Minor comments added. More to come.
Change-Id: I97511db54d59e1009ef934da38f306a2dc83a6e9
Reviewed-on: https://go-review.googlesource.com/6898
Reviewed-by: Rob Pike <r@golang.org>
Starting it lazily causes a memory allocation (for the goroutine) during GC.
First use of channels for runtime implementation.
Change-Id: I9cd24dcadbbf0ee5070ee6d0ed7ea415504f316c
Reviewed-on: https://go-review.googlesource.com/6960
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Previously, gc would compile code like
func foo() { ... }
var bar = foo
by emitting a static closure to wrap "foo", but then emitting runtime
initialization code to assign the closure to "bar". This CL changes
gc to instead statically initialize "bar".
Notably, this change shrinks the "go" tool's text segment by ~7.4kB on
linux/amd64 while only increasing the data segment by ~100B:
text data bss dec hex filename
7237819 122412 215616 7575847 739927 go.before
7230398 122540 215232 7568170 737b2a go.after
Fixes issue #10081.
Change-Id: If5e26cf46b323393ba6f2199a82a06e9e4baf411
Reviewed-on: https://go-review.googlesource.com/6880
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Remove the per-achitecture formatter for Prog and replace it with
a global String method. Clean up and regularize the output. Update
tests affected by the format; some tests are made correct now when
they were broken before (and known to be).
Also, related: Change the encoding of the (R1+R2) syntax on ppc64
to be equivalent to (R1)(R2*1), which means it needs no special
handling.
Delete the now unused STRINGSZ constant.
Change-Id: I7f6654d11f80065f3914a3f19353f2f12edfe310
Reviewed-on: https://go-review.googlesource.com/6931
Reviewed-by: Russ Cox <rsc@golang.org>
Use optimized formatBits function to format mantissa and exponent.
Add benchmark for binary exponent float format.
on darwin/386
benchmark old ns/op new ns/op delta
BenchmarkAppendFloatBinaryExp 520 122 -76.54%
on darwin/amd64
benchmark old ns/op new ns/op delta
BenchmarkAppendFloatBinaryExp 76.9 84.3 +9.62%
Change-Id: If543552f1960e1655bed3a4130914e5eaa3aac69
Reviewed-on: https://go-review.googlesource.com/5600
Reviewed-by: Robert Griesemer <gri@golang.org>
I asked for this in CL 3742 and it was ignored.
Change-Id: I30ad05f87c7d9eccb11df7e19288e3ed2c7e2e3f
Reviewed-on: https://go-review.googlesource.com/6930
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
With the new unificiation, the flag must be TYPE_CONST to print
properly.
Change-Id: I7cd1c56355724f08cbe9afc6ab7a66904031adc9
Reviewed-on: https://go-review.googlesource.com/6903
Reviewed-by: Russ Cox <rsc@golang.org>
This was in i386 but not in x86 and was missed during the merge.
Needed for linux/386.
Change-Id: Ia6e495c044f53bcb98f3bb03e20d8f6d35a8f8ff
Reviewed-on: https://go-review.googlesource.com/6902
Reviewed-by: Rob Pike <r@golang.org>
Now unused.
Change-Id: I0ba27e58721ad66cc3068346d6d31ba0ac37ad64
Reviewed-on: https://go-review.googlesource.com/6893
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Support the old syntax for AX:DX by rewriting into the new form,
AX, DX. Delete now-unnecessary hacks for some special cases.
Change-Id: Icd42697c7617f8a50864ca8b0c69469321a2296e
Reviewed-on: https://go-review.googlesource.com/6901
Reviewed-by: Russ Cox <rsc@golang.org>
(Because that's what the assembly files actually say - no $ on the constant.)
Change-Id: Idb774cdca0e089c4ac24ab665e23290bf7b565bf
Reviewed-on: https://go-review.googlesource.com/6895
Reviewed-by: Rob Pike <r@golang.org>
Nothing uses it, nothing should start using it.
Stop leaving plausible-looking values there.
It would be nice to remove entirely, but that would
require a new version number for the object file format,
in order not to break external readers like debug/gosym.
It's easier to leave and poison.
I came across an old mail thread suggesting we start using it
to speed up tracebacks. I want to make sure that doesn't happen.
(The values there were never quite right, and the number is
fundamentally PC-specific anyway.)
Change-Id: Iaf38e8a6b523cbae30b69c28497c4588ef397519
Reviewed-on: https://go-review.googlesource.com/6890
Reviewed-by: Minux Ma <minux@golang.org>
Make cmd/internal/obj/x86 support 32-bit mode and use
instead of cmd/internal/obj/i386. Delete cmd/internal/obj/i386.
Clean up encoding of PINSRQ, CMPSD to use explicit third arg
instead of jamming it into an unused slot of a different arg.
Also fix bug in old6a, which declared the wrong grammar.
The accepted (and encoded) arguments to CMPSD etc are mem,reg not reg,mem.
Code that did try to use mem,reg before would be rejected by liblink,
so only reg,reg ever worked, so existing code is not affected.
After this change, code can use mem,reg successfully.
The real bug here is that the encoding tables inverted the argument
order, making the comparisons all backward from what they say on the page.
It's too late to swap them, though: people have already written code that
expects the inverted comparisons (like in package math, and likely externally).
The best we can do is make the argument that should and can take a
memory operand accept it.
Bit-for-bit compatibility checked against tree without this CL.
Change-Id: Ife5685bc98c95001f64407f35066b34b4dae11c1
Reviewed-on: https://go-review.googlesource.com/6810
Reviewed-by: Rob Pike <r@golang.org>
Add unused (but initialized) from3 field to ytab, f3t to movtab.
Remove level of indentation in movtab processing.
Change-Id: I8475988f46b541ecaccf8d34608da8bef7d12e24
Reviewed-on: https://go-review.googlesource.com/6892
Reviewed-by: Rob Pike <r@golang.org>
Node.Needzero only has two values and acts as a bool, so make it a bool.
Change-Id: Ica46e5ebafbe478017ea52ce6bb335f404059677
Reviewed-on: https://go-review.googlesource.com/6800
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This avoids repeated allocation and map lookups
when constructing the pcln tables.
For 6g compiling cmd/internal/gc/*.go this saves about 8% wall time.
Change-Id: I6a1a80e278ae2c2a44bd1537015ea7b4e7a4d6ca
Reviewed-on: https://go-review.googlesource.com/6793
Reviewed-by: Rob Pike <r@golang.org>
For OSes that use elf on intel, 2*Ptrsize bytes are reserved for TLS.
But only one pointer (g) has been stored in the TLS for a while now.
So we can set it to just Ptrsize, which happily matches what happens
when externally linking.
Fixes#9913
Change-Id: Ic816369d3a55a8cdcc23be349b1a1791d53f5f81
Reviewed-on: https://go-review.googlesource.com/6584
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: Ice4f78e74ec3025a974ffd9ca5e3d28bb3164f40
Reviewed-on: https://go-review.googlesource.com/6794
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
This is an experiment to see if removing the boundary bit logic will
lead to fewer cache misses and improved performance. Instead of using
boundary bits we use the span information to get element size and use
some bit whacking to get the boundary without having to touch the
random heap bits which cause cache misses.
Furthermore once the boundary bit is removed we can either use that
bit for a simpler checkmark routine or we can reduce the number of
bits in the GC bitmap to 2 bits per pointer sized work. For example
the 2 bits at the boundary can be used for marking and pointer/scalar
differentiation. Since we don't need the mark bit except at the
boundary nibble of the object other nibbles can use this bit
as a noscan bit to indicate that there are no more pointers in
the object.
Currently the changed included in this CL slows down the garbage
benchmark. With the boundary bits garbage gives 5.78 and without
(this CL) it gives 5.88 which is a 2% slowdown.
Change-Id: Id68f831ad668176f7dc9f7b57b339e4ebb6dc4c2
Reviewed-on: https://go-review.googlesource.com/6665
Reviewed-by: Austin Clements <austin@google.com>
Shifts are trivially implemented by combining
Float.MantExp and Float.SetMantExp.
