1037 Commits

Author SHA1 Message Date
Cherry Zhang
ef3571bf07 cmd/internal/obj/mips: mark restartable sequences
Following CL 208126, do the same for MIPS.

Change-Id: I95f8fc99a234524119a4d29c7695676dc0ea1025
Reviewed-on: https://go-review.googlesource.com/c/go/+/208217
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2020-05-06 15:41:25 +00:00
Cherry Zhang
ee330385ca cmd/internal/obj, runtime: preempt & restart some instruction sequences
On some architectures, for async preemption the injected call
needs to clobber a register (usually REGTMP) in order to return
to the preempted function. As a consequence, the PC ranges where
REGTMP is live are not preemptible.

The uses of REGTMP are usually generated by the assembler, where
it needs to load or materialize a large constant or offset that
doesn't fit into the instruction. In those cases, REGTMP is not
live at the start of the instruction sequence. Instead of giving
up preemption in those cases, we could preempt it and restart the
sequence when resuming the execution. Basically, this is like
reissuing an interrupted instruction, except that here the
"instruction" is a Prog that consists of multiple machine
instructions. For this to work, we need to generate PC data to
mark the start of the Prog.

Currently this is only done for ARM64.

TODO: the split-stack function prologue is currently not async
preemptible. We could use this mechanism, preempt it and restart
at the function entry.

Change-Id: I37cb282f8e606e7ab6f67b3edfdc6063097b4bd1
Reviewed-on: https://go-review.googlesource.com/c/go/+/208126
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2020-05-06 15:41:12 +00:00
fanzha02
cb00d93431 doc, cmd/internal/obj/arm64: update the directives in the doc
Adding the usage of PCALIGN directive for arm64, and updating some
details on using some directives defined in the textflag.h file.

Change-Id: I43d363e3337939bab69b856831caf06803a292d2
Reviewed-on: https://go-review.googlesource.com/c/go/+/227801
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-05-01 20:39:53 +00:00
Mark Ryan
30f8074e35 cmd/internal/obj/x86: prevent jumps crossing 32 byte boundaries
This commit adds a new option to the x86 assembler.  If the
GOAMD64 environment variable is set to alignedjumps (the
default) and we're doing a 64 bit build, the assembler will
make sure that neither stand alone nor macro-fused jumps will
end on or cross 32 byte boundaries.  To achieve this, functions
are aligned on 32 byte boundaries, rather than 16 bytes, and
jump instructions are padded to ensure that they do not
cross or end on 32 byte boundaries.  Jumps are padded
by adding a NOP instruction of the appropriate length before
the jump.

The commit is likely to result in larger binary sizes when
GOAMD64=alignedjumps.  On the binaries tested so far, an
increase of between 1.4% and 1.5% has been observed.

Updates #35881

Co-authored-by: David Chase <drchase@google.com>

Change-Id: Ief0722300bc3f987098e4fd92b22b14ad6281d91
Reviewed-on: https://go-review.googlesource.com/c/go/+/219357
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-05-01 19:55:48 +00:00
Cherry Zhang
d0754cfe4a cmd: merge branch 'dev.link' into master
In the dev.link branch we continued developing the new object
file format support and the linker improvements described in
https://golang.org/s/better-linker . Since the last merge, more
progress has been made to improve the new linker.

This is a clean merge.

Change-Id: Ide5ad6fcec9cede99e9b21c4548929b4ba1f4185
2020-04-30 17:08:35 -04:00
Austin Clements
9d812cfa5c cmd/compile,runtime: stack maps only at calls, remove register maps
Currently, we emit stack maps and register maps at almost every
instruction. This was originally intended to support non-cooperative
preemption, but was only ever used for debug call injection. Now debug
call injection also uses conservative frame scanning. As a result,
stack maps are only needed at call sites and register maps aren't
needed at all except that we happen to also encode unsafe-point
information in the register map PCDATA stream.

This CL reduces stack maps to only appear at calls, and replace full
register maps with just safe/unsafe-point information.

This is all protected by the go115ReduceLiveness feature flag, which
is defined in both runtime and cmd/compile.

