[binutils-gdb] Store estimated istrances in compressed_size

[H.J.Lu <hjl at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4a539596f5d54d3116c5fdebd8be56998757288b

commit 4a539596f5d54d3116c5fdebd8be56998757288b
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Tue Feb 2 08:14:43 2016 -0800

    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.

Diff:
---
 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 81e751c..e862c3c 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2016-02-02  H.J. Lu  <hongjiu.lu@intel.com>
+
+	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  <amodra@gmail.com>
 
 	* elf64-ppc.c (ppc64_elf_relocate_section): Further restrict
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 88ed00e..8118c1d 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;
 	}