Currently, for external relocations, the ExtReloc structure
contains all the fields of the relocation. In fact, many of the
fields are the same with the original relocation. So, instead, we
can just use an index to reference the original relocation and
not expand the fields.
There is one place where we modify relocation type: changing
R_DWARFSECTREF to R_ADDR. Get away with it by changing
downstreams.
It also makes it easier to retrieve the reloc variant.
This reduces some allocation. Linking cmd/compile with external
linking,
name old alloc/op new alloc/op delta
Reloc_GC 34.1MB ± 0% 22.7MB ± 0% -33.30% (p=0.000 n=5+4)
Change-Id: Id08a89ed2aee705296886d3b95014b806a0d55cf
Reviewed-on: https://go-review.googlesource.com/c/go/+/231217
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Adddynrel2 is a function pointer. In dynrelocsym we pass &r to
it, which will cause r to escape. Pass it by value instead.
Linking cmd/compile,
name old alloc/op new alloc/op delta
Dodata_GC 15.8MB ± 0% 5.9MB ± 0% -62.55% (p=0.008 n=5+5)
Change-Id: Ib86005d1026ebaca57777b27ead037e613585f44
Reviewed-on: https://go-review.googlesource.com/c/go/+/231045
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Archreloc2 is a function pointer. It will escape its pointer
arguments. In relocsym, as we pass &r and &rr to Archreloc2, it
causes them to escape, even if Archreloc2 is not actually called.
Instead, pass r by value. loader.Reloc2 is a small structure
which is intended to be passed by value.
For rr, as Archreloc2 will likely return true, we speculatively
add it to extRelocs slice and use that space to pass to
Archreloc2.
Linking cmd/compile,
name old alloc/op new alloc/op delta
Dwarfcompress_GC 110MB ± 0% 24MB ± 0% -78.34% (p=0.008 n=5+5)
Reloc_GC 24.6MB ± 0% 0.0MB ± 0% -100.00% (p=0.029 n=4+4)
Linking cmd/compile using external linking
name old alloc/op new alloc/op delta
Reloc_GC 152MB ± 0% 36MB ± 0% -76.07% (p=0.008 n=5+5)
Change-Id: I1415479e0c17ea9787f9a62453dce00ad9ea792f
Reviewed-on: https://go-review.googlesource.com/c/go/+/231077
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Non functional, but required by the majority of the architectures.
Change-Id: I57601016c28ce665a9d434e283a1db8bded9b133
Reviewed-on: https://go-review.googlesource.com/c/go/+/230858
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
When applying relocations, we need to resolve ABI aliases.
relocsym does that. Architecture-specific archreloc also needs to
do that. The old code doesn't do that since ABI aliases are
resolved in loadlibfull, or, in the old linker, in a much earlier
stage. We don't do this in the new linker, as we want to avoid
mutating relocations.
While here, move R_CONST and R_GOTOFF handling to generic code.
They appear on several architectures and the handling are same.
Should fix 386-clang and *bsd-386 builds.
Change-Id: I6681c94f0327555d6cf329d0a518c88848773671
Reviewed-on: https://go-review.googlesource.com/c/go/+/230857
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Remove the "ElfSym" and "LocalElfSym" fields from sym.Symbol,
replacing uses with loader method calls as needed.
Change-Id: I3828f13203ece2bdc03eeb09ab37a5c94e21a726
Reviewed-on: https://go-review.googlesource.com/c/go/+/230462
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Make Wasm more like other architectures, writing data sections to
heap in Asmb instead of Asmb2. Then we can remove the
copy-on-write logic in applying relocations.
Change-Id: I26d5315ea9fba032fe4bdb9b5c7fe483611c4373
Reviewed-on: https://go-review.googlesource.com/c/go/+/230465
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Add elf/386 arch support for the new dodata() phase.
Change-Id: I78341dfe70a90719d95c0044183980f348a3369f
Reviewed-on: https://go-review.googlesource.com/c/go/+/229797
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Recreation of CL 228317.
The problem with that original CL was a late requested change,
reordering reloc and asmb, resulting in symbols having stale pointers to
their data. I've fixed this by preallocating the heap variable in OutBuf
for platforms w/o mmap.
Change-Id: Icdb392ac2c8d6518830f4c84cf422e78b8ab68c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/228782
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Begin the job of converting the linker's "gentext" phase over to use
loader APIs. This patch includes most architectures except for s390x
and PPC (these will be added in subsequent patches, since they require
a couple of loader changes first).
Change-Id: Ic7f55c207dcdbbba657330ef007a72ff7c837416
Reviewed-on: https://go-review.googlesource.com/c/go/+/227017
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Introduces a parallel OutBuf implementation, and POC on amd64. Due to
some of the weird behaviors I saw on MacOS (SIGBUS while calling msync),
I will wait for feedback to port to other architectures.
On my mac, sped up Asmb by ~78% for cmd/compile (below). Will likely
have an appreciable speedup on kubelet benchmark.
