Most write barrier calls are inserted by SSA, but copy and append are
lowered to runtime.typedslicecopy during walk. Fix these to set
Func.WBPos and emit the "write barrier" warning, as done for the write
barriers inserted by SSA. As part of this, we refactor setting WBPos
and emitting this warning into the frontend so it can be shared by
both walk and SSA.
Change-Id: I5fe9997d9bdb55e03e01dd58aee28908c35f606b
Reviewed-on: https://go-review.googlesource.com/73411
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
We used to have {Arg,Auto,Extern}Symbol structs with which we wrapped
a *gc.Node or *obj.LSym before storing them in the Aux field
of an ssa.Value. This let the SSA part of the compiler distinguish
between autos and args, for example. We no longer need the wrappers
as we can query the underlying objects directly.
There was also some sloppy usage, where VarDef had a *gc.Node
directly in its Aux field, whereas the use of that variable had
that *gc.Node wrapped in an AutoSymbol. Thus the Aux fields didn't
match (using ==) when they probably should.
This sloppy usage cleanup is the only thing in the CL that changes the
generated code - we can get rid of some more unused auto variables if
the matching happens reliably.
Removing this wrapper also lets us get rid of the varsyms cache
(which was used to prevent wrapping the same *gc.Node twice).
Change-Id: I0dedf8f82f84bfee413d310342b777316bd1d478
Reviewed-on: https://go-review.googlesource.com/64452
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This adds rules to match the code in math/bits RotateLeft,
RotateLeft32, and RotateLef64 to allow them to be inlined.
The rules are complicated because the code in these function
use different types, and the non-const version of these
shifts generate Mask and Carry instructions that become
subexpressions during the match process.
Also adds a testcase to asm_test.go.
Improvement in math/bits:
BenchmarkRotateLeft-16 1.57 1.32 -15.92%
BenchmarkRotateLeft32-16 1.60 1.37 -14.37%
BenchmarkRotateLeft64-16 1.57 1.32 -15.92%
Updates #21390
Change-Id: Ib6f17669ecc9cab54f18d690be27e2225ca654a4
Reviewed-on: https://go-review.googlesource.com/59932
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
CL 54410 and CL 56250 recently added use of the MOVOstore
instruction to improve performance.
However, we can't use the MOVOstore instruction on Plan 9,
because floating point operations are not allowed in the
note handler.
This change adds a configuration flag useSSE to enable the
use of SSE instructions for non-floating point operations.
This flag is enabled by default and disabled on Plan 9.
When this flag is disabled, the MOVOstore instruction is
not used and the MOVQstoreconst instruction is used instead.
Fixes#21599
Change-Id: Ie609e5d9b82ec0092ae874bab4ce01caa5bc8fb8
Reviewed-on: https://go-review.googlesource.com/58850
Reviewed-by: Keith Randall <khr@golang.org>
When package ssa was created, Type was in package gc.
To avoid circular dependencies, we used an interface (ssa.Type)
to represent type information in SSA.
In the Go 1.9 cycle, gri extricated the Type type from package gc.
As a result, we can now use it in package ssa.
Now, instead of package types depending on package ssa,
it is the other way.
This is a more sensible dependency tree,
and helps compiler performance a bit.
Though this is a big CL, most of the changes are
mechanical and uninteresting.
Interesting bits:
* Add new singleton globals to package types for the special
SSA types Memory, Void, Invalid, Flags, and Int128.
* Add two new Types, TSSA for the special types,
and TTUPLE, for SSA tuple types.
ssa.MakeTuple is now types.NewTuple.
* Move type comparison result constants CMPlt, CMPeq, and CMPgt
to package types.
* We had picked the name "types" in our rules for the handy
list of types provided by ssa.Config. That conflicted with
the types package name, so change it to "typ".
* Update the type comparison routine to handle tuples and special
types inline.
* Teach gc/fmt.go how to print special types.
* We can now eliminate ElemTypes in favor of just Elem,
and probably also some other duplicated Type methods
designed to return ssa.Type instead of *types.Type.