This CL significantly reduces binary sizes and also speeds up compiles
and links:

name                      old exe-bytes     new exe-bytes     delta
BinGoSize                      15.0MB ± 0%       14.1MB ± 0%   -5.72%

name                      old pcln-bytes    new pcln-bytes    delta
BinGoSize                      3.14MB ± 0%       2.48MB ± 0%  -21.08%

name                      old time/op       new time/op       delta
Template                        178ms ± 7%        172ms ±14%  -3.59%  (p=0.005 n=19+19)
Unicode                        71.0ms ±12%       69.8ms ±10%    ~     (p=0.126 n=18+18)
GoTypes                         655ms ± 8%        615ms ± 8%  -6.11%  (p=0.000 n=19+19)
Compiler                        3.27s ± 6%        3.15s ± 7%  -3.69%  (p=0.001 n=20+20)
SSA                             7.10s ± 5%        6.85s ± 8%  -3.53%  (p=0.001 n=19+20)
Flate                           124ms ±15%        116ms ±22%  -6.57%  (p=0.024 n=18+19)
GoParser                        156ms ±26%        147ms ±34%    ~     (p=0.070 n=19+19)
Reflect                         406ms ± 9%        387ms ±21%  -4.69%  (p=0.028 n=19+20)
Tar                             163ms ±15%        162ms ±27%    ~     (p=0.370 n=19+19)
XML                             223ms ±13%        218ms ±14%    ~     (p=0.157 n=20+20)
LinkCompiler                    503ms ±21%        484ms ±23%    ~     (p=0.072 n=20+20)
ExternalLinkCompiler            1.27s ± 7%        1.22s ± 8%  -3.85%  (p=0.005 n=20+19)
LinkWithoutDebugCompiler        294ms ±17%        273ms ±11%  -7.16%  (p=0.001 n=19+18)

(https://perf.golang.org/search?q=upload:20200428.8)

The binary size improvement is even slightly better when you include
the CLs leading up to this. Relative to the parent of "cmd/compile:
mark PanicBounds/Extend as calls":

name                      old exe-bytes     new exe-bytes     delta
BinGoSize                      15.0MB ± 0%       14.1MB ± 0%   -6.18%

name                      old pcln-bytes    new pcln-bytes    delta
BinGoSize                      3.22MB ± 0%       2.48MB ± 0%  -22.92%

(https://perf.golang.org/search?q=upload:20200428.9)

For #36365.

Change-Id: I69448e714f2a44430067ca97f6b78e08c0abed27
Reviewed-on: https://go-review.googlesource.com/c/go/+/230544
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 21:29:21 +00:00
Lynn Boger
56933fb838 cmd/compile,cmd/internal/obj/ppc64: use mod instructions on power9
This updates the PPC64.rules file to use the MOD instructions
that are available in power9. Prior to power9 this is done
using a longer sequence with multiply and divide.

Included in this change is removal of the REM* opcode variations
that set the CC or OV bits since their settings are based
on the DIV and are not appropriate for the REM.

Change-Id: Iceed9ce33e128e1911c15592ee674276ce8ba3fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/229761
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-29 14:45:56 +00:00
Cherry Zhang
e08f10b8b5 [dev.link] cmd/internal/goobj2: add index fingerprint to object file
The new object files use indices for symbol references, instead
of names. Fundamental to the design, it requires that the
importing and imported packages have consistent view of symbol
indices. The Go command should already ensure this, when using
"go build". But in case it goes wrong, it could lead to obscure
errors like run-time crashes. It would be better to check the
index consistency at build time.

To do that, we add a fingerprint to each object file, which is
a hash of symbol indices. In the object file it records the
fingerprints of all imported packages, as well as its own
fingerprint. At link time, the linker checks that a package's
fingerprint matches the fingerprint recorded in the importing
packages, and issue an error if they don't match.

This CL does the first part: introducing the fingerprint in the
object file, and propagating fingerprints through
importing/exporting by the compiler. It is not yet used by the
linker. Next CL will do.

Change-Id: I0aa372da652e4afb11f2867cb71689a3e3f9966e
Reviewed-on: https://go-review.googlesource.com/c/go/+/229617
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2020-04-24 17:47:14 +00:00
David Chase
f5fcc9b8e0 cmd/internal/obj: add IsAsm flag
This allows more exciting changes to compiler-generated assembly
language that might not be correct for tricky hand-crafted
assembly (e.g., nop padding breaking tables of call or branch
instructions).

Updates #35881

Change-Id: I842b811796076c160180a364564f2844604df3fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/229708
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-24 01:48:48 +00:00
Lynn Boger
91b9c2f350 cmd/asm,cmd/internal/obj/ppc64: update instructions and tests
This change adds some instructions that were missing from the
ppc64 assembler, mostly power9 but a few others from earlier.

Tests in cmd/asm for ppc64 were updated: ppc64.s includes the
new instructions, and ppc64enc.s now includes not only the
new instructions but most ppc64 opcodes to provide a more
complete test of the ppc64 assembler.

The ppc64 instruction set is used for linux/ppc64le,
linux/ppc64, and aix/ppc64.

Change-Id: I8695f89dbca06174847963f4ef869f2e584d5bbf
Reviewed-on: https://go-review.googlesource.com/c/go/+/229479
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-23 19:28:16 +00:00
Michael Munday
ab7a65f283 cmd/compile: clean up codegen for branch-on-carry on s390x
This CL optimizes code that uses a carry from a function such as
bits.Add64 as the condition in an if statement. For example:

    x, c := bits.Add64(a, b, 0)
    if c != 0 {
        panic("overflow")
    }

Rather than converting the carry into a 0 or a 1 value and using
that as an input to a comparison instruction the carry flag is now
used as the input to a conditional branch directly. This typically
removes an ADD LOGICAL WITH CARRY instruction when user code is
doing overflow detection and is closer to the code that a user
would expect to generate.

Change-Id: I950431270955ab72f1b5c6db873b6abe769be0da
Reviewed-on: https://go-review.googlesource.com/c/go/+/219757
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-04-22 20:11:06 +00:00
Ruixin(Peter) Bao
a45ea55da7 cmd/internal: allow ADDE to work with memory location on s390x
Originally on s390x, ADDE does not work when adding numbers from a memory location.
For example: ADDE (R3), R4 will result in a failure.

Since ADDC, ADD and ADDW already supports adding from memory location,
let's support that for ADDE as well.

Change-Id: I7cbe112ea154733a621b948c6a21bbee63fb0c62
Reviewed-on: https://go-review.googlesource.com/c/go/+/229304
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-22 11:37:03 +00:00
Josh Bleecher Snyder
1dcf34f2ec cmd/compile: speed up compiling with -S
Compiling with -S was not implemented with performance in mind.
It allocates profligately. Compiling with -S is ~58% slower,
allocates ~47% more memory, and does ~183% more allocations.

compilecmp now uses -S to do finer-grained comparisons between
compiler versions, so I now care about its performance.

This change picks some of the lowest hanging fruit,
mostly by modifying printing routines to print directly to a writer,
rather than constructing a string first.

I have confirmed that compiling std+cmd with "-gcflags=all=-S -p=1"
and CGO_ENABLED=0 yields identical results before/after this change.
(-p=1 makes package compilation order deterministic. CGO_ENABLED=0
prevents cgo temp workdirs from showing up in filenames.)

Using the -S flag, the compiler performance impact is:

name        old time/op       new time/op       delta
Template          344ms ± 2%        301ms ± 2%  -12.45%  (p=0.000 n=22+24)
Unicode           136ms ± 3%        121ms ± 3%  -11.40%  (p=0.000 n=24+25)
GoTypes           1.24s ± 5%        1.09s ± 3%  -12.58%  (p=0.000 n=25+25)
Compiler          5.66s ± 4%        5.06s ± 2%  -10.56%  (p=0.000 n=25+20)
SSA               19.9s ± 3%        17.2s ± 4%  -13.64%  (p=0.000 n=25+25)
Flate             212ms ± 2%        188ms ± 2%  -11.33%  (p=0.000 n=25+24)
GoParser          278ms ± 3%        242ms ± 1%  -12.84%  (p=0.000 n=23+24)
Reflect           743ms ± 3%        657ms ± 5%  -11.56%  (p=0.000 n=24+25)
Tar               295ms ± 2%        263ms ± 2%  -10.78%  (p=0.000 n=25+25)
XML               409ms ± 2%        360ms ± 3%  -12.03%  (p=0.000 n=24+25)
[Geo mean]        714ms             629ms       -11.92%

name        old user-time/op  new user-time/op  delta
Template          430ms ± 5%        388ms ± 3%   -9.76%  (p=0.000 n=21+24)
Unicode           202ms ±12%        171ms ± 5%  -15.21%  (p=0.000 n=25+23)
GoTypes           1.58s ± 3%        1.42s ± 3%   -9.58%  (p=0.000 n=24+24)
Compiler          7.42s ± 3%        6.68s ± 8%   -9.93%  (p=0.000 n=25+25)
SSA               26.9s ± 3%        22.9s ± 3%  -14.85%  (p=0.000 n=25+25)
Flate             260ms ± 6%        234ms ± 3%   -9.69%  (p=0.000 n=23+25)
GoParser          354ms ± 1%        296ms ± 3%  -16.46%  (p=0.000 n=23+25)
Reflect           953ms ± 2%        865ms ± 4%   -9.14%  (p=0.000 n=24+24)
Tar               380ms ± 2%        348ms ± 2%   -8.28%  (p=0.000 n=25+22)
XML               530ms ± 3%        451ms ± 3%  -15.01%  (p=0.000 n=24+23)
[Geo mean]        929ms             819ms       -11.84%

name        old alloc/op      new alloc/op      delta
Template         54.1MB ± 0%       44.3MB ± 0%  -18.24%  (p=0.000 n=24+24)
Unicode          33.5MB ± 0%       30.6MB ± 0%   -8.57%  (p=0.000 n=25+25)
GoTypes           189MB ± 0%        152MB ± 0%  -19.55%  (p=0.000 n=25+23)
Compiler          875MB ± 0%        703MB ± 0%  -19.70%  (p=0.000 n=25+25)
SSA              3.19GB ± 0%       2.51GB ± 0%  -21.50%  (p=0.000 n=25+25)
Flate            32.9MB ± 0%       27.3MB ± 0%  -17.04%  (p=0.000 n=25+25)
GoParser         43.9MB ± 0%       35.1MB ± 0%  -20.19%  (p=0.000 n=25+25)
Reflect           117MB ± 0%         96MB ± 0%  -18.22%  (p=0.000 n=24+23)
Tar              48.6MB ± 0%       40.6MB ± 0%  -16.39%  (p=0.000 n=25+24)
XML              65.7MB ± 0%       53.9MB ± 0%  -17.93%  (p=0.000 n=25+23)
[Geo mean]        118MB              97MB       -17.80%

name        old allocs/op     new allocs/op     delta
Template          1.07M ± 0%        0.60M ± 0%  -43.90%  (p=0.000 n=25+24)
Unicode            539k ± 0%         398k ± 0%  -26.20%  (p=0.000 n=23+25)
GoTypes           3.97M ± 0%        2.19M ± 0%  -44.90%  (p=0.000 n=25+24)
Compiler          17.6M ± 0%         9.5M ± 0%  -46.39%  (p=0.000 n=22+23)
SSA               66.1M ± 0%        34.1M ± 0%  -48.41%  (p=0.000 n=25+22)
Flate              629k ± 0%         365k ± 0%  -41.95%  (p=0.000 n=25+25)
GoParser           929k ± 0%         500k ± 0%  -46.11%  (p=0.000 n=25+25)
Reflect           2.49M ± 0%        1.47M ± 0%  -41.00%  (p=0.000 n=24+25)
Tar                919k ± 0%         534k ± 0%  -41.94%  (p=0.000 n=25+24)
XML               1.28M ± 0%        0.71M ± 0%  -44.72%  (p=0.000 n=25+24)
[Geo mean]        2.32M             1.33M       -42.82%

This change also speeds up cmd/objdump a modest amount, ~4%.

Change-Id: I7c7aa2b365688bc44b3ef6e1d03bcf934699cabc
Reviewed-on: https://go-review.googlesource.com/c/go/+/216857
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2020-04-20 00:23:45 +00:00
Quey-Liang Kao
b89f4c6720 runtime: add async preemption support on riscv64
This CL adds support of call injection and async preemption on
riscv64. We also clobbered REG_TMP for the injected call. Unsafe
points related to REG_TMP access have been marked in previous commits.

Fixes #36711.

Change-Id: I1a1df5b7fc23eaafc34a6a6448fcc3c91054496e
GitHub-Last-Rev: f6110d470713be70d960fd3e984fea89bb371719
GitHub-Pull-Request: golang/go#38146
Reviewed-on: https://go-review.googlesource.com/c/go/+/226206
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Joel Sing <joel@sing.id.au>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-16 05:29:18 +00:00
Lynn Boger
c79c5e1aa4 cmd/internal/obj/ppc64: add support for PCALIGN 32
This adds support support for the PCALIGN value 32. When this
directive occurs code will be aligned to 32 bytes unless
too many NOPs are needed, and then will fall back to 16
byte alignment.

On Linux the function's alignment is promoted from 16 to 32
in functions where PCALIGN 32 appears. On AIX the function's
alignment is left at 16 due to complexity with modifying its
alignment, which means code will be aligned to at least 16,
possibly 32 at times, which is still good.

Test was updated to accept new value.

Change-Id: I28e72d5f30ca472ed9ba736ddeabfea192d11797
Reviewed-on: https://go-review.googlesource.com/c/go/+/228258
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-04-15 12:17:15 +00:00
Tobias Klauser
cdaf8b6469 cmd/internal/obj/riscv: gofmt
gofmt the changes from CL 226397

Change-Id: Ibb252ddb8164573af15fc882ac48b5c01dd87cf3
Reviewed-on: https://go-review.googlesource.com/c/go/+/228059
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
2020-04-14 18:52:52 +00:00
Cherry Zhang
53a2a6a7fc [dev.link] all: merge branch 'master' into dev.link
Clean merge.

Change-Id: Ic3634fa450e42635e2daafb53b7dedc6c954d072
2020-04-10 13:50:52 -04:00
Cherry Zhang
a1c29156ae [dev.link] cmd/internal/goobj2: remove "2"
Rename
Sym2 -> Sym
Reloc2 -> Reloc
Aux2 -> Aux

Also the Reader methods.

Change-Id: I49f29e2d1cb480f5309e01d7a74b5e0897d826fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/227900
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2020-04-10 17:38:25 +00:00
Keith Randall
ea7126fe14 cmd/compile: use a Sym type instead of interface{} for symbolic offsets
Will help with strongly typed rewrite rules.

Change-Id: Ifbf316a49f4081322b3b8f13bc962713437d9aba
Reviewed-on: https://go-review.googlesource.com/c/go/+/227785
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
2020-04-10 16:24:46 +00:00
Cherry Zhang
88d6d37b77 [dev.link] cmd/internal/obj: change writer to use new-style accessors
Introduce field setters and use them on the writer side. Now we
are able to eliminate the old-style types.

Change-Id: I650d837328dc02f9be839d16a31812be86721b91
Reviewed-on: https://go-review.googlesource.com/c/go/+/227640
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-04-09 16:36:46 +00:00
Andy Pan
a3ef804891 cmd/internal/obj/ppc64: leverage AND operation to calculate remainder
Change-Id: I03e2a573eb778591071db4f783585a5d71a14c03
Reviewed-on: https://go-review.googlesource.com/c/go/+/227005
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
2020-04-09 15:56:51 +00:00
Ruixin(Peter) Bao
553a8626ba cmd/internal: add MVCIN instruction to s390x assembler
On s390x, we already have MVCIN opcode in asmz.go,
but we did not use it. This CL uses that opcode and adds MVCIN
instruction.

MVCIN instruction can be used to move data from one storage location
to another while reversing the order of bytes within the field. This
could be useful when transforming data from little-endian to big-endian.

Change-Id: Ifa1a911c0d3442f4a62f91f74ed25b196d01636b
Reviewed-on: https://go-review.googlesource.com/c/go/+/227478
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-07 15:03:09 +00:00
Cherry Zhang
5dde10c304 cmd/internal/obj/mips: don't emit spurious CALLIND relocations
Generate a CALLIND relocation only for indirect calls, not for
indirect jumps. In particular, the RET instruction is lowered to
JMP (LR), an indirect jump, and occurs frequently. The large
amount of spurious relocations causes the linker to do a lot of
extra work.

Change-Id: Ie0edc04609788f5a687fd00c22558c3f83867697
Reviewed-on: https://go-review.googlesource.com/c/go/+/227079
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: David Chase <drchase@google.com>
2020-04-03 13:43:12 +00:00
Cherry Zhang
6b6eb23041 [dev.link] all: merge branch 'master' into dev.link
The only conflict is a modify-deletion conflict in
cmd/link/internal/ld/link.go, where the old error reporter is
deleted in the new linker. Ported to
cmd/link/internal/ld/errors.go.

Change-Id: I5c78f398ea95bc1d7e6579c84dd8252c9f2196b7
2020-04-02 14:06:19 -04:00
Cherry Zhang
d92a5a80b5 [dev.link] cmd: support large function alignment
This ports CL 226997 to the dev.link branch.
- The assembler part and old object file writing are unchanged.
- Changes to cmd/link are applied to cmd/oldlink.
- Add alignment field to new object files for the new linker.

Change-Id: Id00f323ae5bdd86b2709a702ee28bcaa9ba962f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/227025
Reviewed-by: Than McIntosh <thanm@google.com>
2020-04-02 17:24:05 +00:00
fanzha02
1dbcbcfca4 cmd/asm: align an instruction or a function's address
Recently, the gVisor project needs an instruction's address
with 128 bytes alignment to fit the architecture requirement
for interrupt table.

This patch allows aligning an instruction's address to be
aligned to a specific value (2^n and in the range [8, 2048])

The main changes include:

1. Adds a new element in the FuncInfo structure defined in
cmd/internal/obj/link.go file to record the alignment
information.

2. Adds a new element in the Func structure defined in
cmd/internal/goobj/read.go file to read the alignment
information.

3. Adds the assembler support to align an intruction's offset
with a specific value (2^n and in the range [8, 2048]).
e.g. "PCALIGN $256" indicates that the next instruction should
be aligned to 256 bytes.

4. An instruction's alignment is relative to the start of the
function where this instruction is located, so the function's
address must be aligned to the same or coarser boundary.

This CL also adds a test.

Change-Id: I9b365c111b3a12f767728f1b45aa0c00f073c37d
Reviewed-on: https://go-review.googlesource.com/c/go/+/226997
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-04-02 15:05:15 +00:00
Bryan C. Mills
5970480c68 Revert "cmd/asm: align an instruction or a function's address"
This reverts CL 212767.

Reason for revert: new test is persistently failing on freebsd-arm64-dmgk builder.

Change-Id: Ifd1227628e0e747688ddb4dc580170b2a103a89e
Reviewed-on: https://go-review.googlesource.com/c/go/+/226597
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-31 16:55:59 +00:00
Joel Sing
a3d8c210ad cmd/asm,cmd/internal/obj/riscv: provide branch pseudo-instructions
Implement various branch pseudo-instructions for riscv64. These make it easier
to read/write assembly and will also make it easier for the compiler to generate
optimised code.

Change-Id: Ic31a7748c0e1495522ebecf34b440842b8d12c04
Reviewed-on: https://go-review.googlesource.com/c/go/+/226397
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-31 13:13:58 +00:00
fanzha02
71d477469c cmd/asm: align an instruction or a function's address
Recently, the gVisor project needs an instruction's address
with 128 bytes alignment and a function's start address with
2K bytes alignment to fit the architecture requirement for
interrupt table.

This patch allows aligning the address of an instruction to be
aligned to a specific value (2^n and not higher than 2048) and
the address of a function to be 2048 bytes.

The main changes include:

1. Adds ALIGN2048 flag to align a function's address with
2048 bytes.
e.g. "TEXT ·Add(SB),NOSPLIT|ALIGN2048" indicates that the
address of Add function should be aligned to 2048 bytes.

2. Adds a new element in the FuncInfo structure defined in
cmd/internal/obj/link.go file to record the alignment
information.

3. Adds a new element in the Func structure defined in
cmd/internal/goobj/read.go file to read the alignment
information.

4. Because go introduces a new object file format, also add
a new element in the FuncInfo structure defined in
cmd/internal/goobj2/funcinfo.go to record the alignment
information.

5. Adds the assembler support to align an intruction's offset
with a specific value (2^n and not higher than 2048).
e.g. "PCALIGN $256" indicates that the next instruction should
be aligned to 256 bytes.

This CL also adds a test.

Change-Id: I31cfa6fb5bc35dee2c44bf65913e90cddfcb492a
Reviewed-on: https://go-review.googlesource.com/c/go/+/212767
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-31 02:37:05 +00:00
Cherry Zhang
53a3b600a4 [dev.link] all: merge branch 'master' into dev.link
The only merge conflict is the addition of -spectre flag on
master and the addition of -go115newobj flag on dev.link.
Resolved trivially.

Change-Id: I5b46c2b25e140d6c3d8cb129acbd7a248ff03bb9
2020-03-27 13:39:19 -04:00
Cherry Zhang
89f7bd5781 cmd/internal/obj/arm64: write test output to temp dir
Write the test output to the temporary directory, not the current
directory.

May fix linux-mips64le-mengzhuo builder.

Change-Id: Ibfeb3d2879c11d498abc31df4efe776fc09a6ad6
Reviewed-on: https://go-review.googlesource.com/c/go/+/225440
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Bonventre <andybons@golang.org>
2020-03-25 20:43:24 +00:00
diaxu01
2f8798ed07 cmd/internal/obj/arm64: add support of PCALIGN directive
Recently, we get requirements of instructions and functions alignment
from the gVisor project. To fit the alignment requirement of interrupt
table, they require an instruction's address to be aligned 128 bytes
and a function's entry address to be aligned 2K bytes. Thus we add
support for PCALIGN directive first. Below is a discussion about this
topic. https://groups.google.com/forum/m/#!topic/golang-dev/RPj90l5x86I

Functions in Go are aligned to 16 bytes on arm64, thus now we only
support 8 and 16 bytes alignment.

This patch adds support for PCALIGN directive. This directive can be
used within Go asm to align instruction by padding NOOP directives.

This patch also adds a test to verify the correnctness of the PCALIGN
directive. The test is contributed by Fannie Zhang <Fannie.Zhang@arm.com>.

Change-Id: I709e6b94847fe9e1824f42f4155355f90c63d523
Reviewed-on: https://go-review.googlesource.com/c/go/+/207117
Reviewed-by: eric fang <eric.fang@arm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-25 14:28:26 +00:00
Lynn Boger
60a964ea45 cmd/internal/obj/ppc64: fix PCALIGN on ppc64le
This fixes a potential issue with the previous implementation
of PCALIGN on ppc64. Previously PCALIGN was processed inside of
asmout and indicated the padding size by setting the value in
the optab, changing it back after the alignment instructions
were added. Now PCALIGN is processed outside of asmout, and optab
is not changed.

