Commit Graph

55 Commits

Author SHA1 Message Date
David Chase 9d3718e834 cmd/compile: remove I-saw-a-register-pragma chatter
It is not multithreaded-compilation-safe, and also seems
to cause problems on the noopt-builder.

Change-Id: I52dbcd507d256990f1ec7c8040ec7b76595aae4f
Reviewed-on: https://go-review.googlesource.com/c/go/+/298850
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-03-04 21:47:26 +00:00
David Chase c015f76acb cmd/compile: implement too-big-to-SSA struct passing in registers
Added a test that exercises named results

Change-Id: Ie228b68f4f846266595a95e0f65a6e4b8bf79635
Reviewed-on: https://go-review.googlesource.com/c/go/+/297029
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-03-04 20:18:16 +00:00
David Chase a2d92b5143 cmd/compile: register abi, morestack work and mole whacking
Morestack works for non-pointer register parameters

Within a function body, pointer-typed parameters are correctly
tracked.

Results still not hooked up.

For #40724.

Change-Id: Icaee0b51d0da54af983662d945d939b756088746
Reviewed-on: https://go-review.googlesource.com/c/go/+/294410
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-03-04 16:19:12 +00:00
David Chase d6f6ef6358 cmd/compile: remove races introduced in abiutils field update
This fix uses mutex around the problematic store and subsequent access;
if this causes performance problems later a better fix is to do all the
ABI binding in gc/walk where it is single-threaded.

Change-Id: I488f28ab75beb8351c856fd50b0095cab463642e
Reviewed-on: https://go-review.googlesource.com/c/go/+/298109
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2021-03-03 17:59:50 +00:00
David Chase 9f33dc3ca1 cmd/compile: handle aggregate OpArg in registers
Also handles case where OpArg does not escape but has its address
taken.

May have exposed a lurking bug in 1.16 expandCalls,
if e.g., loading len(someArrayOfstructThing[0].secondStringField)
from a local.  Maybe.

For #40724.

Change-Id: I0298c4ad5d652b5e3d7ed6a62095d59e2d8819c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/293396
Trust: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-03-03 15:00:48 +00:00
David Chase f2df1e3c34 cmd/compile: retrieve Args from registers
in progress; doesn't fully work until they are also passed on
register on the caller side.

For #40724.

Change-Id: I29a6680e60bdbe9d132782530214f2a2b51fb8f6
Reviewed-on: https://go-review.googlesource.com/c/go/+/293394
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-03-03 03:02:39 +00:00
David Chase 77973863c3 cmd/compile: use abiutils for all rcvr/in/out frame offsets.
types thought it knew how to do this, but that's a lie, because types
doesn't know what the ABI is.

includes extra checking to help prevent things from accidentally working
if they need to be changed but aren't.

For #40724.

Change-Id: I166cd948f262344b7bebde6a2c25e7a7f878bbfb
Reviewed-on: https://go-review.googlesource.com/c/go/+/293393
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>
2021-03-03 01:45:33 +00:00
David Chase 97b32a6724 cmd/compile: better version of check frame offsets against abi
improved to run on more architectures.

this is in preparation for turning off calculation of frame offsets
in types.CalcSize.

Replaces https://go-review.googlesource.com/c/go/+/293392 .
Updates #44675.
For #40724.

Change-Id: I40ba496172447cf09b86bc646148859363c11ad9
Reviewed-on: https://go-review.googlesource.com/c/go/+/297637
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>
2021-03-02 15:26:33 +00:00
Bryan C. Mills a400eb3261 Revert "cmd/compile: check frame offsets against abi"
This reverts CL 293392.

Reason for revert: broke most non-x86 builders

Fixes #44675

Change-Id: I1e815c3ab27a02e83a2f0d221a617909dd021403
Reviewed-on: https://go-review.googlesource.com/c/go/+/297549
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2021-03-01 15:24:01 +00:00
David Chase 5ff7ec98b7 cmd/compile: check frame offsets against abi
this is in preparation for turning off calculation of frame offsets
in types.CalcSize

For #40724.

Change-Id: I2c29fd289c014674076e5ec5170055dbca5ea64b
Reviewed-on: https://go-review.googlesource.com/c/go/+/293392
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2021-02-27 22:39:54 +00:00
David Chase 998fe70b68 cmd/compile: fixed which-result confusion in presence of 0-width types
A function returning multiple results, some of them zero-width,
will have more than one result present at an offset.  Be sure
that offset AND type match.

Includes test.

Change-Id: I3eb1f56116d989b4e73f533fefabb1bf554c901b
Reviewed-on: https://go-review.googlesource.com/c/go/+/297169
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2021-02-27 18:38:31 +00:00
David Chase e25040d162 cmd/compile: change StaticCall to return a "Results"
StaticLECall (multiple value in +mem, multiple value result +mem) ->
StaticCall (multiple ergister value in +mem,
   multiple register-sized-value result +mem) ->
ARCH CallStatic (multiple ergister value in +mem,
   multiple register-sized-value result +mem)

But the architecture-dependent stuff is indifferent to whether
it is mem->mem or (mem)->(mem) until Prog generation.

Deal with OpSelectN -> Prog in ssagen/ssa.go, others, as they
appear.

For #40724.

Change-Id: I1d0436f6371054f1881862641d8e7e418e4a6a16
Reviewed-on: https://go-review.googlesource.com/c/go/+/293391
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>
2021-02-26 02:52:33 +00:00
Josh Bleecher Snyder 4ebb6f5110 cmd/compile: automate resultInArg0 register checks
No functional changes; passes toolstash-check.
No measureable performance changes.

Change-Id: I2629f73d4a3cc56d80f512f33cf57cf41d8f15d3
Reviewed-on: https://go-review.googlesource.com/c/go/+/296010
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2021-02-25 18:57:20 +00:00
David Chase 7a2f3273c5 cmd/compile: plumb abi info into ssagen/ssa
Plumb abi information into ssa/ssagen for plain calls
and plain functions (not methods).  Does not extend all the
way through the compiler (yet).

One test disabled because it extends far enough to break the test.

Normalized all the compiler's register args TODOs to
// TODO(register args) ...

For #40724.

Change-Id: I0173a4579f032ac3c9db3aef1749d40da5ea01ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/293389
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>
2021-02-24 17:54:29 +00:00
Cuong Manh Le 2a18e37c4e cmd/compile: remove backend's "scratch mem" support
This CL rebases CL 273987 on top of master with @mdempsky's permission.

The last (only?) use for this feature was 387 support, which was
removed in golang.org/cl/258957.

Change-Id: I4f79fee8d0c336c9b6082bcd5eb6ece52c032dc0
Reviewed-on: https://go-review.googlesource.com/c/go/+/292893
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-02-23 06:01:42 +00:00
Cuong Manh Le e52149822b cmd/compile: simplify assert{E,I}2I{,2} calling conventions
This CL rebases CL 273694 on top of master with @mdempsky's permission.

For assertE2I and assertI2I, there's no need to pass through the
interface's data pointer: it's always going to come back unmodified.

For assertE2I2 and assertI2I2, there's no need for an extra bool
result parameter: it's redundant with testing the returned interface
value for nil.

Change-Id: Ic92d4409ad381952f875d3d74b8cf11c32702fa6
Reviewed-on: https://go-review.googlesource.com/c/go/+/292892
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-02-23 06:01:29 +00:00
Cherry Zhang 401d7e5a24 [dev.regabi] cmd/compile: reserve X15 as zero register on AMD64
In ABIInternal, reserve X15 as constant zero, and use it to zero
memory. (Maybe there can be more use of it?)

The register is zeroed when transition to ABIInternal from ABI0.

Caveat: using X15 generates longer instructions than using X0.
Maybe we want to use X0?

Change-Id: I12d5ee92a01fc0b59dad4e5ab023ac71bc2a8b7d
Reviewed-on: https://go-review.googlesource.com/c/go/+/288093
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2021-02-03 22:44:53 +00:00
David Chase 9b636feafe [dev.regabi] cmd/compile: missing last patch set for cl286013
Forgot to mail last patch set before committing, repair that.

Change-Id: I1ef72d0d7df56e89369e6fb4d6e5690f254e6aa8
Reviewed-on: https://go-review.googlesource.com/c/go/+/286912
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-26 19:56:01 +00:00
David Chase f7dad5eae4 [dev.regabi] cmd/compile: remove leftover code form late call lowering work
It's no longer conditional.

