Change-Id: Ib6ea1bd04d9b06542ed2b0f453c718115417c62c
Reviewed-on: https://go-review.googlesource.com/c/go/+/449755
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@google.com>
This adds the function "start line number" to runtime._func and
runtime.inlinedCall objects. The "start line number" is the line number
of the func keyword or TEXT directive for assembly.
Subtracting the start line number from PC line number provides the
relative line offset of a PC from the the start of the function. This
helps with source stability by allowing code above the function to move
without invalidating samples within the function.
Encoding start line rather than relative lines directly is convenient
because the pprof format already contains a start line field.
This CL uses a straightforward encoding of explictly including a start
line field in every _func and inlinedCall. It is possible that we could
compress this further in the future. e.g., functions with a prologue
usually have <line of PC 0> == <start line>. In runtime.test, 95% of
functions have <line of PC 0> == <start line>.
According to bent, this is geomean +0.83% binary size vs master and
-0.31% binary size vs 1.19.
Note that //line directives can change the file and line numbers
arbitrarily. The encoded start line is as adjusted by //line directives.
Since this can change in the middle of a function, `line - start line`
offset calculations may not be meaningful if //line directives are in
use.
For #55022.
Change-Id: Iaabbc6dd4f85ffdda294266ef982ae838cc692f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/429638
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Since CL 391014, cmd/compile now requires the -p flag to be set the
build system. This CL changes it to initialize LocalPkg.Path to the
provided path, rather than relying on writing out `"".` into object
files and expecting cmd/link to substitute them.
However, this actually involved a rather long tail of fixes. Many have
already been submitted, but a few notable ones that have to land
simultaneously with changing LocalPkg:
1. When compiling package runtime, there are really two "runtime"
packages: types.LocalPkg (the source package itself) and
ir.Pkgs.Runtime (the compiler's internal representation, for synthetic
references). Previously, these ended up creating separate link
symbols (`"".xxx` and `runtime.xxx`, respectively), but now they both
end up as `runtime.xxx`, which causes lsym collisions (notably
inittask and funcsyms).
2. test/codegen tests need to be updated to expect symbols to be named
`command-line-arguments.xxx` rather than `"".foo`.
3. The issue20014 test case is sensitive to the sort order of field
tracking symbols. In particular, the local package now sorts to its
natural place in the list, rather than to the front.
Thanks to David Chase for helping track down all of the fixes needed
for this CL.
Updates #51734.
Change-Id: Iba3041cf7ad967d18c6e17922fa06ba11798b565
Reviewed-on: https://go-review.googlesource.com/c/go/+/393715
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
The Go object file references (some of) symbols from other
packages by indices, not by names. The linker doesn't need the
symbol names to do the linking. The names are included in the
object file so it is self-contained and tools (objdump, nm) can
read the referenced symbol names. Including the names increases
object file size. Add a flag to disable it on demand (off by
default).
Change-Id: I143a0eb656997497c750b8eb1541341b2aee8f30
Reviewed-on: https://go-review.googlesource.com/c/go/+/404297
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Implemented an assembler for LoongArch64(loong64 is short name) -
this provides register definitions and instruction encoding as
defined in the LoongArch Instruction Set Manual.
LoongArch Instruction Set Manual:
https://github.com/loongson/LoongArch-Documentation/releases
Contributors to the linux/loong64 port are:
Weining Lu <luweining@loongson.cn>
Lei Wang <wanglei@loongson.cn>
Lingqin Gong <gonglingqin@loongson.cn>
Xiaolin Zhao <zhaoxiaolin@loongson.cn>
Meidan Li <limeidan@loongson.cn>
Xiaojuan Zhai <zhaixiaojuan@loongson.cn>
Qiyuan Pu <puqiyuan@loongson.cn>
Guoqi Chen <chenguoqi@loongson.cn>
This port has been updated to Go 1.15.6:
https://github.com/loongson/go
Updates #46229
Change-Id: I930d2a19246496e3ca36d55539183c0f9f650ad9
Reviewed-on: https://go-review.googlesource.com/c/go/+/342309
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Storing this information in the Arch eliminates some code duplication
between the compiler and linker. This information is entirely
determined by the Arch, so the current approach of attaching it to an
entire Ctxt is a little silly. This will also make it easier to use
this information from tests.
The next CL will be a rote refactoring to eliminate the
Ctxt.FixedFrameSize methods.
Change-Id: I315c524fa66a0ea99f63ae5a2a6fdc367d843bad
Reviewed-on: https://go-review.googlesource.com/c/go/+/400818
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Performance is kind of hard to exactly quantify.
One big difference between jump tables and the old binary search
scheme is that there's only 1 branch statement instead of O(n) of
them. That can be both a blessing and a curse, and can make evaluating
jump tables very hard to do.
The single branch can become a choke point for the hardware branch
predictor. A branch table jump must fit all of its state in a single
branch predictor entry (technically, a branch target predictor entry).
With binary search that predictor state can be spread among lots of
entries. In cases where the case selection is repetitive and thus
predictable, binary search can perform better.
The big win for a jump table is that it doesn't consume so much of the
branch predictor's resources. But that benefit is essentially never
observed in microbenchmarks, because the branch predictor can easily
keep state for all the binary search branches in a microbenchmark. So
that benefit is really hard to measure.
So predictable switch microbenchmarks are ~useless - they will almost
always favor the binary search scheme. Fully unpredictable switch
microbenchmarks are better, as they aren't lying to us quite so
much. In a perfectly unpredictable situation, a jump table will expect
to incur 1-1/N branch mispredicts, where a binary search would incur
lg(N)/2 of them. That makes the crossover point at about N=4. But of
course switches in real programs are seldom fully unpredictable, so
we'll use a higher crossover point.
Beyond the branch predictor, jump tables tend to execute more
instructions per switch but have no additional instructions per case,
which also argues for a larger crossover.
As far as code size goes, with this CL cmd/go has a slightly smaller
code segment and a slightly larger overall size (from the jump tables
themselves which live in the data segment).
This is a case where some FDO (feedback-directed optimization) would
be really nice to have. #28262
Some large-program benchmarks might help make the case for this
CL. Especially if we can turn on branch mispredict counters so we can
see how much using jump tables can free up branch prediction resources
that can be gainfully used elsewhere in the program.
name old time/op new time/op delta
Switch8Predictable 1.89ns ± 2% 1.27ns ± 3% -32.58% (p=0.000 n=9+10)
Switch8Unpredictable 9.33ns ± 1% 7.50ns ± 1% -19.60% (p=0.000 n=10+9)
Switch32Predictable 2.20ns ± 2% 1.64ns ± 1% -25.39% (p=0.000 n=10+9)
Switch32Unpredictable 10.0ns ± 2% 7.6ns ± 2% -24.04% (p=0.000 n=10+10)
Fixes#5496
Update #34381
Change-Id: I3ff56011d02be53f605ca5fd3fb96b905517c34f
Reviewed-on: https://go-review.googlesource.com/c/go/+/357330
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@google.com>
The previous code treats some operands such as EQ, LT, etc. as special
registers. However, they are not. This CL adds a new AddrType TYPE_SPOPD
and a new class C_SPOPD to support this kind of special operands, and
refactors the relevant code.
This patch is a copy of CL 260861, contributed by Junchen Li(junchen.li@arm.com).
Co-authored-by: Junchen Li(junchen.li@arm.com)
Change-Id: I57b28da458ee3332f610602632e7eda03af435f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/302849
Reviewed-by: Cherry Mui <cherryyz@google.com>
Trust: Eric Fang <eric.fang@arm.com>
Run-TryBot: Eric Fang <eric.fang@arm.com>
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With the switch to the register ABI, we now generate wrapper
functions for go statements in many cases. A new goroutine's start
PC now points to the wrapper function. This does not affect
execution, but the runtime tracer uses the start PC and the
function name as the name/label of that goroutine. If the start
function is a named function, using the name of the wrapper loses
that information. Furthur, the tracer's goroutine view groups
goroutines by start PC. For multiple go statements with the same
callee, they are grouped together. With the wrappers, which is
context-dependent as it is a closure, they are no longer grouped.
This CL fixes the problem by providing the underlying unwrapped
PC for tracing. The compiler emits metadata to link the unwrapped
PC to the wrapper function. And the runtime reads that metadata
and record that unwrapped PC for tracing.
(This doesn't work for shared buildmode. Unfortunate.)
TODO: is there a way to test?
Fixes#50622.
Change-Id: Iaa20e1b544111c0255eb0fc04427aab7a5e3b877
Reviewed-on: https://go-review.googlesource.com/c/go/+/384158
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
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This adds a debugging hook for optionally calling a "maymorestack"
function in the prologue of any function that might call morestack
(whether it does at run time or not). The maymorestack function will
let us improve lock checking and add debugging modes that stress
function preemption and stack growth.
Passes toolstash-check -all (except on js/wasm, where toolstash
appears to be broken)
Fixes#48297.
