The cycle hacks existed because gc needed to import ssa
which need to know about gc.Node. But now that's ir.Node,
and there's no cycle anymore.
Don't know how much it matters but LocalSlot is now
one word shorter than before, because it holds a pointer
instead of an interface for the *Node. That won't last long.
Now that they're not necessary for interface satisfaction,
IsSynthetic and IsAutoTmp can move to top-level ir functions.
Change-Id: Ie511e93466cfa2b17d9a91afc4bd8d53fdb80453
Reviewed-on: https://go-review.googlesource.com/c/go/+/272931
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This adds a pass to detect common selection operations,
to avoid generating duplicates. Duplicate offsets are
also detected.
All aggregate types are now handled; there is some freedom in where
expand_calls is run, though it must run before softfloat.
Debug-name-maintenance is now incremental both in decompose builtin
and in expand_calls; it might be good to push this into all the
decompose passes.
(this is a smash of 5 CLs that rewrote some of the same code several
times to deal with phase-ordering problems, and included an abandoned
attempt.)
For #40724.
Change-Id: I2a0c32f20660bf8b99e2bcecd33545d97d2bd3c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/249458
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Turns out if your failure is in a function with a name like "Reset()"
there will be a lot of hits on the same hashcode. Adding package sensitivity
solves this problem.
In additionm, it turned out that in the case that a logfile was specified
for the GOSSAHASH logging, that it was opened in create mode, which meant
that multiple compiler invocations would reset the file to zero length.
Opening in append mode works better; the automated harness
(github.com/dr2chase/gossahash) takes care of truncating the file before use.
Change-Id: I5601bc280faa94cbd507d302448831849db6c842
Reviewed-on: https://go-review.googlesource.com/c/go/+/246937
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Right now the Aux and AuxInt fields of ssa.Values are typed as
interface{} and int64, respectively. Each rule that uses these values
must cast them to the type they actually are (*obj.LSym, or int32, or
ValAndOff, etc.), use them, and then cast them back to interface{} or
int64.
We know for each opcode what the types of the Aux and AuxInt fields
should be. So let's modify the rule generator to declare the types to
be what we know they should be, autoconverting to and from the generic
types for us. That way we can make the rules more type safe.
It's difficult to make a single CL for this, so I've coopted the "=>"
token to indicate a rule that is strongly typed. "->" rules are
processed as before. That will let us migrate a few rules at a time in
separate CLs. Hopefully we can reach a state where all rules are
strongly typed and we can drop the distinction.
This CL changes just a few rules to get a feel for what this
transition would look like.
I've decided not to put explicit types in the rules. I think it
makes the rules somewhat clearer, but definitely more verbose.
In particular, the passthrough rules that don't modify the fields
in question are verbose for no real reason.
Change-Id: I63a1b789ac5702e7caf7934cd49f784235d1d73d
Reviewed-on: https://go-review.googlesource.com/c/go/+/190197
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Change the type printer to take a map of types that we're currently
printing. When we happen upon a type that we're already in the middle
of printing, print a reference to it instead.
A reference to another type is built using the offset of the first
byte of that type's string representation in the result. To facilitate
that computation (and it's probably more efficient, regardless), we
print the type to a buffer as we go, and build the string at the end.
It would be nice to use string.Builder instead of bytes.Buffer, but
string.Builder wasn't around in Go 1.4, and we'd like to bootstrap
from that version.
Fixes#29312
Change-Id: I49d788c1fa20f770df7b2bae3b9979d990d54803
Reviewed-on: https://go-review.googlesource.com/c/go/+/214239
Reviewed-by: Robert Griesemer <gri@golang.org>
The goal of this change is to move work from walk to SSA,
and simplify things along the way.
This is hard to accomplish cleanly with small incremental changes,
so this large commit message aims to provide a roadmap to the diff.
High level description:
Prior to this change, walk was responsible for constructing (most of) the stack for function calls.
ascompatte gathered variadic arguments into a slice.
It also rewrote n.List from a list of arguments to a list of assignments to stack slots.
ascompatte was called multiple times to handle the receiver in a method call.
reorder1 then introduced temporaries into n.List as needed to avoid smashing the stack.
adjustargs then made extra stack space for go/defer args as needed.
Node to SSA construction evaluated all the statements in n.List,
and issued the function call, assuming that the stack was correctly constructed.