Change-Id: I697bb0e9ffe9644ec4d2766f7e8be8b82d3b0638
Reviewed-on: https://go-review.googlesource.com/c/go/+/286013
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-26 18:35:19 +00:00
Matthew Dempsky 7eaaf28cae [dev.regabi] cmd/compile: disallow taking address of SSA'd values
Adds some extra validation that the frontend is setting flags like
Addrtaken correctly.

Change-Id: Iffde83e32ba1c4c917ab8cb3fe410a4f623cf635
Reviewed-on: https://go-review.googlesource.com/c/go/+/286434
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2021-01-25 22:46:58 +00:00
Cuong Manh Le fd9a391cdd [dev.regabi] cmd/compile: remove CallExpr.Rargs
Instead, push the temps assignments to init. This does not pass
toolstash, since when before this, the temps were evaluated after
function callee, now we evaluate them before.

Change-Id: Icb9cb10e036925b56c1ef3eec468416a11f4932f
Reviewed-on: https://go-review.googlesource.com/c/go/+/284894
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-21 06:38:25 +00:00
David Chase 92cb157cf3 [dev.regabi] cmd/compile: late expansion of return values
By-hand rebase of earlier CL, because that was easier than
letting git try to figure things out.

This will naively insert self-moves; in the case that these
involve memory, the expander detects these and removes them
and their vardefs.

Change-Id: Icf72575eb7ae4a186b0de462bc8cf0bedc84d3e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/279519
Trust: David Chase <drchase@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2021-01-20 19:57:48 +00:00
Matthew Dempsky 4a4212c0e5 [dev.regabi] cmd/compile: refactor Linksym creation
Currently there's a lot of logic within package types for creating
Linksyms. This CL pulls it out into base, where it can be more easily
reused by other compiler code that shouldn't need to depend on package
types.

Package base probably isn't the best place for this, but it's
convenient because it's a package that types already depends on. It's
also where the Ctxt object lives, which these functions depend upon.

Passes toolstash -cmp w/ -gcflags=all=-abiwrap.

Change-Id: I50d8b7e4596955205036969eab24d7dab053b363
Reviewed-on: https://go-review.googlesource.com/c/go/+/284231
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
2021-01-19 02:41:42 +00:00
Matthew Dempsky 4f5c603c0f [dev.regabi] cmd/compile: cleanup callTargetLSym
Now that TailCallStmt carries an *ir.Name instead of a *types.Sym,
callTargetLSym can be similarly updated to take the target function as
an *ir.Name.

This inches us closer towards being able to move Linksym and other
properties from *types.Sym to *ir.Name, where they belong.

Passes toolstash -cmp w/ -gcflags=all=-abiwrap.

Change-Id: I091da290751970eba8ed0438f66d6cca88b665a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/284228
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
2021-01-19 02:41:30 +00:00
Matthew Dempsky 422f38fb6c [dev.regabi] cmd/compile: move stack objects to liveness
Calculating and emitting stack objects are essentially part of
liveness analysis, so move the code from ssagen to liveness. Allows
unexporting liveness.ShouldTrack.

Passes toolstash -cmp.

Change-Id: I88b5b2e75b8dfb46b8b03a2fa09a9236865cbf3e
Reviewed-on: https://go-review.googlesource.com/c/go/+/284413
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
2021-01-18 06:33:56 +00:00
Matthew Dempsky 99a5db11ac [dev.regabi] cmd/compile: use LinksymOffsetExpr in walkConvInterface
This CL updates walkConvInterface to use LinksymOffsetExpr for
referencing runtime.staticuint64s and runtime.zerobase.

Passes toolstash -cmp (surprisingly).

Change-Id: Iad7e30371f89c8a5e176b5ddbc53faf57012ba0d
Reviewed-on: https://go-review.googlesource.com/c/go/+/284229
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-01-17 11:17:54 +00:00
Matthew Dempsky 87845d14f9 [dev.regabi] cmd/compile: add ir.TailCallStmt
This CL splits out ORETJMP as a new TailCallStmt node, separate from
the other BranchStmt nodes. In doing so, this allows us to change it
from identifying a function by *types.Sym to identifying one by
directly pointing to the *ir.Func.

While here, also rename the operation to OTAILCALL.

Passes toolstash -cmp.