Change-Id: I8b0093a0e2b7e06176af27e05150d04ae2c55d60
Reviewed-on: https://go-review.googlesource.com/c/go/+/225198
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-24 20:55:08 +00:00
Cherry Zhang
6c7d6cefd0 [dev.link] cmd/internal/obj: restore old DWARF symbol handling
When old object file format is used, serialize DWARF symbols in
the old way.

Change-Id: I73a97f10bba367ac29c52f8f3d0f8f3b34a42523
Reviewed-on: https://go-review.googlesource.com/c/go/+/224624
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-03-23 14:39:03 +00:00
Cherry Zhang
330f53b615 [dev.link] cmd/asm, cmd/compile: add back newobj flag
Add back the newobj flag, renamed to go115newobj, for feature
gating. The flag defaults to true.

This essentially reverts CL 206398 as well as CL 220060.

The old object format isn't working yet. Will fix in followup CLs.

Change-Id: I1ace2a9cbb1a322d2266972670d27bda4e24adbc
Reviewed-on: https://go-review.googlesource.com/c/go/+/224623
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2020-03-23 14:38:49 +00:00
Than McIntosh
0dff5b0b9e [dev.link] cmd/compile, cmd/link: move away from DWARF file renumbering
This patch moves the compiler and linker away from the current scheme
used to generate file references in DWARF subprogram dies.

Up until now the scheme has been to have the compiler emit a special
relocation on a DIE file reference that points to the file symbol in
question. The linker then reads this relocation and updates the addend
to the index of the appropriate file in the line table of the
compilation unit of the DIE (the linker emits the comp unit file
table, so it knows at that point what number use). The drawback of
this scheme is that it requires a lot of relocation processing.

With this patch, we switch to having the compiler emit the file index
directly, and then have the linker use the compiler-generated file
table to emit the line table file section (no renumbering, no
relocations, etc).

Change-Id: Id4fbe67b28a64200a083e3c5ea358dbe091ec917
Reviewed-on: https://go-review.googlesource.com/c/go/+/223318
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-20 16:19:22 +00:00
Than McIntosh
673a02a235 [dev.link] cmd/compile, cmd/link: move DWARF info sym to anonymous aux data
Switch the primary subprogram die DWARF symbol emitted by the compiler
from named+dupOK to anonymous aux. This should help performance wise
by not having to add these symbols to the linker's symbol name lookup
tables.

Change-Id: Idf66662b8bf60b3dee9a55e6cd5137b24a9f5ab6
Reviewed-on: https://go-review.googlesource.com/c/go/+/223669
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-20 16:19:15 +00:00
Than McIntosh
62b0790a79 [dev.link] cmd/compile: refactor aux handling in newobj sym traversal
Generalize symbol traversal code for aux symbols to allow for client
control over whether the walk incldues symbols referenced by
relocations on visited aux syms. This is not needed just yet but will
be required in order to support anonymous aux syms that have
relocations.

Change-Id: I898c1f398213c8d9d777dd3c40524a013b25e348
Reviewed-on: https://go-review.googlesource.com/c/go/+/223668
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-20 16:19:07 +00:00
Joel Sing
7ec4adbc91 cmd/internal/obj/riscv: add comments for Go registers
Change-Id: Id9aa6ba268eee67f2dc74096d4ec3bc0a80aefe2
Reviewed-on: https://go-review.googlesource.com/c/go/+/223563
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-17 01:24:51 +00:00
Joel Sing
25da2ea72c cmd/internal/obj/riscv: add NEG/NEGW pseudo-instructions
Provide NEG/NEGW pseudo-instructions, which translate to SUB/SUBW with the
zero register as a source.

Change-Id: I2c1ec1e75611c234c5ee8e39390dd188f8e42bae
Reviewed-on: https://go-review.googlesource.com/c/go/+/221689
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-15 08:15:09 +00:00
Joel Sing
dc3255391a cmd/internal/obj/riscv: add NOT pseudo-instruction
Add a NOT pseudo-instruction that translates to XORI $-1.

Change-Id: I2be4cfe2939e988cd7f8d30260b704701d78475f
Reviewed-on: https://go-review.googlesource.com/c/go/+/221688
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-15 08:14:24 +00:00
Joel Sing
32dbccde78 cmd/internal/obj/riscv: add FCLASSS/FCLASSD instructions
Add support for floating-point classification instructions.