Change-Id: Ia2fb49297d8ea7aa7d64c8b1318dc3dc7c8af2f7
Reviewed-on: https://go-review.googlesource.com/6671
Reviewed-by: Alan Donovan <adonovan@google.com>
This change represents Accuracy as a bit pattern rather than
an ordered value; with a new value Undef which is both Below
and Above.
Change-Id: Ibb96294c1417fb3cf2c3cf2374c993b0a4e106b3
Reviewed-on: https://go-review.googlesource.com/6650
Reviewed-by: Alan Donovan <adonovan@google.com>
This change introduces NaNs (for situations like Inf-Inf, etc.).
The implementation is incomplete (the four basic operations produce
a NaN if any of the operands is an Inf or a NaN); and some operations
produce incorrect accuracy for NaN arguments. These are known bugs
which are documented.
Change-Id: Ia88841209e47930681cef19f113e178f92ceeb33
Reviewed-on: https://go-review.googlesource.com/6540
Reviewed-by: Alan Donovan <adonovan@google.com>
Gc already calculates n as an int, so converting to int64 to call
growslice doesn't serve any purpose except to emit slightly larger
code on 32-bit platforms. Passing n as an int shrinks godoc's text
segment by 8kB (9472633 => 9464133) when building for ARM.
Change-Id: Ief9492c21d01afcb624d3f2a484df741450b788d
Reviewed-on: https://go-review.googlesource.com/6231
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
SHRQ CX, DX:AX is changing to SHRQ CX, AX, DX.
This is the first step: using SHRQ From=CX, From3=AX, To=DX
as the preferred encoding.
Once the assemblers and 6g have been updated,
support for the old encoding can be removed.
Change-Id: Ie603fb8ac25a6df78e42f7ddcae078a7684a7c26
Reviewed-on: https://go-review.googlesource.com/6693
Reviewed-by: Rob Pike <r@golang.org>
The unbounded list-based defer pool can grow infinitely.
This can happen if a goroutine routinely allocates a defer;
then blocks on one P; and then unblocked, scheduled and
frees the defer on another P.
The scenario was reported on golang-nuts list.
We've been here several times. Any unbounded local caches
are bad and grow to infinite size. This change introduces
central defer pool; local pools become fixed-size
with the only purpose of amortizing accesses to the
central pool.
Freedefer now executes on system stack to not consume
nosplit stack space.
Change-Id: I1a27695838409259d1586a0adfa9f92bccf7ceba
Reviewed-on: https://go-review.googlesource.com/3967
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
The unbounded list-based sudog cache can grow infinitely.
This can happen if a goroutine is routinely blocked on one P
and then unblocked and scheduled on another P.
The scenario was reported on golang-nuts list.
We've been here several times. Any unbounded local caches
are bad and grow to infinite size. This change introduces
central sudog cache; local caches become fixed-size
with the only purpose of amortizing accesses to the
central cache.
The change required to move sudog cache from mcache to P,
because mcache is not scanned by GC.
Change-Id: I3bb7b14710354c026dcba28b3d3c8936a8db4e90
Reviewed-on: https://go-review.googlesource.com/3742
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
The original C code is: (x->type & SHIDDEN) ? 2 : 0, however when
cleaning up the code for c2go, the ternary operator is rewritten in
the exact opposite way.
We need a test for this, and that's being tracked as #10070.
Fixes#10067.
Change-Id: I24a5e021597d8bc44218c6e75bab6446513b76cf
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/6730
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The creation of liblink and subsequent introduction of more explicit
TLS handling broke 6l's (unsupported) -shared flag. This change adds
-shared flags to cmd/asm and 6g and changes liblink to generate shared-
library compatible instruction sequences when they are passed, and
changes 6l to emit the appropriate ELF relocation.
A proper fix probably also requires go tool changes.
Fixes#9652.
Change-Id: I7b7718fe7305c802ac994f4a5c8de68cfbe6c76b
Reviewed-on: https://go-review.googlesource.com/4321
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
