In addition to duplicating the logic, the old code was
clearing the line number, which led to missing source line
information in the -S output.
Also fix nopout, which was incomplete.
Change-Id: Ic2b596a2f9ec2fe85642ebe125cca8ef38c83085
Reviewed-on: https://go-review.googlesource.com/3512
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
The overflow checking was causing more problems than it was avoiding,
so get rid of it. But because arithmetic is done with uint64s, to simplify
dealing with large constants, complain about right shift and divide with
huge numbers to avoid ambiguity about signed shifts.
Change-Id: I5b5ea55d8e8c02846605f4a3f8fd7a176b1e962b
Reviewed-on: https://go-review.googlesource.com/3531
Reviewed-by: Russ Cox <rsc@golang.org>
Set -S to false and add -debug to control the other debugging print.
Change-Id: I864866c3d264a33e6dd0ce12a86a050a5fe0f875
Reviewed-on: https://go-review.googlesource.com/3453
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Like the -exec flag, which specifies a program to use to run a built executable,
the -toolexec flag specifies a program to use to run a tool like 5a, 5g, or 5l.
This flag enables running the toolchain under common testing environments,
such as valgrind.
This flag also enables the use of custom testing environments or the substitution
of alternate tools. See https://godoc.org/rsc.io/toolstash for one possibility.
Change-Id: I256aa7af2d96a4bc7911dc58151cc2155dbd4121
Reviewed-on: https://go-review.googlesource.com/3351
Reviewed-by: Rob Pike <r@golang.org>
Language specification says that variables are captured by reference.
And that is what gc compiler does. However, in lots of cases it is
possible to capture variables by value under the hood without
affecting visible behavior of programs. For example, consider
the following typical pattern:
func (o *Obj) requestMany(urls []string) []Result {
wg := new(sync.WaitGroup)
wg.Add(len(urls))
res := make([]Result, len(urls))
for i := range urls {
i := i
go func() {
res[i] = o.requestOne(urls[i])
wg.Done()
}()
}
wg.Wait()
return res
}
Currently o, wg, res, and i are captured by reference causing 3+len(urls)
allocations (e.g. PPARAM o is promoted to PPARAMREF and moved to heap).
But all of them can be captured by value without changing behavior.
This change implements simple strategy for capturing by value:
if a captured variable is not addrtaken and never assigned to,
then it is captured by value (it is effectively const).
This simple strategy turned out to be very effective:
~80% of all captures in std lib are turned into value captures.
The remaining 20% are mostly in defers and non-escaping closures,
that is, they do not cause allocations anyway.
benchmark old allocs new allocs delta
BenchmarkCompressedZipGarbage 153 126 -17.65%
BenchmarkEncodeDigitsSpeed1e4 91 69 -24.18%
BenchmarkEncodeDigitsSpeed1e5 178 129 -27.53%
BenchmarkEncodeDigitsSpeed1e6 1510 1051 -30.40%
BenchmarkEncodeDigitsDefault1e4 100 75 -25.00%
BenchmarkEncodeDigitsDefault1e5 193 139 -27.98%
BenchmarkEncodeDigitsDefault1e6 1420 985 -30.63%
BenchmarkEncodeDigitsCompress1e4 100 75 -25.00%
BenchmarkEncodeDigitsCompress1e5 193 139 -27.98%
BenchmarkEncodeDigitsCompress1e6 1420 985 -30.63%
BenchmarkEncodeTwainSpeed1e4 109 81 -25.69%
BenchmarkEncodeTwainSpeed1e5 211 151 -28.44%
BenchmarkEncodeTwainSpeed1e6 1588 1097 -30.92%
BenchmarkEncodeTwainDefault1e4 103 77 -25.24%
BenchmarkEncodeTwainDefault1e5 199 143 -28.14%
BenchmarkEncodeTwainDefault1e6 1324 917 -30.74%
BenchmarkEncodeTwainCompress1e4 103 77 -25.24%
BenchmarkEncodeTwainCompress1e5 190 137 -27.89%
BenchmarkEncodeTwainCompress1e6 1327 919 -30.75%
BenchmarkConcurrentDBExec 16223 16220 -0.02%
BenchmarkConcurrentStmtQuery 17687 16182 -8.51%
BenchmarkConcurrentStmtExec 5191 5186 -0.10%
BenchmarkConcurrentTxQuery 17665 17661 -0.02%
BenchmarkConcurrentTxExec 15154 15150 -0.03%
BenchmarkConcurrentTxStmtQuery 17661 16157 -8.52%
BenchmarkConcurrentTxStmtExec 3677 3673 -0.11%
BenchmarkConcurrentRandom 14000 13614 -2.76%
BenchmarkManyConcurrentQueries 25 22 -12.00%
BenchmarkDecodeComplex128Slice 318 252 -20.75%
BenchmarkDecodeFloat64Slice 318 252 -20.75%
BenchmarkDecodeInt32Slice 318 252 -20.75%
BenchmarkDecodeStringSlice 2318 2252 -2.85%
BenchmarkDecode 11 8 -27.27%
BenchmarkEncodeGray 64 56 -12.50%
BenchmarkEncodeNRGBOpaque 64 56 -12.50%
BenchmarkEncodeNRGBA 67 58 -13.43%
BenchmarkEncodePaletted 68 60 -11.76%
BenchmarkEncodeRGBOpaque 64 56 -12.50%
BenchmarkGoLookupIP 153 139 -9.15%
BenchmarkGoLookupIPNoSuchHost 508 466 -8.27%
BenchmarkGoLookupIPWithBrokenNameServer 245 226 -7.76%
BenchmarkClientServer 62 59 -4.84%
BenchmarkClientServerParallel4 62 59 -4.84%
BenchmarkClientServerParallel64 62 59 -4.84%
BenchmarkClientServerParallelTLS4 79 76 -3.80%
BenchmarkClientServerParallelTLS64 112 109 -2.68%
BenchmarkCreateGoroutinesCapture 10 6 -40.00%
BenchmarkAfterFunc 1006 1005 -0.10%
Fixes#6632.
Change-Id: I0cd51e4d356331d7f3c5f447669080cd19b0d2ca
Reviewed-on: https://go-review.googlesource.com/3166
Reviewed-by: Russ Cox <rsc@golang.org>
This patch was previously sent for review using hg:
golang.org/cl/173930043
Change-Id: I559a2f2ee07990d0c23d2580381e32f8e23077a5
Reviewed-on: https://go-review.googlesource.com/3033
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The internal size of integers is not part of the definition of the assembler,
so if bits roll out the top it's a portability problem at best.
If you need to use shift to create a mask, use & to restrict the bit count
before shifting. That will make it portable, too.
Change-Id: I24f9a4d2152c3f9f253e22ff75270fe50c18612b
Reviewed-on: https://go-review.googlesource.com/3451
Reviewed-by: Russ Cox <rsc@golang.org>
Rewrite the grammar to have one more production so it parses
~0*0
correctly and write tests to prove it.
Change-Id: I0dd652baf65b48a3f26c9287c420702db4eaec59
Reviewed-on: https://go-review.googlesource.com/3443
Reviewed-by: Russ Cox <rsc@golang.org>
If result of string(i) does not escape,
allocate a [4]byte temp on stack for it.
Change-Id: If31ce9447982929d5b3b963fd0830efae4247c37
Reviewed-on: https://go-review.googlesource.com/3411
Reviewed-by: Russ Cox <rsc@golang.org>
Allow TEXT to have two or three operands.
In
TEXT foo(SB),flag,$0
the flag can be missing, in which case we take it to be zero.
Change-Id: I7b88543b52019f7890baac4b95f9e63884d43c83
Reviewed-on: https://go-review.googlesource.com/3440
Reviewed-by: Russ Cox <rsc@golang.org>
Currently we always allocate string buffers in heap.
For example, in the following code we allocate a temp string
just for comparison:
if string(byteSlice) == "abc" { ... }
This change extends escape analysis to cover []byte->string
conversions and string concatenation. If the result of operations
does not escape, compiler allocates a small buffer
on stack and passes it to slicebytetostring and concatstrings.
Then runtime uses the buffer if the result fits into it.
Size of the buffer is 32 bytes. There is no fundamental theory
behind this number. Just an observation that on std lib
tests/benchmarks frequency of string allocation is inversely
proportional to string length; and there is significant number
of allocations up to length 32.
benchmark old allocs new allocs delta
BenchmarkFprintfBytes 2 1 -50.00%
BenchmarkDecodeComplex128Slice 318 316 -0.63%
BenchmarkDecodeFloat64Slice 318 316 -0.63%
BenchmarkDecodeInt32Slice 318 316 -0.63%
BenchmarkDecodeStringSlice 2318 2316 -0.09%
BenchmarkStripTags 11 5 -54.55%
BenchmarkDecodeGray 111 102 -8.11%
BenchmarkDecodeNRGBAGradient 200 188 -6.00%
BenchmarkDecodeNRGBAOpaque 165 152 -7.88%
BenchmarkDecodePaletted 319 309 -3.13%
BenchmarkDecodeRGB 166 157 -5.42%
BenchmarkDecodeInterlacing 279 268 -3.94%
BenchmarkGoLookupIP 153 135 -11.76%
BenchmarkGoLookupIPNoSuchHost 508 466 -8.27%
BenchmarkGoLookupIPWithBrokenNameServer 245 226 -7.76%
BenchmarkClientServerParallel4 62 61 -1.61%
BenchmarkClientServerParallel64 62 61 -1.61%
BenchmarkClientServerParallelTLS4 79 78 -1.27%
BenchmarkClientServerParallelTLS64 112 111 -0.89%
benchmark old ns/op new ns/op delta
BenchmarkFprintfBytes 381 311 -18.37%
BenchmarkStripTags 2615 2351 -10.10%
BenchmarkDecodeNRGBAGradient 3715887 3635096 -2.17%
BenchmarkDecodeNRGBAOpaque 3047645 2928644 -3.90%
BenchmarkGoLookupIP 153 135 -11.76%
BenchmarkGoLookupIPNoSuchHost 508 466 -8.27%
Change-Id: I9ec01da816945c3329d7be3c7794b520418c3f99
Reviewed-on: https://go-review.googlesource.com/3120
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Currently we allocate a new string during []byte->string conversion
in string comparison expressions. String allocation is unnecessary in
this case, because comparison does memorize the strings for later use.
