No point in doing anything for x=x assignments.
In addition, skipping these assignments prevents generating:
VARDEF x
COPY x -> x
which is bad because x is incorrectly considered
dead before the vardef.
Fixes#14904
Change-Id: I6817055ec20bcc34a9648617e0439505ee355f82
Reviewed-on: https://go-review.googlesource.com/21470
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Dave Cheney <dave@cheney.net>
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Change-Id: I91873aaebf79bdf1c00d38aacc1a1fb8d79656a7
Reviewed-on: https://go-review.googlesource.com/21433
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Replace isideal(t) with t.IsUntyped().
Replace Istype(t, k) with t.IsKind(k).
Replace isnilinter(t) with t.IsEmptyInterface().
Also replace a lot of t.IsKind(TFOO) with t.IsFoo().
Replacements prepared mechanically with gofmt -w -r.
Passes toolstash -cmp.
Change-Id: Iba48058f3cc863e15af14277b5ff5e729e67e043
Reviewed-on: https://go-review.googlesource.com/21424
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
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>
Replace Isfixedarray, Isslice, and Isinter with the IsArray, IsSlice,
and IsInterface methods added for SSA. Rewrite performed mechanically
using gofmt -w -r "Isfoo(t) -> t.IsFoo()".
Because the IsFoo methods panic when given a nil pointer, a handful of
call sites had to be modified to check for nil Type values. These
aren't strictly necessary, because nil Type values should only occur
in invalid Go source programs, so it would be okay if we panicked on
them and gave up type checking the rest of the package. However, there
are a couple regress tests that expect we continue, so add checks to
keep those tests passing. (See #15029.)
Passes toolstash -cmp.
Change-Id: I511c6ac4cfdf3f9cbdb3e52a5fa91b6d09d82f80
Reviewed-on: https://go-review.googlesource.com/21336
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This removes almost all direct access to
Type’s heavily overloaded Type field.
Mostly generated by eg, manually checked.
Significant manual changes:
* reflect.go's typPkg used Type indiscriminately.
Use it only for specific etypes.
* gen.go's visitComponents contained a usage of Type
with structs. Using Type for structs no longer
occurs, and the Fatal contained therein has not triggered,
so it has been axed.
* Scary code in cgen.go's cgen_slice is now explicitly scary.
Passes toolstash -cmp.
Change-Id: I2dbfb3c959da7ae239f964d83898c204affcabc6
Reviewed-on: https://go-review.googlesource.com/21331
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Previously, t.IsPtr() reported whether t was represented with a
pointer, but some of its callers expected it to report whether t is an
actual Go pointer. Resolve this by renaming t.IsPtr to t.IsPtrShaped
and adding a new t.IsPtr method to report Go pointer types.
Updated a couple callers in gc/ssa.go to use IsPtr instead of
IsPtrShaped.
Passes toolstash -cmp.
Updates #15028.
Change-Id: I0a8154b5822ad8a6ad296419126ad01a3d2a5dc5
Reviewed-on: https://go-review.googlesource.com/21232
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
One intrinsic was needed to help get the very best
performance out of a future GC; as long as that one was
being added, I also added Bswap since that is sometimes
a handy thing to have. I had intended to fill out the
bit-scan intrinsic family, but the mismatch between the
"scan forward" instruction and "count leading zeroes"
was large enough to cause me to leave it out -- it poses
a dilemma that I'd rather dodge right now.
These intrinsics are not exposed for general use.
That's a separate issue requiring an API proposal change
( https://github.com/golang/proposal )
All intrinsics are tested, both that they are substituted
on the appropriate architecture, and that they produce the
expected result.
Change-Id: I5848037cfd97de4f75bdc33bdd89bba00af4a8ee
Reviewed-on: https://go-review.googlesource.com/20564
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Start working on arm port. Gets close to correct
code for fibonacci:
func fib(n int) int {
if n < 2 {
return n
}
return fib(n-1) + fib(n-2)
}
Still a lot to do, but this is a good starting point.
Cleaned up some arch-specific dependencies in regalloc.
Change-Id: I4301c6c31a8402168e50dcfee8bcf7aee73ea9d5
Reviewed-on: https://go-review.googlesource.com/21000
Reviewed-by: David Chase <drchase@google.com>
Don't write back parts of a slicing operation if they
are unchanged from the source of the slice. For example:
x.s = x.s[0:5] // don't write back pointer or cap
x.s = x.s[:5] // don't write back pointer or cap
x.s = x.s[:5:7] // don't write back pointer
There is more to be done here, for example:
x.s = x.s[:len(x.s):7] // don't write back ptr or len
This CL can't handle that one yet.
Fixes#14855
Change-Id: Id1e1a4fa7f3076dc1a76924a7f1cd791b81909bb
Reviewed-on: https://go-review.googlesource.com/20954
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Also give them more idiomatic Go names. Adding godocs is outside the
scope of this CL. (Besides, the method names almost all directly
parallel an underlying math/big.Int or math/big.Float method.)
