1) The arrayindexof lookup function is O(n). Replace with O(1) lookups.
2) The checkptxt function is O(n²) and is purely for debugging.
Only run when the debugging flags are turned on.
3) Iterating over sparse bitmaps can be done faster word by word.
Introduce and use bvnext for that.
Run times before and after, on my 2.5 GHz Core i5 MacBook Pro.
x.go 9.48 0.84 issue 8259
x100.go 0.01 0.01 issue 8354
x1000.go 0.10 0.10
x2000.go 0.62 0.19
x3000.go 1.33 0.34
x4000.go 2.29 0.49
x5000.go 3.89 0.67
x6000.go 5.00 0.90
x7000.go 6.70 1.13
x8000.go 9.44 1.38
x9000.go 11.23 1.87
x10000.go 13.78 2.09
Fixes#8259.
Fixes#8354.
LGTM=iant, r
R=golang-codereviews, iant, r
CC=golang-codereviews
https://golang.org/cl/125720043
Since CL 115060044, mkanames declares an empty
array in anames8.c and anames6.c, which is not
valid for the Plan 9 compiler.
char* cnames8[] = {
};
This change makes mkanames not declaring the
cnames array when no C_ constants are found.
LGTM=iant
R=minux, iant
CC=golang-codereviews
https://golang.org/cl/117680043
The helps certain diagnostics and also removed duplicated enums as a side effect.
LGTM=dave, rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/115060044
Instead of immediately completing pointer type mappings, add them to
a queue to allow them to be completed later. This fixes issues caused
by Type() returning arbitrary in-progress type mappings.
Fixes#8368.
Fixes#8441.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/122850043
Instead of including <sys/types.h> to get size_t, instead include
the ISO C standard <stddef.h> header, which defines fewer additional
types at risk of colliding with the user code. In particular, this
prevents collisions between <sys/types.h>'s userspace definitions with
the kernel definitions needed by defs_linux.go.
Also, -cdefs mode uses #pragma pack, so we can keep misaligned fields.
Fixes#8477.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/120610043
Update #6677
When a struct contains an anonymous union, use the type and
name of the first field in the union.
This should make the glibc <sys/resource.h> file work; in that
file struct rusage has fields like
__extension__ union
{
long int ru_maxrss;
__syscall_slong_t __ru_maxrss_word;
};
in which the field that matters is ru_maxrss and
__ru_maxrss_word just exists to advance to the next field on
systems where the kernel uses long long fields but userspace
expects long fields.
LGTM=mikioh.mikioh
R=golang-codereviews, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/106260044
We have an autogenerated version in zruntime_defs.
I am not sure what are the consequences as gdb never printed any values for me.
But it looks unnecessary to manually duplicate it.
LGTM=rsc
R=golang-codereviews, rsc
CC=golang-codereviews, iant, khr
https://golang.org/cl/115660043
A good cleanup anyway, and it makes some room for an additional
field needed for issue 8412.
Update #8412
LGTM=iant
R=iant, khr
CC=golang-codereviews
https://golang.org/cl/112700043
Create proper closures so hash functions can be called
directly from Go. Rearrange calling convention so return
value is directly accessible.
LGTM=dvyukov
R=golang-codereviews, dvyukov, dave, khr
CC=golang-codereviews
https://golang.org/cl/119360043
This change introduces gomallocgc, a Go clone of mallocgc.
Only a few uses have been moved over, so there are still
lots of uses from C. Many of these C uses will be moved
over to Go (e.g. in slice.goc), but probably not all.
What should remain of C's mallocgc is an open question.
LGTM=rsc, dvyukov
R=rsc, khr, dave, bradfitz, dvyukov
CC=golang-codereviews
https://golang.org/cl/108840046
Implement the design described in:
https://docs.google.com/document/d/1v4Oqa0WwHunqlb8C3ObL_uNQw3DfSY-ztoA-4wWbKcg/pub
Summary of the changes:
GC uses "2-bits per word" pointer type info embed directly into bitmap.
Scanning of stacks/data/heap is unified.
The old spans types go away.
Compiler generates "sparse" 4-bits type info for GC (directly for GC bitmap).
Linker generates "dense" 2-bits type info for data/bss (the same as stacks use).
Summary of results:
-1680 lines of code total (-1000+ in mgc0.c only)
-25% memory consumption
-3-7% binary size
-15% GC pause reduction
-7% run time reduction
LGTM=khr
R=golang-codereviews, rsc, christoph, khr
CC=golang-codereviews, rlh
https://golang.org/cl/106260045
selv is created with temp() which calls tempname, which marks
the new n with EscNever, so there is no need to explicitly set
EscNone on the select descriptor.