* The ssa tests were using their own dummy types,
and they were not particularly careful about types in general.
Of necessity, this CL switches them to use *types.Type;
it does not make them more type-accurate.
Unfortunately, using types.Type means initializing a bit
of the types universe.
This is prime for refactoring and improvement.
This shrinks ssa.Value; it now fits in a smaller size class
on 64 bit systems. This doesn't have a giant impact,
though, since most Values are preallocated in a chunk.
name old alloc/op new alloc/op delta
Template 37.9MB ± 0% 37.7MB ± 0% -0.57% (p=0.000 n=10+8)
Unicode 28.9MB ± 0% 28.7MB ± 0% -0.52% (p=0.000 n=10+10)
GoTypes 110MB ± 0% 109MB ± 0% -0.88% (p=0.000 n=10+10)
Flate 24.7MB ± 0% 24.6MB ± 0% -0.66% (p=0.000 n=10+10)
GoParser 31.1MB ± 0% 30.9MB ± 0% -0.61% (p=0.000 n=10+9)
Reflect 73.9MB ± 0% 73.4MB ± 0% -0.62% (p=0.000 n=10+8)
Tar 25.8MB ± 0% 25.6MB ± 0% -0.77% (p=0.000 n=9+10)
XML 41.2MB ± 0% 40.9MB ± 0% -0.80% (p=0.000 n=10+10)
[Geo mean] 40.5MB 40.3MB -0.68%
name old allocs/op new allocs/op delta
Template 385k ± 0% 386k ± 0% ~ (p=0.356 n=10+9)
Unicode 343k ± 1% 344k ± 0% ~ (p=0.481 n=10+10)
GoTypes 1.16M ± 0% 1.16M ± 0% -0.16% (p=0.004 n=10+10)
Flate 238k ± 1% 238k ± 1% ~ (p=0.853 n=10+10)
GoParser 320k ± 0% 320k ± 0% ~ (p=0.720 n=10+9)
Reflect 957k ± 0% 957k ± 0% ~ (p=0.460 n=10+8)
Tar 252k ± 0% 252k ± 0% ~ (p=0.133 n=9+10)
XML 400k ± 0% 400k ± 0% ~ (p=0.796 n=10+10)
[Geo mean] 428k 428k -0.01%
Removing all the interface calls helps non-trivially with CPU, though.
name old time/op new time/op delta
Template 178ms ± 4% 173ms ± 3% -2.90% (p=0.000 n=94+96)
Unicode 85.0ms ± 4% 83.9ms ± 4% -1.23% (p=0.000 n=96+96)
GoTypes 543ms ± 3% 528ms ± 3% -2.73% (p=0.000 n=98+96)
Flate 116ms ± 3% 113ms ± 4% -2.34% (p=0.000 n=96+99)
GoParser 144ms ± 3% 140ms ± 4% -2.80% (p=0.000 n=99+97)
Reflect 344ms ± 3% 334ms ± 4% -3.02% (p=0.000 n=100+99)
Tar 106ms ± 5% 103ms ± 4% -3.30% (p=0.000 n=98+94)
XML 198ms ± 5% 192ms ± 4% -2.88% (p=0.000 n=92+95)
[Geo mean] 178ms 173ms -2.65%
name old user-time/op new user-time/op delta
Template 229ms ± 5% 224ms ± 5% -2.36% (p=0.000 n=95+99)
Unicode 107ms ± 6% 106ms ± 5% -1.13% (p=0.001 n=93+95)
GoTypes 696ms ± 4% 679ms ± 4% -2.45% (p=0.000 n=97+99)
Flate 137ms ± 4% 134ms ± 5% -2.66% (p=0.000 n=99+96)
GoParser 176ms ± 5% 172ms ± 8% -2.27% (p=0.000 n=98+100)
Reflect 430ms ± 6% 411ms ± 5% -4.46% (p=0.000 n=100+92)
Tar 128ms ±13% 123ms ±13% -4.21% (p=0.000 n=100+100)
XML 239ms ± 6% 233ms ± 6% -2.50% (p=0.000 n=95+97)
[Geo mean] 220ms 213ms -2.76%
Change-Id: I15c7d6268347f8358e75066dfdbd77db24e8d0c1
Reviewed-on: https://go-review.googlesource.com/42145
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Now only cmd/asm and cmd/compile depend on cmd/internal/obj. Changing
the assembler backends no longer requires reinstalling cmd/link or
cmd/addr2line.
