44 Commits

Author SHA1 Message Date
Josh Bleecher Snyder
34975095d0 cmd/compile: provide pos and curfn to temp
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>
2017-03-25 00:09:21 +00:00
Josh Bleecher Snyder
a68e5d94fa cmd/compile: clean up SSA test API
I noted in CL 38327 that the SSA test API felt a bit
clunky after the ssa.Func/ssa.Cache/ssa.Config refactoring,
and promised to clean it up once the dust settled.
The dust has settled.

Along the way, this CL fixes a potential latent bug,
in which the amd64 test context was used for all dummy Syslook calls.
The lone SSA test using the s390x context did not depend on the
Syslook context being correct, so the bug did not arise in practice.

Change-Id: If964251d1807976073ad7f47da0b1f1f77c58413
Reviewed-on: https://go-review.googlesource.com/38346
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-19 05:37:39 +00:00
Josh Bleecher Snyder
872db79989 cmd/compile: add more types to ssa.Types
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>
2017-03-19 02:03:44 +00:00
Josh Bleecher Snyder
aea3aff669 cmd/compile: separate ssa.Frontend and ssa.TypeSource
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>
2017-03-19 00:21:23 +00:00
Josh Bleecher Snyder
2cdb7f118a cmd/compile: move Frontend field from ssa.Config to ssa.Func
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>
2017-03-17 23:18:57 +00:00
Cherry Zhang
1b85300602 cmd/compile: clean up SSA-building code
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>
2017-03-16 14:24:40 +00:00
Cherry Zhang
9ebf3d5100 cmd/compile: move write barrier insertion to SSA
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>
2017-03-16 14:24:21 +00:00
philhofer
295307ae78 cmd/compile: de-virtualize interface calls
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>
2017-03-14 18:49:23 +00:00
David Chase
b59a405656 Revert "cmd/compile: de-virtualize interface calls"
This reverts commit 4e0c7c3f61475116c4ae8d11ef796819d9c404f0.

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>
2017-03-13 21:15:32 +00:00
Philip Hofer
4e0c7c3f61 cmd/compile: de-virtualize interface calls
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>
2017-03-13 18:24:57 +00:00
David Chase
d71f36b5aa cmd/compile: check loop rescheduling with stack bound, not counter
After benchmarking with a compiler modified to have better
spill location, it became clear that this method of checking
was actually faster on (at least) two different architectures
(ppc64 and amd64) and it also provides more timely interruption
of loops.

This change adds a modified FOR loop node "FORUNTIL" that
checks after executing the loop body instead of before (i.e.,
always at least once).  This ensures that a pointer past the
end of a slice or array is not made visible to the garbage
collector.

Without the rescheduling checks inserted, the restructured
loop from this  change apparently provides a 1% geomean
improvement on PPC64 running the go1 benchmarks; the
improvement on AMD64 is only 0.12%.

Inserting the rescheduling check exposed some peculiar bug
with the ssa test code for s390x; this was updated based on
initial code actually generated for GOARCH=s390x to use
appropriate OpArg, OpAddr, and OpVarDef.

NaCl is disabled in testing.

Change-Id: Ieafaa9a61d2a583ad00968110ef3e7a441abca50
Reviewed-on: https://go-review.googlesource.com/36206
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2017-03-08 18:52:12 +00:00
Dave Cheney
d945b28675 cmd/compile/internal/ssa: remove unused PrintFunc variable
Change-Id: I8c581eec77beacaddc0aac29e7d380a4d5ca8acc
Reviewed-on: https://go-review.googlesource.com/37551
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-01 01:23:31 +00:00
Michael Munday
4dbcb53d0b cmd/compile: fix merging of s390x conditional moves into branch conditions
A type conversion inserted between MOVD{LT,LE,GT,GE,EQ,NE} and CMPWconst
by CL 36256 broke the rewrite rule designed to merge the two.
This results in simple for loops (e.g. for i := 0; i < N; i++ {})
emitting two comparisons instead of one, plus a conditional move.

This CL explicitly types the input to CMPWconst so that the type conversion
can be omitted. It also adds a test to check that conditional moves aren't
emitted for loops with 'less than' conditions (i.e. i < N) on s390x.

Fixes #19227.