This change uses slicebytetostringtmp to construct temp string directly
from []byte buffer and passes it to runtime.eqstring.
Change-Id: If00f1faaee2076baa6f6724d245d5b5e0f59b563
Reviewed-on: https://go-review.googlesource.com/3410
Reviewed-by: Russ Cox <rsc@golang.org>
It was too complicated, assuming the syntax is more general than reality.
It must be a possibly negative integer followed by an optional minus sign
and positive integer. Literals only, no expresssions.
Also put in a TODO about address parsing and clean up a couple of types.
Change-Id: If8652249c742e42771ccf2e3024f77307b2e5d9a
Reviewed-on: https://go-review.googlesource.com/3370
Reviewed-by: Russ Cox <rsc@golang.org>
Escape analysis treats everything assigned to OIND/ODOTPTR as escaping.
As the result b escapes in the following code:
func (b *Buffer) Foo() {
n, m := ...
b.buf = b.buf[n:m]
}
This change recognizes such assignments and ignores them.
Update issue #9043.
Update issue #7921.
There are two similar cases in std lib that benefit from this optimization.
First is in archive/zip:
type readBuf []byte
func (b *readBuf) uint32() uint32 {
v := binary.LittleEndian.Uint32(*b)
*b = (*b)[4:]
return v
}
Second is in time:
type data struct {
p []byte
error bool
}
func (d *data) read(n int) []byte {
if len(d.p) < n {
d.p = nil
d.error = true
return nil
}
p := d.p[0:n]
d.p = d.p[n:]
return p
}
benchmark old ns/op new ns/op delta
BenchmarkCompressedZipGarbage 32431724 32217851 -0.66%
benchmark old allocs new allocs delta
BenchmarkCompressedZipGarbage 153 143 -6.54%
Change-Id: Ia6cd32744e02e36d6d8c19f402f8451101711626
Reviewed-on: https://go-review.googlesource.com/3162
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Currently all PTRLIT element initializers escape. There is no reason for that.
This change links STRUCTLIT to PTRLIT; STRUCTLIT element initializers are
already linked to the STRUCTLIT. As the result, PTRLIT element initializers
escape when PTRLIT itself escapes.
Change-Id: I89ecd8677cbf81addcfd469cd2fd461c0e9bf7dd
Reviewed-on: https://go-review.googlesource.com/3031
Reviewed-by: Russ Cox <rsc@golang.org>
For some reason the current conditions require the type to be "uintptr-shaped".
This cuts off structs and arrays with a pointer.
isdirectiface and width==widthptr is sufficient condition to enable the fast paths.
Change-Id: I11842531e7941365413606cfd6c34c202aa14786
Reviewed-on: https://go-review.googlesource.com/3414
Reviewed-by: Russ Cox <rsc@golang.org>
Consider the following code:
s := "(" + string(byteSlice) + ")"
Currently we allocate a new string during []byte->string conversion,
and pass it to concatstrings. String allocation is unnecessary in
this case, because concatstrings does memorize the strings for later use.
This change uses slicebytetostringtmp to construct temp string directly
from []byte buffer and passes it to concatstrings.
I've found few such cases in std lib:
s += string(msg[off:off+c]) + "."
buf.WriteString("Sec-WebSocket-Accept: " + string(c.accept) + "\r\n")
bw.WriteString("Sec-WebSocket-Key: " + string(nonce) + "\r\n")
err = xml.Unmarshal([]byte("<Top>"+string(data)+"</Top>"), &logStruct)
d.err = d.syntaxError("invalid XML name: " + string(b))
return m, ProtocolError("malformed MIME header line: " + string(kv))
But there are much more in our internal code base.
Change-Id: I42f401f317131237ddd0cb9786b0940213af16fb
Reviewed-on: https://go-review.googlesource.com/3163
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This is another case where we can say that the address refers to stack.
We create such temps for OSTRUCTLIT initialization.
This eliminates a handful of write barriers today.
But this come up a prerequisite for another change (capturing vars by value),
otherwise we emit writebarriers in writebarrier itself when
capture writebarrier arguments by value.
Change-Id: Ibba93acd0f5431c5a4c3d90ef1e622cb9a7ff50e
Reviewed-on: https://go-review.googlesource.com/3285
Reviewed-by: Russ Cox <rsc@golang.org>
Typecheck for range variables before typechecking for range body.
Body can refer to new vars declared in for range,
so it is preferable to typecheck them before the body.
Makes typecheck order consistent between ORANGE and OFOR.
This come up during another change that computes some predicates
on variables during typechecking.
Change-Id: Ic975db61b1fd5b7f9ee78896d4cc7d93c593c532
Reviewed-on: https://go-review.googlesource.com/3284
Reviewed-by: Russ Cox <rsc@golang.org>
Currently we scan maps even if k/v does not contain pointers.
This is required because overflow buckets are hanging off the main table.
This change introduces a separate array that contains pointers to all
overflow buckets and keeps them alive. Buckets themselves are marked
as containing no pointers and are not scanned by GC (if k/v does not
contain pointers).
This brings maps in line with slices and chans -- GC does not scan
their contents if elements do not contain pointers.
Currently scanning of a map[int]int with 2e8 entries (~8GB heap)
takes ~8 seconds. With this change scanning takes negligible time.
Update #9477.
Change-Id: Id8a04066a53d2f743474cad406afb9f30f00eaae
Reviewed-on: https://go-review.googlesource.com/3288
Reviewed-by: Keith Randall <khr@golang.org>
- Remove more ? : expressions.
- Use uint32 **hash instead of uint32 *hash[] in function argument.
- Change array.c API to use int, not int32, to match Go's slices.
- Rename strlit to newstrlit, to avoid case-insensitive collision with Strlit.
- Fix a few incorrect printf formats.
- Rename a few variables from 'len' to n or length.
- Eliminate direct string editing building up names like convI2T.
Change-Id: I754cf553402ccdd4963e51b7039f589286219c29
Reviewed-on: https://go-review.googlesource.com/3278
Reviewed-by: Rob Pike <r@golang.org>
cmd/gc contains symbol references into the back end dirs like 6g.
It also contains a few files that include the back end header files and
are compiled separately for each back end, despite being in cmd/gc.
cmd/gc also defines main, which makes at least one reverse symbol
reference unavoidable. (Otherwise you can't get into back-end code.)
This was all expedient, but it's too tightly coupled, especially for a
program written Go.
Make cmd/gc into a true library, letting the back end define main and
call into cmd/gc after making the necessary references available.
cmd/gc being a real library will ease the transition to Go.
Change-Id: I4fb9a0e2b11a32f1d024b3c56fc3bd9ee458842c
Reviewed-on: https://go-review.googlesource.com/3277
Reviewed-by: Rob Pike <r@golang.org>
- Change forward reference to struct Node* to void* in liblink.
- Use explicit (Node*) casts in cmd/gc to get at that field.
- Define struct Array in go.h instead of hiding it in array.c.
- Remove some sizeof(uint32), sizeof(uint64) uses.
- Remove some ? : expressions.
- Rewrite some problematic mid-expression assignments.
Change-Id: I308c70140238a0cfffd90e133f86f442cd0e17d4
Reviewed-on: https://go-review.googlesource.com/3276
Reviewed-by: Rob Pike <r@golang.org>
Fix up a couple of minor things pointed out in the last review.
Also:
1. If the symbol starts with center dot, prefix the name with "".
2. If there is no locals size specified, use ArgsSizeUnknown (sic).
3. Do not emit a history point at the start of a macro invocation,
since we do not pop it at the end, behavior consistent with the
old code.
With these changes, old and new assemblers produce identical
output at least for my simple test case, so that provides a verifiable
check for future cleanups.
Change-Id: Iaa91d8e453109824b4be44321ec5e828f39f0299
Reviewed-on: https://go-review.googlesource.com/3242
Reviewed-by: Russ Cox <rsc@golang.org>
Add main.go, the simple driver for the assembler, and the
subdirectory internal/asm, which contains the parser and
instruction generator.
It's likely that much of the implementation is superstition,
or at best experimental phenomenology, but it does generate
working binaries.
Change-Id: I322a9ae8a20174b6693153f30e39217ba68f8032
Reviewed-on: https://go-review.googlesource.com/3196
Reviewed-by: Russ Cox <rsc@golang.org>
Add the lexing code for the new portable assembler.
It is internal to the assembler, so lives in a subdirectory of cmd/asm/internal.
Its only new dependency is the flags package for the assembler, so
add that too; it's trivial. That package manages the command-line
flags in a central place.
The lexer builds on text/scanner to lex the input, including doing a
Plan 9-level implementation of the C preprocessor.
Change-Id: I262e8717b8c797010afaa5051920839906c0dd19
Reviewed-on: https://go-review.googlesource.com/3195
Reviewed-by: Russ Cox <rsc@golang.org>
This simple package holds the definition of the Addr (address) type
that represents addresses inside the assembler.
It has no dependencies.
Change-Id: I7573fd70f1847ef68e3d6b663dc4c39eb2ebf8b3
Reviewed-on: https://go-review.googlesource.com/3193
Reviewed-by: Russ Cox <rsc@golang.org>
This package builds the representation of the machine architecture
for the new assembler.