Asmb 39.1ms ±11% 8.5ms ±10% -78.17% (p=0.000 n=10+9)
TotalTime 596ms ± 2% 577ms ± 8% -3.07% (p=0.034 n=8+10)
Change-Id: Id2a2577c3f4da155d8dccc862897f43b941877ac
Reviewed-on: https://go-review.googlesource.com/c/go/+/223742
Run-TryBot: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
It is needed in Xcoffadddynrel. And it will be needed once we
move more things to new style (the sym.Symbol parameters will
also need to change).
Change-Id: Ie12683f9b44e21f1e6ea711bf2f4c5c32282e5b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/225203
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
dodata is a pile of dependencies on *Link. Pull some of these
dependencies out, and tighten up the visibility on the functions.
Change-Id: Id213f19ae7b63dd246ddb47b77ffde99f615aa80
Reviewed-on: https://go-review.googlesource.com/c/go/+/222061
Reviewed-by: Than McIntosh <thanm@google.com>
Also correct a few places I hadn't switched over to Target from *Link
context.
Change-Id: I6de6b39723762de3fa5f8d12800085421aca76fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/220840
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
We need to propogate Target through the relocation functions.
Change-Id: I1192d54a20a34569fd13c1511d2b21ebf2d1272e
Reviewed-on: https://go-review.googlesource.com/c/go/+/220839
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Also a similar 'elapsed' function and its usages were deleted.
Fixes#19865.
Change-Id: Ib125365e69cf2eda60de64fa74290c8c7d1fd65a
Reviewed-on: https://go-review.googlesource.com/c/go/+/171730
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
This is part two if the nacl removal. Part 1 was CL 199499.
This CL removes amd64p32 support, which might be useful in the future
if we implement the x32 ABI. It also removes the nacl bits in the
toolchain, and some remaining nacl bits.
Updates #30439
Change-Id: I2475d5bb066d1b474e00e40d95b520e7c2e286e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/200077
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Use mmap for writing most of the output file content,
specifically, the sections and segments. After layout, we
already know the sizes and file offsets for the sections and
segments. So we can just write the bytes by copying to a mmap'd
backing store.
The writing of the output file is split into two parts. The first
part writes the sections and segments to the mmap'd region. The
second part writes some extra content, for which we don't know
the size, so we use direct file IO.
This is in preparation for mmap'ing input files read-only.
Change-Id: I9f3b4616a9f96bfd5c940d74c50aacd6d330f7d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/170738
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Currently the offset values of ELF relocations and Macho relocations
are 256 and 512 respectively, which means that the space reserved for
ELF relocations is only 256. But AARCH64 has more than 256 ELF relocation
types, in fact the maximum AARCH64 ELF relocation type recorded in file
src/debug/elf/elf.go is 1032 currently. So this CL increases the offset
of Macho relocations to 2048 to leave enough space for AARCH64 ELF
relocations.
Change-Id: I784ac38aeb3e102ac7825f6d621086849c8d3146
Reviewed-on: https://go-review.googlesource.com/c/go/+/172497
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The sym.Symbol 'Plt' and 'Got' field are used only with cgo and/or
external linking and are not needed for most symbols. Relocate them to
sym.AuxSymbol so as to shrink the main Symbol struct.
Updates #26186
Change-Id: I170d628a760be300a0c1f738f0998970e91ce3d6
Reviewed-on: https://go-review.googlesource.com/125478
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Archreloc had this signature:
func(*Link, *sym.Reloc, *sym.Symbol, *int64) bool
The last *int64 argument is used as out parameter.
Passed valus could be allocated on stack, but escape analysis
fails here, leading to high number of unwanted allocs.
If instead 4th arg is passed by value, and modified values is returned,
no problems with allocations arise:
func(*Link, *sym.Reloc, *sym.Symbol, int64) (int64, bool)
There are 2 benefits:
1. code becomes more readable.
2. less allocations.
For linking "hello world" example from net/http:
name old time/op new time/op delta
Linker-4 530ms ± 2% 520ms ± 2% -1.83% (p=0.001 n=17+16)
It's top 1 in alloc_objects from memprofile:
flat flat% sum% cum cum%
229379 33.05% 33.05% 229379 33.05% cmd/link/internal/ld.relocsym
...
list relocsym:
229379 229379 (flat, cum) 33.05% of Total
229379 229379 183: var o int64
After the patch, ~230k of int64 allocs (~ 1.75mb) removed.
Passes toolshash-check (toolstash cmp).
Change-Id: I25504fe27967bcff70c4b7338790f3921d15473d
Reviewed-on: https://go-review.googlesource.com/113637
Run-TryBot: Iskander Sharipov <iskander.sharipov@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Replace thread creation with calls to the pthread
library in libc.
Update #17490
Change-Id: I1e19965c45255deb849b059231252fc6a7861d6c
Reviewed-on: https://go-review.googlesource.com/108679
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
New relocation flavor R_DWARFFILEREF, to be applied to DWARF attribute
values that correspond to file references (ex: DW_AT_decl_file,
DW_AT_call_file). The LSym for this relocation is the file itself; the
linker replaces the relocation target with the index of the specified
file in the line table's file section.