Change-Id: I27197947482b329af75dafb9971fc0d3a52eaf31
Reviewed-on: https://go-review.googlesource.com/c/go/+/359795
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Currently, for stack traces (e.g. at panic or when runtime.Stack
is called), we print argument values from the stack. With register
ABI, we may never store the argument to stack therefore the
argument value on stack may be meaningless. This causes confusion.
This CL makes the compiler keep trace of which argument stack
slots are meaningful. If it is meaningful, it will be printed in
stack traces as before. If it may not be meaningful, it will be
printed as the stack value with a question mark ("?"). In general,
the value could be meaningful on some code paths but not others
depending on the execution, and the compiler couldn't know
statically, so we still print the stack value, instead of not
printing it at all. Also note that if the argument variable is
updated in the function body the printed value may be stale (like
before register ABI) but still considered meaningful.
Arguments passed on stack are always meaningful therefore always
printed without a question mark. Results are never printed, as
before.
(Due to a bug in the compiler we sometimes don't spill args into
their dedicated spill slots (as we should), causing it having
fewer meaningful values than it should be.)
This increases binary sizes a bit:
old new
hello 1129760 1142080 +1.09%
cmd/go 13932320 14088016 +1.12%
cmd/link 6267696 6329168 +0.98%
Fixes#45728.
Change-Id: I308a0402e5c5ab94ca0953f8bd85a56acd28f58c
Reviewed-on: https://go-review.googlesource.com/c/go/+/352057
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
FUNCDATA is always a symbol reference with 0 offset. Assert the
offset is 0 and remove funcdataoff.
Change-Id: I326815365c9db5aeef6b869df5d78a9957bc16a6
Reviewed-on: https://go-review.googlesource.com/c/go/+/352894
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
When writing an object file, most symbols are indexed in
NumberSyms. Currently, pcdata symbols are indexed late and
separately. This is not really necessary, as pcdata symbols
already exist at the time of NumberSyms. Just do it there.
As pcdata symbols are laid out in the pclntab in a special way at
link time, distinguish them from other symbols in the content
hash. (In the old code this was partly achieved by indexing them
late.)
Change-Id: Ie9e721382b0af2cfb39350d031e2e66d79095a3c
Reviewed-on: https://go-review.googlesource.com/c/go/+/352611
Trust: Cherry Mui <cherryyz@google.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Change-Id: I9921ba5c29ada6ff06d147f6d9b46a29101c449c
Reviewed-on: https://go-review.googlesource.com/c/go/+/350694
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: David Chase <drchase@google.com>
Change-Id: I8a51f054e017e0116dee4e435b60c08d72e998e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/351331
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
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Reviewed-by: Than McIntosh <thanm@google.com>
Currently, when the runtime printing a stack track (at panic, or
when runtime.Stack is called), it prints the function arguments
as words in memory. With a register-based calling convention,
the layout of argument area of the memory changes, so the
printing also needs to change. In particular, the memory order
and the syntax order of the arguments may differ. To address
that, this CL lets the compiler to emit some metadata about the
memory layout of the arguments, and the runtime will use this
information to print arguments in syntax order.
Previously we print the memory contents of the results along with
the arguments. The results are likely uninitialized when the
traceback is taken, so that information is rarely useful. Also,
with a register-based calling convention the results may not
have corresponding locations in memory. This CL changes it to not
print results.
Previously the runtime simply prints the memory contents as
pointer-sized words. With a register-based calling convention,
as the layout changes, arguments that were packed in one word
may no longer be in one word. Also, as the spill slots are not
always initialized, it is possible that some part of a word
contains useful informationwhile the rest contains garbage.
Instead of letting the runtime recreating the ABI0 layout and
print them as words, we now print each component separately.
Aggregate-typed argument/component is surrounded by "{}".
For example, for a function
F(int, [3]byte, byte) int
when called as F(1, [3]byte{2, 3, 4}, 5), it used to print
F(0x1, 0x5040302, 0xXXXXXXXX) // assuming little endian, 0xXXXXXXXX is uninitilized result
Now prints
F(0x1, {0x2, 0x3, 0x4}, 0x5).
Note: the liveness tracking of the spill splots has not been
implemented in this CL. Currently the runtime just assumes all
the slots are live and print them all.
Increase binary sizes by ~1.5%.
old new
hello (println) 1171328 1187712 (+1.4%)
hello (fmt) 1877024 1901600 (+1.3%)
cmd/compile 22326928 22662800 (+1.5%)
cmd/go 13505024 13726208 (+1.6%)
Updates #40724.
Change-Id: I351e0bf497f99bdbb3f91df2fb17e3c2c5c316dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/304470
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
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Reviewed-by: Michael Knyszek <mknyszek@google.com>
This CL restructures how we track function ABIs and generate ABI
wrappers in the compiler and adds import/export of ABIs across package
boundaries.
Currently, we start by tracking definition and referencing ABIs in two
global maps and eventually move some of this information into the
LSyms for functions. This complicates a lot of the existing code for
handling wrappers and makes it particularly hard to export ABI
information across packages. This change is built around instead
recording this information on the ir.Func.
First, this change replaces the global ABI def/ref maps with a type,
which makes the data flow and lifetime of this information clear in
gc.Main. These are populated during flag parsing.
Then, early in the front-end, we loop over all ir.Funcs to 1. attach
ABI def/ref information to the ir.Funcs and 2. create new ir.Funcs for
ABI wrappers. Step 1 is slightly subtle because the information is
keyed by linker symbol names, so we can't simply look things up in the
compiler's regular symbol table.
By generating ABI wrappers early in the front-end, we decouple this
step from LSym creation, which makes LSym creation much simpler (like
it was before ABI wrappers). In particular, LSyms for wrappers are now
created at the same time as all other functions instead of by
makeABIWrapper, which means we're back to the simpler, old situation
where InitLSym was the only thing responsible for constructing
function LSyms. Hence, we can restore the check that InitLSym is
called exactly once per function.
Attaching the ABI information to the ir.Func has several follow-on
benefits:
1. It's now easy to include in the export info. This enables direct
cross-package cross-ABI calls, which are important for the performance
of calling various hot assembly functions (e.g., internal/bytealg.*).
This was really the point of this whole change.
2. Since all Funcs, including wrappers, now record their definition
ABI, callTargetLSym no longer needs to distinguish wrappers from
non-wrappers, so it's now nearly trivial (it would be completely
trivial except that it has to work around a handful of cases where
ir.Name.Func is nil).
The simplification of callTargetLSym has one desirable but potentially
surprising side-effect: the compiler will now generate direct calls to
the definition ABI even when ABI wrappers are turned off. This is
almost completely unnoticeable except that cmd/internal/obj/wasm looks
for the call from runtime.deferreturn (defined in Go) to
runtime.jmpdefer (defined in assembly) to compile is specially. That
now looks like a direct call to ABI0 rather than going through the
ABIInternal alias.
While we're in here, we also set up the structures to support more
than just ABI0 and ABIInternal and add various additional consistency
checks all around.
Performance-wise, this reduces the overhead induced by wrappers from
1.24% geomean (on Sweet) to 0.52% geomean, and reduces the number of
benchmarks impacts >2% from 5 to 3. It has no impact on compiler speed.
Impact of wrappers before this change:
name old time/op new time/op delta
BiogoIgor 15.8s ± 2% 15.8s ± 1% ~ (p=0.863 n=25+25)
BiogoKrishna 18.3s ± 6% 18.1s ± 7% -1.39% (p=0.015 n=25+25)
BleveIndexBatch100 5.88s ± 3% 6.04s ± 6% +2.72% (p=0.000 n=25+25)
BleveQuery 6.42s ± 1% 6.76s ± 1% +5.31% (p=0.000 n=24+24)
CompileTemplate 245ms ± 3% 250ms ± 6% ~ (p=0.068 n=22+25)
CompileUnicode 93.6ms ± 2% 93.9ms ± 5% ~ (p=0.958 n=22+25)
CompileGoTypes 1.60s ± 2% 1.59s ± 2% ~ (p=0.115 n=24+24)