Almost nothing in it is likely to last but this will get things running.
Change-Id: I8edd891f927a81f76d2dbdcd7484b9c87ac0fb2e
Reviewed-on: https://go-review.googlesource.com/3194
Reviewed-by: Russ Cox <rsc@golang.org>
The compiler has a phase ordering problem. Escape analysis runs
before wrapper generation. When a generated wrapper calls a method
defined in a different package, if that call is inlined, there will be
no escape information for the variables defined in the inlined call.
Those variables will be placed on the stack, which fails if they
actually do escape.
There are probably various complex ways to fix this. This is a simple
way to avoid it: when a generated wrapper calls a method defined in a
different package, treat all local variables as escaping.
Fixes#9537.
Change-Id: I530f39346de16ad173371c6c3f69cc189351a4e9
Reviewed-on: https://go-review.googlesource.com/3092
Reviewed-by: Russ Cox <rsc@golang.org>
cmd/internal/obj reconverted using rsc.io/c2go rev 40275b8.
All Prog*s need Ctxt field set so that the printer can tell
which architecture the Prog belongs to.
Use ctxt.NewProg consistently for this.
Change-Id: Ic981b3d68f24931ffae74a772e83a3dc2fdf518a
Reviewed-on: https://go-review.googlesource.com/3152
Reviewed-by: Rob Pike <r@golang.org>
For new assembler, reconvert using rsc.io/c2go rev f9db76e.
- Removes trailing _ from Go keywords that are exported.
- Export regstr as Register, anames[5689] as Anames.
Also update clients.
Change-Id: I41c8fd2d14490236f548b4aa0ed0b9bd7571d2d7
Reviewed-on: https://go-review.googlesource.com/3151
Reviewed-by: Rob Pike <r@golang.org>
When an assembly file must be assembled, cmd/go now runs
both (say) 6a and new6a and checks that they write identical
output files.
This serves as a build-time test that the new assemblers are accurate
conversions of the old ones. As long as they are producing identical
bytes, there's no need for run-time testing.
Once the C conversion is done, we'll throw away the C code
and this checking.
Change-Id: I0216dad56b7e79011eecd27f1aff4fe79bfe720b
Reviewed-on: https://go-review.googlesource.com/3145
Reviewed-by: Rob Pike <r@golang.org>
The change to the bootstrap import conversion is
for the a.y files, which use import dot.
While we're editing the tool list, add "cmd/dist".
Right now 'go install cmd/dist' installs to $GOROOT/bin/dist.
(A new bug since cmd/dist has been rewritten in Go.
When cmd/dist was a C program, go install cmd/dist just didn't work.)
Change-Id: I362208dcfb4ae64c987f60b95dc946829fa506d8
Reviewed-on: https://go-review.googlesource.com/3144
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
These assemblers produce byte-for-byte identical output
to the ones written in C.
They are primarily a proof that cmd/internal/obj can be used
standalone to produce working object files. (The use via objwriter
starts by deserializing an already-constructed internal representation,
so objwriter does not exercise the code in cmd/internal/obj that
creates such a representation from scratch.)
Change-Id: I1793d8d010046cfb9d8b4d2d4469e7f47a3d3ac7
Reviewed-on: https://go-review.googlesource.com/3143
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is the raw output of c2go. It needs fixes to make it compile.
Rather than make c2go do a 100% conversion (like we're doing for
liblink and the Go compilers), since this is so trivial I'm going to
make the remaining changes by hand in a followup CL.
This CL makes the next CL's diffs useful.
Also copy unmodified .y files (5a/a.y → new5a/a.y and so on)
The converted 6a/lex.c has been written to new6a/lex.go
but also to internal/asm/asm.go, because I'm going to factor
out some common code rather than convert it four times.
Change-Id: I01d5dfd6a9be3ef6191581560bdddd0ac0e8bc58
Reviewed-on: https://go-review.googlesource.com/3142
Reviewed-by: Rob Pike <r@golang.org>
Using rsc.io/c2go repo revision 60c9302.
- Export a few symbols needed by assemblers.
- Implement Getgoroot etc directly, and add Getgoversion.
- Removes dependency on Go 1.4 go/build.
- Change magic history name <no name> to <pop>
The <pop> change requires adjustment to the liblink serializer.
Change-Id: If5fb52ac9e91d50805263070b3fc5cc05d8b7632
Reviewed-on: https://go-review.googlesource.com/3141
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
cmd/internal/obj needs information about the default
values of GOROOT, GOARM, GOEXPERIMENT, Version, and so on.
It cannot ask package runtime, because during bootstrap
package runtime comes from Go 1.4.
So it must have its own copy.
Change-Id: I73d3e75a3d47210b3184a51a810ebb44826b81e5
Reviewed-on: https://go-review.googlesource.com/3140
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
New code but nothing interesting.
It's nearly all parsing code for the format written by liblink.
The interesting part is the call to obj.Writeobjdirect, which
is the Go translation of the C liblink writeobjdirect function.
Change-Id: I2e9e755e7a3c999302e2ef2c7475c0af9c5acdd2
Reviewed-on: https://go-review.googlesource.com/3047
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This CL adds the real cmd/internal/obj packages.
Collectively they correspond to the liblink library.
The conversion was done using rsc.io/c2go's run script
at rsc.io/c2go repo version 706fac7.
This is not the final conversion, just the first working draft.
There will be more updates, but this works well enough
to use with go tool objwriter and pass all.bash.
Change-Id: I9359e835425f995a392bb2fcdbebf29511477bed
Reviewed-on: https://go-review.googlesource.com/3046
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Bootstrap the Go parts of the Go toolchain using Go 1.4,
as described in https://golang.org/s/go15bootstrap.
The first Go part of the Go toolchain will be cmd/objwriter,
but for now that's just an empty program to test that this
new code works.
Once the build dashboard is okay with this change,
we'll make objwriter a real program depended upon by the build.
Change-Id: Iad3dce675571cbdb5ab6298fe6f98f53ede47d5c
Reviewed-on: https://go-review.googlesource.com/3044
Reviewed-by: Ian Lance Taylor <iant@golang.org>
cmd/internal/obj is the name for the Go translation of the C liblink library.
cmd/objwriter is the name of a Go binary that runs liblink's writeobj function.
When the bulk of liblink has been converted to Go but the assemblers and
compilers are still written in C, the C writeobj will shell out to the Go objwriter
to actually write the object file. This lets us manage the transition in smaller
pieces.
The objwriter tool is purely transitional.
It will not ship in any release (enforced in cmd/dist).
Adding a dummy program and some dummy imports here so that we
can work on the bootstrap mechanisms that will be necessary to build it.
Once the build process handles objwriter properly,
we'll work on the actual implementation.
Change-Id: I675c818b3a513c26bb91c6dba564c6ace3b7fcd4
Reviewed-on: https://go-review.googlesource.com/3043
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Needed for invoking a Go subprocess in the C code.
The Go tools live in $GOROOT/pkg/tool/$GOHOSTARCH_$GOHOSTOS.
Change-Id: I961b6b8a07de912de174b758b2fb87d77080546d
Reviewed-on: https://go-review.googlesource.com/3042
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Can't use bgwait, both because it can only be used from
one goroutine at a time and because it ends up queued
behind all the other pending commands. Use a separate
signaling mechanism so that we can notice we're dying
sooner.
Change-Id: I8652bfa2f9bb5725fa5968d2dd6a745869d01c01
Reviewed-on: https://go-review.googlesource.com/3010
Reviewed-by: Ian Lance Taylor <iant@golang.org>
cmd/dist now requires $GOROOT to be set explicitly.
Set it when invoking via 'go tool dist' so that users are unaffected.
Also, change go tool -n to drop trailing space in output
for 'go tool -n <anything>'.
Change-Id: I9b2c020e0a2f3fa7c9c339fadcc22cc5b6cb7cac
Reviewed-on: https://go-review.googlesource.com/3011
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
gofmt inserts a blank line line between const and var declarations
Change-Id: I3f2ddbd9e66a74eb3f37a2fe641b93820b02229e
Reviewed-on: https://go-review.googlesource.com/3022
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This brings in cmd/dist written in Go, which is working on the primary builders.
If this breaks your build, you need to get Go 1.4 and put it in $HOME/go1.4
(or, if you want to use some other directory, set $GOROOT_BOOTSTRAP
to that directory).
To build Go 1.4 from source:
git clone -b release-branch.go1.4 $GOROOT $HOME/go1.4
cd $HOME/go1.4/src
./make.bash
Or use a binary release: https://golang.org/dl/.
See https://golang.org/s/go15bootstrap for more information.
Change-Id: Ie4ae834c76ea35e39cc54e9878819a9e51b284d9
We were failing ^uint16(0xffff) == 0, as we computed 0xffff0000 instead.
I could only trigger a failure for the above case, the other two tests
^uint16(0xfffe) == 1 and -uint16(0xffff) == 1 didn't seem to fail
previously. Somehow they get MOVHUs inserted for other reasons (used
by CMP instead of TST?). I fixed OMINUS anyway, better safe than
sorry.
Fixes#9604
Change-Id: I4c2d5bdc667742873ac029fdbe3db0cf12893c27
Reviewed-on: https://go-review.googlesource.com/2940
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Mostly this is using uint32 instead of int32 for unsigned values
like instruction encodings or float32 bit representations,
removal of ternary operations, and removal of #defines.
Delete sched9.c, because it is not compiled (it is still in the history
if we ever need it).
Change-Id: I68579cfea679438a27a80416727a9af932b088ae
Reviewed-on: https://go-review.googlesource.com/2658
Reviewed-by: Austin Clements <austin@google.com>
This change implements the requirement of
old Go to build new Go on Plan 9. Also fix
the build of the new cmd/dist written in Go.
This is similar to the make.bash change in
CL 2470, but applied to make.rc for Plan 9.
