Differential revision: https://reviews.llvm.org/D26834

llvm-svn: 287326

llvm-svn: 287325

llvm-svn: 287324

llvm-svn: 287323

Differential revision: https://reviews.llvm.org/D26792

llvm-svn: 287322

readVersionDeclaration was to read anonymous version definition and
named version definition. Splitting it into two functions should
improve readability as the two cases are different enough.

I also changed a few helper functions to return values instead of
mutating given references.

llvm-svn: 287319

llvm-svn: 287318

MergeOutputSection class was a bit hard to use because it provdes
a series of finalize functions that have to be called in a right way
at a right time. It also intereacted with MergeInputSection, and the
logic was somewhat entangled between the two classes.

This patch simplifies it by providing only one finalize function.
Now, all you have to do is to call MergeOutputSection::finalize
when you have added all sections to the output section. Then, it
internally merges strings and initliazes StringPiece objects.
I think this is much easier to understand.

This patch also adds comments.

llvm-svn: 287314

llvm-svn: 287297

llvm-svn: 287296

llvm-svn: 287284

Since the output has a section table too, it is meaningful to compute
the sh_link. In a more practical note, the binutils' strip crashes if
sh_link is not set for SHT_ARM_EXIDX.

llvm-svn: 287280

Also add new comments with MIPS GOT description.

llvm-svn: 287264

I hit an internal linker script that was defining _DYNAMIC instead of
letting the linker do it. It turns out that both bfd and gold allow
that.

This is pretty easy to implement, just make the linker defined symbol
weak. This should have no impact in the case where there is no user
defined symbol: The visibility is hidden, which causes the output to
still be local.

llvm-svn: 287260

Linker script doesn't create a section if it has no content. So the following
script doesn't create .norelocs section if it doesn't have any .rel* sections.

  .norelocs : { *(.rel*) }

Later, if you assert that the size of .norelocs is 0, LLD printed out
an error message, because it didn't allow calling SIZEOF() on nonexistent
sections.

This patch allows SIZEOF() on nonexistent sections, so that you can do
something like this.

  ASSERT(SIZEOF(.norelocs), "shouldn't contain .rel sections!")

Note that this behavior is compatible with GNU.

Differential Revision: https://reviews.llvm.org/D26810

llvm-svn: 287257

llvm-svn: 287254

llvm-svn: 287253

llvm-svn: 287252

LLD supports multi-threading, and it seems to be working well as
you can see in r287140. In short, LLD runs a few percent to 30%
faster with -threads and more than 50% faster if you are using
-build-id (your mileage may vary depending on your computer).

However, I don't think most users even don't know about that because
-threads is not a default option.

This patch enables it by default.

Discussion thread:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107160.html

llvm-svn: 287237

llvm-svn: 287234

llvm-svn: 287231

llvm-svn: 287225

llvm-svn: 287218

Differential revision: https://reviews.llvm.org/D26740

llvm-svn: 287216

This patch updates a couple places where add_dependencies was being explicitly called to add dependencies on intrinsics_gen to instead use the DEPENDS named parameter. This cleanup is needed for a patch I'm working on to add a dependency debugging mode to the build system.

llvm-svn: 287205

llvm-svn: 287202

llvm-svn: 287200

Because it is uint16_t in the ELF spec. Using size_t was confusing.

llvm-svn: 287198

llvm-svn: 287197

We used to create a vector contantaining all version definitions
with wildcards because doing that was efficient. All patterns were
compiled to a regexp and matched against symbol names. Because
a regexp can be converted to a DFA, matching against union of patterns
is as cheap as matching against one patter.

We are no longer converting them to regexp. Our own glob pattern
handler doesn't do such optimization. Therefore, creating a vector
no longer makes sense.

llvm-svn: 287196

llvm-svn: 287192

llvm-svn: 287191

MIPS GOT handling is very different from other targets so it is better
to keep the code in the separatre section class MipsGotSection. This
patch introduces the new section and moves all MIPS specific code from
GotSection to the new class. I did not rename fields and methods in the
MipsGotSection class to reduce the diff and plan to do that by the
separate commit.

Differential revision: https://reviews.llvm.org/D26733

llvm-svn: 287150

Apparently this is wrong because it's legal to have a filename
on UNIX which contains a backslash.

Differential Revision:  https://reviews.llvm.org/D26734

llvm-svn: 287143

TaskGroup has a fairly high overhead, so we don't want to partition
tasks into too small tasks. This patch partition tasks into up to
1024 tasks.

I compared this patch with the original LLD's parallel_for_each.
I reverted r287042 locally for comparison.

With this patch, time to self-link lld with debug info changed from
6.23 seconds to 4.62 seconds (-25.8%), with -threads and without -build-id.
With both -threads and -build-id, it improved from 11.71 seconds
to 4.94 seconds (-57.8%). Full results are below.

BTW, GNU gold takes 11.65 seconds to link the same binary.