CompileCompiler 104ms ± 4% 104ms ± 3% ~ (p=0.453 n=22+25)
CompileSSA 11.0s ± 2% 11.0s ± 1% ~ (p=0.789 n=24+25)
CompileFlate 153ms ± 2% 153ms ± 1% ~ (p=0.055 n=21+20)
CompileGoParser 229ms ± 2% 230ms ± 2% ~ (p=0.305 n=21+22)
CompileReflect 585ms ± 5% 582ms ± 3% ~ (p=0.365 n=25+25)
CompileTar 211ms ± 1% 211ms ± 3% ~ (p=0.592 n=20+22)
CompileXML 282ms ± 3% 281ms ± 2% ~ (p=0.937 n=22+23)
CompileStdCmd 13.7s ± 3% 13.6s ± 2% ~ (p=0.700 n=25+25)
FoglemanFauxGLRenderRotateBoat 8.67s ± 1% 8.78s ± 1% +1.30% (p=0.000 n=25+25)
FoglemanPathTraceRenderGopherIter1 20.5s ± 2% 20.9s ± 2% +1.85% (p=0.000 n=25+25)
GopherLuaKNucleotide 30.1s ± 2% 31.1s ± 2% +3.38% (p=0.000 n=25+25)
MarkdownRenderXHTML 246ms ± 5% 250ms ± 1% +1.42% (p=0.002 n=25+23)
Tile38WithinCircle100kmRequest 828µs ± 6% 885µs ± 6% +6.85% (p=0.000 n=23+25)
Tile38IntersectsCircle100kmRequest 1.04ms ± 5% 1.10ms ± 7% +5.63% (p=0.000 n=25+25)
Tile38KNearestLimit100Request 974µs ± 4% 972µs ± 4% ~ (p=0.356 n=25+24)
[Geo mean] 588ms 595ms +1.24%
(https://perf.golang.org/search?q=upload:20210328.5)
And after this change:
name old time/op new time/op delta
BiogoIgor 15.9s ± 1% 15.8s ± 1% -0.48% (p=0.008 n=22+25)
BiogoKrishna 18.4s ± 6% 17.8s ± 6% -3.55% (p=0.008 n=25+25)
BleveIndexBatch100 5.86s ± 3% 5.97s ± 4% +1.88% (p=0.001 n=25+25)
BleveQuery 6.42s ± 1% 6.75s ± 1% +5.14% (p=0.000 n=25+25)
CompileTemplate 246ms ± 5% 245ms ± 2% ~ (p=0.472 n=23+23)
CompileUnicode 93.7ms ± 3% 93.5ms ± 2% ~ (p=0.813 n=22+23)
CompileGoTypes 1.60s ± 2% 1.60s ± 2% ~ (p=0.108 n=25+23)
CompileCompiler 104ms ± 3% 104ms ± 2% ~ (p=0.845 n=23+23)
CompileSSA 11.0s ± 2% 11.0s ± 2% ~ (p=0.525 n=25+25)
CompileFlate 152ms ± 1% 153ms ± 2% ~ (p=0.408 n=22+22)
CompileGoParser 230ms ± 1% 230ms ± 1% ~ (p=0.363 n=21+23)
CompileReflect 582ms ± 3% 584ms ± 4% ~ (p=0.658 n=25+25)
CompileTar 212ms ± 2% 211ms ± 2% ~ (p=0.315 n=23+24)
CompileXML 282ms ± 1% 282ms ± 1% ~ (p=0.991 n=23+22)
CompileStdCmd 13.6s ± 2% 13.6s ± 2% ~ (p=0.699 n=25+24)
FoglemanFauxGLRenderRotateBoat 8.66s ± 1% 8.69s ± 1% +0.28% (p=0.002 n=25+24)
FoglemanPathTraceRenderGopherIter1 20.5s ± 3% 20.5s ± 2% ~ (p=0.407 n=25+25)
GopherLuaKNucleotide 30.1s ± 2% 31.2s ± 2% +3.82% (p=0.000 n=25+25)
MarkdownRenderXHTML 246ms ± 3% 245ms ± 1% ~ (p=0.478 n=23+22)
Tile38WithinCircle100kmRequest 820µs ± 4% 856µs ± 5% +4.39% (p=0.000 n=24+25)
Tile38IntersectsCircle100kmRequest 1.05ms ± 6% 1.07ms ± 6% +1.91% (p=0.014 n=25+25)
Tile38KNearestLimit100Request 970µs ± 4% 970µs ± 3% ~ (p=0.819 n=22+24)
[Geo mean] 588ms 591ms +0.52%
(https://perf.golang.org/search?q=upload:20210328.6)
For #40724.
Change-Id: I1c374e32d4bbc88efed062a1b360017d3642140d
Reviewed-on: https://go-review.googlesource.com/c/go/+/305274
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
The assember uses R15 as scratch space when assembling global variable
references in dynamically linked code. If the assembly code uses the
clobbered value of R15, report an error. The user is probably expecting
some other value in that register.
Getting rid of the R15 use isn't very practical (we could save a
register to a field in the G maybe, but that gets cumbersome).
Fixes#43661
Change-Id: I43f848a3d8b8a28931ec733386b85e6e9a42d8ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/283474
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Morestack works for non-pointer register parameters
Within a function body, pointer-typed parameters are correctly
tracked.
Results still not hooked up.
For #40724.
Change-Id: Icaee0b51d0da54af983662d945d939b756088746
Reviewed-on: https://go-review.googlesource.com/c/go/+/294410
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
These are the the most common uses, and they reduce line noise.