Change-Id: Ifd9a3bd8658e2cee6f92b4c7f29ce86ee2a93c53
Reviewed-on: https://go-review.googlesource.com/2662
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
These are corresponding Windows changes for the GOROOT_BOOTSTRAP and
dist changes in https://golang.org/cl/2470
Change-Id: I21da2d63a60d8ae278ade9bb71ae0c314a2cf9b5
Reviewed-on: https://go-review.googlesource.com/2674
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
While we're here, rename TestIssue7234 to Test7234 for consistency
with other tests.
Fixes#9557.
Change-Id: I22b0a212b31e7b4f199f6a70deb73374beb80f84
Reviewed-on: https://go-review.googlesource.com/2654
Reviewed-by: Ian Lance Taylor <iant@golang.org>
* Use WORD declaration so 5a can't rewrite the instruction or complain
about forms it doesn't know about.
* Add the interpunct to function declaration.
Change-Id: I8494548db21b3ea52f0e1e0e547d9ead8b93dfd1
Reviewed-on: https://go-review.googlesource.com/2682
Reviewed-by: Minux Ma <minux@golang.org>
Renaming the function broke the race detector since it looked for the
name, didn't find it anymore and didn't insert the necessary
instrumentation.
Change-Id: I11fed6e807cc35be5724d26af12ceff33ebf4f7b
Reviewed-on: https://go-review.googlesource.com/2661
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
This CL introduces the bootstrap requirement that in order to
build the current release (or development version) of Go, you
need an older Go release (1.4 or newer) already installed.
This requirement is the whole point of this CL.
To enforce the requirement, convert cmd/dist from C to Go.
With this bootstrapping out of the way, we can move on to
replacing other, larger C programs like the Go compiler,
the assemblers, and the linker.
See golang.org/s/go15bootstrap for details.
Change-Id: I53fd08ddacf3df9fae94fe2c986dba427ee4a21d
Reviewed-on: https://go-review.googlesource.com/2470
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
This CL makes the next one have nice cross-file diffs.
Change-Id: I9ce897dc505dea9923be4e823bae31f4f7fa2ee2
Reviewed-on: https://go-review.googlesource.com/2471
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also fix one unaligned stack size for nacl that is caught
by this change.
Fixes#9539.
Change-Id: Ib696a573d3f1f9bac7724f3a719aab65a11e04d3
Reviewed-on: https://go-review.googlesource.com/2600
Reviewed-by: Keith Randall <khr@golang.org>
CL 2520 omitted to set the type for an OCONVNOP node.
Typechecking obviously cannot do it for us.
5g inserts float64 <--> [u]int64 conversions at walk time.
The missing type caused it to crash.
Change-Id: Idce381f219bfef2e3a3be38d3ba3c258b71310ae
Reviewed-on: https://go-review.googlesource.com/2640
Reviewed-by: Keith Randall <khr@golang.org>
Recognize loops of the form
for i := range a {
a[i] = zero
}
in which the evaluation of a is free from side effects.
Replace these loops with calls to memclr.
This occurs in the stdlib in 18 places.
The motivating example is clearing a byte slice:
benchmark old ns/op new ns/op delta
BenchmarkGoMemclr5 3.31 3.26 -1.51%
BenchmarkGoMemclr16 13.7 3.28 -76.06%
BenchmarkGoMemclr64 50.8 4.14 -91.85%
BenchmarkGoMemclr256 157 6.02 -96.17%
Update #5373.
Change-Id: I99d3e6f5f268e8c6499b7e661df46403e5eb83e4
Reviewed-on: https://go-review.googlesource.com/2520
Reviewed-by: Keith Randall <khr@golang.org>
This is a replay of CL 189760043 that is in release-branch.go1.4,
but not in master branch somehow.
Change-Id: I11eb40a24273e7be397e092ef040e54efb8ffe86
Reviewed-on: https://go-review.googlesource.com/2541
Reviewed-by: Andrew Gerrand <adg@golang.org>
For a non-zero-sized struct with a final zero-sized field,
add a byte to the size (before rounding to alignment). This
change ensures that taking the address of the zero-sized field
will not incorrectly leak the following object in memory.
reflect.funcLayout also needs this treatment.
Fixes#9401
Change-Id: I1dc503dc5af4ca22c8f8c048fb7b4541cc957e0f
Reviewed-on: https://go-review.googlesource.com/2452
Reviewed-by: Russ Cox <rsc@golang.org>
Now that there's no 6c compiler anymore, there's no need for cgo to
generate C headers that are compatible with it.
Fixes#9528
Change-Id: I43f53869719eb9a6065f1b39f66f060e604cbee0
Reviewed-on: https://go-review.googlesource.com/2482
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The compiler converts 'val, ok = m[key]' to
tmp, ok = <runtime call>
val = *tmp
For lookups of the form '_, ok = m[key]',
the second statement is unnecessary.
By not generating it we save a nil check.
Change-Id: I21346cc195cb3c62e041af8b18770c0940358695
Reviewed-on: https://go-review.googlesource.com/1975
Reviewed-by: Russ Cox <rsc@golang.org>
The equal algorithm used to take the size
equal(p, q *T, size uintptr) bool
With this change, it does not
equal(p, q *T) bool
Similarly for the hash algorithm.
The size is rarely used, as most equal functions know the size
of the thing they are comparing. For instance f32equal already
knows its inputs are 4 bytes in size.
For cases where the size is not known, we allocate a closure
(one for each size needed) that points to an assembly stub that
reads the size out of the closure and calls generic code that
has a size argument.
Reduces the size of the go binary by 0.07%. Performance impact
is not measurable.
Change-Id: I6e00adf3dde7ad2974adbcff0ee91e86d2194fec
Reviewed-on: https://go-review.googlesource.com/2392
Reviewed-by: Russ Cox <rsc@golang.org>
Use a lookup table to find the function which contains a pc. It is
faster than the old binary search. findfunc is used primarily for
stack copying and garbage collection.
benchmark old ns/op new ns/op delta
BenchmarkStackCopy 294746596 255400980 -13.35%
(findfunc is one of several tasks done by stack copy, the findfunc
time itself is about 2.5x faster.)
The lookup table is built at link time. The table grows the binary
size by about 0.5% of the text segment.
We impose a lower limit of 16 bytes on any function, which should not
have much of an impact. (The real constraint required is <=256
functions in every 4096 bytes, but 16 bytes/function is easier to
implement.)
Change-Id: Ic315b7a2c83e1f7203cd2a50e5d21a822e18fdca
Reviewed-on: https://go-review.googlesource.com/2097
Reviewed-by: Russ Cox <rsc@golang.org>
This implements support for calls to and from C in the ppc64 C ABI, as
well as supporting functionality such as an entry point from the
dynamic linker.
Change-Id: I68da6df50d5638cb1a3d3fef773fb412d7bf631a
Reviewed-on: https://go-review.googlesource.com/2009
Reviewed-by: Russ Cox <rsc@golang.org>
R13 is the C TLS pointer. Once we're calling to and from C code, if
we clobber R13 in our code, sigtramp won't know whether to get the
current g from REGG or from C TLS. The simplest solution is for Go
code to preserve the C TLS pointer. This is equivalent to what other
platforms do, except that on other platforms the TLS pointer is in a
special register.
Change-Id: I076e9cb83fd78843eb68cb07c748c4705c9a4c82
Reviewed-on: https://go-review.googlesource.com/2007
Reviewed-by: Minux Ma <minux@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This implements the ELF relocations and dynamic linking tables
necessary to support internal linking on ppc64. It also marks ppc64le
ELF files as ABI v2; failing to do this doesn't seem to confuse the
loader, but it does confuse libbfd (and hence gdb, objdump, etc).
Change-Id: I559dddf89b39052e1b6288a4dd5e72693b5355e4
Reviewed-on: https://go-review.googlesource.com/2006
Reviewed-by: Russ Cox <rsc@golang.org>
Most ppc64 relocations come in six or more variants where the basic
relocation formula is the same, but which bits of the computed value
are installed where changes. Introduce the concept of "variants" for
internal relocations to support this. Since this applies to
architecture-independent relocation types like R_PCREL, we do this in
relocsym.
Currently there is only an identity variant. A later CL that adds
support for ppc64 ELF relocations will introduce more.
Change-Id: I0c5f0e7dbe5beece79cd24fe36267d37c52f1a0c
Reviewed-on: https://go-review.googlesource.com/2005
Reviewed-by: Russ Cox <rsc@golang.org>
ppc64 has a bunch of these.
Change-Id: I3b93ed2bae378322a8dec036b1681e520b56ff53
Reviewed-on: https://go-review.googlesource.com/2003
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
ppc64 function symbols have both a global entry point and a local
entry point, where the difference is stashed in sym.other. We'll need
this information to generate calls to ELF ABI functions.
Change-Id: Ibe343923f56801de7ebec29946c79690a9ffde57
Reviewed-on: https://go-review.googlesource.com/2002
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
The ones at the end of M and G are just used to compute
their size for use in assembly. Generate the size explicitly.
The one at the end of itab is variable-sized, and at least one.
The ones at the end of interfacetype and uncommontype are not
needed, as the preceding slice references them (the slice was
originally added for use by reflect?).
The one at the end of stackmap is already accessed correctly,
and the runtime never allocates one.
Update #9401
Change-Id: Ia75e3aaee38425f038c506868a17105bd64c712f
Reviewed-on: https://go-review.googlesource.com/2420
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The gc toolchain no longer includes a C compiler, so mentions of "6c"
can be removed or replaced by 6g as appropriate. Similarly, some cgo
functions that previously generated C source output no longer need to.