There's also now one canonical definition of the object file format in
cmd/internal/objabi/doc.go, with a warning to update all three
implementations.
objabi is still something of a grab bag of unrelated code (e.g., flag
and environment variable handling probably belong in a separate "tool"
package), but this is still progress.
Fixes#15165.
Fixes#20026.
Change-Id: Ic4b92fac7d0d35438e0d20c9579aad4085c5534c
Reviewed-on: https://go-review.googlesource.com/40972
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Prior to this CL, the SSA backend reported violations
of the //go:nowritebarrier annotation immediately.
This necessitated emitting errors during SSA compilation,
which is not compatible with a concurrent backend.
Instead, check for such violations later.
We already save the data required to do a late check
for violations of the //go:nowritebarrierrec annotation.
Use the same data, and check //go:nowritebarrier at the same time.
One downside to doing this is that now only a single
violation will be reported per function.
Given that this is for the runtime only,
and violations are rare, this seems an acceptable cost.
While we are here, remove several 'nerrors != 0' checks
that are rendered pointless.
Updates #15756Fixes#19250 (as much as it ever can be)
Change-Id: Ia44c4ad5b6fd6f804d9f88d9571cec8d23665cb3
Reviewed-on: https://go-review.googlesource.com/38973
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Concurrent compilation requires providing an
explicit position and curfn to temp.
This implementation of tempAt temporarily
continues to use the globals lineno and Curfn,
so as not to collide with mdempsky's
work for #19683 eliminating the Curfn dependency
from func nod.
Updates #15756
Updates #19683
Change-Id: Ib3149ca4b0740e9f6eea44babc6f34cdd63028a9
Reviewed-on: https://go-review.googlesource.com/38592
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Starting in go1.9, the minimum processor requirement for ppc64 is POWER8.
Therefore, the checks for OldArch and the code enabled by it are not necessary
anymore.
Updates #19074
Change-Id: I33d6a78b2462c80d57c5dbcba2e13424630afab4
Reviewed-on: https://go-review.googlesource.com/38404
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This reduces the number of calls back into the
gc Type routines, which will help performance
in a concurrent backend.
It also reduces the number of callsites
that must be considered in making the transition.
Passes toolstash-check -all. No compiler performance changes.
Updates #15756
Change-Id: Ic7a8f1daac7e01a21658ae61ac118b2a70804117
Reviewed-on: https://go-review.googlesource.com/38340
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Prior to this CL, the ssa.Frontend field was responsible
for providing types to the backend during compilation.
However, the types needed by the backend are few and static.
It makes more sense to use a struct for them
and to hang that struct off the ssa.Config,
which is the correct home for readonly data.
Now that Types is a struct, we can clean up the names a bit as well.
This has the added benefit of allowing early construction
of all types needed by the backend.
This will be useful for concurrent backend compilation.
Passes toolstash-check -all. No compiler performance change.
Updates #15756
Change-Id: I021658c8cf2836d6a22bbc20cc828ac38c7da08a
Reviewed-on: https://go-review.googlesource.com/38336
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Suggested by mdempsky in CL 38232.
This allows us to use the Frontend field
to associate frontend state and information
with a function.
See the following CL in the series for examples.
This is a giant CL, but it is almost entirely routine refactoring.
The ssa test API is starting to feel a bit unwieldy.
I will clean it up separately, once the dust has settled.
Passes toolstash -cmp.
Updates #15756
Change-Id: I71c573bd96ff7251935fce1391b06b1f133c3caf
Reviewed-on: https://go-review.googlesource.com/38327
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Prior to this CL, config was an explicit argument
to the SSA rewrite rules, and rules that needed
a Frontend got at it via config.
An upcoming CL moves Frontend from Config to Func,
so rules can no longer reach Frontend via Config.
Passing a Frontend as an argument to the rewrite rules
causes a 2-3% regression in compile times.
This CL takes a different approach:
It treats the variable names "config" and "fe"
as special and calculates them as needed.
The "as needed part" is also important to performance:
If they are calculated eagerly, the nilchecks themselves
cause a regression.
This introduces a little bit of magic into the rewrite
generator. However, from the perspective of the rules,
the config variable was already more or less magic.
And it makes the upcoming changes much clearer.
Passes toolstash -cmp.
Change-Id: I173f2bcc124cba43d53138bfa3775e21316a9107
Reviewed-on: https://go-review.googlesource.com/38326
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This makes ssa.Func, ssa.Cache, and ssa.Config fulfill
the roles laid out for them in CL 38160.
The only non-trivial change in this CL is how cached
values and blocks get IDs. Prior to this CL, their IDs were
assigned as part of resetting the cache, and only modified
IDs were reset. This required knowing how many values and
blocks were modified, which required a tight coupling between
ssa.Func and ssa.Config. To eliminate that coupling,
we now zero values and blocks during reset,
and assign their IDs when they are used.
Since unused values and blocks have ID == 0,
we can efficiently find the last used value/block,
to avoid zeroing everything.
Bulk zeroing is efficient, but not efficient enough
to obviate the need to avoid zeroing everything every time.
As a happy side-effect, ssa.Func.Free is no longer necessary.
DebugHashMatch and friends now belong in func.go.
They have been left in place for clarity and review.
I will move them in a subsequent CL.
Passes toolstash -cmp. No compiler performance impact.
No change in 'go test cmd/compile/internal/ssa' execution time.
Change-Id: I2eb7af58da067ef6a36e815a6f386cfe8634d098
Reviewed-on: https://go-review.googlesource.com/38167
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Now that the write barrier insertion is moved to SSA, the SSA
building code can be simplified.
Updates #17583.
Change-Id: I5cacc034b11aa90b0abe6f8dd97e4e3994e2bc25
Reviewed-on: https://go-review.googlesource.com/36840
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
When the compiler insert write barriers, the frontend makes
conservative decisions at an early stage. This sometimes have
false positives because of the lack of information, for example,
writes on stack. SSA's writebarrier pass identifies writes on
stack and eliminates write barriers for them.
This CL moves write barrier insertion into SSA. The frontend no
longer makes decisions about write barriers, and simply does
normal assignments and emits normal Store ops when building SSA.
SSA writebarrier pass inserts write barrier for Stores when needed.
There, it has better information about the store because Phi and
Copy propagation are done at that time.
This CL only changes StoreWB to Store in gc/ssa.go. A followup CL
simplifies SSA building code.
Updates #17583.
Change-Id: I4592d9bc0067503befc169c50b4e6f4765673bec
Reviewed-on: https://go-review.googlesource.com/36839
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The line between ssa.Func and ssa.Config has blurred.
Concurrent compilation in the backend will require more precision.
This CL lays out an (aspirational) organization.
The implementation will come in follow-up CLs,
once the organization is settled.
ssa.Config holds basic compiler configuration,
mostly arch-specific information.
It is configured once, early on, and is readonly,
so it is safe for concurrent use.
ssa.Func is a single-shot object used for
compiling a single Func. It is not concurrency-safe
and not re-usable.
ssa.Cache is a multi-use object used to avoid
expensive allocations during compilation.
Each ssa.Func is given an ssa.Cache to use.
ssa.Cache is not concurrency-safe.
Change-Id: Id02809b6f3541541cac6c27bbb598834888ce1cc
Reviewed-on: https://go-review.googlesource.com/38160
Reviewed-by: Keith Randall <khr@golang.org>
With this change, code like
h := sha1.New()
h.Write(buf)
sum := h.Sum()
gets compiled into static calls rather than
interface calls, because the compiler is able
to prove that 'h' is really a *sha1.digest.
The InterCall re-write rule hits a few dozen times
during make.bash, and hundreds of times during all.bash.
The most common pattern identified by the compiler
is a constructor like
func New() Interface { return &impl{...} }
where the constructor gets inlined into the caller,
and the result is used immediately. Examples include
{sha1,md5,crc32,crc64,...}.New, base64.NewEncoder,
base64.NewDecoder, errors.New, net.Pipe, and so on.
Some existing benchmarks that change on darwin/amd64:
Crc64/ISO4KB-8 2.67µs ± 1% 2.66µs ± 0% -0.36% (p=0.015 n=10+10)
Crc64/ISO1KB-8 694ns ± 0% 690ns ± 1% -0.59% (p=0.001 n=10+10)
Adler32KB-8 473ns ± 1% 471ns ± 0% -0.39% (p=0.010 n=10+9)
On architectures like amd64, the reduction in code size
appears to contribute more to benchmark improvements than just
removing the indirect call, since that branch gets predicted
accurately when called in a loop.
Updates #19361
Change-Id: I57d4dc21ef40a05ec0fbd55a9bb0eb74cdc67a3d
Reviewed-on: https://go-review.googlesource.com/38139
Run-TryBot: Philip Hofer <phofer@umich.edu>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
This reverts commit 4e0c7c3f61.
Reason for revert: The presence-of-optimization test program is fragile, breaks under noopt, and might break if the Go libraries are tweaked. It needs to be (re)written without reference to other packages.
Change-Id: I3aaf1ab006a1a255f961a978e9c984341740e3c7
Reviewed-on: https://go-review.googlesource.com/38097
Reviewed-by: Keith Randall <khr@golang.org>
With this change, code like
h := sha1.New()
h.Write(buf)
sum := h.Sum()
gets compiled into static calls rather than
interface calls, because the compiler is able
to prove that 'h' is really a *sha1.digest.
The InterCall re-write rule hits a few dozen times
during make.bash, and hundreds of times during all.bash.
The most common pattern identified by the compiler
is a constructor like
func New() Interface { return &impl{...} }
where the constructor gets inlined into the caller,
and the result is used immediately. Examples include
{sha1,md5,crc32,crc64,...}.New, base64.NewEncoder,
base64.NewDecoder, errors.New, net.Pipe, and so on.
Some existing benchmarks that change on darwin/amd64:
Crc64/ISO4KB-8 2.67µs ± 1% 2.66µs ± 0% -0.36% (p=0.015 n=10+10)
Crc64/ISO1KB-8 694ns ± 0% 690ns ± 1% -0.59% (p=0.001 n=10+10)
Adler32KB-8 473ns ± 1% 471ns ± 0% -0.39% (p=0.010 n=10+9)
On architectures like amd64, the reduction in code size
appears to contribute more to benchmark improvements than just
removing the indirect call, since that branch gets predicted
accurately when called in a loop.
Updates #19361
Change-Id: Ia9d30afdd5f6b4d38d38b14b88f308acae8ce7ed
Reviewed-on: https://go-review.googlesource.com/37751
Run-TryBot: Philip Hofer <phofer@umich.edu>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Gc's Sym type represents a package-qualified identifier, which is a
frontend concept and doesn't belong in SSA. Bonus: we can replace some
interface{} types with *obj.LSym.
Passes toolstash -cmp.
Change-Id: I456eb9957207d80f99f6eb9b8eab4a1f3263e9ed
Reviewed-on: https://go-review.googlesource.com/36415
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
XPos is a compact (8 instead of 16 bytes on a 64bit machine) source
position representation. There is a 1:1 correspondence between each
XPos and each regular Pos, translated via a global table.
In some sense this brings back the LineHist, though positions can
track line and column information; there is a O(1) translation
between the representations (no binary search), and the translation
is factored out.
The size increase with the prior change is brought down again and
the compiler speed is in line with the master repo (measured on
the same "quiet" machine as for prior change):
name old time/op new time/op delta
Template 256ms ± 1% 262ms ± 2% ~ (p=0.063 n=5+4)
Unicode 132ms ± 1% 135ms ± 2% ~ (p=0.063 n=5+4)
GoTypes 891ms ± 1% 871ms ± 1% -2.28% (p=0.016 n=5+4)
Compiler 3.84s ± 2% 3.89s ± 2% ~ (p=0.413 n=5+4)
MakeBash 47.1s ± 1% 46.2s ± 2% ~ (p=0.095 n=5+5)
name old user-ns/op new user-ns/op delta
Template 309M ± 1% 314M ± 2% ~ (p=0.111 n=5+4)
Unicode 165M ± 1% 172M ± 9% ~ (p=0.151 n=5+5)
GoTypes 1.14G ± 2% 1.12G ± 1% ~ (p=0.063 n=5+4)
Compiler 5.00G ± 1% 4.96G ± 1% ~ (p=0.286 n=5+4)
Change-Id: Icc570cc60ab014d8d9af6976f1f961ab8828cc47
Reviewed-on: https://go-review.googlesource.com/34506
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Change-Id: I429637ca91f7db4144f17621de851a548dc1ce76
Reviewed-on: https://go-review.googlesource.com/34923
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Using a variable instead of a composite literal makes
the code independent of implementation changes of Pos.
Per David Lazar's suggestion.
Change-Id: I336967ac12a027c51a728a58ac6207cb5119af4a
Reviewed-on: https://go-review.googlesource.com/34148
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Adjust cmd/compile accordingly.
This will make it easier to replace the underlying implementation.
Change-Id: I33645850bb18c839b24785b6222a9e028617addb
Reviewed-on: https://go-review.googlesource.com/34133
Reviewed-by: David Lazar <lazard@golang.org>
This is a step toward chosing a different position representation.
By introducing an explicit type, it will be easier to make the
transition step-wise while ensuring everything keeps running.
This has been reviewed via https://go-review.googlesource.com/#/c/34025/.
Change-Id: Ibceddcd62d8f346321ac3250e3940e9c436ed684
Reviewed-on: https://go-review.googlesource.com/34132
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Lazar <lazard@golang.org>
We used to have to keep on-stack copies of these types.
Now they can be registerized.
[0]T is kind of trivial but might as well handle it.
This change enables another change I'm working on to improve how x.(T)
expressions are handled (#17405). This CL helps because now all
types that are direct interface types are registerizeable (e.g. [1]*byte).
No higher-degree arrays for now because non-constant indexes are hard.
Update #17405
Change-Id: I2399940965d17b3969ae66f6fe447a8cefdd6edd
Reviewed-on: https://go-review.googlesource.com/32416
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
When the compiler insert write barriers, the frontend makes
conservative decisions at an early stage. This may have false
positives which result in write barriers for stack writes.
A new phase, writebarrier, is added to the SSA backend, to delay
the decision and eliminate false positives. The frontend still
makes conservative decisions. When building SSA, instead of
emitting runtime calls directly, it emits WB ops (StoreWB,
MoveWB, etc.), which will be expanded to branches and runtime
calls in writebarrier phase. Writes to static locations on stack
are detected and write barriers are removed.
All write barriers of stack writes found by the script from
issue #17330 are eliminated (except two false positives).
Fixes#17330.
Change-Id: I9bd66333da9d0ceb64dcaa3c6f33502798d1a0f8
Reviewed-on: https://go-review.googlesource.com/31131
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
We save and restore the link register in non-leaf functions because
it is clobbered by CALLs. It is therefore available for general
purpose use.
Only enabled on s390x currently. The RC4 benchmarks in particular
benefit from the extra register:
name old speed new speed delta
RC4_128 243MB/s ± 2% 341MB/s ± 2% +40.46% (p=0.008 n=5+5)
RC4_1K 267MB/s ± 0% 359MB/s ± 1% +34.32% (p=0.008 n=5+5)
RC4_8K 271MB/s ± 0% 362MB/s ± 0% +33.61% (p=0.008 n=5+5)
Change-Id: Id23bff95e771da9425353da2f32668b8e34ba09f
Reviewed-on: https://go-review.googlesource.com/30597
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Identify live stack variables during SSA and compute the stack frame
layout earlier so that we can emit instructions with the correct
offsets upfront.
Passes toolstash/buildall.
Change-Id: I191100dba274f1e364a15bdcfdc1d1466cdd1db5
Reviewed-on: https://go-review.googlesource.com/30216
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Abandoned earlier efforts to expose zero register,
but left it in numbering to decrease squirrelyness of
register allocator.
ISELrelOp used in code generation of bool := x relOp y.
Some patterns added to better elide zero case and
some sign extension.
Updates: #17109
Change-Id: Ida7839f0023ca8f0ffddc0545f0ac269e65b05d9
Reviewed-on: https://go-review.googlesource.com/29380
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
On ARM, DIV, DIVU, MOD, MODU are pseudo instructions that makes
runtime calls _div/_udiv/_mod/_umod, which themselves are wrappers
of udiv. The udiv function does the real thing.
Instead of generating these pseudo instructions, call to udiv
directly. This removes one layer of wrappers (which has an awkward
way of passing argument), and also allows combining DIV and MOD
if both results are needed.
Change-Id: I118afc3986db3a1daabb5c1e6e57430888c91817
Reviewed-on: https://go-review.googlesource.com/29390
Reviewed-by: David Chase <drchase@google.com>
Binary search remains our friend.
Suppose you add an ought-to-be-benign pattern to PPC64.rules,
and make.bash starts crashing. You can guard the pattern(s)
with config.DebugTest:
(Eq8 x y) && config.DebugTest && isSigned(x.Type) &&
isSigned(y.Type) ->
(Equal (CMPW (SignExt8to32 x) (SignExt8to32 y)))
and then
gossahash -s ./make.bash
...
(go drink beer while silicon minions toil)
...
Trying ./make.bash args=[], env=[GOSSAHASH=100110010111110]
./make.bash failed (1 distinct triggers): exit status 1
Trigger string is 'GOSSAHASH triggered (*importReader).readByte',
repeated 1 times
Review GSHS_LAST_FAIL.0.log for failing run
Finished with GOSSAHASH=100110010111110
Change-Id: I4eff46ebaf496baa2acedd32e217005cb3ac1c62
Reviewed-on: https://go-review.googlesource.com/29273
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Rip out the code that allows SSA to be used conditionally.
No longer exists:
ssa=0 flag
GOSSAHASH
GOSSAPKG
SSATEST
GOSSAFUNC now only controls the printing of the IR/html.
Still need to rip out all of the old backend. It should no longer be
callable after this CL.
Update #16357
Change-Id: Ib30cc18fba6ca52232c41689ba610b0a94aa74f5
Reviewed-on: https://go-review.googlesource.com/29155
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
It passed tests once, if anything's wrong, better to fail
sooner than later.
Change-Id: Ibb1c5db3f4c5535a4ff4681fd157db77082c5041
Reviewed-on: https://go-review.googlesource.com/28982
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The new SSA backend modifies the ABI slightly: R0 is now a usable
general purpose register.
Fixes#16677.
Change-Id: I367435ce921e0c7e79e021c80cf8ef5d1d1466cf
Reviewed-on: https://go-review.googlesource.com/28978
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
As cmd/internal/obj is coordinating the definition of GOOS, GOARCH,
etc across the compiler and linker, turn its functions into globals
and use them everywhere.
Change-Id: I5db5addda3c6b6435c37fd5581c7c3d9a561f492
Reviewed-on: https://go-review.googlesource.com/28854
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