CL prepared mechanically with sed (for rewriting mpint.go/mpfloat.go)
and gofmt (for rewriting call sites).
Passes toolstash -cmp.
Change-Id: Id76f4aee476ba740f48db33162463e7978c2083d
Reviewed-on: https://go-review.googlesource.com/20909
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The Node type ODOT and its variants all represent a selector, with a
simple name to the right of the dot. Before this change this was
represented by using an ONAME Node in the Right field. This ONAME node
served no useful purpose. This CL changes these Node types to store the
symbol in the Sym field instead, thus not requiring allocating a Node
for each selector.
When compiling x/tools/go/types this CL eliminates nearly 5000 calls to
newname and reduces the total number of Nodes allocated by about 6.6%.
It seems to cut compilation time by 1 to 2 percent.
Getting this right was somewhat subtle, and I added two dubious changes
to produce the exact same output as before. One is to ishairy in
inl.go: the ONAME node increased the cost of ODOT and friends by 1, and
I retained that, although really ODOT is not more expensive than any
other node. The other is to varexpr in walk.go: because the ONAME in
the Right field of an ODOT has no class, varexpr would always return
false for an ODOT, although in fact for some ODOT's it seemingly ought
to return true; I added an && false for now. I will send separate CLs,
that will break toolstash -cmp, to clean these up.
This CL passes toolstash -cmp.
Change-Id: I4af8a10cc59078c436130ce472f25abc3a9b2f80
Reviewed-on: https://go-review.googlesource.com/20890
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Make sure we don't generate write barriers in runtime
code that is marked to forbid write barriers.
Implement the optimization that if we're writing a sliced
slice back to the location it came from, we don't need a
write barrier.
Fixes#14784
Change-Id: I04b6a3b2ac303c19817e932a36a3b006de103aaa
Reviewed-on: https://go-review.googlesource.com/20791
Reviewed-by: Austin Clements <austin@google.com>
This is an automated rewrite of all the calls of the form:
for f, it := IterFields(t); f != nil; f = it.Next() { ... }
Followup CLs will work on cleaning up the remaining cases.
Change-Id: Ic1005ad45ae0b50c63e815e34e507e2d2644ba1a
Reviewed-on: https://go-review.googlesource.com/20794
Reviewed-by: David Crawshaw <crawshaw@golang.org>
For every string constant the compiler was creating 2 Sym's and 2
Node's. It would never refer to them again, but would keep them alive
in gostringpkg. This changes the code to just use obj.LSym's instead.
When compiling x/tools/go/types, this yields about a 15% reduction in
the number of calls to newname and a 3% reduction in the total number of
Node objects. Unfortunately I couldn't see any change in compile time,
but reducing memory usage is desirable anyhow.
Passes toolstash -cmp.
Change-Id: I24f1cb1e6cff0a3afba4ca66f7166874917a036b
Reviewed-on: https://go-review.googlesource.com/20792
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Keep track of how many uses each Value has. Each appearance in
Value.Args and in Block.Control counts once.
The number of uses of a value is generically useful to
constrain rewrite rules. For instance, we might want to
prevent merging index operations into loads if the same
index expression is used lots of times.
But I have one use in particular for which the use count is required.
We must make sure we don't combine ops with loads if the load has
more than one use. Otherwise, we may split a single load
into multiple loads and that breaks perceived behavior in
the presence of races. In particular, the load of m.state
in sync/mutex.go:Lock can't be done twice. (I have a separate
CL which triggers the mutex failure. This CL has a test which
demonstrates a similar failure.)
Change-Id: Icaafa479239f48632a069d0c3f624e6ebc6b1f0e
Reviewed-on: https://go-review.googlesource.com/20790
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
All of a struct's fields have to fit into memory anyway, so index them
with int instead of int64. This also makes it nicer for
cmd/compile/internal/gc to reuse the same NumFields function.
Change-Id: I210be804a0c33370ec9977414918c02c675b0fbe
Reviewed-on: https://go-review.googlesource.com/20691
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Turns out there were only two call sites that expected
t.Field(t.NumFields()) to return nil.
Change-Id: I4679988d38ee9d7c9d89883537a17046717b2a77
Reviewed-on: https://go-review.googlesource.com/20731
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Parts of the SSA compiler in package gc contain amd64-specific code,
most notably Prog generation. Move this code into package amd64, so that
other architectures can be added more easily.
In package gc, this change is just moving code. There are no functional
changes or even any larger structural changes beyond changing function
names (mostly for export).
In the cmd/compile/internal/ssa/gen tool, more information is included
in arch to remove the AMD64-specific behavior in the main portion of the
tool. The generated opGen.go is identical.
Change-Id: I8eb37c6e6df6de1b65fa7dab6f3bc32c29daf643
Reviewed-on: https://go-review.googlesource.com/20609
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
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>
Reuse auto symbols so cse can eliminate OpAddrs that refer to
them.
Change-Id: I69e6a3f77a3a33946459cf8c6eccf223f6125048
Reviewed-on: https://go-review.googlesource.com/20569
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The location of VARDEFs is incorrect for PPARAMOUT variables
which are also used as temporary locations. We put in VARDEFs
when setting the variable at return time, but when the location
is also used as a temporary the lifetime values are wrong.
