offset=166 .Linfo_string7: .asciz "x" # string offset=168 .Linfo_string8: .asciz "r" # string offset=170 .section .debug_str_offsets,"",@progbits .long .Linfo_string0 .long .Linfo_string1 .long .Linfo_string2 .long .Linfo_string3 .long .Linfo_string4 .long .Linfo_string5 .long .Linfo_string6 .long .Linfo_string7 .long .Linfo_string8 .section .debug_addr,"",@progbits .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution .Ldebug_addr_start0: .short 5 # DWARF version number .byte 8 # Address size .byte 0 # Segment selector size .Laddr_table_base0: .quad .Lfunc_begin0 .quad .Ltmp2 .Ldebug_addr_end0: .ident "clang version 22.0.0git (https://github.com/UltimateForce21/llvm-project.git 79c0a9e1e7da0f727c41d27c9c6ff8a28bb7d06f)" .section ".note.GNU-stack","",@progbits .addrsig .section .debug_line,"",@progbits .Lline_table_start0: