576 Commits

Author SHA1 Message Date
Michael Hudson-Doyle
f4d38a8792 cmd/compile: de-dup the gclocals symbols in compiler too
These symbols are de-duplicated in the linker but the compiler generates quite
many duplicates too: 2425 of 13769 total symbols for runtime.a for example.
De-duplicating them in the compiler saves the linker a bit of work.

Fixes #14983

Change-Id: I5f18e5f9743563c795aad8f0a22d17a7ed147711
Reviewed-on: https://go-review.googlesource.com/22293
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-04-27 22:07:17 +00:00
Dave Cheney
d3c79d324a cmd/compile/internal/gc: remove oconv(op, 0) calls
Updates #15462

Automatic refactor with sed -e.

Replace all oconv(op, 0) to string conversion with the raw op value
which fmt's %v verb can print directly.

The remaining oconv(op, FmtSharp) will be replaced with op.GoString and
%#v in the next CL.

Change-Id: I5e2f7ee0bd35caa65c6dd6cb1a866b5e4519e641
Reviewed-on: https://go-review.googlesource.com/22499
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-27 21:39:39 +00:00
Keith Randall
a19e60b2c3 cmd/compile: don't use line numbers from ONAME and named OLITERALs
The line numbers of ONAMEs are the location of their
declaration, not their use.

The line numbers of named OLITERALs are also the location
of their declaration.

Ignore both of these.  Instead, we will inherit the line number from
the containing syntactic item.

Fixes #14742
Fixes #15430

Change-Id: Ie43b5b9f6321cbf8cead56e37ccc9364d0702f2f
Reviewed-on: https://go-review.googlesource.com/22479
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-27 15:03:38 +00:00
Dave Cheney
8f2e780e8a cmd/compile/internal: unexport gc.Oconv
Updates #15462

Semi automatic change with gofmt -r and hand fixups for callers outside
internal/gc.

All the uses of gc.Oconv outside cmd/compile/internal/gc were for the
Oconv(op, 0) form, which is already handled the Op.String method.

Replace the use of gc.Oconv(op, 0) with op itself, which will call
Op.String via the %v or %s verb. Unexport Oconv.

Change-Id: I84da2a2e4381b35f52efce427b2d6a3bccdf2526
Reviewed-on: https://go-review.googlesource.com/22496
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-27 06:18:46 +00:00
Alexandru Moșoi
8b92397bcd cmd/compile: introduce bool operations.
Introduce OrB, EqB, NeqB, AndB to handle bool operations.

Change-Id: I53e4d5125a8090d5eeb4576db619103f19fff58d
Reviewed-on: https://go-review.googlesource.com/22412
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-25 20:43:04 +00:00
Josh Bleecher Snyder
f12bd8a5a8 cmd/compile: encapsulate OSLICE* representation
As a nice side-effect, this allows us to
unify several code paths.

The terminology (low, high, max, simple slice expr,
full slice expr) is taken from the spec and
the examples in the spec.

This is a trial run. The plan, probably for Go 1.8,
is to change slice expressions to use Node.List
instead of OKEY, and to do some similar
tree structure changes for other ops.

Passes toolstash -cmp. No performance change.
all.bash passes with GO_GCFLAGS=-newexport.

Updates #15350

Change-Id: Ic1efdc36e79cdb95ae1636e9817a3ac8f83ab1ac
Reviewed-on: https://go-review.googlesource.com/22425
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-25 18:39:33 +00:00
Josh Bleecher Snyder
fca0f331c8 cmd/compile: use gc.Etype's String method
Passes toolstash -cmp.

Change-Id: I42c962cc5a3ffec2969f223cf238c2fdadbf5857
Reviewed-on: https://go-review.googlesource.com/22381
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-24 21:36:23 +00:00
Josh Bleecher Snyder
f027241445 cmd/compile: give gc.Op a String method, use it
Passes toolstash -cmp.

Change-Id: I915e76374fd64aa2597e6fa47e4fa95ca00ca643
Reviewed-on: https://go-review.googlesource.com/22380
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-04-24 21:36:13 +00:00
Matthew Dempsky
97360096e5 cmd/compile: replace Ctype switches with type switches
Instead of switching on Ctype (which internally uses a type switch)
and then scattering lots of type assertions throughout the CTFOO case
clauses, just use type switches directly on the underlying constant
value.

Passes toolstash/buildall.

Change-Id: I9bc172cc67e5f391cddc15539907883b4010689e
Reviewed-on: https://go-review.googlesource.com/22384
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-22 21:34:25 +00:00
Keith Randall
3c1a4c1902 cmd/compile: don't nilcheck newobject and return values from mapaccess{1,2}
They are guaranteed to be non-nil, no point in inserting
nil checks for them.

Fixes #15390

Change-Id: I3b9a0f2319affc2139dcc446d0a56c6785ae5a86
Reviewed-on: https://go-review.googlesource.com/22291
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-22 16:18:42 +00:00
Matthew Dempsky
40f1d0ca9f cmd/compile: split TSLICE into separate Type kind
Instead of using TARRAY for both arrays and slices, create a new
TSLICE kind to handle slices.

Also, get rid of the "DDDArray" distinction. While kinda ugly, it
seems likely we'll need to defer evaluating the constant bounds
expressions for golang.org/issue/13890.

Passes toolstash/buildall.

Change-Id: I8e45d4900e7df3a04cce59428ec8b38035d3cc3a
Reviewed-on: https://go-review.googlesource.com/22329
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 21:03:22 +00:00
Cherry Zhang
508a424eed cmd/compile/internal/gc: fix return value offset for SSA backend on ARM
Progress on SSA backend for ARM. Still not complete. It compiles a
Fibonacci function, but the caller picked the return value from an
incorrect offset. This CL adjusts it to match the stack frame layout
for architectures with link register.

Updates #15365.

Change-Id: I01e03c3e95f5503a185e8ac2b6d9caf4faf3d014
Reviewed-on: https://go-review.googlesource.com/22186
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-21 16:53:53 +00:00
Keith Randall
bfe0cbdc50 cmd/compile,runtime: pass elem type to {make,grow}slice
No point in passing the slice type to these functions.
All they need is the element type.  One less indirection,
maybe a few less []T type descriptors in the binary.

Change-Id: Ib0b83b5f14ca21d995ecc199ce8ac00c4eb375e6
Reviewed-on: https://go-review.googlesource.com/22275
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2016-04-20 00:31:16 +00:00
Josh Bleecher Snyder
03e216f30d cmd/compile: re-enable in-place append optimization
CL 21891 was too clever in its attempts to avoid spills.
Storing newlen too early caused uses of append in the runtime
itself to receive an inconsistent view of a slice,
leading to corruption.

This CL makes the generate code much more similar to
the old backend. It spills more than before,
but those spills have been contained to the grow path.
It recalculates newlen unnecessarily on the fast path,
but that's measurably cheaper than spilling it.

CL 21891 caused runtime failures in 6 of 2000 runs
of net/http and crypto/x509 in my test setup.
This CL has gone 6000 runs without a failure.


Benchmarks going from master to this CL:

name                         old time/op  new time/op  delta
AppendInPlace/NoGrow/Byte-8   439ns ± 2%   436ns ± 2%  -0.72%  (p=0.001 n=28+27)
AppendInPlace/NoGrow/1Ptr-8   901ns ± 0%   856ns ± 0%  -4.95%  (p=0.000 n=26+29)
AppendInPlace/NoGrow/2Ptr-8  2.15µs ± 1%  1.95µs ± 0%  -9.07%  (p=0.000 n=28+30)
AppendInPlace/NoGrow/3Ptr-8  2.66µs ± 0%  2.45µs ± 0%  -7.93%  (p=0.000 n=29+26)
AppendInPlace/NoGrow/4Ptr-8  3.24µs ± 1%  3.02µs ± 1%  -6.75%  (p=0.000 n=28+30)
AppendInPlace/Grow/Byte-8     269ns ± 1%   271ns ± 1%  +0.84%  (p=0.000 n=30+29)
AppendInPlace/Grow/1Ptr-8     275ns ± 1%   280ns ± 1%  +1.75%  (p=0.000 n=30+30)
AppendInPlace/Grow/2Ptr-8     384ns ± 0%   391ns ± 0%  +1.94%  (p=0.000 n=27+30)
AppendInPlace/Grow/3Ptr-8     455ns ± 0%   462ns ± 0%  +1.43%  (p=0.000 n=29+29)
AppendInPlace/Grow/4Ptr-8     478ns ± 0%   479ns ± 0%  +0.23%  (p=0.000 n=30+27)


However, for the large no-grow cases, there is still more work to be done.
Going from this CL to the non-SSA backend:

name                         old time/op  new time/op  delta
AppendInPlace/NoGrow/Byte-8   436ns ± 2%   436ns ± 2%     ~     (p=0.967 n=27+29)
AppendInPlace/NoGrow/1Ptr-8   856ns ± 0%   884ns ± 0%   +3.28%  (p=0.000 n=29+26)
AppendInPlace/NoGrow/2Ptr-8  1.95µs ± 0%  1.56µs ± 0%  -20.28%  (p=0.000 n=30+29)
AppendInPlace/NoGrow/3Ptr-8  2.45µs ± 0%  1.89µs ± 0%  -22.88%  (p=0.000 n=26+28)
AppendInPlace/NoGrow/4Ptr-8  3.02µs ± 1%  2.56µs ± 1%  -15.35%  (p=0.000 n=30+28)
AppendInPlace/Grow/Byte-8     271ns ± 1%   283ns ± 1%   +4.56%  (p=0.000 n=29+29)
AppendInPlace/Grow/1Ptr-8     280ns ± 1%   288ns ± 1%   +2.99%  (p=0.000 n=30+30)
AppendInPlace/Grow/2Ptr-8     391ns ± 0%   409ns ± 0%   +4.66%  (p=0.000 n=30+29)
AppendInPlace/Grow/3Ptr-8     462ns ± 0%   481ns ± 0%   +4.13%  (p=0.000 n=29+30)
AppendInPlace/Grow/4Ptr-8     479ns ± 0%   502ns ± 0%   +4.81%  (p=0.000 n=27+26)


New generated code:

var x []byte

func a() {
	x = append(x, 1)
}


"".a t=1 size=208 args=0x0 locals=0x48
	0x0000 00000 (a.go:5)	TEXT	"".a(SB), $72-0
	0x0000 00000 (a.go:5)	MOVQ	(TLS), CX
	0x0009 00009 (a.go:5)	CMPQ	SP, 16(CX)
	0x000d 00013 (a.go:5)	JLS	190
	0x0013 00019 (a.go:5)	SUBQ	$72, SP
	0x0017 00023 (a.go:5)	FUNCDATA	$0, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (a.go:5)	FUNCDATA	$1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (a.go:6)	MOVQ	"".x+16(SB), CX
	0x001e 00030 (a.go:6)	MOVQ	"".x+8(SB), DX
	0x0025 00037 (a.go:6)	MOVQ	"".x(SB), BX
	0x002c 00044 (a.go:6)	LEAQ	1(DX), BP
	0x0030 00048 (a.go:6)	CMPQ	BP, CX
	0x0033 00051 (a.go:6)	JGT	$0, 73
	0x0035 00053 (a.go:6)	LEAQ	1(DX), AX
	0x0039 00057 (a.go:6)	MOVQ	AX, "".x+8(SB)
	0x0040 00064 (a.go:6)	MOVB	$1, (BX)(DX*1)
	0x0044 00068 (a.go:7)	ADDQ	$72, SP
	0x0048 00072 (a.go:7)	RET
	0x0049 00073 (a.go:6)	LEAQ	type.[]uint8(SB), AX
	0x0050 00080 (a.go:6)	MOVQ	AX, (SP)
	0x0054 00084 (a.go:6)	MOVQ	BX, 8(SP)
	0x0059 00089 (a.go:6)	MOVQ	DX, 16(SP)
	0x005e 00094 (a.go:6)	MOVQ	CX, 24(SP)
	0x0063 00099 (a.go:6)	MOVQ	BP, 32(SP)
	0x0068 00104 (a.go:6)	PCDATA	$0, $0
	0x0068 00104 (a.go:6)	CALL	runtime.growslice(SB)
	0x006d 00109 (a.go:6)	MOVQ	40(SP), CX
	0x0072 00114 (a.go:6)	MOVQ	48(SP), DX
	0x0077 00119 (a.go:6)	MOVQ	DX, "".autotmp_0+64(SP)
	0x007c 00124 (a.go:6)	MOVQ	56(SP), BX
	0x0081 00129 (a.go:6)	MOVQ	BX, "".x+16(SB)
	0x0088 00136 (a.go:6)	MOVL	runtime.writeBarrier(SB), AX
	0x008e 00142 (a.go:6)	TESTB	AL, AL
	0x0090 00144 (a.go:6)	JNE	$0, 162
	0x0092 00146 (a.go:6)	MOVQ	CX, "".x(SB)
	0x0099 00153 (a.go:6)	MOVQ	"".x(SB), BX
	0x00a0 00160 (a.go:6)	JMP	53
	0x00a2 00162 (a.go:6)	LEAQ	"".x(SB), BX
	0x00a9 00169 (a.go:6)	MOVQ	BX, (SP)
	0x00ad 00173 (a.go:6)	MOVQ	CX, 8(SP)
	0x00b2 00178 (a.go:6)	PCDATA	$0, $0
	0x00b2 00178 (a.go:6)	CALL	runtime.writebarrierptr(SB)
	0x00b7 00183 (a.go:6)	MOVQ	"".autotmp_0+64(SP), DX
	0x00bc 00188 (a.go:6)	JMP	153
	0x00be 00190 (a.go:6)	NOP
	0x00be 00190 (a.go:5)	CALL	runtime.morestack_noctxt(SB)
	0x00c3 00195 (a.go:5)	JMP	0


Fixes #14969 again

Change-Id: Ia50463b1f506011aad0718a4fef1d4738e43c32d
Reviewed-on: https://go-review.googlesource.com/22197
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-19 18:48:05 +00:00
Matthew Dempsky
980ab12ade cmd/compile/internal/gc: change flags to bool where possible
Some of the Debug[x] flags are actually boolean too, but not all, so
they need to be handled separately.

While here, change some obj.Flagstr and obj.Flagint64 calls to
directly use flag.StringVar and flag.Int64Var instead.

Change-Id: Iccedf6fed4328240ee2257f57fe6d66688f237c4
Reviewed-on: https://go-review.googlesource.com/22052
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
2016-04-14 02:10:35 +00:00
Josh Bleecher Snyder
811ebb6ac9 cmd/compile: temporarily disable inplace append special case
Fixes #15246
Re-opens #14969

Change-Id: Ic0b41c5aa42bbb229a0d62b7f3e5888c6b29293d
Reviewed-on: https://go-review.googlesource.com/21891
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-12 17:44:43 +00:00
Josh Bleecher Snyder
a4650a2111 cmd/compile: avoid write barrier in append fast path
When we are writing the result of an append back
to the same slice, we don’t need a write barrier
on the fast path.

This re-implements an optimization that was present
in the old backend.

Updates #14921
Fixes #14969

Sample code:

var x []byte

func p() {
	x = append(x, 1, 2, 3)
}

Before:

"".p t=1 size=224 args=0x0 locals=0x48
	0x0000 00000 (append.go:21)	TEXT	"".p(SB), $72-0
	0x0000 00000 (append.go:21)	MOVQ	(TLS), CX
	0x0009 00009 (append.go:21)	CMPQ	SP, 16(CX)
	0x000d 00013 (append.go:21)	JLS	199
	0x0013 00019 (append.go:21)	SUBQ	$72, SP
	0x0017 00023 (append.go:21)	FUNCDATA	$0, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (append.go:21)	FUNCDATA	$1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (append.go:19)	MOVQ	"".x+16(SB), CX
	0x001e 00030 (append.go:19)	MOVQ	"".x(SB), DX
	0x0025 00037 (append.go:19)	MOVQ	"".x+8(SB), BX
	0x002c 00044 (append.go:19)	MOVQ	BX, "".autotmp_0+64(SP)
	0x0031 00049 (append.go:22)	LEAQ	3(BX), BP
	0x0035 00053 (append.go:22)	CMPQ	BP, CX
	0x0038 00056 (append.go:22)	JGT	$0, 131
	0x003a 00058 (append.go:22)	MOVB	$1, (DX)(BX*1)
	0x003e 00062 (append.go:22)	MOVB	$2, 1(DX)(BX*1)
	0x0043 00067 (append.go:22)	MOVB	$3, 2(DX)(BX*1)
	0x0048 00072 (append.go:22)	MOVQ	BP, "".x+8(SB)
	0x004f 00079 (append.go:22)	MOVQ	CX, "".x+16(SB)
	0x0056 00086 (append.go:22)	MOVL	runtime.writeBarrier(SB), AX
	0x005c 00092 (append.go:22)	TESTB	AL, AL
	0x005e 00094 (append.go:22)	JNE	$0, 108
	0x0060 00096 (append.go:22)	MOVQ	DX, "".x(SB)
	0x0067 00103 (append.go:23)	ADDQ	$72, SP
	0x006b 00107 (append.go:23)	RET
	0x006c 00108 (append.go:22)	LEAQ	"".x(SB), CX
	0x0073 00115 (append.go:22)	MOVQ	CX, (SP)
	0x0077 00119 (append.go:22)	MOVQ	DX, 8(SP)
	0x007c 00124 (append.go:22)	PCDATA	$0, $0
	0x007c 00124 (append.go:22)	CALL	runtime.writebarrierptr(SB)
	0x0081 00129 (append.go:23)	JMP	103
	0x0083 00131 (append.go:22)	LEAQ	type.[]uint8(SB), AX
	0x008a 00138 (append.go:22)	MOVQ	AX, (SP)
	0x008e 00142 (append.go:22)	MOVQ	DX, 8(SP)
	0x0093 00147 (append.go:22)	MOVQ	BX, 16(SP)
	0x0098 00152 (append.go:22)	MOVQ	CX, 24(SP)
	0x009d 00157 (append.go:22)	MOVQ	BP, 32(SP)
	0x00a2 00162 (append.go:22)	PCDATA	$0, $0
	0x00a2 00162 (append.go:22)	CALL	runtime.growslice(SB)
	0x00a7 00167 (append.go:22)	MOVQ	40(SP), DX
	0x00ac 00172 (append.go:22)	MOVQ	48(SP), AX
	0x00b1 00177 (append.go:22)	MOVQ	56(SP), CX
	0x00b6 00182 (append.go:22)	ADDQ	$3, AX
	0x00ba 00186 (append.go:19)	MOVQ	"".autotmp_0+64(SP), BX
	0x00bf 00191 (append.go:22)	MOVQ	AX, BP
	0x00c2 00194 (append.go:22)	JMP	58
	0x00c7 00199 (append.go:22)	NOP
	0x00c7 00199 (append.go:21)	CALL	runtime.morestack_noctxt(SB)
	0x00cc 00204 (append.go:21)	JMP	0

After:

"".p t=1 size=208 args=0x0 locals=0x48
	0x0000 00000 (append.go:21)	TEXT	"".p(SB), $72-0
	0x0000 00000 (append.go:21)	MOVQ	(TLS), CX
	0x0009 00009 (append.go:21)	CMPQ	SP, 16(CX)
	0x000d 00013 (append.go:21)	JLS	191
	0x0013 00019 (append.go:21)	SUBQ	$72, SP
	0x0017 00023 (append.go:21)	FUNCDATA	$0, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (append.go:21)	FUNCDATA	$1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (append.go:19)	MOVQ	"".x+16(SB), CX
	0x001e 00030 (append.go:19)	MOVQ	"".x+8(SB), DX
	0x0025 00037 (append.go:19)	MOVQ	DX, "".autotmp_0+64(SP)
	0x002a 00042 (append.go:19)	MOVQ	"".x(SB), BX
	0x0031 00049 (append.go:22)	LEAQ	3(DX), BP
	0x0035 00053 (append.go:22)	MOVQ	BP, "".x+8(SB)
	0x003c 00060 (append.go:22)	CMPQ	BP, CX
	0x003f 00063 (append.go:22)	JGT	$0, 84
	0x0041 00065 (append.go:22)	MOVB	$1, (BX)(DX*1)
	0x0045 00069 (append.go:22)	MOVB	$2, 1(BX)(DX*1)
	0x004a 00074 (append.go:22)	MOVB	$3, 2(BX)(DX*1)
	0x004f 00079 (append.go:23)	ADDQ	$72, SP
	0x0053 00083 (append.go:23)	RET
	0x0054 00084 (append.go:22)	LEAQ	type.[]uint8(SB), AX
	0x005b 00091 (append.go:22)	MOVQ	AX, (SP)
	0x005f 00095 (append.go:22)	MOVQ	BX, 8(SP)
	0x0064 00100 (append.go:22)	MOVQ	DX, 16(SP)
	0x0069 00105 (append.go:22)	MOVQ	CX, 24(SP)
	0x006e 00110 (append.go:22)	MOVQ	BP, 32(SP)
	0x0073 00115 (append.go:22)	PCDATA	$0, $0
	0x0073 00115 (append.go:22)	CALL	runtime.growslice(SB)
	0x0078 00120 (append.go:22)	MOVQ	40(SP), CX
	0x007d 00125 (append.go:22)	MOVQ	56(SP), AX
	0x0082 00130 (append.go:22)	MOVQ	AX, "".x+16(SB)
	0x0089 00137 (append.go:22)	MOVL	runtime.writeBarrier(SB), AX
	0x008f 00143 (append.go:22)	TESTB	AL, AL
	0x0091 00145 (append.go:22)	JNE	$0, 168
	0x0093 00147 (append.go:22)	MOVQ	CX, "".x(SB)
	0x009a 00154 (append.go:22)	MOVQ	"".x(SB), BX
	0x00a1 00161 (append.go:19)	MOVQ	"".autotmp_0+64(SP), DX
	0x00a6 00166 (append.go:22)	JMP	65
	0x00a8 00168 (append.go:22)	LEAQ	"".x(SB), DX
	0x00af 00175 (append.go:22)	MOVQ	DX, (SP)
	0x00b3 00179 (append.go:22)	MOVQ	CX, 8(SP)
	0x00b8 00184 (append.go:22)	PCDATA	$0, $0
	0x00b8 00184 (append.go:22)	CALL	runtime.writebarrierptr(SB)
	0x00bd 00189 (append.go:22)	JMP	154
	0x00bf 00191 (append.go:22)	NOP
	0x00bf 00191 (append.go:21)	CALL	runtime.morestack_noctxt(SB)
	0x00c4 00196 (append.go:21)	JMP	0

Change-Id: I77a41ad3a22557a4bb4654de7d6d24a029efe34a
Reviewed-on: https://go-review.googlesource.com/21813
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-11 21:38:18 +00:00
Keith Randall
b04e145248 cmd/compile: fix naming of decomposed structs
When a struct is SSAable, we will name its component parts
by their field names.  For example,
type T struct {
     a, b, c int
}
If we ever need to spill a variable x of type T, we will
spill its individual components to variables named x.a, x.b,
and x.c.

Change-Id: I857286ff1f2597f2c4bbd7b4c0b936386fb37131
Reviewed-on: https://go-review.googlesource.com/21389
Reviewed-by: David Chase <drchase@google.com>
2016-04-11 17:11:23 +00:00
Josh Bleecher Snyder
6b33b0e98e cmd/compile: avoid a spill in append fast path
Instead of spilling newlen, recalculate it.
This removes a spill from the fast path,
at the cost of a cheap recalculation
on the (rare) growth path.
This uses 8 bytes less of stack space.
It generates two more bytes of code,
but that is due to suboptimal register allocation;
see far below.

Runtime append microbenchmarks are all over the map,
presumably due to incidental code movement.

Sample code:

func s(b []byte) []byte {
	b = append(b, 1, 2, 3)
	return b
}

Before:

"".s t=1 size=160 args=0x30 locals=0x48
	0x0000 00000 (append.go:8)	TEXT	"".s(SB), $72-48
	0x0000 00000 (append.go:8)	MOVQ	(TLS), CX
	0x0009 00009 (append.go:8)	CMPQ	SP, 16(CX)
	0x000d 00013 (append.go:8)	JLS	149
	0x0013 00019 (append.go:8)	SUBQ	$72, SP
	0x0017 00023 (append.go:8)	FUNCDATA	$0, gclocals·6432f8c6a0d23fa7bee6c5d96f21a92a(SB)
	0x0017 00023 (append.go:8)	FUNCDATA	$1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (append.go:9)	MOVQ	"".b+88(FP), CX
	0x001c 00028 (append.go:9)	LEAQ	3(CX), DX
	0x0020 00032 (append.go:9)	MOVQ	DX, "".autotmp_0+64(SP)
	0x0025 00037 (append.go:9)	MOVQ	"".b+96(FP), BX
	0x002a 00042 (append.go:9)	CMPQ	DX, BX
	0x002d 00045 (append.go:9)	JGT	$0, 86
	0x002f 00047 (append.go:8)	MOVQ	"".b+80(FP), AX
	0x0034 00052 (append.go:9)	MOVB	$1, (AX)(CX*1)
	0x0038 00056 (append.go:9)	MOVB	$2, 1(AX)(CX*1)
	0x003d 00061 (append.go:9)	MOVB	$3, 2(AX)(CX*1)
	0x0042 00066 (append.go:10)	MOVQ	AX, "".~r1+104(FP)
	0x0047 00071 (append.go:10)	MOVQ	DX, "".~r1+112(FP)
	0x004c 00076 (append.go:10)	MOVQ	BX, "".~r1+120(FP)
	0x0051 00081 (append.go:10)	ADDQ	$72, SP
	0x0055 00085 (append.go:10)	RET
	0x0056 00086 (append.go:9)	LEAQ	type.[]uint8(SB), AX
	0x005d 00093 (append.go:9)	MOVQ	AX, (SP)
	0x0061 00097 (append.go:9)	MOVQ	"".b+80(FP), BP
	0x0066 00102 (append.go:9)	MOVQ	BP, 8(SP)
	0x006b 00107 (append.go:9)	MOVQ	CX, 16(SP)
	0x0070 00112 (append.go:9)	MOVQ	BX, 24(SP)
	0x0075 00117 (append.go:9)	MOVQ	DX, 32(SP)
	0x007a 00122 (append.go:9)	PCDATA	$0, $0
	0x007a 00122 (append.go:9)	CALL	runtime.growslice(SB)
	0x007f 00127 (append.go:9)	MOVQ	40(SP), AX
	0x0084 00132 (append.go:9)	MOVQ	56(SP), BX
	0x0089 00137 (append.go:8)	MOVQ	"".b+88(FP), CX
	0x008e 00142 (append.go:9)	MOVQ	"".autotmp_0+64(SP), DX
	0x0093 00147 (append.go:9)	JMP	52
	0x0095 00149 (append.go:9)	NOP
	0x0095 00149 (append.go:8)	CALL	runtime.morestack_noctxt(SB)
	0x009a 00154 (append.go:8)	JMP	0

After:

"".s t=1 size=176 args=0x30 locals=0x40
	0x0000 00000 (append.go:8)	TEXT	"".s(SB), $64-48
	0x0000 00000 (append.go:8)	MOVQ	(TLS), CX
	0x0009 00009 (append.go:8)	CMPQ	SP, 16(CX)
	0x000d 00013 (append.go:8)	JLS	151
	0x0013 00019 (append.go:8)	SUBQ	$64, SP
	0x0017 00023 (append.go:8)	FUNCDATA	$0, gclocals·6432f8c6a0d23fa7bee6c5d96f21a92a(SB)
	0x0017 00023 (append.go:8)	FUNCDATA	$1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	0x0017 00023 (append.go:9)	MOVQ	"".b+80(FP), CX
	0x001c 00028 (append.go:9)	LEAQ	3(CX), DX
	0x0020 00032 (append.go:9)	MOVQ	"".b+88(FP), BX
	0x0025 00037 (append.go:9)	CMPQ	DX, BX
	0x0028 00040 (append.go:9)	JGT	$0, 81
	0x002a 00042 (append.go:8)	MOVQ	"".b+72(FP), AX
	0x002f 00047 (append.go:9)	MOVB	$1, (AX)(CX*1)
	0x0033 00051 (append.go:9)	MOVB	$2, 1(AX)(CX*1)
	0x0038 00056 (append.go:9)	MOVB	$3, 2(AX)(CX*1)
	0x003d 00061 (append.go:10)	MOVQ	AX, "".~r1+96(FP)
	0x0042 00066 (append.go:10)	MOVQ	DX, "".~r1+104(FP)
	0x0047 00071 (append.go:10)	MOVQ	BX, "".~r1+112(FP)
	0x004c 00076 (append.go:10)	ADDQ	$64, SP
	0x0050 00080 (append.go:10)	RET
	0x0051 00081 (append.go:9)	LEAQ	type.[]uint8(SB), AX
	0x0058 00088 (append.go:9)	MOVQ	AX, (SP)
	0x005c 00092 (append.go:9)	MOVQ	"".b+72(FP), BP
	0x0061 00097 (append.go:9)	MOVQ	BP, 8(SP)
	0x0066 00102 (append.go:9)	MOVQ	CX, 16(SP)
	0x006b 00107 (append.go:9)	MOVQ	BX, 24(SP)
	0x0070 00112 (append.go:9)	MOVQ	DX, 32(SP)
	0x0075 00117 (append.go:9)	PCDATA	$0, $0
	0x0075 00117 (append.go:9)	CALL	runtime.growslice(SB)
	0x007a 00122 (append.go:9)	MOVQ	40(SP), AX
	0x007f 00127 (append.go:9)	MOVQ	48(SP), CX
	0x0084 00132 (append.go:9)	MOVQ	56(SP), BX
	0x0089 00137 (append.go:9)	ADDQ	$3, CX
	0x008d 00141 (append.go:9)	MOVQ	CX, DX
	0x0090 00144 (append.go:8)	MOVQ	"".b+80(FP), CX
	0x0095 00149 (append.go:9)	JMP	47
	0x0097 00151 (append.go:9)	NOP
	0x0097 00151 (append.go:8)	CALL	runtime.morestack_noctxt(SB)
	0x009c 00156 (append.go:8)	JMP	0

Observe that in the following sequence,
we should use DX directly instead of using
CX as a temporary register, which would make
the new code a strict improvement on the old:

	0x007f 00127 (append.go:9)	MOVQ	48(SP), CX
	0x0084 00132 (append.go:9)	MOVQ	56(SP), BX
	0x0089 00137 (append.go:9)	ADDQ	$3, CX
	0x008d 00141 (append.go:9)	MOVQ	CX, DX
	0x0090 00144 (append.go:8)	MOVQ	"".b+80(FP), CX

Change-Id: I4ee50b18fa53865901d2d7f86c2cbb54c6fa6924
Reviewed-on: https://go-review.googlesource.com/21812
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-04-10 20:02:04 +00:00
David Chase
c3b3e7b4ef cmd/compile: insert instrumentation more carefully in racewalk
Be more careful about inserting instrumentation in racewalk.
If the node being instrumented is an OAS, and it has a non-
empty Ninit, then append instrumentation to the Ninit list
rather than letting it be inserted before the OAS (and the
compilation of its init list).  This deals with the case that
the Ninit list defines a variable used in the RHS of the OAS.

Fixes #15091.

Change-Id: Iac91696d9104d07f0bf1bd3499bbf56b2e1ef073
Reviewed-on: https://go-review.googlesource.com/21771
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: David Chase <drchase@google.com>
2016-04-08 21:06:39 +00:00
Matthew Dempsky
c6e11fe037 cmd: add new common architecture representation
Information about CPU architectures (e.g., name, family, byte
ordering, pointer and register size) is currently redundantly
scattered around the source tree. Instead consolidate the basic
information into a single new package cmd/internal/sys.

Also, introduce new sys.I386, sys.AMD64, etc. names for the constants
'8', '6', etc. and replace most uses of the latter. The notable
exceptions are a couple of error messages that still refer to the old
char-based toolchain names and function reltype in cmd/link.

Passes toolstash/buildall.

Change-Id: I8a6f0cbd49577ec1672a98addebc45f767e36461
Reviewed-on: https://go-review.googlesource.com/21623
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-07 01:23:25 +00:00
Josh Bleecher Snyder
f38f43d029 cmd/compile: shrink gc.Type in half
Many of Type's fields are etype-specific.
This CL organizes them into their own auxiliary types,
duplicating a few fields as necessary,
and adds an Extra field to hold them.
It also sorts the remaining fields for better struct packing.
It also improves documentation for most fields.

This reduces the size of Type at the cost of some extra allocations.
There's no CPU impact; memory impact below.
It also makes the natural structure of Type clearer.

Passes toolstash -cmp on all architectures.

Ideas for future work in this vein:

(1) Width and Align probably only need to be
stored for Struct and Array types.
The refactoring to accomplish this would hopefully
also eliminate TFUNCARGS and TCHANARGS entirely.

(2) Maplineno is sparsely used and could probably better be
stored in a separate map[*Type]int32, with mapqueue updated
to store both a Node and a line number.

(3) The Printed field may be removable once the old (non-binary)
importer/exported has been removed.

(4) StructType's fields field could be changed from *[]*Field to []*Field,
which would remove a common allocation.

(5) I believe that Type.Nod can be moved to ForwardType. Separate CL.

name       old alloc/op     new alloc/op     delta
Template       57.9MB ± 0%      55.9MB ± 0%  -3.43%        (p=0.000 n=50+50)
Unicode        38.3MB ± 0%      37.8MB ± 0%  -1.39%        (p=0.000 n=50+50)
GoTypes         185MB ± 0%       180MB ± 0%  -2.56%        (p=0.000 n=50+50)
Compiler        824MB ± 0%       806MB ± 0%  -2.19%        (p=0.000 n=50+50)

name       old allocs/op    new allocs/op    delta
Template         486k ± 0%        497k ± 0%  +2.25%        (p=0.000 n=50+50)
Unicode          377k ± 0%        379k ± 0%  +0.55%        (p=0.000 n=50+50)
GoTypes         1.39M ± 0%       1.42M ± 0%  +1.63%        (p=0.000 n=50+50)
Compiler        5.52M ± 0%       5.57M ± 0%  +0.84%        (p=0.000 n=47+50)

Change-Id: I828488eeb74902b013d5ae4cf844de0b6c0dfc87
Reviewed-on: https://go-review.googlesource.com/21611
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-06 19:10:10 +00:00
Keith Randall
309144b7f1 cmd/compile: fix x=x assignments
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>
2016-04-06 15:04:32 +00:00
Josh Bleecher Snyder
5e1b7bdecf cmd/compile: pull ssa OAPPEND expression handing into its own function
Pure code movement.

Change-Id: Ia07ee0b0041c931b08adf090f262a6f74a6fdb01
Reviewed-on: https://go-review.googlesource.com/21546
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 20:31:38 +00:00
Eric Engestrom
7a8caf7d43 all: fix spelling mistakes
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>
2016-04-03 17:03:15 +00:00
Josh Bleecher Snyder
5cab01698a cmd/compile: rename Node.Int to Node.Int64
gorename -from '"cmd/compile/internal/gc".Node.Int' -to 'Int64'

Change-Id: I2fe3bf9a26ae6b0600d990d0c981e4b8b53020a4
Reviewed-on: https://go-review.googlesource.com/21426
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-01 22:00:47 +00:00
Matthew Dempsky
00e5a68c3e cmd/compile: more Isfoo Type cleanups
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>
2016-04-01 21:08:39 +00:00
Josh Bleecher Snyder
e504055e78 cmd/compile: use Node.Int more
Generated by eg.

Passes toolstash -cmp.

Change-Id: I7516c211ca9aacf824f74894671dc62d31763b01
Reviewed-on: https://go-review.googlesource.com/21422
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-01 20:03:39 +00:00
Josh Bleecher Snyder
3a0783c504 cmd/compile: use NumElem instead of Type.Bound
This eliminates all direct reads of Type.Bound
outside type.go.

Change-Id: I0a9a72539f8f4c0de7f5e05e1821936bf7db5eb7
Reviewed-on: https://go-review.googlesource.com/21421
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-01 20:03:19 +00:00
Keith Randall
4a7aba775d cmd/compile: better job of naming compound types
Compound AUTO types weren't named previously.  That was because live
variable analysis (plive.go) doesn't handle spilling to compound types.
It can't handle them because there is no valid place to put VARDEFs when
regalloc is spilling compound types.

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

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

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

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

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

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

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

Change-Id: I8ef2b5ab91e43a0d2136bfc231c05d100ec0b801
Reviewed-on: https://go-review.googlesource.com/21233
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-03-31 22:18:26 +00:00
Matthew Dempsky
3efefd9395 cmd/compile: use t.IsFoo() instead of t.Etype == TFOO
CL produced mechanically using gofmt -w -r.

Passes toolstash -cmp.

Change-Id: Ib2e8710ebd844e2149125b41c335b71a02fcab53
Reviewed-on: https://go-review.googlesource.com/21338
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-30 22:31:07 +00:00
Matthew Dempsky
1624a9c9e7 cmd/compile: get rid of redundant Type helper functions
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>
2016-03-30 21:58:18 +00:00
Josh Bleecher Snyder
8640b51df8 cmd/compile: add Type.Elem
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>
2016-03-30 21:21:55 +00:00
Matthew Dempsky
788f11263a cmd/compile: rename Type.IsPtr to Type.IsPtrShaped
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>
2016-03-30 19:11:16 +00:00
Josh Bleecher Snyder
361b334cbd cmd/compile: encapsulate Type.Argwid
Passes toolstash -cmp.