Change-Id: I273e6ea5d92bf3005ae02fb59b3240a190a6cf1b
Reviewed-on: https://go-review.googlesource.com/c/go/+/284227
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-01-17 11:14:51 +00:00
Cuong Manh Le 59ff93fe64 [dev.regabi] cmd/compile: rename NameOffsetExpr to LinksymOffsetExpr
Updates #43737

[git-generate]

cd src/cmd/compile/internal/ir

rf '
  mv NameOffsetExpr LinksymOffsetExpr
  mv ONAMEOFFSET OLINKSYMOFFSET
'

go generate

Change-Id: I8c6b8aa576e88278c0320d16bb2e8e424a15b907
Reviewed-on: https://go-review.googlesource.com/c/go/+/284120
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-17 06:38:07 +00:00
Cuong Manh Le 82b9cae700 [dev.regabi] cmd/compile: change ir.NameOffsetExpr to use *obj.LSym instead of *Name
Because NameOffsetExpr is always used with global variables, and SSA
backend only needs (*Name).Linksym() to generate value for them.

Passes toolstash -cmp.

Updates #43737

Change-Id: I17209e21383edb766070c0accd1fa4660659caef
Reviewed-on: https://go-review.googlesource.com/c/go/+/284119
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-17 06:37:42 +00:00
Dan Scales a956a0e909 [dev.regabi] cmd/compile, runtime: fix up comments/error messages from recent renames
Went in a semi-automated way through the clearest renames of functions,
and updated comments and error messages where it made sense.

Change-Id: Ied8e152b562b705da7f52f715991a77dab60da35
Reviewed-on: https://go-review.googlesource.com/c/go/+/284216
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-16 02:31:08 +00:00
Cuong Manh Le ab3b67abfd [dev.regabi] cmd/compile: remove ONEWOBJ
After CL 283233, SSA can now handle new(typ) without the frontend to
generate the type address, so we can remove ONEWOBJ in favor of ONEW
only.

This is also not save for toolstash, the same reason with CL 284115.

Change-Id: Ie03ea36b3b6f95fc7ce080376c6f7afc402d51a3
Reviewed-on: https://go-review.googlesource.com/c/go/+/284117
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-16 01:36:46 +00:00
Cuong Manh Le c9b1445ac8 [dev.regabi] cmd/compile: remove TypeAssertExpr {Src,Dst}Type fields
CL 283233 added reflectType method to ssagen.state, which we can use to
setup type address in the SSA backend in favor of the frontend. However,
this will change the order of symbols generation, so not safe for toolstash.

Change-Id: Ib6932ec42a9d28c3fd7a1c055596e75494c29843
Reviewed-on: https://go-review.googlesource.com/c/go/+/284115
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-01-16 01:36:11 +00:00
Matthew Dempsky 14537e6e54 [dev.regabi] cmd/compile: move stkobj symbol generation to SSA
The code for allocating linksyms and recording that we need runtime
type descriptors is now concurrent-safe, so move it to where those
symbols are actually needed to reduce complexity and risk of failing
to generate all needed symbols in advance.

For #43701.

Change-Id: I759d2508213ac9a4e0b504b51a75fa10dfa37a8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/284076
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Trust: Matthew Dempsky <mdempsky@google.com>
2021-01-15 16:13:14 +00:00
Matthew Dempsky ab523fc510 [dev.regabi] cmd/compile: don't promote Byval CaptureVars if Addrtaken
We decide during escape analysis whether to pass closure variables by
value or reference. One of the factors that's considered is whether a
variable has had its address taken.

However, this analysis is based only on the user-written source code,
whereas order+walk may introduce rewrites that take the address of a
variable (e.g., passing a uint16 key by reference to the size-generic
map runtime builtins).

Typically this would be harmless, albeit suboptimal. But in #43701 it
manifested as needing a stack object for a function where we didn't
realize we needed one up front when we generate symbols.

Probably we should just generate symbols on demand, now that those
routines are all concurrent-safe, but this is a first fix.

Thanks to Alberto Donizetti for reporting the issue, and Cuong Manh Le
for initial investigation.

Fixes #43701.

Change-Id: I16d87e9150723dcb16de7b43f2a8f3cd807a9437
Reviewed-on: https://go-review.googlesource.com/c/go/+/284075
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-01-15 16:13:04 +00:00
Matthew Dempsky f97983249a [dev.regabi] cmd/compile: move more PAUTOHEAP to SSA construction
This CL moves almost all PAUTOHEAP handling code to SSA construction.
Instead of changing Names to PAUTOHEAP, escape analysis now only sets
n.Esc() to ir.EscHeap, and SSA handles creating the "&x"
pseudo-variables and associating them via Heapaddr.