Intrinsic calls had to dig around inside n.List to extract the arguments,
since intrinsics don't use the stack to make function calls.
This change moves stack construction to the SSA construction phase.
ascompatte, now called walkParams, does all the work that ascompatte and reorder1 did.
It handles variadic arguments, inserts the method receiver if needed, and allocates temporaries.
It does not, however, make any assignments to stack slots.
Instead, it moves the function arguments to n.Rlist, leaving assignments to temporaries in n.List.
(It would be better to use Ninit instead of List; future work.)
During SSA construction, after doing all the temporary assignments in n.List,
the function arguments are assigned to stack slots by
constructing the appropriate SSA Value, using (*state).storeArg.
SSA construction also now handles adjustments for go/defer args.
This change also simplifies intrinsic calls, since we no longer need to undo walk's work.
Along the way, we simplify nodarg by pushing the fp==1 case to its callers, where it fits nicely.
Generated code differences:
There were a few optimizations applied along the way, the old way.
f(g()) was rewritten to do a block copy of function results to function arguments.
And reorder1 avoided introducing the final "save the stack" temporary in n.List.
The f(g()) block copy optimization never actually triggered; the order pass rewrote away g(), so that has been removed.
SSA optimizations mostly obviated the need for reorder1's optimization of avoiding the final temporary.
The exception was when the temporary's type was not SSA-able;
in that case, we got a Move into an autotmp and then an immediate Move onto the stack,
with the autotmp never read or used again.
This change introduces a new rewrite rule to detect such pointless double Moves
and collapse them into a single Move.
This is actually more powerful than the original optimization,
since the original optimization relied on the imprecise Node.HasCall calculation.
The other significant difference in the generated code is that the stack is now constructed
completely in SP-offset order. Prior to this change, the stack was constructed somewhat
haphazardly: first the final argument that Node.HasCall deemed to require a temporary,
then other arguments, then the method receiver, then the defer/go args.
SP-offset is probably a good default order. See future work.
There are a few minor object file size changes as a result of this change.
I investigated some regressions in early versions of this change.
One regression (in archive/tar) was the addition of a single CMPQ instruction,
which would be eliminated were this TODO from flagalloc to be done:
// TODO: Remove original instructions if they are never used.
One regression (in text/template) was an ADDQconstmodify that is now
a regular MOVQLoad+ADDQconst+MOVQStore, due to an unlucky change
in the order in which arguments are written. The argument change
order can also now be luckier, so this appears to be a wash.
All in all, though there will be minor winners and losers,
this change appears to be performance neutral.
Future work:
Move loading the result of function calls to SSA construction; eliminate OINDREGSP.
Consider pushing stack construction deeper into SSA world, perhaps in an arch-specific pass.
Among other benefits, this would make it easier to transition to a new calling convention.
This would require rethinking the handling of stack conflicts and is non-trivial.
Figure out some clean way to indicate that stack construction Stores/Moves
do not alias each other, so that subsequent passes may do things like
CSE+tighten shared stack setup, do DSE using non-first Stores, etc.
This would allow us to eliminate the minor text/template regression.
Possibly make assignments to stack slots not treated as statements by DWARF.