Note: for testing purposes this patch changes the DWARF function
subprogram DIE abbrev to include DW_AT_decl_file (allowed by DWARF
but not especially useful) so as to have a way to test this
functionality. This attribute will be removed once there are other
file reference attributes (coming as part of inlining support).
Change-Id: Icf676beb60fcc33f06d78e747ef717532daaa3ba
Reviewed-on: https://go-review.googlesource.com/73330
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
There is some stuff I don't understand very well involved in SSUB, better words
for the documentation gratefully accepted.
As this is the last use of a bit in SMASK, kill that off too.
Change-Id: Iddff1c9b2af02c9dfb12ac8e668d004e4642f997
Reviewed-on: https://go-review.googlesource.com/42026
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
For #22095
Change-Id: Idcfdfe8a94db8626392658bb93429454238f648a
Reviewed-on: https://go-review.googlesource.com/70835
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #22095
Change-Id: Iba3dffc782cecc15ea0e90a971a2734729984945
Reviewed-on: https://go-review.googlesource.com/70834
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is https://go-review.googlesource.com/42025 but with some more fixes --
hidden symbols implicitly passed "Type == 0 || Type == SXREF" checks. (This
sort of thing is part of why I wanted to make this change)
Change-Id: I2273ee98570fd7f2dd8a799c692a2083c014235e
Reviewed-on: https://go-review.googlesource.com/42330
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Along the way, switch to using relocation constants from debug/elf.
For #22095
Change-Id: I1a64353619f95dde5aa39060c4b9d001af7dc1e4
Reviewed-on: https://go-review.googlesource.com/69013
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Replace Buildmode with BuildMode and Linkmode with LinkMode.
For #22095
Change-Id: I51a6f5719d107727bca29ec8e68e3e9d87e31e33
Reviewed-on: https://go-review.googlesource.com/68334
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
For #22095
Change-Id: I07c288208d94dabae164c2ca0a067402a8e5c2e6
Reviewed-on: https://go-review.googlesource.com/68331
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also reduce the passed context from *Link to *sys.Arch, so fewer
data dependencies need to be wired through all the code dealing
with symbols.
For #22095
Change-Id: I50969405d6562c5152bd1a3c443b72413e9b70bc
Reviewed-on: https://go-review.googlesource.com/67313
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Begin passing coutbuf by as a parameter. To make the initial plumbing
pass easier, it is also a field in the standard ctxt parameter.
Consolidate the byte writing functions into the OutBuf object.
The result is less architecture-dependent initialization.
To avoid plumbing out everywhere we want to report an error, move
handling of out file deletion to an AtExit function.
For #22095
Change-Id: I0863695241562e0662ae3669666c7922b8c846f9
Reviewed-on: https://go-review.googlesource.com/67318
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
For #22095
Change-Id: I9d1f0d93f8fd701a24af826dc903eea2bc235de2
Reviewed-on: https://go-review.googlesource.com/67317
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Adddynrel does nothing on windows. We can make code don't call Adddynrel
on windows in the first place.
Change-Id: I376cc36d44a5df18bda13be57e3916ca3062f181
Reviewed-on: https://go-review.googlesource.com/62611
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
* use bool instead of int if it's adequate.
* remove blank lines.
Change-Id: Ic4a5644a33ed9fc7ce388ef8ba15f1732446fcfc
Reviewed-on: https://go-review.googlesource.com/59375
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I7f7b1e7ef832d53a93562b08ae914d023247c2c0
Reviewed-on: https://go-review.googlesource.com/56312
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
ld.SymKind and objabi.RelocType have string representations,
which is human friendly. Prefer to use it.
Change-Id: I458ee0ca5866be0db8462c36cd053561a8206c95
Reviewed-on: https://go-review.googlesource.com/55253
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Many (most!) of the values of objapi.SymKind are used only in the linker, so
this creates a separate cmd/link/internal/ld.SymKind type, removes most values
from SymKind and maps one to the other when reading object files in the linker.
Two of the remaining objapi.SymKind values are only checked for, never set and
so will never be actually found but I wanted to keep this to the most
mechanical change possible.
Change-Id: I4bbc5aed6713cab3e8de732e6e288eb77be0474c
Reviewed-on: https://go-review.googlesource.com/40985
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Now only cmd/asm and cmd/compile depend on cmd/internal/obj. Changing
the assembler backends no longer requires reinstalling cmd/link or
cmd/addr2line.
There's also now one canonical definition of the object file format in
cmd/internal/objabi/doc.go, with a warning to update all three
implementations.
objabi is still something of a grab bag of unrelated code (e.g., flag
and environment variable handling probably belong in a separate "tool"
package), but this is still progress.
Fixes#15165.
Fixes#20026.
Change-Id: Ic4b92fac7d0d35438e0d20c9579aad4085c5534c
Reviewed-on: https://go-review.googlesource.com/40972
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