Change-Id: Ia39e806ed723791c3c755951aef23f957828ea3e
Reviewed-on: https://go-review.googlesource.com/37334
Reviewed-by: Keith Randall <khr@golang.org>
2017-02-28 02:57:23 +00:00
Matthew Dempsky
87c475c227 cmd/compile/internal/ssa: use obj.LSym instead of gc.Sym
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>
2017-02-06 22:45:34 +00:00
Robert Griesemer
472c792e0a [dev.inline] cmd/internal/src: introduce compact source position representation
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>
2017-01-09 22:43:22 +00:00
Robert Griesemer
24597c080b [dev.inline] cmd/compile: introduce cmd/internal/src.Pos type for line numbers
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>
2016-12-08 21:26:25 +00:00
Cherry Zhang
ed0b232cdc cmd/compile: find last StoreWB explicitly
In writebarrier phase, a chain of StoreWBs is rewritten to branchy
code to invoke write barriers, and the last store in the chain is
spliced into a Phi op to join the memory of the two branches. We
must find the last store explicitly, since the values are not
scheduled and they may not come in dependency order.

Fixes #18169.

Change-Id: If547e3c562ef0669bc5622c1bb711904dc36314d
Reviewed-on: https://go-review.googlesource.com/33915
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-12-05 03:53:56 +00:00
Keith Randall
741445068f cmd/compile: make [0]T and [1]T SSAable types
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>
2016-10-31 19:44:19 +00:00
Cherry Zhang
f6aec889e1 cmd/compile: add a writebarrier phase in SSA
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>
2016-10-25 21:53:40 +00:00
Matthew Dempsky
8c24bff52b cmd/compile: layout stack frame during SSA
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>
2016-10-04 17:07:36 +00:00
Keith Randall
167e381f40 cmd/compile: make ssa compilation unconditional
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>
2016-09-14 17:38:04 +00:00
Cherry Zhang
8756d9253f [dev.ssa] cmd/compile: decompose 64-bit integer on ARM
Introduce dec64 rules to (generically) decompose 64-bit integer on
32-bit architectures. 64-bit integer is composed/decomposed with
Int64Make/Hi/Lo ops, as for complex types.

The idea of dealing with Add64 is the following:

(Add64 (Int64Make xh xl) (Int64Make yh yl))
->
(Int64Make
	(Add32withcarry xh yh (Select0 (Add32carry xl yl)))
	(Select1 (Add32carry xl yl)))

where Add32carry returns a tuple (flags,uint32). Select0 and Select1
read the first and the second component of the tuple, respectively.
The two Add32carry will be CSE'd.

Similarly for multiplication, Mul32uhilo returns a tuple (hi, lo).

Also add support of KeepAlive, to fix build after merge.

Tests addressed_ssa.go, array_ssa.go, break_ssa.go, chan_ssa.go,
cmp_ssa.go, ctl_ssa.go, map_ssa.go, and string_ssa.go in
cmd/compile/internal/gc/testdata passed.

Progress on SSA for ARM. Still not complete.

Updates #15365.

Change-Id: I7867c76785a456312de5d8398a6b3f7ca5a4f7ec
Reviewed-on: https://go-review.googlesource.com/23213
Reviewed-by: Keith Randall <khr@golang.org>
2016-06-02 13:01:09 +00:00
Keith Randall
d610d304f8 cmd/compile: reorg copyelim to avoid O(n^2) problem
Make sure we don't do O(n^2) work to eliminate a chain
of n copies.

benchmark                     old ns/op       new ns/op     delta
BenchmarkCopyElim1-8          1418            1406          -0.85%
BenchmarkCopyElim10-8         5289            5162          -2.40%
BenchmarkCopyElim100-8        52618           41684         -20.78%
BenchmarkCopyElim1000-8       2473878         424339        -82.85%
BenchmarkCopyElim10000-8      269373954       6367971       -97.64%
BenchmarkCopyElim100000-8     31272781165     104357244     -99.67%

Change-Id: I680f906f70f2ee1a8615cb1046bc510c77d59284
Reviewed-on: https://go-review.googlesource.com/22535
Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
2016-04-28 17:40:08 +00:00
Keith Randall
b04e145248 cmd/compile: fix naming of decomposed structs
When a struct is SSAable, we will name its component parts
by their field names.  For example,
type T struct {
     a, b, c int
}
If we ever need to spill a variable x of type T, we will
spill its individual components to variables named x.a, x.b,
and x.c.

Change-Id: I857286ff1f2597f2c4bbd7b4c0b936386fb37131
Reviewed-on: https://go-review.googlesource.com/21389
Reviewed-by: David Chase <drchase@google.com>
2016-04-11 17:11:23 +00:00
Keith Randall
4a7aba775d cmd/compile: better job of naming compound types
Compound AUTO types weren't named previously.  That was because live
variable analysis (plive.go) doesn't handle spilling to compound types.
It can't handle them because there is no valid place to put VARDEFs when
regalloc is spilling compound types.

compound types = multiword builtin types: complex, string, slice, and
interface.

Instead, we split named AUTOs into individual one-word variables.  For
example, a string s gets split into a byte ptr s.ptr and an integer
s.len.  Those two variables can be spilled to / restored from
independently.  As a result, live variable analysis can handle them
because they are one-word objects.

This CL will change how AUTOs are described in DWARF information.
Consider the code:

func f(s string, i int) int {
    x := s[i:i+5]
    g()
    return lookup(x)
}

The old compiler would spill x to two consecutive slots on the stack,
both named x (at offsets 0 and 8).  The new compiler spills the pointer
of x to a slot named x.ptr.  It doesn't spill x.len at all, as it is a
constant (5) and can be rematerialized for the call to lookup.

So compound objects may not be spilled in their entirety, and even if
they are they won't necessarily be contiguous.  Such is the price of
optimization.

Re-enable live variable analysis tests.  One test remains disabled, it
fails because of #14904.

Change-Id: I8ef2b5ab91e43a0d2136bfc231c05d100ec0b801
Reviewed-on: https://go-review.googlesource.com/21233
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-03-31 22:18:26 +00:00
Todd Neal
98b88de56f cmd/compile: change the type of ssa Warnl line number
Line numbers are always int32, so the Warnl function should take the
line number as an int32 as well.  This matches gc.Warnl and removes
a cast every place it's used.

Change-Id: I5d6201e640d52ec390eb7174f8fd8c438d4efe58
Reviewed-on: https://go-review.googlesource.com/20662
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-03-14 11:04:40 +00:00
David Chase
88b230eaa6 [dev.ssa] cmd/compile: exposed do-log boolean to reduce allocations
From memory profiling, about 3% reduction in allocation count.

Change-Id: I4b662d55b8a94fe724759a2b22f05a08d0bf40f8
Reviewed-on: https://go-review.googlesource.com/19103
Reviewed-by: Keith Randall <khr@golang.org>
2016-01-29 21:30:29 +00:00
Keith Randall
6a96a2fe5a [dev.ssa] cmd/compile: make cse faster
It is one of the slowest compiler phases right now, and we
run two of them.

Instead of using a map to make the initial partition, use a sort.
It is much less memory intensive.

Do a few optimizations to avoid work for size-1 equivalence classes.

Implement -N.

Change-Id: I1d2d85d3771abc918db4dd7cc30b0b2d854b15e1
Reviewed-on: https://go-review.googlesource.com/19024
Reviewed-by: David Chase <drchase@google.com>
2016-01-28 20:59:20 +00:00
Keith Randall
b5c5efd5de [dev.ssa] cmd/compile: optimize phi ops
Redo how we keep track of forward references when building SSA.
When the forward reference is resolved, update the Value node
in place.

Improve the phi elimination pass so it can simplify phis of phis.

Give SSA package access to decoded line numbers.  Fix line numbers
for constant booleans.

Change-Id: I3dc9896148d260be2f3dd14cbe5db639ec9fa6b7
Reviewed-on: https://go-review.googlesource.com/18674
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
2016-01-20 21:45:37 +00:00
Keith Randall
da8af47710 [dev.ssa] cmd/compile: report better line numbers for Unimplemented/Fatal
If a failure occurs in SSA processing, we always report the
last line of the function we're compiling.  Modify the callbacks
from SSA to the GC compiler so we can pass a line number back
and use it in Fatalf.

Change-Id: Ifbfad50d5e167e997e0a96f0775bcc369f5c397e
Reviewed-on: https://go-review.googlesource.com/18599
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-01-19 15:43:32 +00:00
David Chase
729abfa35c [dev.ssa] cmd/compile: default compile+test with SSA
Some tests disabled, some bifurcated into _ssa and not,
with appropriate logging added to compiler.

"tests/live.go" in particular needs attention.

SSA-specific testing removed, since it's all SSA now.

Added "-run_skips" option to tests/run.go to simplify
checking whether a test still fails (or how it fails)
on a skipped platform.

The compiler now compiles with SSA by default.
If you don't want SSA, specify GOSSAHASH=n (or N) as
an environment variable.  Function names ending in "_ssa"
are always SSA-compiled.

GOSSAFUNC=fname retains its "SSA for fname, log to ssa.html"
GOSSAPKG=pkg only has an effect when GOSSAHASH=n
GOSSAHASH=10101 etc retains its name-hash-matching behavior
for purposes of debugging.