Change-Id: I72fb271052e449a83adfa9bd3b923d40781d6341
Reviewed-on: https://go-review.googlesource.com/21243
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-29 00:08:56 +00:00
Matthew Dempsky
62dddd4770 cmd/compile: rename Field's Width field to Offset
gorename -from '"cmd/compile/internal/gc".Field.Width' -to Offset

Passes toolstash -cmp.

Change-Id: I310538a1f60bbab470a6375e813e9d5eb52c5bbf
Reviewed-on: https://go-review.googlesource.com/21230
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-03-28 20:13:51 +00:00
David Chase
8eec2bbfbc cmd/compile: added some intrinsics to SSA back end
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>
2016-03-28 16:29:59 +00:00
Keith Randall
4c9a470d46 cmd/compile: start on ARM port
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>
2016-03-23 17:46:05 +00:00
Keith Randall
69a7c152a7 cmd/compile: change the way SSA does slice zero-cap detection
There is a special case for slicing s[i:j] when the resulting
slice has zero capacity, to prevent pointing to the next object
in memory.

Change this special case code from:
  rptr := rcap == 0 ? ptr : ptr+i*elemsize
to
  rptr := ptr + (rcap == 0 ? 0 : i) * elemsize

This change leads to slightly smaller generated code, replacing
a load with a register zero.

old:
	0x002e 00046 (slice.go:8)	CMPQ	BX, $0
	0x0032 00050 (slice.go:8)	JEQ	$0, 78
	0x0034 00052 (slice.go:8)	MOVQ	"".a+8(FP), BP
	0x0039 00057 (slice.go:8)	LEAQ	(BP)(CX*8), AX
	0x003e 00062 ... rest of function ...

	0x004e 00078 (slice.go:7)	MOVQ	"".a+8(FP), AX
	0x0053 00083 (slice.go:8)	JMP	62

new:
	0x002e 00046 (slice.go:8)	CMPQ	BX, $0
	0x0032 00050 (slice.go:8)	JEQ	$0, 78
	0x0034 00052 (slice.go:8)	MOVQ	"".a+8(FP), BP
	0x0039 00057 (slice.go:8)	LEAQ	(BP)(CX*8), AX
	0x003e 00062 ... rest of function...

	0x004e 00078 (slice.go:8)	MOVQ	$0, CX
	0x0050 00080 (slice.go:8)	JMP	52

Change-Id: I2a396616b0d7b090c226a47c92a7ba14b128401f
Reviewed-on: https://go-review.googlesource.com/20994
Reviewed-by: David Chase <drchase@google.com>
2016-03-22 02:21:20 +00:00
Keith Randall
d4663e1353 cmd/compile: don't write back unchanged slice results
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>
2016-03-21 23:40:18 +00:00
Matthew Dempsky
d3253876f2 cmd/compile: change Mp{int,flt} functions into methods
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>
2016-03-21 17:25:50 +00:00
Ian Lance Taylor
5f525ca60d cmd/compile: change ODOT and friends to use Sym, not Right
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>
2016-03-19 00:45:09 +00:00
Matthew Dempsky
dbed1c6361 cmd/compile: eliminate NumFields wrapper functions
Change-Id: I3c6035559288cfdc33857216f50241b81932c8a4
Reviewed-on: https://go-review.googlesource.com/20811
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-03-17 20:43:18 +00:00
Keith Randall
15ed37d7b7 cmd/compile: enforce nowritebarrier in SSA compiler
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>
2016-03-17 20:13:24 +00:00
Matthew Dempsky
f6bca3f32d cmd/compile: eliminate a bunch of IterFields/IterMethods calls
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>
2016-03-17 19:38:15 +00:00
Ian Lance Taylor
65b4020403 cmd/compile: don't create 2 Sym's and 2 Node's for every string
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>
2016-03-17 16:15:11 +00:00
Keith Randall
56e0ecc5ea cmd/compile: keep value use counts in SSA
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>
2016-03-17 04:20:02 +00:00
Dave Cheney
cb1f2afc99 cmd/compile/internal/gc: disable logProgs debug flag
Spotted while splunking in the compiler with GOGC=off.

name       old time/op     new time/op     delta
Template       407ms ± 5%      402ms ± 6%     ~           (p=0.301 n=20+20)
GoTypes        1.33s ± 2%      1.29s ± 1%   -3.47%        (p=0.000 n=20+20)
Compiler       6.21s ± 1%      5.91s ± 2%   -4.83%        (p=0.000 n=20+20)

name       old alloc/op    new alloc/op    delta
Template      66.8MB ± 0%     63.9MB ± 0%   -4.46%        (p=0.000 n=19+20)
GoTypes        232MB ± 0%      220MB ± 0%   -5.16%        (p=0.000 n=19+17)
Compiler      1.02GB ± 0%     0.97GB ± 0%   -5.81%        (p=0.000 n=20+20)

name       old allocs/op   new allocs/op   delta
Template        789k ± 0%       708k ± 0%  -10.28%        (p=0.000 n=19+20)
GoTypes        2.49M ± 0%      2.20M ± 0%  -11.57%        (p=0.000 n=20+20)
Compiler       10.8M ± 0%       9.4M ± 0%  -12.82%        (p=0.000 n=20+20)

Change-Id: I76615cab912dde10595ca6ab9979ff6c5f1aec49
Reviewed-on: https://go-review.googlesource.com/20782
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2016-03-17 03:50:54 +00:00
Matthew Dempsky
1b9f168f73 cmd/compile: use int for field index
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>
2016-03-15 19:56:43 +00:00
Matthew Dempsky
f6fab93a46 cmd/compile: make Type.Field stricter about bounds checking
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>
2016-03-15 18:46:03 +00:00