I don't love adding new deprecated APIs,
but since they're trivial wrappers,
it'll be very easy to update them along with the rest.
No functional changes; passes toolstash-check.
Change-Id: I691a8175cfef9081180e463c63f326376af3f3a6
Reviewed-on: https://go-review.googlesource.com/c/go/+/296009
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The runtime traceback code has its own definition of which functions
mark the top frame of a stack, separate from the TOPFRAME bits that
exist in the assembly and are passed along in DWARF information.
It's error-prone and redundant to have two different sources of truth.
This CL provides the actual TOPFRAME bits to the runtime, so that
the runtime can use those bits instead of reinventing its own category.
This CL also adds a new bit, SPWRITE, which marks functions that
write directly to SP (anything but adding and subtracting constants).
Such functions must stop a traceback, because the traceback has no
way to rederive the SP on entry. Again, the runtime has its own definition
which is mostly correct, but also missing some functions. During ordinary
goroutine context switches, such functions do not appear on the stack,
so the incompleteness in the runtime usually doesn't matter.
But profiling signals can arrive at any moment, and the runtime may
crash during traceback if it attempts to unwind an SP-writing frame
and gets out-of-sync with the actual stack. The runtime contains code
to try to detect likely candidates but again it is incomplete.
Deriving the SPWRITE bit automatically from the actual assembly code
provides the complete truth, and passing it to the runtime lets the
runtime use it.
This CL is part of a stack adding windows/arm64
support (#36439), intended to land in the Go 1.17 cycle.
This CL is, however, not windows/arm64-specific.
It is cleanup meant to make the port (and future ports) easier.
Change-Id: I227f53b23ac5b3dabfcc5e8ee3f00df4e113cf58
Reviewed-on: https://go-review.googlesource.com/c/go/+/288800
Trust: Russ Cox <rsc@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Symbol's Attributes and ABI are in the same word. In the
concurrent backend, we may read one symbol's ABI (the callee)
while setting its attributes in another goroutine.
Fix racecompile build.
Change-Id: I500e869bafdd72080119ab243db94eee3afcf926
Reviewed-on: https://go-review.googlesource.com/c/go/+/289290
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
This CL backports a bunch of changes that landed on dev.typeparams,
but are not dependent on types2 or generics. By backporting, we reduce
the divergence between development branches, hopefully improving test
coverage and reducing risk of merge conflicts.
Updates #43866.
Change-Id: I382510855c9b5fac52b17066e44a00bd07fe86f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/286172
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
This is a selected copy from the register ABI experiment CL, focused
on the files and data structures that handle spilling around morestack.
Unnecessary code from the experiment was removed, other code was adapted.
Would it make sense to leave comments in the experiment as pieces are
brought over?
Experiment CL (for comparison purposes)
https://go-review.googlesource.com/c/go/+/28832
Change-Id: I92136f070351d4fcca1407b52ecf9b80898fed95
Reviewed-on: https://go-review.googlesource.com/c/go/+/279520
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Add compiler support for emitting ABI wrappers by creating real IR as
opposed to introducing ABI aliases. At the moment these are "no-op"
wrappers in the sense that they make a simple call (using the existing
ABI) to their target. The assumption here is that once late call
expansion can handle both ABI0 and the "new" ABIInternal (register
version), it can expand the call to do the right thing.
Note that the runtime contains functions that do not strictly follow
the rules of the current Go ABI0; this has been handled in most cases
by treating these as ABIInternal instead (these changes have been made
in previous patches).
Generation of ABI wrappers (as opposed to ABI aliases) is currently
gated by GOEXPERIMENT=regabi -- wrapper generation is on by default if
GOEXPERIMENT=regabi is set and off otherwise (but can be turned on
using "-gcflags=all=-abiwrap -ldflags=-abiwrap"). Wrapper generation
currently only workd on AMD64; explicitly enabling wrapper for other
architectures (via the command line) is not supported.
Also in this patch are a few other command line options for debugging
(tracing and/or limiting wrapper creation). These will presumably go
away at some point.
Updates #27539, #40724.
Change-Id: I1ee3226fc15a3c32ca2087b8ef8e41dbe6df4a75
Reviewed-on: https://go-review.googlesource.com/c/go/+/270863
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Than McIntosh <thanm@google.com>
Deleting the Pc assignment from Patch is safe because the actual PCs
are not assigned until well after the compiler is done patching jumps.
And it proves that replacing uses of Patch with SetTarget will be safe later.