Change-Id: I1ae6b02630cff9eaadeae6f3176c0c7824e8fbe5
Reviewed-on: https://go-review.googlesource.com/2391
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: I5624b509a36650bce6834cf394b9da163abbf8c0
Reviewed-on: https://go-review.googlesource.com/2310
Reviewed-by: Rick Hudson <rlh@golang.org>
A side effect of this change is that when assertI2T writes to the
memory for the T being extracted, it can use typedmemmove
for write barriers.
There are other ways we could have done this, but this one
finishes a TODO in package runtime.
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: Icbc8aabfd8a9b1f00be2e421af0e3b29fa54d01e
Reviewed-on: https://go-review.googlesource.com/2279
Reviewed-by: Keith Randall <khr@golang.org>
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: I1320d5340a9e421c779f24f3b170e33974e56e4f
Reviewed-on: https://go-review.googlesource.com/2278
Reviewed-by: Rick Hudson <rlh@golang.org>
Preparation for replacing many memmove calls in runtime
with typedmemmove, which is a clearer description of what
the routine is doing.
For the same reason, rename writebarriercopy to typedslicecopy.
Change-Id: I6f23bef2c2215509fefba175b16908f76dc7538c
Reviewed-on: https://go-review.googlesource.com/2276
Reviewed-by: Rick Hudson <rlh@golang.org>
This reverts commit ab0535ae3f.
I think it will remain useful to distinguish code that must
run on a system stack from code that can run on either stack,
even if that distinction is no
longer based on the implementation language.
That is, I expect to add a //go:systemstack comment that,
in terms of the old implementation, tells the compiler,
to pretend this function was written in C.
Change-Id: I33d2ebb2f99ae12496484c6ec8ed07233d693275
Reviewed-on: https://go-review.googlesource.com/2275
Reviewed-by: Russ Cox <rsc@golang.org>
Previously, we ended up passing two compiled objects for the package
being tested when linking the test executable. Somewhat by luck, this
worked most of the time but occasionally it did not. This changes the
linking code to not pass two objects for the same ImportPath and to
always pass the object for the test version of the package and removes
some unecessary nil checks.
Change-Id: I7bbd3fc708f14672ee2cc6aed3397421fceb8a38
Reviewed-on: https://go-review.googlesource.com/1840
Reviewed-by: Ian Lance Taylor <iant@golang.org>
If the user provided a key but no value via -ldflag -X,
another linker flag was used as the value.
Placing the user's flags at the end avoids this problem.
It also provides the user the opportunity to
override existing linker flags.
Fixes#8810.
Change-Id: I96f4190713dc9a9c29142e56658446fba7fb6bc8
Reviewed-on: https://go-review.googlesource.com/2242
Reviewed-by: Minux Ma <minux@golang.org>
Updated the issue tracker link the compiler prints out
when asking for a bug report after an internal error.
Change-Id: I092b118130f131c6344d9d058bea4ad6379032b8
Reviewed-on: https://go-review.googlesource.com/2218
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
%lL will prepend the current directory to the filename, which is not
what we want here (as the file name is already absolute).
Fixes#9150.
Change-Id: I4c9386be6baf421393b92d9401a264b4692986d0
Reviewed-on: https://go-review.googlesource.com/2231
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Now that we've removed all the C code in runtime and the C compilers,
there is no need to have a separate stackguard field to check for C
code on Go stack.
Remove field g.stackguard1 and rename g.stackguard0 to g.stackguard.
Adjust liblink and cmd/ld as necessary.
Change-Id: I54e75db5a93d783e86af5ff1a6cd497d669d8d33
Reviewed-on: https://go-review.googlesource.com/2144
Reviewed-by: Keith Randall <khr@golang.org>
Use log.Fatalf for formatting directives instead of log.Fatal
Change-Id: Ia207b320f5795c63cdfa71f92c19ca6d05cc833f
Reviewed-on: https://go-review.googlesource.com/2160
Reviewed-by: Minux Ma <minux@golang.org>
When go parses #cgo lines, expand ${SRCDIR} into the path to the
source directory. This allows options to be passed to the
compiler and linker that involve file paths relative to the
source code directory. Without the expansion the paths would be
invalid when the current working directory changes.
Fixes#7891Fixes#5428
Change-Id: I343a145a9771a5ccbaa958e4a1ecd1716fcae52d
Reviewed-on: https://go-review.googlesource.com/1756
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Calls to goproc/deferproc used to push & pop two extra arguments,
the argument size and the function to call. Now, we allocate space
for those arguments in the outargs section so we don't have to
modify the SP.
Defers now use the stack pointer (instead of the argument pointer)
to identify which frame they are associated with.
A followon CL might simplify funcspdelta and some of the stack
walking code.
Fixes issue #8641
Change-Id: I835ec2f42f0392c5dec7cb0fe6bba6f2aed1dad8
Reviewed-on: https://go-review.googlesource.com/1601
Reviewed-by: Russ Cox <rsc@golang.org>
Previously, this code generated bogus section indexes for dynamic
symbols. It turns out this didn't matter, since we only emit these
when generating an executable and in an executable it only matters
whether a symbol is defined or undefined, but it leads to perplexing
code full of mysterious constants.
Unfortunately, this happens too early to put in real section indexes,
so just use section index 1 to distinguish the symbol from an
undefined symbol.
Change-Id: I0e514604bf31f21683598ebd3e020b66acf767ef
Reviewed-on: https://go-review.googlesource.com/1720
Reviewed-by: Russ Cox <rsc@golang.org>
This will be used by ppc64 to add call stubs to the .text section.
ARM needs a similar pass to generate veneers for arm->thumb
transitions.
Change-Id: Iaee74036e60643a56fab15b564718f359c5910eb
Reviewed-on: https://go-review.googlesource.com/2004
Reviewed-by: Russ Cox <rsc@golang.org>
Pointers to zero-sized values may end up pointing to the next
object in memory, and possibly off the end of a span. This
can cause memory leaks and/or confuse the garbage collector.
By putting the overflow pointer at the end of the bucket, we
make sure that pointers to any zero-sized keys or values don't
accidentally point to the next object in memory.
fixes#9384
Change-Id: I5d434df176984cb0210b4d0195dd106d6eb28f73
Reviewed-on: https://go-review.googlesource.com/1869
Reviewed-by: Russ Cox <rsc@golang.org>
Instead of relying on the asm names declared in the gccgo version of
cgo_export.h, just emit a dummy symbol with the right asm name. This
is enough to let the _cgo_main link succeed, which is all that matters
here.
Fixes#9294.
Change-Id: I803990705b6b226ed0adf17dc57b58a9f501b213
Reviewed-on: https://go-review.googlesource.com/1901
Reviewed-by: Minux Ma <minux@golang.org>
Previously, liblink would silently truncate register offset constants
to 32 bits. For example,
MOVD $0x200000004(R2),R3
would assemble to
addis r31,r2,0
addi r3,r31,4
To fix this, limit C_LACON to 32 bit (signed) offsets and introduce a
new C_DACON operand type for larger register offsets. We don't
implement this currently, but at least liblink will now give an error
if it encounters an address like this.
Change-Id: I8e87def8cc4cc5b75498b0fb543ac7666cf2964e
Reviewed-on: https://go-review.googlesource.com/1758
Reviewed-by: Minux Ma <minux@golang.org>
On ppc64, there are three ELF ABI versions an ELF file can request.
Previously, we used 0, which means "unspecified". On our test
machines, this meant to use the default (v1 for big endian and v2 for
little endian), but apparently some systems can pick the wrong ABI if
neither is requested. Leaving this as 0 also confuses libbfd, which
confuses gdb, objdump, etc.
Fix these problems by specifying ABI v1 for big endian and v2 for
little endian.
Change-Id: I4d3d5478f37f11baab3681a07daff3da55802322
Reviewed-on: https://go-review.googlesource.com/1800
Reviewed-by: Minux Ma <minux@golang.org>
When we do y = &x for global variables x and y, y gets initialized
at link time. Do the same for y = &x.f if x is a struct and y=&x[5]
if x is an array.
fixes#9217fixes#9355
Change-Id: Iea3c0ce2ce1b309e2b760e345608fd95460b5713
Reviewed-on: https://go-review.googlesource.com/1691
Reviewed-by: Minux Ma <minux@golang.org>
On ppc64, liblink rewrites MOVD's of >32-bit constants by putting the
constant in memory and rewriting the MOVD to load from that memory
address. However, there were two bugs in the condition:
a) owing to an incorrect sign extension, it triggered for all negative
constants, and
b) it could trigger for constant offsets from registers (addresses of
the form $n(Rm) in assembly)
Together, these meant instructions of the form MOVD $-n(Rm), x were
compiled by putting -n in memory and rewriting the MOVD to load this
constant from memory (completely dropping Rm).
Change-Id: I1f6cc980efa3e3d6f164b46c985b2c3b55971cca
Reviewed-on: https://go-review.googlesource.com/1752
Reviewed-by: Minux Ma <minux@golang.org>
People are probably not making this mistake anymore.
Fixes#9164
Change-Id: I86b440ed63d09b4ca676bba7034838860f1a5d8b
Reviewed-on: https://go-review.googlesource.com/1782
Reviewed-by: Minux Ma <minux@golang.org>
Most types are reflexive (k == k for all k of type t), so don't
bother calling equal(k, k) when the key type is reflexive.
Change-Id: Ia716b4198b8b298687843b94b878dbc5e8fc2c65
Reviewed-on: https://go-review.googlesource.com/1480
Reviewed-by: Russ Cox <rsc@golang.org>
Remove carriage returns from //go:generate lines.
Carriage returns are the predecessor of BOMs and still
live on Windows.
Fixes#9264
Change-Id: I637748c74335c696b3630f52f2100061153fcdb4
Reviewed-on: https://go-review.googlesource.com/1564
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
//go:nowritebarrier can only be used in package runtime.
It does not disable write barriers; it is an assertion, checked
by the compiler, that the following function needs no write
barriers.