NOW

--no-threads --build-id=none
       6789.847776 task-clock (msec)         #    1.000 CPUs utilized            ( +-  1.86% )
               685 context-switches          #    0.101 K/sec                    ( +-  2.82% )
                 4 cpu-migrations            #    0.001 K/sec                    ( +- 31.18% )
         1,424,690 page-faults               #    0.210 M/sec                    ( +-  1.07% )
    21,339,542,522 cycles                    #    3.143 GHz                      ( +-  1.49% )
    13,092,260,230 stalled-cycles-frontend   #   61.35% frontend cycles idle     ( +-  2.23% )
   <not supported> stalled-cycles-backend
    21,462,051,828 instructions              #    1.01  insns per cycle
                                             #    0.61  stalled cycles per insn  ( +-  0.41% )
     3,955,296,378 branches                  #  582.531 M/sec                    ( +-  0.39% )
        75,699,909 branch-misses             #    1.91% of all branches          ( +-  0.08% )

       6.787630744 seconds time elapsed                                          ( +-  1.86% )

--threads --build-id=none
      14767.148697 task-clock (msec)         #    3.196 CPUs utilized            ( +-  2.56% )
            28,891 context-switches          #    0.002 M/sec                    ( +-  1.99% )
               905 cpu-migrations            #    0.061 K/sec                    ( +-  5.49% )
         1,262,122 page-faults               #    0.085 M/sec                    ( +-  1.68% )
    43,116,163,217 cycles                    #    2.920 GHz                      ( +-  3.07% )
    33,690,171,242 stalled-cycles-frontend   #   78.14% frontend cycles idle     ( +-  3.67% )
   <not supported> stalled-cycles-backend
    22,836,731,536 instructions              #    0.53  insns per cycle
                                             #    1.48  stalled cycles per insn  ( +-  1.13% )
     4,382,712,998 branches                  #  296.788 M/sec                    ( +-  1.33% )
        78,622,295 branch-misses             #    1.79% of all branches          ( +-  0.54% )

       4.621228056 seconds time elapsed                                          ( +-  1.90% )

--threads --build-id=sha1
      24594.457135 task-clock (msec)         #    4.974 CPUs utilized            ( +-  1.78% )
            29,902 context-switches          #    0.001 M/sec                    ( +-  2.62% )
             1,097 cpu-migrations            #    0.045 K/sec                    ( +-  6.29% )
         1,313,947 page-faults               #    0.053 M/sec                    ( +-  2.36% )
    70,516,415,741 cycles                    #    2.867 GHz                      ( +-  0.78% )
    47,570,262,296 stalled-cycles-frontend   #   67.46% frontend cycles idle     ( +-  0.86% )
   <not supported> stalled-cycles-backend
    73,124,599,029 instructions              #    1.04  insns per cycle
                                             #    0.65  stalled cycles per insn  ( +-  0.33% )
    10,495,266,104 branches                  #  426.733 M/sec                    ( +-  0.41% )
        91,444,149 branch-misses             #    0.87% of all branches          ( +-  0.83% )

       4.944291711 seconds time elapsed                                          ( +-  1.72% )

PREVIOUS

--threads --build-id=none
       7307.437544 task-clock (msec)         #    1.160 CPUs utilized            ( +-  2.34% )
             3,128 context-switches          #    0.428 K/sec                    ( +-  4.37% )
               352 cpu-migrations            #    0.048 K/sec                    ( +-  5.98% )
         1,354,450 page-faults               #    0.185 M/sec                    ( +-  2.20% )
    22,081,733,098 cycles                    #    3.022 GHz                      ( +-  1.46% )
    13,709,991,267 stalled-cycles-frontend   #   62.09% frontend cycles idle     ( +-  1.77% )
   <not supported> stalled-cycles-backend
    21,634,468,895 instructions              #    0.98  insns per cycle
                                             #    0.63  stalled cycles per insn  ( +-  0.86% )
     3,993,062,361 branches                  #  546.438 M/sec                    ( +-  0.83% )
        76,188,819 branch-misses             #    1.91% of all branches          ( +-  0.19% )

       6.298101157 seconds time elapsed                                          ( +-  2.03% )

--threads --build-id=sha1
      12845.420265 task-clock (msec)         #    1.097 CPUs utilized            ( +-  1.95% )
             4,020 context-switches          #    0.313 K/sec                    ( +-  2.89% )
               369 cpu-migrations            #    0.029 K/sec                    ( +-  6.26% )
         1,464,822 page-faults               #    0.114 M/sec                    ( +-  1.37% )
    40,668,449,813 cycles                    #    3.166 GHz                      ( +-  0.96% )
    18,863,982,388 stalled-cycles-frontend   #   46.38% frontend cycles idle     ( +-  1.82% )
   <not supported> stalled-cycles-backend
    71,560,499,058 instructions              #    1.76  insns per cycle
                                             #    0.26  stalled cycles per insn  ( +-  0.14% )
    10,044,152,441 branches                  #  781.925 M/sec                    ( +-  0.19% )
        87,835,773 branch-misses             #    0.87% of all branches          ( +-  0.09% )

      11.711773314 seconds time elapsed                                          ( +-  1.51% )

llvm-svn: 287140

Also add a comment saying that check() returns a value.

llvm-svn: 287136

This change separates all versioned locals to be a separate list in config,
that was suggested by Rafael and simplifies the logic a bit.

Differential revision: https://reviews.llvm.org/D26754

llvm-svn: 287132

Turns out some systems do define it. Not producing an error in this
case matches gold and bfd.

llvm-svn: 287125

Previously we did not support them,
patch implements this functionality

Differential revision: https://reviews.llvm.org/D26604

llvm-svn: 287124

Forgot about that, I am sorry.

llvm-svn: 287123