This CL also gets rid of n.Stackcopy, which was used to distinguish
the heap copy of a parameter used within a function from the stack
copy used in the function calling convention. In practice, this is
always obvious from context: liveness and function prologue/epilogue
want to know about the stack copies, and everywhere else wants the
heap copy.

Hopefully moving all parameter/result handling into SSA helps with
making the register ABI stuff easier.

Also, the only remaining uses of PAUTOHEAP are now for closure
variables, so I intend to rename it to PCLOSUREVAR or get rid of those
altogether too. But this CL is already big and scary enough.

Change-Id: Ief5ef6205041b9d0ee445314310c0c5a98187e77
Reviewed-on: https://go-review.googlesource.com/c/go/+/283233
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Chase <drchase@google.com>
2021-01-14 06:10:09 +00:00
David Chase 861707a8c8 [dev.regabi] cmd/compile: added limited //go:registerparams pragma for new ABI dev
This only works for functions; if you try it with a method, it will
fail.  It does work for both local package and imports.  For now,
it tells you when it thinks it sees either a declaration or a call of
such a function (this will normally be silent since no existing
code uses this pragma).

Note: it appears to be really darn hard to figure out if this
pragma was set for a method, and the method's call site.  Better
ir.Node wranglers than I might be able to make headway, but it
seemed unnecessary for this experiment.

Change-Id: I601c2ddd124457bf6d62f714d7ac871705743c0a
Reviewed-on: https://go-review.googlesource.com/c/go/+/279521
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jeremy Faller <jeremy@golang.org>
2021-01-13 15:50:04 +00:00
Matthew Dempsky 7fd84c6e46 [dev.regabi] cmd/compile: remove OCLOSUREREAD
After the previous CLs, all closure reads are handled during SSA
construction.

Change-Id: Iad67b01fa2d3798f50ea647be7ccf8195f189c27
Reviewed-on: https://go-review.googlesource.com/c/go/+/281512
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-01-10 08:02:23 +00:00
Matthew Dempsky 950cf4d46c [dev.regabi] cmd/compile: bind closure vars during SSA constructions
For function literals that aren't inlined or directly called, we need
to pass their arguments via a closure struct. This also means we need
to rewrite uses of closure variables to access from this closure
struct.

Currently we do this rewrite in a pass before walking begins. This CL
moves the code to SSA construction instead, alongside binding other
input parameters.

Change-Id: I13538ef3394e2d6f75d5b7b2d0adbb00db812dc2
Reviewed-on: https://go-review.googlesource.com/c/go/+/281352
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
2021-01-10 08:02:06 +00:00
Matthew Dempsky 8b2efa990b [dev.regabi] cmd/compile: deref PAUTOHEAPs during SSA construction
Currently, during walk we rewrite PAUTOHEAP uses into derefs of their
corresponding Heapaddr, but we can easily do this instead during SSA
construction. This does involve updating two test cases:

* nilptr3.go

This file had a test that we emit a "removed nil check" diagnostic for
the implicit dereference from accessing a PAUTOHEAP variable. This CL
removes this diagnostic, since it's not really useful to end users:
from the user's point of view, there's no pointer anyway, so they
needn't care about whether we check for nil or not. That's a purely
internal detail. And with the PAUTOHEAP dereference handled during SSA
construction, we can more robustly ensure this happens, rather than
relying on setting a flag in walk and hoping that SSA sees it.

* issue20780.go

Previously, when PAUTOHEAPs were dereferenced during walk, it had a
consequence that when they're passed as a function call argument, they
would first get copied to the stack before being copied to their
actual destination. Moving the dereferencing to SSA had a side-effect
of eliminating this unnecessary temporary, and copying directly to the
destination parameter.

The test is updated to instead call "g(h(), h())" where h() returns a
large value, as the first result will always need to be spilled
somewhere will calling the second function. Maybe eventually we're
smart enough to realize it can be spilled to the heap, but we don't do
that today.

Because I'm concerned that the direct copy-to-parameter optimization
could interfere with race-detector instrumentation (e.g., maybe the
copies were previously necessary to ensure they're not clobbered by
inserted raceread calls?), I've also added issue20780b.go to exercise
this in a few different ways.