Change-Id: Id7978b779b66dc1feea39ee6bda9fd4d80280b7c
Reviewed-on: https://go-review.googlesource.com/1224
Reviewed-by: Rick Hudson <rlh@golang.org>
Still using the ancient go/types API. Updating that to the modern API
should be a separate effort in a separate change.
Change-Id: Ic1c5ae3c13711d34fe757507ecfc00ee883810bf
Reviewed-on: https://go-review.googlesource.com/1404
Reviewed-by: David Symonds <dsymonds@golang.org>
We forgot to do the usual API review.
Make that not possible in the future.
I'll pull this change over to the main
branch too, but it's more important
(and only testable) here.
LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/185050043
I read through and vetted these but others should look too.
LGTM=bradfitz, adg
R=r, minux, bradfitz, adg
CC=adg, golang-codereviews, gri, iant
https://golang.org/cl/182560043
This flag no longer exists. It has been replaced with -unit=byte.
Change-Id: Iff9fc501f2c666067c9b1948c4623c8e3adddb8d
Reviewed-on: https://go-review.googlesource.com/1287
Reviewed-by: Russ Cox <rsc@golang.org>
Avoids a potential O(n^2) performance problem when dequeueing
from very popular channels.
benchmark old ns/op new ns/op delta
BenchmarkChanPopular 2563782 627201 -75.54%
Change-Id: I231aaeafea0ecd93d27b268a0b2128530df3ddd6
Reviewed-on: https://go-review.googlesource.com/1200
Reviewed-by: Russ Cox <rsc@golang.org>
When we start work on Gerrit, ppc64 and garbage collection
work will continue in the master branch, not the dev branches.
(We may still use dev branches for other things later, but
these are ready to be merged, and doing it now, before moving
to Git means we don't have to have dev branches working
in the Gerrit workflow on day one.)
TBR=rlh
CC=golang-codereviews
https://golang.org/cl/183140043
This is the last system-dependent file written by cmd/dist.
They are all now written by go generate.
cmd/dist is not needed to start building package runtime
for a different system anymore.
Now all the generated files can be assumed generated, so
delete the clumsy hacks in cmd/api.
Re-enable api check in run.bash.
LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/185040044
Frankly, I don't understand how the current code could possibly work except
when every android program is using cgo. Discovered this while working on
the iOS port.
LGTM=crawshaw, rsc
R=rsc, crawshaw
CC=golang-codereviews
https://golang.org/cl/177470043
The new semantics of split require the newline be present.
The test was stale.
LGTM=adg
R=golang-codereviews, adg
CC=golang-codereviews
https://golang.org/cl/182480043
Scanner can't handle stupid long lines and there are
reports of stupid long lines in production.
Note the issue isn't long "//go:generate" lines, but
any long line in any Go source file.
To be fair, if you're going to have a stupid long line
it's not a bad bet you'll want to run it through go
generate, because it's some embeddable asset that
has been machine generated. (One could ask why
that generation process didn't add a newline or two,
but we should cope anyway.)
Rewrite the file scanner in "go generate" so it can
handle arbitrarily long lines, and only stores in memory
those lines that start "//go:generate".
Also: Adjust the documentation to make clear that it
does not parse the file.
Fixes#9143.
Fixes#9196.
LGTM=rsc, dominik.honnef
R=rsc, cespare, minux, dominik.honnef
CC=golang-codereviews
https://golang.org/cl/182970043
While we're at there, also add a message to prompt the user to install
Graphviz if "dot" command is not found.
Fixes#9178.
LGTM=adg, alex.brainman, cookieo9, rsc
R=rsc, adg, bradfitz, alex.brainman, cookieo9, smyrman
CC=golang-codereviews
https://golang.org/cl/180380043
Move change from CL 170770043 to correct file and regenerate docs
for changes from CL 164120043.
LGTM=adg
R=golang-codereviews, adg, bradfitz
CC=golang-codereviews
https://golang.org/cl/183000043
These accomplished the same thing, but R_CALLPOWER expected
the whole instruction to be in the addend (and completely
overwrote what was in the text section), while R_PPC64_REL24
overwrites only bits 6 through 24 of whatever was in the text
section. Make R_CALLPOWER work like R_PPC64_REL24 to ease the
implementation of dynamic linking.
LGTM=rsc
R=rsc
CC=golang-codereviews, minux
https://golang.org/cl/177430043
warning: src/cmd/5g/reg.c:461 format mismatch d VLONG, arg 5
warning: src/cmd/6g/reg.c:396 format mismatch d VLONG, arg 5
warning: src/cmd/9g/reg.c:440 format mismatch d VLONG, arg 5
LGTM=minux
R=rsc, minux
CC=golang-codereviews
https://golang.org/cl/179300043
This was based on the 9c peephole optimizer, modified to work
with code generated by gc and use the proginfo infrastructure
in gc.
LGTM=rsc
R=rsc, bradfitz, minux
CC=golang-codereviews
https://golang.org/cl/179190043
This adds some utilities for converting between the CC, V, and
VCC variants of operations and uses these to derive the
ProgInfo entries for these variants (which are identical to
the ProgInfo for the base operations).
The 9g peephole optimizer will also use these conversion
utilities.
LGTM=minux, rsc
R=rsc, dave, minux
CC=golang-codereviews
https://golang.org/cl/180110044
Previously, 9a was the only assembler that had a different
name for RET, causing unnecessary friction in simple files
that otherwise assembled on all architectures. Add RET so
these work on 9a.
This also renames "R30" to "g" to avoid unintentionally
clobbering g in assembly code. This parallels a change made
to 5a.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/178030043
Eventually I'd like almost everything cmd/dist generates
to be done with 'go generate' and checked in, to simplify
the bootstrap process. The only thing cmd/dist really needs
to do is write things like the current experiment info and
the current version.
This is a first step toward that. It replaces the _NaCl etc
constants with generated ones goos_nacl, goos_darwin,
goarch_386, and so on.
LGTM=dave, austin
R=austin, dave, bradfitz
CC=golang-codereviews, iant, r
https://golang.org/cl/174290043
getFunctionSource gathers five lines of "margin" around every
requested sample line. However, if this margin went past the
end of the source file, getFunctionSource would encounter an
io.EOF error and abort with this error, resulting in listings
like
(pprof) list main.main
ROUTINE ======================== main.main in ...
0 8.33s (flat, cum) 99.17% of Total
Error: EOF
(pprof)
Modify the error handling in getFunctionSource so io.EOF is
always considered non-fatal. If it reaches EOF, it simply
returns the lines it has.
LGTM=bradfitz
R=rsc, bradfitz
CC=golang-codereviews
https://golang.org/cl/172600043
debug/goobj is not ready to be published but it is
needed for the various binary-reading commands.
Move to cmd/internal/goobj.
(The Go 1.3 release branch deleted it, but that's not
an option anymore due to the command dependencies.
The API is still not vetted nor terribly well designed.)
LGTM=adg, dsymonds
R=adg, dsymonds
CC=golang-codereviews
https://golang.org/cl/174250043
This change works around the "out of fixed registers"
issue with the Plan 9 C compiler on 386, introduced by
the Bits change to uint64 in CL 169060043.
The purpose of this CL is to be able to properly
follow the conversion of the Plan 9 runtime to Go
on the Plan 9 builders.
This CL could be reverted once the Go compilers will
be converted to Go.
Thanks to Nick Owens for investigating this issue.
LGTM=rsc
R=rsc
CC=austin, golang-codereviews, mischief
https://golang.org/cl/177860043
The garbage collector is now written in Go.
There is plenty to clean up (just like on dev.cc).
all.bash passes on darwin/amd64, darwin/386, linux/amd64, linux/386.
TBR=rlh
R=austin, rlh, bradfitz
CC=golang-codereviews
https://golang.org/cl/173250043
The pretty printers for these make it hard to understand
what's actually in the fields of these structures. These
"ugly printers" show exactly what's in each field, which can
be useful for understanding and debugging code.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/175780043
This is to reduce the delta between dev.cc and dev.garbage to just garbage collector changes.
These are the files that had merge conflicts and have been edited by hand:
malloc.go
mem_linux.go
mgc.go
os1_linux.go
proc1.go
panic1.go
runtime1.go
LGTM=austin
R=austin
CC=golang-codereviews
https://golang.org/cl/174180043
Now the only difference between dev.cc and dev.garbage
is the runtime conversion on the one side and the
garbage collection on the other. They both have the
same set of changes from default and dev.power64.
LGTM=austin
R=austin
CC=golang-codereviews
https://golang.org/cl/172570043
This is more complicated than the other enums because the D_*
enums are full of explicit initializers and repeated values.
This tries its best. (This will get much cleaner once we
tease these constants apart better.)
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/166700043
Theses were very helpful in understanding the regions and
register selection when porting regopt to 9g. Add them to the
other compilers (and improve 9g's successor debug print).
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/174130043
I added several comments to the regopt-related structures when
porting it to 9g. Synchronize those comments back in to the
other compilers.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/175720043
This adds registerization support to 9g equivalent to what the
other compilers have.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/174980043
None of the other compilers have a tag for this enum.
Cleaning all of this up to use proper types will happen after
the conversion.
LGTM=minux, rsc
R=rsc, minux
CC=golang-codereviews
https://golang.org/cl/166690043
Previously, the 6g and 8g registerizers scanned for used
registers beyond the end of a region being considered for
registerization. This ancient artifact was copied from the C
compilers, where it was probably necessary to track implicitly
used registers. In the Go compilers it's harmless (because it
can only over-restrict the set of available registers), but no
longer necessary because the Go compilers correctly track
register use/set information. The consequences of this extra
scan were (at least) that 1) we would not consider allocating
the AX register if there was a deferproc call in the future
because deferproc uses AX as a return register, so we see the
use of AX, but don't track that AX is set by the CALL, and 2)
we could not consider allocating the DX register if there was
a MUL in the future because MUL implicitly sets DX and (thanks
to an abuse of copyu in this code) we would also consider DX
used.