Change-Id: Iffcbe03f0b5949ccd4c91e79c1272cd06be0f434
Reviewed-on: https://go-review.googlesource.com/c/go/+/279296
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
It's currently hard to automate refactorings around the Value.Aux
field, because we don't have any static typing information for it.
Adding a tag interface will make subsequent CLs easier and safer.
Passes buildall w/ toolstash -cmp.
Updates #42982.
Change-Id: I41ae8e411a66bda3195a0957b60c2fe8a8002893
Reviewed-on: https://go-review.googlesource.com/c/go/+/275756
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
These messages can happen if there are
duplicate body-less function declarations.
Using panic gives the panic handler
a chance to handle the panic by printing the
queued error messages instead of an internal error.
And if there are no queued error messages,
using panic pinpoints the stack trace leading
to the incorrect use of NewFuncInfo/NewFileInfo.
Change-Id: I7e7ea9822ff9a1e7140f5e5b7cfd6437ff9318a7
Reviewed-on: https://go-review.googlesource.com/c/go/+/266338
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
This patch adds support for CASx and CASPx atomic instructions.
go syntax gnu syntax
CASD Rs, (Rn|RSP), Rt => cas Xs, Xt, (Xn|SP)
CASALW Rs, (Rn|RSP), Rt => casal Ws, Wt, (Xn|SP)
CASPD (Rs, Rs+1), (Rn|RSP), (Rt, Rt+1) => casp Xs, Xs+1, Xt, Xt+1, (Xn|SP)
CASPW (Rs, Rs+1), (Rn|RSP), (Rt, Rt+1) => casp Ws, Ws+1, Wt, Wt+1, (Xn|SP)
This patch changes the type of prog.RestArgs from "[]Addr" to
"[]struct{Addr, Pos}", Pos is a enum, indicating the position of
the operand.
This patch also adds test cases.
Change-Id: Ib971cfda7890b7aa895d17bab22dea326c7fcaa4
Reviewed-on: https://go-review.googlesource.com/c/go/+/233277
Trust: fannie zhang <Fannie.Zhang@arm.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This commit contains the compiler support for //go:embed lines.
The go command passes to the compiler an "embed config"
that maps literal patterns like *.txt to the set of files to embed.
The compiler then lays out the content of those files as static data
in the form of an embed.Files or string or []byte in the final object file.
The test for this code is the end-to-end test hooking up the
embed, cmd/compile, and cmd/go changes, in the next CL.
For #41191.
Change-Id: I916e57f8cc65871dc0044c13d3f90c252a3fe1bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/243944
Trust: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Function symbols defined and referenced by assembly source currently
always default to ABI0; this patch adds preliminary support for
accepting an explicit ABI selector clause for func defs/refs. This
functionality is currently only enabled when compiling runtime-related
packages (runtime, syscall, reflect). Examples:
TEXT ·DefinedAbi0Symbol<ABI0>(SB),NOSPLIT,$0
RET
TEXT ·DefinedAbi1Symbol<ABIInternal>(SB),NOSPLIT,$0
CALL ·AbiZerolSym<ABI0>(SB)
...
JMP ·AbiInternalSym<ABIInternal>(SB)
RET
Also included is a small change to the code in the compiler that reads
the symabis file emitted by the assembler.
New behavior is currently gated under GOEXPERIMENT=regabi.
Updates #27539, #40724.
Change-Id: Ia22221fe26df0fa002191cfb13bdfaaa38d7df38
Reviewed-on: https://go-review.googlesource.com/c/go/+/260477
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Than McIntosh <thanm@google.com>
This creates space for a different kind of extension field
in LSym without making the struct any larger.
(There are many LSym, so we care about keeping the struct small.)
Change-Id: Ib16edb9e15f54c2a7351c8b875e19684058711e5
Reviewed-on: https://go-review.googlesource.com/c/go/+/243943
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
LSym.RefIdx was for the old object files. I should have deleted
it when I deleted old object file code.
Change-Id: I8294f43a1e7ba45b1d75e84cc83cbaf2cb32f025
Reviewed-on: https://go-review.googlesource.com/c/go/+/262077
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
We currently use two fields to store the targets of branches.
Some phases use p.To.Val, some use p.Pcond. Rewrite so that
every branch instruction uses p.To.Val.
p.From.Val is also used in rare instances.
Introduce a Pool link for use by arm/arm64, instead of
repurposing Pcond.
This is a cleanup CL in preparation for some stack frame CLs.
Change-Id: If8239177e4b1ea2bccd0608eb39553d23210d405
Reviewed-on: https://go-review.googlesource.com/c/go/+/251437
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This reverts CL 243318.