Change-Id: I720598cb32b17518bc10a03e555620c0f25fd28d
Reviewed-on: https://go-review.googlesource.com/c/go/+/281293
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-01-10 08:01:49 +00:00
Matthew Dempsky f24e40c14a [dev.regabi] cmd/compile: remove Name.Class_ accessors
These aren't part of the Node interface anymore, so no need to keep
them around.

Passes toolstash -cmp.

[git-generate]
cd src/cmd/compile/internal/ir

: Fix one off case that causes trouble for rf.
sed -i -e 's/n.SetClass(ir.PAUTO)/n.Class_ = ir.PAUTO/' ../ssa/export_test.go

pkgs=$(go list . ../...)
rf '
	ex '"$(echo $pkgs)"' {
		var n *Name
		var c Class
		n.Class() -> n.Class_
		n.SetClass(c) -> n.Class_ = c
	}

	rm Name.Class
	rm Name.SetClass
	mv Name.Class_ Name.Class
'

Change-Id: Ifb304bf4691a8c455456aabd8aa77178d4a49500
Reviewed-on: https://go-review.googlesource.com/c/go/+/281294
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2021-01-04 10:30:09 +00:00
Matthew Dempsky fd22df9905 [dev.regabi] cmd/compile: remove idempotent Name() calls [generated]
[git-generate]
cd src/cmd/compile/internal/ir
pkgs=$(grep -l -w Name ../*/*.go | xargs dirname | sort -u | grep -v '/ir$')
rf '
	ex . '"$(echo $pkgs)"' {
		var n *Name
		n.Name() -> n
	}
'

Change-Id: I6bfce6417a6dba833d2f652ae212a32c11bc5ef6
Reviewed-on: https://go-review.googlesource.com/c/go/+/280972
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
2021-01-01 03:02:29 +00:00
Cuong Manh Le 77fd81a3e6 [dev.regabi] cmd/compile: use names for keep alive variables in function call
Back to pre Russquake, Node.Nbody of OCALL* node is used to attach
variables which must be kept alive during that call.

Now after Russquake, we have CallExpr to represent a function call,
so use a dedicated field for those variables instead.

Passes toolstash -cmp.

Change-Id: I4f40ebefcc7c41cdcc4e29c7a6d8496a083b68f4
Reviewed-on: https://go-review.googlesource.com/c/go/+/280733
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-12-31 09:43:13 +00:00
Cuong Manh Le 82ab3d1448 [dev.regabi] cmd/compile: use *ir.Name for Decl.X
Passes toolstash -cmp.

Change-Id: I505577d067eda3512f6d78618fc0eff061a71e3c
Reviewed-on: https://go-review.googlesource.com/c/go/+/280732
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-12-30 00:48:19 +00:00
Matthew Dempsky a5ec920160 [dev.regabi] cmd/compile: more Linksym cleanup
This largely gets rid of the remaining direct Linksym calls, hopefully
enough to discourage people from following bad existing practice until
Sym.Linksym can be removed entirely.

Passes toolstash -cmp.

Change-Id: I5d8f8f703ace7256538fc79648891ede0d879dc2
Reviewed-on: https://go-review.googlesource.com/c/go/+/280641
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-12-29 07:55:00 +00:00
Matthew Dempsky ec59b197d5 [dev.regabi] cmd/compile: rewrite to use linksym helpers [generated]
Passes toolstash -cmp.

[git-generate]
cd src/cmd/compile/internal/gc
pkgs=$(grep -l -w Linksym ../*/*.go | xargs dirname | grep -v '/gc$' | sort -u)
rf '
	ex . '"$(echo $pkgs)"' {
		import "cmd/compile/internal/ir"
		import "cmd/compile/internal/reflectdata"
		import "cmd/compile/internal/staticdata"
		import "cmd/compile/internal/types"

		avoid reflectdata.TypeLinksym
		avoid reflectdata.TypeLinksymLookup
		avoid reflectdata.TypeLinksymPrefix
		avoid staticdata.FuncLinksym

		var f *ir.Func
		var n *ir.Name
		var s string
		var t *types.Type

		f.Sym().Linksym() -> f.Linksym()
		n.Sym().Linksym() -> n.Linksym()

		reflectdata.TypeSym(t).Linksym() -> reflectdata.TypeLinksym(t)
		reflectdata.TypeSymPrefix(s, t).Linksym() -> reflectdata.TypeLinksymPrefix(s, t)
		staticdata.FuncSym(n.Sym()).Linksym() -> staticdata.FuncLinksym(n)
		types.TypeSymLookup(s).Linksym() -> reflectdata.TypeLinksymLookup(s)
	}
'