See #13068

Change-Id: I8217bfeb34173533eaeb391b5f6935483c7d6b43
Reviewed-on: https://go-review.googlesource.com/16299
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
2015-10-30 20:35:20 +00:00
Keith Randall
c24681ae2e [dev.ssa] cmd/compile: remember names of values
For debugging, spill values to named variables instead of autotmp_
variables if possible.  We do this by keeping a name -> value map
for each function, keep it up-to-date during deadcode elim, and use
it to override spill decisions in stackalloc.

It might even make stack frames a bit smaller, as it makes it easy
to identify a set of spills which are likely not to interfere.

This just works for one-word variables for now.  Strings/slices
will be a separate CL.

Change-Id: Ie89eba8cab16bcd41b311c479ec46dd7e64cdb67
Reviewed-on: https://go-review.googlesource.com/16336
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2015-10-28 17:00:31 +00:00
David Chase
3abb844108 [dev.ssa] cmd/compile: repair ssa testing build and test
Calls to NewConfig required an extra parameter that
sometimes could not be nil.

Change-Id: I806dd53c045056a0c2d30d641a20fe27fb790539
Reviewed-on: https://go-review.googlesource.com/16272
Reviewed-by: Keith Randall <khr@golang.org>
2015-10-23 17:30:09 +00:00
Keith Randall
37590bddc4 [dev.ssa] cmd/compile: move un-SSAable objects
We need to move any objects whose types are not SSA-able.

Fixes the "not lowered: Load ARRAY PTR64 mem" errors.

Change-Id: I7a0b609f917d7fb34bc9215fee4da15f9961cf6c
Reviewed-on: https://go-review.googlesource.com/14753
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-09-19 18:22:46 +00:00
Keith Randall
d2107fc987 [dev.ssa] cmd/runtime: generate gc bitmaps for SSA-compiled code
This change is all about leveraging the gc bitmap generation
that is already done by the current compiler.  We rearrange how
stack allocation is done so that we generate a variable declaration
for each spill.  We also reorganize how args/locals are recorded
during SSA.  Then we can use the existing allocauto/defframe to
allocate the stack frame and liveness to make the gc bitmaps.

With this change, stack copying works correctly and we no longer
need hacks in runtime/stack*.go to make tests work.  GC is close
to working, it just needs write barriers.

Change-Id: I990fb4e3fbe98850c6be35c3185a1c85d9e1a6ba
Reviewed-on: https://go-review.googlesource.com/13894
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2015-09-05 06:41:05 +00:00
David Chase
525785885e [dev.ssa] cmd/compile: add compose/decompose for complex, phi, constants
Still to do: arithmetic

Change-Id: I31fd23b34980c9ed4b4e304b8597134b2ba6ca5c
Reviewed-on: https://go-review.googlesource.com/14024
Reviewed-by: Keith Randall <khr@golang.org>
2015-08-28 20:20:43 +00:00
Josh Bleecher Snyder
85e0329fbc [dev.ssa] cmd/compile: move most types outside SSA
The only types that remain in the ssa package
are special compiler-only types.

Change-Id: If957abf128ec0778910d67666c297f97f183b7ee
Reviewed-on: https://go-review.googlesource.com/12933
Reviewed-by: Keith Randall <khr@golang.org>
2015-07-30 21:30:59 +00:00
Josh Bleecher Snyder
8d31df18af [dev.ssa] cmd/compile: use string contents instead of offset from string header
This generates more efficient code.

Before:

	0x003a 00058 (rr.go:7)	LEAQ	go.string.hdr."="(SB), BX
	0x0041 00065 (rr.go:7)	LEAQ	16(BX), BP
	0x0045 00069 (rr.go:7)	MOVQ	BP, 16(SP)

After:

	0x003a 00058 (rr.go:7)	LEAQ	go.string."="(SB), BX
	0x0041 00065 (rr.go:7)	MOVQ	BX, 16(SP)

It also matches the existing backend
and is more robust to other changes,
such as CL 11698, which I believe broke
the current code.

This CL fixes the encoding/base64 tests, as run with:

	GOGC=off GOSSAPKG=base64 go test -a encoding/base64

Change-Id: I3c475bed1dd3335cc14e13309e11d23f0ed32c17
Reviewed-on: https://go-review.googlesource.com/12654
Reviewed-by: Keith Randall <khr@golang.org>
2015-07-24 20:43:32 +00:00
Josh Bleecher Snyder
1746e711ad [dev.ssa] cmd/compile/ssa: add nilcheckelim benchmarks
These benchmarks demonstrate that
the nilcheckelim pass is roughly O(n^2):

BenchmarkNilCheckDeep1    	 2000000	       741 ns/op	   1.35 MB/s
BenchmarkNilCheckDeep10   	 1000000	      2237 ns/op	   4.47 MB/s
BenchmarkNilCheckDeep100  	   20000	     60713 ns/op	   1.65 MB/s
BenchmarkNilCheckDeep1000 	     200	   7925198 ns/op	   0.13 MB/s
BenchmarkNilCheckDeep10000	       1	1220104252 ns/op	   0.01 MB/s

Profiling suggests that building the
dominator tree is also O(n^2),
and before size factors take over,
considerably more expensive than nilcheckelim.