Compiler benchmarks:
name old time/op new time/op delta
Template 182ms ± 2% 179ms ± 2% -1.69% (p=0.000 n=47+48)
Unicode 86.3ms ± 5% 85.1ms ± 4% -1.36% (p=0.001 n=50+50)
GoTypes 646ms ± 1% 642ms ± 1% -0.63% (p=0.000 n=49+48)
Compiler 2.89s ± 1% 2.86s ± 2% -1.36% (p=0.000 n=48+50)
SSA 8.47s ± 1% 8.37s ± 2% -1.22% (p=0.000 n=47+50)
Flate 122ms ± 2% 121ms ± 2% -0.66% (p=0.000 n=47+45)
GoParser 147ms ± 2% 146ms ± 2% -0.53% (p=0.006 n=46+49)
Reflect 406ms ± 2% 403ms ± 2% -0.76% (p=0.000 n=48+43)
Tar 162ms ± 3% 162ms ± 4% ~ (p=0.191 n=46+50)
XML 223ms ± 2% 222ms ± 2% -0.37% (p=0.031 n=45+49)
[Geo mean] 382ms 378ms -0.89%
name old user-time/op new user-time/op delta
Template 219ms ± 3% 216ms ± 3% -1.56% (p=0.000 n=50+48)
Unicode 109ms ± 6% 109ms ± 5% ~ (p=0.190 n=50+49)
GoTypes 836ms ± 2% 828ms ± 2% -0.96% (p=0.000 n=49+48)
Compiler 3.87s ± 2% 3.80s ± 1% -1.81% (p=0.000 n=49+46)
SSA 12.0s ± 1% 11.8s ± 1% -2.01% (p=0.000 n=48+50)
Flate 142ms ± 3% 141ms ± 3% -0.85% (p=0.003 n=50+48)
GoParser 178ms ± 4% 175ms ± 4% -1.66% (p=0.000 n=48+46)
Reflect 520ms ± 2% 512ms ± 2% -1.44% (p=0.000 n=45+48)
Tar 200ms ± 3% 198ms ± 4% -0.61% (p=0.037 n=47+50)
XML 277ms ± 3% 275ms ± 3% -0.85% (p=0.000 n=49+48)
[Geo mean] 482ms 476ms -1.23%
name old alloc/op new alloc/op delta
Template 36.1MB ± 0% 35.3MB ± 0% -2.18% (p=0.008 n=5+5)
Unicode 29.8MB ± 0% 29.3MB ± 0% -1.58% (p=0.008 n=5+5)
GoTypes 125MB ± 0% 123MB ± 0% -2.13% (p=0.008 n=5+5)
Compiler 531MB ± 0% 513MB ± 0% -3.40% (p=0.008 n=5+5)
SSA 2.00GB ± 0% 1.93GB ± 0% -3.34% (p=0.008 n=5+5)
Flate 24.5MB ± 0% 24.3MB ± 0% -1.18% (p=0.008 n=5+5)
GoParser 29.4MB ± 0% 28.7MB ± 0% -2.34% (p=0.008 n=5+5)
Reflect 87.1MB ± 0% 86.0MB ± 0% -1.33% (p=0.008 n=5+5)
Tar 35.3MB ± 0% 34.8MB ± 0% -1.44% (p=0.008 n=5+5)
XML 47.9MB ± 0% 47.1MB ± 0% -1.86% (p=0.008 n=5+5)
[Geo mean] 82.8MB 81.1MB -2.08%
name old allocs/op new allocs/op delta
Template 352k ± 0% 347k ± 0% -1.32% (p=0.008 n=5+5)
Unicode 342k ± 0% 339k ± 0% -0.66% (p=0.008 n=5+5)
GoTypes 1.29M ± 0% 1.27M ± 0% -1.30% (p=0.008 n=5+5)
Compiler 4.98M ± 0% 4.87M ± 0% -2.14% (p=0.008 n=5+5)
SSA 15.7M ± 0% 15.2M ± 0% -2.86% (p=0.008 n=5+5)
Flate 233k ± 0% 231k ± 0% -0.83% (p=0.008 n=5+5)
GoParser 296k ± 0% 291k ± 0% -1.54% (p=0.016 n=5+4)
Reflect 1.05M ± 0% 1.04M ± 0% -0.65% (p=0.008 n=5+5)
Tar 343k ± 0% 339k ± 0% -0.97% (p=0.008 n=5+5)
XML 432k ± 0% 426k ± 0% -1.19% (p=0.008 n=5+5)
[Geo mean] 815k 804k -1.35%
name old object-bytes new object-bytes delta
Template 505kB ± 0% 505kB ± 0% -0.01% (p=0.008 n=5+5)
Unicode 224kB ± 0% 224kB ± 0% ~ (all equal)
GoTypes 1.82MB ± 0% 1.83MB ± 0% +0.06% (p=0.008 n=5+5)
Flate 324kB ± 0% 324kB ± 0% +0.00% (p=0.008 n=5+5)
GoParser 402kB ± 0% 402kB ± 0% +0.04% (p=0.008 n=5+5)
Reflect 1.39MB ± 0% 1.39MB ± 0% -0.01% (p=0.008 n=5+5)
Tar 449kB ± 0% 449kB ± 0% -0.02% (p=0.008 n=5+5)
XML 598kB ± 0% 597kB ± 0% -0.05% (p=0.008 n=5+5)
Change-Id: Ifc9d5c1bd01f90171414b8fb18ffe2290d271143
Reviewed-on: https://go-review.googlesource.com/c/114797
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
On architectures where G is stored in a register, it is
possible for a variable to allocated to it, and subsequently
that variable may be spilled and reloaded, for example
because of an intervening call. If such an allocation
reaches a join point and it is the primary predecessor,
it becomes the target of a reload, which is only usually
right.
