Em Wed, May 21, 2008 at 02:04:26PM +0200, Diego 'Flameeyes' Pettenò escreveu: > > While cleaning up xine-lib's code I found another interesting thing: > > send_ogg_buf | +24 # 3671 -> 3695, # inlines: 0 -> 1, size inlines: 0 -> 859 > send_header | -116 # 7812 -> 7696, # inlines: 13 -> 1, size inlines: 6765 -> 418 > > I'm not sure if this is correct, but if the size of inlines increases so > much and decreases so much, I'd expect the size of the function to > follow suit.. > > The ELF files causing this are at > http://www.flameeyes.eu/tmp/dwarves-notsure.tbz2 . [acme@doppio pahole]$ pfunct -TVi --function send_ogg_buf modified.so | tail int stream_num); /* size=596, low_pc=0x30f3 */ // 646 } /* lexblock size=800 */ { /* send_ogg_buf+0x970 */ const buf_element_t * buf; // 686 const uint32_t * val; // 692 const char * str; // 693 } /* lexblock size=128 */ read_chapter_comment(demux_ogg_t * this, ogg_packet * op); /* size=859, low_pc=0x3460 */ // 657 }/* size: 3695, variables: 3, inline expansions: 1 (859 bytes) */ [acme@doppio pahole]$ in send_ogg_buf we got only one new inline, read_chapter_comment, and this one uses the DW_AT_ranges attribute: <2><552a>: Abbrev Number: 66 (DW_TAG_inlined_subroutine) <552b> DW_AT_abstract_origin: <0x5165> <552f> DW_AT_ranges : 0x4c0 <5533> DW_AT_call_file : 1 <5534> DW_AT_call_line : 657 IIRC this means that the the way the code in the inline was inserted into the target function (send_ogg_buf) wasn't linear... It would be a good idea to create a function that is not inline and includes just read_chapter_comment, produce an object and then disassemble it, then disassemble send_ogg_buf so that we could check the difference trying to validate the code in the dwarves that handles DW__AT_ranges, that is in inline_expansion__new, and that looks quite fishy :-\ send_header, had 13 inline expansions and now has just 1, the only one now is: <3><5afa>: Abbrev Number: 79 (DW_TAG_inlined_subroutine) <5afb> DW_AT_abstract_origin: <0x5600> <5aff> DW_AT_low_pc : 0x3e12 <5b07> DW_AT_high_pc : 0x40e5 <5b0f> DW_AT_call_file : 1 <5b10> DW_AT_call_line : 1337 <5b12> DW_AT_sibling : <0x5b80> That doesn't use DW_AT_ranges, so we can just do a 0x40e5 - 0x3e12 and get 712 bytes... We're not accounting lex block nesting, we have inline expansions inside lex blocks, working on that now. - Arnaldo -- To unsubscribe from this list: send the line "unsubscribe dwarves" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