Change-Id: If966b38ec52243a25f355dab871300d29db02e16
Reviewed-on: https://go-review.googlesource.com/11520
Reviewed-by: Keith Randall <khr@golang.org>
2015-06-29 04:07:11 +00:00
Josh Bleecher Snyder
37ddc270ca [dev.ssa] cmd/compile/ssa: add -f suffix to logging methods
Requested in CL 11380.

Change-Id: Icf0d23fb8d383c76272401e363cc9b2169d11403
Reviewed-on: https://go-review.googlesource.com/11450
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-06-24 21:48:26 +00:00
Josh Bleecher Snyder
8c6abfeacb [dev.ssa] cmd/compile/ssa: separate logging, work in progress, and fatal errors
The SSA implementation logs for three purposes:

	* debug logging
	* fatal errors
	* unimplemented features

Separating these three uses lets us attempt an SSA
implementation for all functions, not just
_ssa functions. This turns the entire standard
library into a compilation test, and makes it
easy to figure out things like
"how much coverage does SSA have now" and
"what should we do next to get more coverage?".

Functions called _ssa are still special.
They log profusely by default and
the output of the SSA implementation
is used. For all other functions,
logging is off, and the implementation
is built and discarded, due to lack of
support for the runtime.

While we're here, fix a few minor bugs and
add some extra Unimplementeds to allow
all.bash to pass.

As of now, SSA handles 20.79% of the functions
in the standard library (689 of 3314).

The top missing features are:

 10.03%  2597 SSA unimplemented: zero for type error not implemented
  7.79%  2016 SSA unimplemented: addr: bad op DOTPTR
  7.33%  1898 SSA unimplemented: unhandled expr EQ
  6.10%  1579 SSA unimplemented: unhandled expr OROR
  4.91%  1271 SSA unimplemented: unhandled expr NE
  4.49%  1163 SSA unimplemented: unhandled expr LROT
  4.00%  1036 SSA unimplemented: unhandled expr LEN
  3.56%   923 SSA unimplemented: unhandled stmt CALLFUNC
  2.37%   615 SSA unimplemented: zero for type []byte not implemented
  1.90%   492 SSA unimplemented: unhandled stmt CALLMETH
  1.74%   450 SSA unimplemented: unhandled expr CALLINTER
  1.74%   450 SSA unimplemented: unhandled expr DOT
  1.71%   444 SSA unimplemented: unhandled expr ANDAND
  1.65%   426 SSA unimplemented: unhandled expr CLOSUREVAR
  1.54%   400 SSA unimplemented: unhandled expr CALLMETH
  1.51%   390 SSA unimplemented: unhandled stmt SWITCH
  1.47%   380 SSA unimplemented: unhandled expr CONV
  1.33%   345 SSA unimplemented: addr: bad op *
  1.30%   336 SSA unimplemented: unhandled OLITERAL 6

Change-Id: I4ca07951e276714dc13c31de28640aead17a1be7
Reviewed-on: https://go-review.googlesource.com/11160
Reviewed-by: Keith Randall <khr@golang.org>
2015-06-21 02:56:36 +00:00
Keith Randall
1114a76ae6 [dev.ssa] cmd/compile/internal/ssa: Add dummy frontend for testing.
Change-Id: Ica26c0297ac7afeb0b5b668cf5f5cd1667c6cc43
Reviewed-on: https://go-review.googlesource.com/10699
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2015-06-04 22:26:22 +00:00
Keith Randall
a9cec30fdc [dev.ssa] cmd/compile/internal/ssa: Implement block rewriting rules
Change-Id: I47e5349e34fc18118c4d35bf433f875b958cc3e5
Reviewed-on: https://go-review.googlesource.com/10495
Reviewed-by: Alan Donovan <adonovan@google.com>
2015-05-30 06:08:26 +00:00
Keith Randall
067e8dfd82 [dev.ssa] Merge remote-tracking branch 'origin/master' into mergebranch
Semi-regular merge of tip to dev.ssa.

Complicated a bit by the move of cmd/internal/* to cmd/compile/internal/*.

Change-Id: I1c66d3c29bb95cce4a53c5a3476373aa5245303d
2015-05-28 13:51:18 -07:00