Change-Id: I7a3ae1dcd61bcdf4a29f708ff12f7f80c2b280c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/280640
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-12-29 07:54:55 +00:00
Matthew Dempsky 25c613c02d [dev.regabi] cmd/compile: add Linksym helpers
Syms are meant to be just interned (pkg, name) tuples, and are a
purely abstract, Go-language concept. As such, associating them with
linker symbols (a low-level, implementation-oriented detail) is
inappropriate.

There's still work to be done before linker symbols can be directly
attached to their appropriate, higher-level objects instead. But in
the mean-time, we can at least add helper functions and discourage
folks from using Sym.Linksym directly. The next CL will mechanically
rewrite code to use these helpers where possible.

Passes toolstash -cmp.

Change-Id: I413bd1c80bce056304f9a7343526bd153f2b9c7d
Reviewed-on: https://go-review.googlesource.com/c/go/+/280639
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-12-29 07:54:40 +00:00
Matthew Dempsky 6acbae4fcc [dev.regabi] cmd/compile: address some ir TODOs
Previously, ODOTTYPE/ODOTTYPE2 were forced to reuse some available
Node fields for storing pointers to runtime type descriptors. This
resulted in awkward field types for TypeAssertExpr and AddrExpr.

This CL gives TypeAssertExpr proper fields for the runtime type
descriptors, and also tightens the field types as
possible/appropriate.

Passes toolstash -cmp.

Change-Id: I521ee7a1462affc5459de33a0de6c68a7d6416ba
Reviewed-on: https://go-review.googlesource.com/c/go/+/280637
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>
2020-12-29 02:49:00 +00:00
Matthew Dempsky 3383b5c74a [dev.regabi] cmd/compile: flatten dependency graph [generated]
This CL shuffles a couple functions around to help flatten the package
dependency graph somewhat:

1. ssa.LosesStmtMark is only ever used in associated with an
objw.Prog, so we might as well move it to that package. This removes a
dependency from objw (a relatively low-level utility package that
wraps cmd/internal/obj) on ssa (a large and relatively high-level
package).

2. Moves liveness.SetTypeBits into a new package typebits. A
single-function package is a bit on the silly side, but reflectdata
shouldn't need to depend on liveness (nor vice versa).

[git-generate]
cd src/cmd/compile/internal/ssa
rf '
	mv LosesStmtMark prog.go
	mv prog.go cmd/compile/internal/objw
'

cd ../liveness
rf '
	mv SetTypeBits Set
	mv Set typebits.go
	rm typebits.go:/Copyright/+4,/^package/-0
	mv typebits.go cmd/compile/internal/typebits
'

Change-Id: Ic9a983f0ad6c0cf1a537f99889699a8444699e6e
Reviewed-on: https://go-review.googlesource.com/c/go/+/280447
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-12-28 08:06:26 +00:00
Matthew Dempsky 135ce1c485 [dev.regabi] cmd/compile: desugar OMETHEXPR into ONAME during walk
A subsequent CL will change FuncName to lazily create the ONAME nodes,
which isn't currently safe to do during SSA construction, because that
phase is concurrent.

Passes toolstash -cmp.

Change-Id: Ic24acc1d1160ad93b70ced3baa468f750e689ea6
Reviewed-on: https://go-review.googlesource.com/c/go/+/280435
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-12-28 07:43:31 +00:00
Matthew Dempsky 0de8eafd98 [dev.regabi] cmd/compile: remove SelectorExpr.Offset field
Now that the previous CL ensures we always set SelectorExpr.Selection,
we can replace the SelectorExpr.Offset field with a helper method that
simply returns SelectorExpr.Selection.Offset.

Passes toolstash -cmp.

Change-Id: Id0f22b8b1980397b668f6860d27cb197b90ff52a
Reviewed-on: https://go-review.googlesource.com/c/go/+/280433
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2020-12-28 03:39:08 +00:00