This commit fixes these problems by nuking this code.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/174110043
For D_OREG addresses, store the used registers in regindex
instead of reguse because they're really part of addressing.
Add implicit register use/set for DUFFZERO/DUFFCOPY.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/174050044
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
- Remove references to C compiler directories.
- Remove generation of special header files.
- Remove generation of Go source files from C declarations.
- Compile Go sources before rest of package (was after),
so that Go compiler can write go_asm.h for use in assembly.
- Move TLS information from cmd/dist (was embedding in output)
to src/runtime/go_tls.h, which it can be maintained directly.
LGTM=r
R=r, dave
CC=austin, golang-codereviews, iant, khr
https://golang.org/cl/172960043
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
Make gcToolchain.cc return an error (no C compiler!).
Adjust expectations of cgo, now that cgo does not write any C files
(no C compiler!).
For packages with .s files, invoke Go compiler with -asmhdr go_asm.h
so that assembly files can use it. This applies to all packages but is only
needed today by package runtime.
LGTM=r
R=r
CC=austin, golang-codereviews, iant, khr
https://golang.org/cl/171470043
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
export.c, lex.c:
Add -asmhdr flag to write assembly header file with struct
field offsets and const values. cmd/dist used to construct this
file by interpreting output from the C compiler.
Generate it from the Go definitions instead.
Also, generate the form we need directly, instead of relying
on cmd/dist for reprocessing.
lex.c, obj.c:
If the C compiler accepted #pragma cgo_xxx, recognize
a directive //go:cgo_xxx instead. The effect is the same as
in the C compiler: accumulate text into a buffer and emit in the
output file, where the linker will find and use it.
lex.c, obj.c:
Accept //go:linkname to control the external symbol name
used for a particular top-level Go variable. This makes it
possible to refer to C symbol names but also symbols from
other packages. It has always been possible to do this from
C and assembly. To drive home the point that this should not
be done lightly, require import "unsafe" in any file containing
//go:linkname.
plive.c, reflect.c, subr.c:
Hard-code that interfaces contain only pointers.
This means code handling multiword values in the garbage
collector and the stack copier can be deleted instead of being
converted. This change is already present in the dev.garbage
branch.
LGTM=r
R=r
CC=austin, golang-codereviews, iant, khr
https://golang.org/cl/169360043
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
We changed cgo to write the actual function wrappers in Go
for Go 1.4. The only code left in C output files was the definitions
for pointers to C data and the #pragma cgo directives.
Write both of those to Go outputs instead, using the new
compiler directives introduced in CL 169360043.
(Still generating C files in gccgo mode.)
LGTM=r
R=r
CC=austin, golang-codereviews, iant, khr
https://golang.org/cl/169330045
Let's just do this up front.
This will break the build (here on the dev.cc branch).
The CLs that follow will take care of fixing it.
Leave behind cmd/cc/lexbody and cmd/cc/macbody for the assemblers.
They'll go away later.
LGTM=dave, r
R=r, dave
CC=golang-codereviews
https://golang.org/cl/172170043
This patch is based only on reading the code. I have not
tried to construct a test case.
Fixes#9077.
LGTM=minux
R=minux
CC=golang-codereviews
https://golang.org/cl/172110043
This was a mistake. The cmd/api tool
depends on an old version of go/types.
««« original CL description
cmd/api: use golang.org/x/... import paths
LGTM=bradfitz, rsc
R=rsc, bradfitz
CC=golang-codereviews
https://golang.org/cl/169000043
»»»
TBR=rsc, bradfitz
R=bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/169320043
This was a mistake; the cmd/api tool
depends on an old version of go/types.
««« original CL description
cmd/api: bump go.tools golden CL hash
TBR=bradfitz
R=rsc
CC=golang-codereviews
https://golang.org/cl/166380043
»»»
TBR=bradfitz, rsc
R=bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/167430043
Replace a bit-wise AND with a logical one. This happened to
work before because bany returns 0 or 1, but the intent here
is clearly logical (and this makes 5g match with 6g and 8g).
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/172850043
This was missing from CL 167320043.
Happy to apply comments in a followup.
TBR to fix build.
TBR=r
CC=golang-codereviews
https://golang.org/cl/171260043
Moving so that new Go 1.4 pprof can use it.
The old 'GNU objdump workalike' mode for 'go tool objdump'
is now gone, as are the tests for that mode. It was used only
by pre-Go 1.4 pprof. You can still specify an address range on
the command line; you just get the same output format as
you do when dumping the entire binary (without an address
limitation).
LGTM=r
R=r
CC=golang-codereviews, iant
https://golang.org/cl/167320043
For OITAB nodes, 5g's naddr was setting the wrong etype and
failing to set the width of the resulting Addr.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/171220043
9g's naddr was missing assignments to a->width in several
cases, so the optimizer was getting bogus width information.
Add them.
This correct width information also lets us enable the width
check in gins for MOV*.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/167310043
The etype of references to strings was being incorrectly set
to TINT32 on all platforms. Change it to TSTRING. It seems
this doesn't matter for compilation, since x86 uses LEA
instructions to load string addresses and arm and power64
disassemble the string into its constituent pieces (with the
correct types), but it helps when debugging.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/170100043
Previously, mkvar treated, for example, 0(AX) the same as AX.
As a result, a move to an indirect address would be marked as
*setting* the register, rather than just using it, resulting
in unnecessary register moves. Fix this by not producing
variables for indirect addresses.
LGTM=rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/164610043
The test intended to skip direct calls when creating
registerization variables was testing p->to.type instead of
p->to.name, so it always failed, causing regopt to create
unnecessary variables for these names.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/169110043
Now each C printf, Go print, or Go println is guaranteed
not to be interleaved with other calls of those functions.
This should help when debugging concurrent failures.
LGTM=rlh
R=rlh
CC=golang-codereviews
https://golang.org/cl/169120043
So far all of our architectures have had at most 32 registers,
so we've been able to use entry 0 in the Bits uint32 array
directly as a register mask. Power64 has 64 registers, so
this converts Bits to a uint64 array so we can continue to use
entry 0 directly as a register mask on Power64.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/169060043
The check for unknown command line debug flags in gc was
incorrect: the loop over debugtab terminates when it reaches a
nil entry, but it was only reporting an error if the parser
had passed the last entry of debugtab (which it never did).
Fix this by reporting the usage error if the loop reaches a
nil entry.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/166110043
Previously, nilopt was disabled on power64x because it threw
away "seemly random segments of code." Indeed, excise on
power64x failed to preserve the link field, so it excised not
only the requested instruction but all following instructions
in the function. Fix excise to retain the link field while
otherwise zeroing the instruction.
This makes nilopt safe on power64x. It still fails
nilptr3.go's tests for removal of repeated nil checks because
those depend on also optimizing away repeated loads, which
doesn't currently happen on power64x.
LGTM=dave, rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/168120043
All three cases of clearfat were wrong on power64x.
The cases that handle 1032 bytes and up and 32 bytes and up
both use MOVDU (one directly generated in a loop and the other
via duffzero), which leaves the pointer register pointing at
the *last written* address. The generated code was not
accounting for this, so the byte fill loop was re-zeroing the
last zeroed dword, rather than the bytes following the last
zeroed dword. Fix this by simply adding an additional 8 byte
offset to the byte zeroing loop.
The case that handled under 32 bytes was also wrong. It
didn't update the pointer register at all, so the byte zeroing
loop was simply re-zeroing the beginning of region. Again,
the fix is to add an offset to the byte zeroing loop to
account for this.
LGTM=dave, bradfitz
R=rsc, dave, bradfitz
CC=golang-codereviews
https://golang.org/cl/168870043
This CL implements the many multiword write barriers by calling
writebarrierptr, so that only writebarrierptr needs the actual barrier.
In lieu of an actual barrier, writebarrierptr checks that the value
being copied is not a small non-zero integer. This is enough to
shake out bugs where the barrier is being called when it should not
(for non-pointer values). It also found a few tests in sync/atomic
that were being too clever.
This CL adds a write barrier for the memory moved during the
builtin copy function, which I forgot when inserting barriers for Go 1.4.
This CL re-enables some write barriers that were disabled for Go 1.4.
Those were disabled because it is possible to change the generated
code so that they are unnecessary most of the time, but we have not
changed the generated code yet. For safety they must be enabled.
None of this is terribly efficient. We are aiming for correct first.
LGTM=rlh
R=rlh
CC=golang-codereviews
https://golang.org/cl/168770043
This removes a bunch of ugly duplicate code.
The end goal is to factor the disassembly code
into cmd/internal/objfile too, so that pprof can use it,
but one step at a time.
LGTM=r, iant
R=r, alex.brainman, iant
CC=golang-codereviews
https://golang.org/cl/149400043
The goal here is to get the big-endian fixes so that
in some upcoming code movement for write barriers
I don't make them unmergeable.
LGTM=rlh
R=rlh
CC=golang-codereviews
https://golang.org/cl/166890043
goprintf is a printf-like print for Go.
It is used in the code generated by 'defer print(...)' and 'go print(...)'.
Normally print(1, 2, 3) turns into
printint(1)
printint(2)
printint(3)
but defer and go need a single function call to give the runtime;
they give the runtime something like goprintf("%d%d%d", 1, 2, 3).
Variadic functions like goprintf cannot be described in the new
type information world, so we have to replace it.
Replace with a custom function, so that defer print(1, 2, 3) turns
into
defer func(a1, a2, a3 int) {
print(a1, a2, a3)
}(1, 2, 3)
(and then the print becomes three different printints as usual).