Change-Id: I64463d477b3db0cca16ff7bced64f154011ef4cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/220542
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-15 08:13:55 +00:00
Joel Sing
10635921e5 cmd/asm,cmd/internal/obj/riscv: add atomic memory operation instructions
Use instructions in place of currently used defines.

Updates #36765

Change-Id: I00bb59e77b1aace549d7857cc9721ba2cb4ac6ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/220541
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-15 08:13:28 +00:00
Joel Sing
85a8526a7e cmd/asm,cmd/internal/obj/riscv: add LR/SC instructions
Add support for Load-Reserved (LR) and Store-Conditional (SC) instructions.

Use instructions in place of currently used defines.

Updates #36765

Change-Id: I77e660639802293ece40cfde4865ac237e3308d6
Reviewed-on: https://go-review.googlesource.com/c/go/+/220540
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-15 07:51:41 +00:00
Joel Sing
2a08f3c181 cmd/internal/obj/riscv: add FENCE instruction
Also remove #define's that were previously in use.

Updates #36765

Change-Id: I90b6a8629c78f549012f3f6c5f3b325336182712
Reviewed-on: https://go-review.googlesource.com/c/go/+/220539
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-15 07:13:18 +00:00
Joel Sing
3e00061f52 cmd/internal/obj/riscv: rework instruction generation
Rework instruction generation so that multiple instructions are generated
from a single obj.Prog, rather than the current approach where obj.Progs
are rewritten. This allows the original obj.Prog to remain intact, before
being converted into an architecture specific instruction form.

This simplifies the code and removes a level of indirection that results
from trying to manipulate obj.Prog.To/obj.Prog.From into forms that match
the instruction encoding. Furthermore, the errors reported make more sense
since it matches up with the actual assembly that was parsed.

Note that the CALL/JMP/JALR type sequences have not yet been migrated to
this framework and will likely be converted at a later time.

Updates #27532

Change-Id: I9fd12562ed1db0a08cfdc32793897d2a1920ebaa
Reviewed-on: https://go-review.googlesource.com/c/go/+/211917
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-15 06:42:43 +00:00
Joel Sing
2b920cba8f cmd/internal/obj/riscv: store relocation details in obj.Prog.RestArgs
Store the relocation offset and symbol in obj.Prog.RestArgs, rather than
overloading obj.Prog.From and having to deal with invalid offsets
potentially existing when the instruction is encoded.

Change-Id: Iff0d678361677e78b41b887f6eba08cee94fccb3
Reviewed-on: https://go-review.googlesource.com/c/go/+/218197
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2020-03-15 06:17:36 +00:00
Russ Cox
fc8a6336d1 cmd/asm, cmd/compile, runtime: add -spectre=ret mode
This commit extends the -spectre flag to cmd/asm and adds
a new Spectre mitigation mode "ret", which enables the use
of retpolines.

Retpolines prevent speculation about the target of an indirect
jump or call and are described in more detail here:
https://support.google.com/faqs/answer/7625886

Change-Id: I4f2cb982fa94e44d91e49bd98974fd125619c93a
Reviewed-on: https://go-review.googlesource.com/c/go/+/222661
Reviewed-by: Keith Randall <khr@golang.org>
2020-03-13 19:05:54 +00:00
Cherry Zhang
440852c464 [dev.link] all: merge branch 'master' into dev.link
Clean merge.

Change-Id: I2ae070c60c011779a0f0a1344f5b6d45ef10d8a1
2020-03-13 14:45:05 -04:00
Lynn Boger
9d67a94217 cmd/internal/obj/ppc64: clean up some opcodes
This does some clean up of the ppc64 opcodes to remove names
from the opcode list that don't actually assemble. At one time
names were added to this list to represent opcode "classes" to
organize other opcodes that have the same set of operand
combinations. Since this is not documented, it is confusing as
to which opcodes can be used in an asm file and which can't, and
which opcodes should be supported in the disassembler. It is
clearer for the user if the list of Go opcodes are all opcodes
that can be assembled with names that match the ppc64 opcode
where possible.

I found this when trying to use Go opcode XXLAND in an asm file
which seems like it should map to ppc64 xxland but when used it
gets this error:

go tool asm test_xxland.s
asm: bad r/r, r/r/r or r/r/r/r opcode XXLAND
asm: assembly failed

This change removes the opcodes that are only used for opcode
"classes" and fixes the case statement where they are referenced.
This also fixes XXLAND and XXPERM which are opcodes that should
assemble to their corresponding ppc64 opcode but do not.

Change-Id: I52300db6b22f7f8b3dd3491c3f35a384b943352c
Reviewed-on: https://go-review.googlesource.com/c/go/+/223138
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-03-13 11:41:22 +00:00