Fix copyelim to update the names map properly. This is a
real name bug fix which, as a result, allows me to
write a reasonable test to trigger the PPARAMOUT bug.
This is kind of a band-aid fix for #14591. A more pricipled
fix (which allows values to be stored in the return variable
earlier than the return point) will be harder.
Fixes#14591
Change-Id: I7df8ae103a982d1f218ed704c080d7b83cdcfdd9
Reviewed-on: https://go-review.googlesource.com/20457
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
I would like to add a
func (t *Type) Elem() *Type
method to package gc, but that would collide with the existing
func (t *Type) Elem() ssa.Type
method needed to make *gc.Type implement ssa.Type. Because the latter
is much less widely used right now than the former will be, this CL
renames it to ElemType.
Longer term, hopefully gc and ssa will share a common Type interface,
and ElemType can go away.
Change-Id: I270008515dc4c01ef531cf715637a924659c4735
Reviewed-on: https://go-review.googlesource.com/20546
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Make sure we do any just-before-return cleanup on all paths out of a
function, including when recovering. Each exit path should include
deferreturn (if there are any defers) and then the exit
code (e.g. copying heap-escaping return values back to the stack).
Introduce a Defer SSA block type which has two outgoing edges - one the
fallthrough edge (the defer was queued successfully) and one which
immediately returns (the defer had a successful recover() call and
normal execution should resume at the return point).
Fixes#14725
Change-Id: Iad035c9fd25ef8b7a74dafbd7461cf04833d981f
Reviewed-on: https://go-review.googlesource.com/20486
Reviewed-by: David Chase <drchase@google.com>
This CL was mostly produced by a one-off automated rewrite tool
looking for statements like "for X := T.Type; X != nil; X = X.Down"
and a few minor variations.
Passes toolstash -cmp.
Change-Id: Ib22705e37d078ef97841ee2e08f60bdbcabb94ad
Reviewed-on: https://go-review.googlesource.com/20520
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Accessing the n'th field of a struct is fairly common, and in
particular accessing the 0'th field of the receiver parameter list is
very common. Add helper methods for both of these tasks and update
code to make use of them.
Change-Id: I81f551fecdca306b3800636caebcd0dc106f2ed7
Reviewed-on: https://go-review.googlesource.com/20498
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Dave Cheney <dave@cheney.net>
Mix in several other minor cleanups, including adding some new methods
to Nodes: Index, Addr, SetIndex, SetNodes.
Passes toolstash -cmp.
Update #14473.
Change-Id: I8bd4ae3fde7c5e20ba66e7dd1654fbc70c3ddeb8
Reviewed-on: https://go-review.googlesource.com/20491
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This CL was automatically generated using a special-purpose AST
rewriting tool, followed by manual editing to put some comments back in
the right places and fix some bad line breaks.
The result is not perfect but it's a big step toward getting back to
sanity, and because it was automatically generated there is a decent
chance that it is correct.
Passes toolstash -cmp.
Update #14473.
Change-Id: I01c09078a6d78e2b008bc304d744b79469a38d3d
Reviewed-on: https://go-review.googlesource.com/20440
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
More idiomatic naming (in particular, matches the naming used for
go/types.Signature).
Also, convert more code to use these methods and/or IterFields.
(Still more to go; only made a quick pass for low hanging fruit.)
Passes toolstash -cmp.
Change-Id: I61831bfb1ec2cd50d4c7efc6062bca4e0dcf267b
Reviewed-on: https://go-review.googlesource.com/20451
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Eliminates type conversions in a bunch of Oconv(int(n.Op), ...) calls.
Notably, this identified a misuse of Oconv in amd64/gsubr.go to try to
print an assembly instruction op instead of a compiler node op.
Change-Id: I93b5aa49fe14a5eaf868b05426d3b8cd8ab52bc5
Reviewed-on: https://go-review.googlesource.com/20298
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
OffPtr allocates less and is easier to optimize.
With this change, the OffPtr collapsing opt
rule matches increase from 160k to 263k,
and the Load-after-Store opt rule matches
increase from 217 to 853.
Change-Id: I763426a3196900f22a367f7f6d8e8047b279653d
Reviewed-on: https://go-review.googlesource.com/20273
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Todd Neal <todd@tneal.org>
Reviewed-by: Keith Randall <khr@golang.org>
Instead make substArgTypes responsible for cloning the function
definition Node and the function signature Type tree.
Passes toolstash -cmp.
Change-Id: I9ec84c90a7ae83d164d3f578e84a91cf1490d8ab
Reviewed-on: https://go-review.googlesource.com/20239
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also fix some uses of nodeSeqIterator.Len, and fix the implementation in
nodesIterator.
Passes toolstash -cmp.
Update #14473.
Change-Id: I228871470234b7f1314ffd2aae8a4c0624c35f98
Reviewed-on: https://go-review.googlesource.com/20231
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