Fixes#8614.
LGTM=austin
R=austin
CC=golang-codereviews, r
https://golang.org/cl/159700043
I removed support for jumping between functions years ago,
as part of doing the instruction layout for each function separately.
Given that, it makes sense to treat labels as function-scoped.
This lets each function have its own 'loop' label, for example.
Makes the assembly much cleaner and removes the last
reason anyone would reach for the 123(PC) form instead.
Note that this is on the dev.power64 branch, but it changes all
the assemblers. The change will ship in Go 1.5 (perhaps after
being ported into the new assembler).
Came up as part of CL 167730043.
LGTM=r
R=r
CC=austin, dave, golang-codereviews, minux
https://golang.org/cl/159670043
The "to" field was the penultimate argument to outgcode,
instead of the last argument, which swapped the third and
fourth operands. The argument order was correct in a.y, so
just swap the meaning of the arguments in outgcode. This
hadn't come up because we hadn't used these more obscure
operations in any hand-written assembly until now.
LGTM=rsc, dave
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/160690043
get -u now checks that remote repo paths match the
ones predicted by the import paths: if you are get -u'ing
rsc.io/pdf, it has to be checked out from the right location.
This is important in case the rsc.io/pdf redirect changes.
In some cases, people have good reasons to use
non-standard remote repos. Add -f flag to allow that.
The f can stand for force or fork, as you see fit.
Fixes#8850.
LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/164120043
This brings dev.power64 up-to-date with the current tip of
default. go_bootstrap is still panicking with a bad defer
when initializing the runtime (even on amd64).
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/152570049
This also removes pkg/runtime/traceback_lr.c, which was ported
to Go in an earlier commit and then moved to
runtime/traceback.go.
Reviewer: rsc@golang.org
rsc: LGTM
Partial undo, changes to ldelf.c retained.
Some platforms are still not working even with the integrated assembler disabled, will have to find another solution.
««« original CL description
cmd/cgo: disable clang's integrated assembler
Fixes#8348.
Clang's internal assembler (introduced by default in clang 3.4) understands the .arch directive, but doesn't change the default value of -march. This causes the build to fail when we use BLX (armv5 and above) when clang is compiled for the default armv4t architecture (which appears to be the default on all the distros I've used).
This is probably a clang bug, so work around it for the time being by disabling the integrated assembler when compiling the cgo assembly shim.
This CL also includes a small change to ldelf.c which was required as clang 3.4 and above generate more weird symtab entries.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/156430044
»»»
LGTM=minux
R=iant, minux
CC=golang-codereviews
https://golang.org/cl/162880044
This brings cmd/gc in line with the spec on this question.
It might break existing code, but that code was not conformant
with the spec.
Credit to Rémy for finding the broken code.
Fixes#6366.
LGTM=r
R=golang-codereviews, r
CC=adonovan, golang-codereviews, gri
https://golang.org/cl/129550043
Fixes#8348.
Clang's internal assembler (introduced by default in clang 3.4) understands the .arch directive, but doesn't change the default value of -march. This causes the build to fail when we use BLX (armv5 and above) when clang is compiled for the default armv4t architecture (which appears to be the default on all the distros I've used).
This is probably a clang bug, so work around it for the time being by disabling the integrated assembler when compiling the cgo assembly shim.
This CL also includes a small change to ldelf.c which was required as clang 3.4 and above generate more weird symtab entries.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/156430044
https://golang.org/cl/152700045/ made it possible for struct literals assigned to globals to use <N> as the RHS. Normally, this is to zero out variables on first use. Because globals are already zero (or their linker initialized value), we just ignored this.
Now that <N> can occur from non-initialization code, we need to emit this code. We don't use <N> for initialization of globals any more, so this shouldn't cause any excessive zeroing.
Fixes#8961.
LGTM=rsc
R=golang-codereviews, rsc
CC=bradfitz, golang-codereviews
https://golang.org/cl/154540044
Better to avoid the memory loads and just use immediate constants.
This especially applies to zeroing, which was being done by
copying zeros from elsewhere in the binary, even if the value
was going to be completely initialized with non-zero values.
The zero writes were optimized away but the zero loads from
the data segment were not.
LGTM=r
R=r, bradfitz, dvyukov
CC=golang-codereviews
https://golang.org/cl/152700045
hg was unable to create a CL on the code review server for this,
so I am submitting the merge by hand.
The only manual edits are in mgc0.c, to reapply the
removal of cached/ncached to the new code.
Both of these forms can avoid writing to the base pointer in x
(in the slice, always, and in the append, most of the time).
For Go 1.5, will need to change the compilation of x = x[0:y]
to avoid writing to the base pointer, so that the elision is safe,
and will need to change the compilation of x = append(x, ...)
to write to the base pointer (through a barrier) only when
growing the underlying array, so that the general elision is safe.
For Go 1.4, elide the write barrier always, a change that should
have equivalent performance characteristics but is much
simpler and therefore safer.
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 3910526122 3918802545 +0.21%
BenchmarkFannkuch11 3747650699 3732600693 -0.40%
BenchmarkFmtFprintfEmpty 106 98.7 -6.89%
BenchmarkFmtFprintfString 280 269 -3.93%
BenchmarkFmtFprintfInt 296 282 -4.73%
BenchmarkFmtFprintfIntInt 467 470 +0.64%
BenchmarkFmtFprintfPrefixedInt 418 398 -4.78%
BenchmarkFmtFprintfFloat 574 535 -6.79%
BenchmarkFmtManyArgs 1768 1818 +2.83%
BenchmarkGobDecode 14916799 14925182 +0.06%
BenchmarkGobEncode 14110076 13358298 -5.33%
BenchmarkGzip 546609795 542630402 -0.73%
BenchmarkGunzip 136270657 136496277 +0.17%
BenchmarkHTTPClientServer 126574 125245 -1.05%
BenchmarkJSONEncode 30006238 27862354 -7.14%
BenchmarkJSONDecode 106020889 102664600 -3.17%
BenchmarkMandelbrot200 5793550 5818320 +0.43%
BenchmarkGoParse 5437608 5463962 +0.48%
BenchmarkRegexpMatchEasy0_32 192 179 -6.77%
BenchmarkRegexpMatchEasy0_1K 462 460 -0.43%
BenchmarkRegexpMatchEasy1_32 168 153 -8.93%
BenchmarkRegexpMatchEasy1_1K 1420 1280 -9.86%
BenchmarkRegexpMatchMedium_32 338 286 -15.38%
BenchmarkRegexpMatchMedium_1K 107435 98027 -8.76%
BenchmarkRegexpMatchHard_32 5941 4846 -18.43%
BenchmarkRegexpMatchHard_1K 185965 153830 -17.28%
BenchmarkRevcomp 795497458 798447829 +0.37%
BenchmarkTemplate 132091559 134938425 +2.16%
BenchmarkTimeParse 604 608 +0.66%
BenchmarkTimeFormat 551 548 -0.54%
LGTM=r
R=r, dave
CC=golang-codereviews, iant, khr, rlh
https://golang.org/cl/159960043
Among other things, *x = T{} does not need a write barrier.
The changes here avoid an unnecessary copy even when
no pointers are involved, so it may have larger effects.
In 6g and 8g, avoid manually repeated STOSQ in favor of
writing explicit MOVs, under the theory that the MOVs
should have fewer dependencies and pipeline better.
Benchmarks compare best of 5 on a 2012 MacBook Pro Core i5
with TurboBoost disabled. Most improvements can be explained
by the changes in this CL.
The effect in Revcomp is real but harder to explain: none of
the instructions in the inner loop changed. I suspect loop
alignment but really have no idea.
benchmark old new delta
BenchmarkBinaryTree17 3809027371 3819907076 +0.29%
BenchmarkFannkuch11 3607547556 3686983012 +2.20%
BenchmarkFmtFprintfEmpty 118 103 -12.71%
BenchmarkFmtFprintfString 289 277 -4.15%
BenchmarkFmtFprintfInt 304 290 -4.61%
BenchmarkFmtFprintfIntInt 507 458 -9.66%
BenchmarkFmtFprintfPrefixedInt 425 408 -4.00%
BenchmarkFmtFprintfFloat 555 555 +0.00%
BenchmarkFmtManyArgs 1835 1733 -5.56%
BenchmarkGobDecode 14738209 14639331 -0.67%
BenchmarkGobEncode 14239039 13703571 -3.76%
BenchmarkGzip 538211054 538701315 +0.09%
BenchmarkGunzip 135430877 134818459 -0.45%
BenchmarkHTTPClientServer 116488 116618 +0.11%
BenchmarkJSONEncode 28923406 29294334 +1.28%
BenchmarkJSONDecode 105779820 104289543 -1.41%
BenchmarkMandelbrot200 5791758 5771964 -0.34%
BenchmarkGoParse 5376642 5310943 -1.22%
BenchmarkRegexpMatchEasy0_32 195 190 -2.56%
BenchmarkRegexpMatchEasy0_1K 477 455 -4.61%
BenchmarkRegexpMatchEasy1_32 170 165 -2.94%
BenchmarkRegexpMatchEasy1_1K 1410 1394 -1.13%
BenchmarkRegexpMatchMedium_32 336 329 -2.08%
BenchmarkRegexpMatchMedium_1K 108979 106328 -2.43%
BenchmarkRegexpMatchHard_32 5854 5821 -0.56%
BenchmarkRegexpMatchHard_1K 185089 182838 -1.22%
BenchmarkRevcomp 834920364 780202624 -6.55%
BenchmarkTemplate 137046937 129728756 -5.34%
BenchmarkTimeParse 600 594 -1.00%
BenchmarkTimeFormat 559 539 -3.58%
LGTM=r
R=r
CC=golang-codereviews, iant, khr, rlh
https://golang.org/cl/157910047
