Hi!
http://dwarfstd.org/ShowIssue.php?issue=161102.1
got accepted today, so DWARF5 is going to use uleb128 sizes instead of
2-byte sizes in .debug_loclists section.
On a randomly chosen *.i file I had around, this results in shrinking
of .debug_loclists section size from 0xef7df to 0xddd65, so around 7.5%
saving, not too bad.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Jan/Mark, are you going to adjust the consumers accordingly? Thanks.
2017-01-03 Jakub Jelinek <ja...@redhat.com>
* dwarf2out.c (output_loc_list): Don't throw away 64K+ location
descriptions for -gdwarf-5 and emit them as uleb128 instead of
2-byte data.
--- gcc/dwarf2out.c.jj 2017-01-03 19:41:45.000000000 +0100
+++ gcc/dwarf2out.c 2017-01-03 20:58:21.304628767 +0100
@@ -9590,7 +9590,7 @@ output_loc_list (dw_loc_list_ref list_he
perhaps put it into DW_TAG_dwarf_procedure and refer to that
in the expression, but >= 64KB expressions for a single value
in a single range are unlikely very useful. */
- if (size > 0xffff)
+ if (dwarf_version < 5 && size > 0xffff)
continue;
if (dwarf_version >= 5)
{
@@ -9642,8 +9642,6 @@ output_loc_list (dw_loc_list_ref list_he
if (strcmp (curr2->begin, curr2->end) == 0
&& !curr2->force)
continue;
- if ((unsigned long) size_of_locs (curr2->expr) > 0xffff)
- continue;
break;
}
if (curr2 == NULL || curr->section != curr2->section)
@@ -9744,8 +9742,13 @@ output_loc_list (dw_loc_list_ref list_he
}
/* Output the block length for this list of location operations. */
- gcc_assert (size <= 0xffff);
- dw2_asm_output_data (2, size, "%s", "Location expression size");
+ if (dwarf_version >= 5)
+ dw2_asm_output_data_uleb128 (size, "Location expression size");
+ else
+ {
+ gcc_assert (size <= 0xffff);
+ dw2_asm_output_data (2, size, "Location expression size");
+ }
output_loc_sequence (curr->expr, -1);
}
Jakub
