diff options
| -rw-r--r-- | gold/ChangeLog | 9 | ||||
| -rw-r--r-- | gold/gc.h | 4 | ||||
| -rw-r--r-- | gold/icf.cc | 21 | ||||
| -rw-r--r-- | gold/icf.h | 13 |
4 files changed, 35 insertions, 12 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog index 22957ec..ef1b6f2 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,12 @@ +2010-01-04 Sriraman Tallam <tmsriram@google.com> + + * gc.h (gc_process_relocs): Call is_section_foldable_candidate to + check for .text or .gnu.linkonce.t sections. + * icf.cc (Icf::find_identical_sections): Ditto. + Change the detection for mangled function name within the section + name. + * icf.h (is_section_foldable_candidate): New function. + 2009-12-30 Ian Lance Taylor <iant@google.com> PR 10980 @@ -1,6 +1,6 @@ // gc.h -- garbage collection of unused sections -// Copyright 2009 Free Software Foundation, Inc. +// Copyright 2009, 2010 Free Software Foundation, Inc. // Written by Sriraman Tallam <tmsriram@google.com>. // This file is part of gold. @@ -163,7 +163,7 @@ gc_process_relocs( bool is_icf_tracked = false; if (parameters->options().icf_enabled() - && is_prefix_of(".text.", (src_obj)->section_name(src_indx).c_str())) + && is_section_foldable_candidate(src_obj->section_name(src_indx).c_str())) { is_icf_tracked = true; Section_id src_id(src_obj, src_indx); diff --git a/gold/icf.cc b/gold/icf.cc index 03b927a..48cb9bf 100644 --- a/gold/icf.cc +++ b/gold/icf.cc @@ -1,6 +1,6 @@ // icf.cc -- Identical Code Folding. // -// Copyright 2009 Free Software Foundation, Inc. +// Copyright 2009, 2010 Free Software Foundation, Inc. // Written by Sriraman Tallam <tmsriram@google.com>. // This file is part of gold. @@ -23,7 +23,7 @@ // Identical Code Folding Algorithm // ---------------------------------- // Detecting identical functions is done here and the basic algorithm -// is as follows. A checksum is computed on each .text section using +// is as follows. A checksum is computed on each foldable section using // its contents and relocations. If the symbol name corresponding to // a relocation is known it is used to compute the checksum. If the // symbol name is not known the stringified name of the object and the @@ -34,8 +34,8 @@ // checking the contents when two sections have the same checksum. // // However, two functions A and B with identical text but with -// relocations pointing to different .text sections can be identical if -// the corresponding .text sections to which their relocations point to +// relocations pointing to different foldable sections can be identical if +// the corresponding foldable sections to which their relocations point to // turn out to be identical. Hence, this checksumming process must be // done repeatedly until convergence is obtained. Here is an example for // the following case : @@ -102,7 +102,7 @@ // behaviour. // // -// How to run : --icf +// How to run : --icf=[safe|all|none] // Optional parameters : --icf-iterations <num> --print-icf-sections // // Performance : Less than 20 % link-time overhead on industry strength @@ -570,17 +570,20 @@ Icf::find_identical_sections(const Input_objects* input_objects, for (unsigned int i = 0;i < (*p)->shnum(); ++i) { const char* section_name = (*p)->section_name(i).c_str(); - // Only looking to fold functions, so just look at .text sections. - if (!is_prefix_of(".text.", section_name)) + if (!is_section_foldable_candidate(section_name)) continue; if (!(*p)->is_section_included(i)) continue; if (parameters->options().gc_sections() && symtab->gc()->is_section_garbage(*p, i)) continue; - // With --icf=safe, check if mangled name is a ctor or a dtor. + // With --icf=safe, check if the mangled function name is a ctor + // or a dtor. The mangled function name can be obtained from the + // section name by stripping the section prefix. + const char* mangled_func_name = strrchr(section_name, '.'); + gold_assert(mangled_func_name != NULL); if (parameters->options().icf_safe_folding() - && !is_function_ctor_or_dtor(section_name + 6)) + && !is_function_ctor_or_dtor(mangled_func_name + 1)) continue; this->id_section_.push_back(Section_id(*p, i)); this->section_id_[Section_id(*p, i)] = section_num; @@ -1,6 +1,6 @@ // icf.h -- Identical Code Folding -// Copyright 2009 Free Software Foundation, Inc. +// Copyright 2009, 2010 Free Software Foundation, Inc. // Written by Sriraman Tallam <tmsriram@google.com>. // This file is part of gold. @@ -139,6 +139,17 @@ class Icf Addend_list addend_reloc_list_; }; +// This function returns true if this section corresponds to a function that +// should be considered by icf as a possible candidate for folding. Some +// earlier gcc versions, like 4.0.3, put constructors and destructors in +// .gnu.linkonce.t sections and hence should be included too. +inline bool +is_section_foldable_candidate(const char* section_name) +{ + return (is_prefix_of(".text", section_name) + || is_prefix_of(".gnu.linkonce.t", section_name)); +} + } // End of namespace gold. #endif |