Reason for revert: Seems to be crashing some builders.
Change-Id: I2ffc59bc5535be60b884b281c8d0eff4647dc756
Reviewed-on: https://go-review.googlesource.com/c/go/+/251169
Reviewed-by: Bryan C. Mills <bcmills@google.com>
We currently use two fields to store the targets of branches.
Some phases use p.To.Val, some use p.Pcond. Rewrite so that
every branch instruction uses p.To.Val.
p.From.Val is also used in rare instances.
Introduce a Pool link for use by arm/arm64, instead of
repurposing Pcond.
This is a cleanup CL in preparation for some stack frame CLs.
Change-Id: I9055bf0a1d986aff421e47951a1dedc301c846f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/243318
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
I think they are no longer experimental status. Might as well promote
them to permanent.
Change-Id: Id1259601b3dd2061dd60df86ee48080bfb575d2f
Reviewed-on: https://go-review.googlesource.com/c/go/+/249857
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Switch pcdata over to content addressable symbols. This is the last
step before removing these from pclntab_old.
No meaningful benchmarks changes come from this work.
Change-Id: I3f74f3d6026a278babe437c8010e22992c92bd89
Reviewed-on: https://go-review.googlesource.com/c/go/+/247399
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Minor cleanup: remove the symbol attribute AttrSeenGlobal, since it is
redundant with the existing attribute AttrOnList (no need to have what
amounts to a separate flag for checking the same property).
Change-Id: Ia269b64de37c2bb4a2314bbecf3d2091c6d57424
Reviewed-on: https://go-review.googlesource.com/c/go/+/239477
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
In order to prevent renumbering of filenames in pclntab generation, use
the per-package file list (previously only used for DWARF generation) as
file-indices. This is the largest step to eliminate renumbering of
filenames in pclntab.
Note, this is probably not the final state of the file table within the
object file. In this form, the linker loads all filenames for all
objects. I'll move to storing the filenames as regular string
symbols,and defaulting all string symbols to using the larger hash value
to make generation of pcln simplest, and most memory friendly.
Change-Id: I23daafa3f4b4535076e23100200ae0e7163aafe0
Reviewed-on: https://go-review.googlesource.com/c/go/+/245485
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Leaving creation of the funcID till the linker requires the linker to
load the function and file names into memory. Moving these into the
compiler/assembler prevents this.
This work is a step towards moving all func metadata into the compiler.
Change-Id: Iebffdc5a909adbd03ac263fde3f4c3d492fb1eac
Reviewed-on: https://go-review.googlesource.com/c/go/+/244024
Run-TryBot: Jeremy Faller <jeremy@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Austin Clements <austin@google.com>
For content-addressable symbols with relocations, we build a
content hash based on its content and relocations. Depending on
the category of the referenced symbol, we choose different hash
algorithms such that the hash is globally consistent.
For now, we only support content-addressable symbols with
relocations when the current package's import path is known, so
that the symbol names are fully expanded. Otherwise, if the
referenced symbol is a named symbol whose name is not fully
expanded, the hash won't be globally consistent, and can cause
erroneous collisions. This is fine for now, as the deduplication
is just an optimization, not a requirement for correctness (until
we get to type descriptors).
Change-Id: I639e4e03dd749b5d71f0a55c2525926575b1ac30
Reviewed-on: https://go-review.googlesource.com/c/go/+/243142
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
For symbols of size 8 bytes or below, we can map them to 64-bit
hash values using the identity function. There is no need to use
longer and more expensive hash functions.
For them, we introduce another pseudo-package, PkgIdxHashed64. It
is like PkgIdxHashed except that the hash function is different.
Note that the hash value is not affected with trailing zeros,
e.g. "A" and "A\0\0\0" have the same hash value. This allows
deduplicating a few more symbols. When deduplicating them, we
need to keep the longer one.
Change-Id: Iad0c2e9e569b6a59ca6a121fb8c8f0c018c6da03
Reviewed-on: https://go-review.googlesource.com/c/go/+/242362
Reviewed-by: Jeremy Faller <jeremy@golang.org>
Fill in the data at compile time, and get rid of the preprocess
function in the linker.
We need to be careful with symbol alignment: data symbols are
generally naturally aligned, except for string symbols which are
not aligned. When deduplicating two symbols with same content but
different alignments, we need to keep the biggest alignment.
Change-Id: I4bd96adfdc5f704b5bf3a0e723457c9bfe16a684
Reviewed-on: https://go-review.googlesource.com/c/go/+/242081
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
