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Wrong mappin of registers in location lists
- From: Michal Ludvig <mludvig at suse dot cz>
- To: Josef Zlomek <zlomekj at suse dot cz>,Daniel Berlin <dberlin at dberlin dot org>, GCC list <gcc at gcc dot gnu dot org>
- Date: Fri, 14 Feb 2003 17:04:18 +0100
- Subject: Wrong mappin of registers in location lists
- Organization: SuSE CR
Hi again,
as far as I can see gcc outputs wrong information to .debug_loc on
x86-64. This is the assembler output:
main:
.LVL22:
pushq %rbx
movl %edi, %ebx
.LVL23:
leal 1(%rbx), %edi
subq $416, %rsp
[...]
This is DIE of argc:
.uleb128 0x3 # (DIE (0xef) DW_TAG_formal_parameter)
.long .LASF4 # DW_AT_name: "argc"
.byte 0x1 # DW_AT_decl_file
.byte 0x17 # DW_AT_decl_line
.long 0x8f # DW_AT_type
.long .LLST3-.Ldebug_loc0 # DW_AT_location
And finally location list of argc:
.LLST3:
.quad .LVL22-.text # Location list begin address (*.LLST3)
.quad .LVL23-.text # Location list end address (*.LLST3)
.value 0x1 # Location expression size
.byte 0x55 # DW_OP_reg5
.quad .LVL23-.text # Location list begin address (*.LLST3)
.quad .LFE7-.text # Location list end address (*.LLST3)
.value 0x1 # Location expression size
.byte 0x53 # DW_OP_reg3
.quad 0x0 # Location list terminator begin (*.LLST3)
.quad 0x0 # Location list terminator end (*.LLST3)
At the entry of the function (.LVL22), argc is dwarf2 register 5
(DW_OP_reg5), ie %rdi on x86-64. From .LVL23 on it is saved in %rbx, ie.
DW_OP_reg1. However debug information says it's in DW_OP_reg3, ie. %rdx.
Something is apparantly wrong - just don't know if it's wrong on Josef's
or Daniel's side. Or perhaps somewhere else...
Michal Ludvig
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