Fixes#8396.
LGTM=dvyukov
R=golang-codereviews, dave, dvyukov
CC=golang-codereviews
https://golang.org/cl/112520043
They do not, but pretend that they do.
The immediate need is that it breaks the new GC because
these are weird symbols as if with pointers but not necessary
pointer aligned.
LGTM=rsc
R=golang-codereviews, dave, josharian, khr, rsc
CC=golang-codereviews, iant, khr, rlh
https://golang.org/cl/116060043
Currently they are scanned conservatively.
But there is no reason to scan them. C world must not contain
pointers into Go heap. Moreover, we don't have enough information
to emit write barriers nor update pointers there in future.
The immediate need is that it breaks the new GC because
these are weird symbols as if with pointers but not necessary
pointer aligned.
LGTM=rsc
R=golang-codereviews, rlh, rsc
CC=golang-codereviews, iant, khr
https://golang.org/cl/117000043
In the runtime, we want to control where allocations happen.
In particular, we don't want the code implementing malloc to
itself trigger a malloc. This change prevents the compiler
from inserting mallocs on our behalf (due to escaping declarations).
This check does not trigger on the current runtime code.
Note: Composite literals are still allowed.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/105280047
So we can tell from a binary which version of
Go built it.
LGTM=minux, rsc
R=golang-codereviews, minux, khr, rsc, dave
CC=golang-codereviews
https://golang.org/cl/117040043
We might want to add a go/build.IsInternal(pkg string) bool
later, but this works for now.
LGTM=dave, rsc
R=rsc, dave
CC=golang-codereviews
https://golang.org/cl/113300044
benchmark old ns/op new ns/op delta
BenchmarkSelectUncontended 220 165 -25.00%
BenchmarkSelectContended 209 161 -22.97%
BenchmarkSelectProdCons 1042 904 -13.24%
But more importantly this change will allow
to get rid of free function in runtime.
Fixes#6494.
LGTM=rsc, khr
R=golang-codereviews, rsc, dominik.honnef, khr
CC=golang-codereviews, remyoudompheng
https://golang.org/cl/107670043
Fix virtual address of the start of the text segment
on amd64 Plan 9.
This issue has been partially fixed in cmd/add2line,
as part of CL 106460044, but we forgot to report the
change to cmd/objdump.
In the meantime, we also fixed the textStart address
in both cmd/add2line and cmd/objdump.
LGTM=aram, ality, mischief
R=rsc, mischief, aram, ality
CC=golang-codereviews, jas
https://golang.org/cl/117920043
Breaks build for FreeBSD. Probably clang related?
««« original CL description
cmd/cgo: disable inappropriate warnings when the gcc struct is empty
package main
//#cgo CFLAGS: -Wall
//void test() {}
import "C"
func main() {
C.test()
}
This code will cause gcc issuing warnings about unused variable.
This commit use offset of the second return value of
Packages.structType to detect whether the gcc struct is empty,
and if it's directly invoke the C function instead of writing an
unused code.
LGTM=dave, minux
R=golang-codereviews, iant, minux, dave
CC=golang-codereviews
https://golang.org/cl/109640045
»»»
TBR=dfc
R=dave
CC=golang-codereviews
https://golang.org/cl/114990044
package main
//#cgo CFLAGS: -Wall
//void test() {}
import "C"
func main() {
C.test()
}
This code will cause gcc issuing warnings about unused variable.
This commit use offset of the second return value of
Packages.structType to detect whether the gcc struct is empty,
and if it's directly invoke the C function instead of writing an
unused code.
LGTM=dave, minux
R=golang-codereviews, iant, minux, dave
CC=golang-codereviews
https://golang.org/cl/109640045
DWARF says only one is necessary.
The count is preferable because it admits 0-length arrays.
Update debug/dwarf to handle either form.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/111230044
They can be large, so use a varint encoding rather than only one byte.
LGTM=iant, rsc
R=rsc, iant
CC=golang-codereviews
https://golang.org/cl/113180043
Russ Cox
Matthew Dempsky
David du Colombier
Shenghou Ma
Ian Lance Taylor
Dmitriy Vyukov
Peter Collingbourne
Keith Randall
Josh Bleecher Snyder
Bobby Powers
Brad Fitzpatrick
snyh
Robert Griesemer
Rob Pike
Yasuhiro Matsumoto
Dave Cheney