From 4a539596f5d54d3116c5fdebd8be56998757288b Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 2 Feb 2016 08:14:43 -0800 Subject: [PATCH] Store estimated istrances in compressed_size elf_x86_64_convert_load is very time consuming since it is called on each input section and has a loop over input text sections to estimate the branch distrance. We can store the estimated distrances in the compressed_size field of the output section, which is only used to decompress the compressed input section. Before the patch, linking clang 3.9 takes 52 seconds. After the patch, it only takes 2.5 seconds. PR ld/19542 * elf64-x86-64.c (elf_x86_64_convert_load): Store the estimated distrances in the compressed_size field of the output section. --- bfd/ChangeLog | 6 ++++++ bfd/elf64-x86-64.c | 38 +++++++++++++++++++++++--------------- 2 files changed, 29 insertions(+), 15 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 81e751c4ea..e862c3c4b4 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2016-02-02 H.J. Lu + + PR ld/19542 + * elf64-x86-64.c (elf_x86_64_convert_load): Store the estimated + distrances in the compressed_size field of the output section. + 2016-02-02 Alan Modra * elf64-ppc.c (ppc64_elf_relocate_section): Further restrict diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 88ed00e2d1..8118c1dec7 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -3190,35 +3190,43 @@ elf_x86_64_convert_load (bfd *abfd, asection *sec, } else { - asection *asect; - bfd_size_type size; + bfd_signed_vma distance; /* At this point, we don't know the load addresses of TSEC section nor SEC section. We estimate the distrance between - SEC and TSEC. */ - size = 0; - for (asect = sec->output_section; - asect != NULL && asect != tsec->output_section; - asect = asect->next) + SEC and TSEC. We store the estimated distrances in the + compressed_size field of the output section, which is only + used to decompress the compressed input section. */ + if (sec->output_section->compressed_size == 0) { - asection *i; - for (i = asect->output_section->map_head.s; - i != NULL; - i = i->map_head.s) + asection *asect; + bfd_size_type size = 0; + for (asect = link_info->output_bfd->sections; + asect != NULL; + asect = asect->next) { - size = align_power (size, i->alignment_power); - size += i->size; + asection *i; + for (i = asect->map_head.s; + i != NULL; + i = i->map_head.s) + { + size = align_power (size, i->alignment_power); + size += i->size; + } + asect->compressed_size = size; } } /* Don't convert GOTPCREL relocations if TSEC isn't placed after SEC. */ - if (asect == NULL) + distance = (tsec->output_section->compressed_size + - sec->output_section->compressed_size); + if (distance < 0) continue; /* Take PT_GNU_RELRO segment into account by adding maxpagesize. */ - if ((toff + size + maxpagesize - roff + 0x80000000) + if ((toff + distance + maxpagesize - roff + 0x80000000) > 0xffffffff) continue; }