Fix: guard all the LoadReg ops, and spill value in the G
register (if any) before merges (in the same way that 387
FP registers are freed between blocks).
Includes test.
Fixes#25504.
Change-Id: I0482a53e20970c7315bf09c0e407ae5bba2fe05d
Reviewed-on: https://go-review.googlesource.com/114695
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This was an artifact from when we had a separate ssa.Type interface to
break circular dependency between packages ssa and gc. It's no longer
needed now that package ssa directly uses package types.
Change-Id: I6a93e5d79082815f7f0eb89507381969cc6cb403
Reviewed-on: https://go-review.googlesource.com/109137
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This reverts commit 080187f4f7.
It broke build of golang.org/x/exp/shiny/iconvg
See issue 24395 for details
Change-Id: Ifd6134f6214e6cee40bd3c63c32941d5fc96ae8b
Reviewed-on: https://go-review.googlesource.com/100755
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
changedVars was functionally a set, but couldn't be iterated over
efficiently. In functions with many variables, the wasted iteration was
costly. Use a sparseSet instead.
(*gc.Node).String() is very expensive: it calls Sprintf, which does
reflection, etc, etc. Instead, just look at .Sym.Name, which is all we
care about.
Change-Id: Ib61cd7b5c796e1813b8859135e85da5bfe2ac686
Reviewed-on: https://go-review.googlesource.com/92402
Reviewed-by: David Chase <drchase@google.com>
Now that the buffered write barrier is implemented for all
architectures, we can remove the old eager write barrier
implementation. This CL removes the implementation from the runtime,
support in the compiler for calling it, and updates some compiler
tests that relied on the old eager barrier support. It also makes sure
that all of the useful comments from the old write barrier
implementation still have a place to live.
Fixes#22460.
Updates #21640 since this fixes the layering concerns of the write
barrier (but not the other things in that issue).
Change-Id: I580f93c152e89607e0a72fe43370237ba97bae74
Reviewed-on: https://go-review.googlesource.com/92705
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Rick Hudson <rlh@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
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>
When the compiler decomposes a user variable, track its origin so that
it can be recomposed during DWARF generation.
Change-Id: Ia71c7f8e7f4d65f0652f1c97b0dda5d9cad41936
Reviewed-on: https://go-review.googlesource.com/50878
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
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>
Type.Size and Type.Alignment are for the front end:
They calculate size and alignment if needed.
Type.MustSize and Type.MustAlignment are for the back end:
They call Fatal if size and alignment are not already calculated.
Most uses are of MustSize and MustAlignment,
but that's because the back end is newer,
and this API was added to support it.
This CL was mostly generated with sed and selective reversion.
The only mildly interesting bit is the change of the ssa.Type interface
and the supporting ssa dummy types.
Follow-up to review feedback on CL 41970.
Passes toolstash-check.
Change-Id: I0d9b9505e57453dae8fb6a236a07a7a02abd459e
Reviewed-on: https://go-review.googlesource.com/42016
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
There were only two versions, 0 and 1,
and the only user of version 1 was the assembler,
to indicate that a symbol was static.
Rename LSym.Version to Static,
and add it to LSym.Attributes.
Simplify call-sites.
Passes toolstash-check.
Change-Id: Iabd39918f5019cce78f381d13f0481ae09f3871f
Reviewed-on: https://go-review.googlesource.com/41201
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
It was simply a wrapper around Link.Lookup.
Unwrap everything.
CL prepared using eg with template:
package p
import "cmd/internal/obj"
func before(ctxt *obj.Link, name string, version int) *obj.LSym {
return obj.Linklookup(ctxt, name, version)
}
func after(ctxt *obj.Link, name string, version int) *obj.LSym {
return ctxt.Lookup(name, version)
}
Then one comment in cmd/asm/internal/asm/parse.go
was manually updated (and gofmt'ed!),
and func Linklookup deleted.
Passes toolstash-check (as a sanity measure).
Change-Id: Icc4d56b0b2b5c8888d3184c1898c48359ea1e638
Reviewed-on: https://go-review.googlesource.com/39715
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
