The new linker will disallow this on arm
(it is already disallowed on amd64 and 386)
in order to be able to lay out each function
separately.
The restriction is only for jumps into the middle
of a function; jumps to the beginning of a function
remain fine.
Prereq for linker cleanup (golang.org/s/go13linker).
R=iant, r, minux.ma
CC=golang-dev
https://golang.org/cl/35800043
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and 35790044 and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/34590045
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and 35790044 and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/34580044
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and 35790044 and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/35830043
There is an enormous amount of code moving around in this CL,
but the code is the same, and it is invoked in the same ways.
This CL is preparation for the new linker structure, not the new
structure itself.
The new library's definition is in include/link.h.
The main change is the use of a Link structure to hold all the
linker-relevant state, replacing the smattering of global variables.
The Link structure should both make it clearer which state must
be carried around and make it possible to parallelize more easily
later.
The main body of the linker has moved into the architecture-independent
cmd/ld directory. That includes the list of known header types, so the
distinction between Hplan9x32 and Hplan9x64 is removed (no other
header type distinguished 32- and 64-bit formats), and code for unused
formats such as ipaq kernels has been deleted.
The code being deleted from 5l, 6l, and 8l reappears in liblink or in ld.
Because multiple files are being merged in the liblink directory,
it is not possible to show the diffs nicely in hg.
The Prog and Addr structures have been unified into an
architecture-independent form and moved to link.h, where they will
be shared by all tools: the assemblers, the compilers, and the linkers.
The unification makes it possible to write architecture-independent
traversal of Prog lists, among other benefits.
The Sym structures cannot be unified: they are too fundamentally
different between the linker and the compilers. Instead, liblink defines
an LSym - a linker Sym - to be used in the Prog and Addr structures,
and the linker now refers exclusively to LSyms. The compilers will
keep using their own syms but will fill out the corresponding LSyms in
the Prog and Addr structures.
Although code from 5l, 6l, and 8l is now in a single library, the
code has been arranged so that only one architecture needs to
be linked into a particular program: 5l will not contain the code
needed for x86 instruction layout, for example.
The object file writing code in liblink/obj.c is from cmd/gc/obj.c.
Preparation for golang.org/s/go13linker work.
This CL does not build by itself. It depends on 35740044
and will be submitted at the same time.
R=iant
CC=golang-dev
https://golang.org/cl/35790044
In addition to adding the library, change the way the anames array is created.
Previously, it was written to src/cmd/6l/enam.c (and similarly for 5l and 8l)
and each of the other tools (6g, 6c, 6a) compiled the 6l/enam.c file in addition
to their own sources.
Now that there is a library shared by all these programs, move the anames
array into that library. To eliminate name conflicts, name the array after
the architecture letter: anames5, anames6, anames8.
First step to linker cleanup (golang.org/s/go13linker).
This CL does not build by itself. It depends on the CLs introducing
liblink and changing commands to use it.
R=iant
CC=golang-dev
https://golang.org/cl/35740044
We are not clearing dead values in the garbage collector so it
is not worth the RSS cost to materialize the data and write it
out to the binary.
R=golang-dev, iant, cshapiro
CC=golang-dev
https://golang.org/cl/38650043
When enabled this new debugging mode will allocate objects on
their own page and never recycle memory addresses. This is an
essential tool to root cause a broad class of heap corruption.
R=golang-dev, dave, daniel.morsing, dvyukov, rsc, iant, cshapiro
CC=golang-dev
https://golang.org/cl/22060046
This change allows the garbage collector to examine stack
slots that are determined as live and containing a pointer
value by the garbage collector. This results in a mean
reduction of 65% in the number of stack slots scanned during
an invocation of "GOGC=1 all.bash".
Unfortunately, this does not yet allow garbage collection to
be precise for the stack slots computed as live. Pointers
confound the determination of what definitions reach a given
instruction. In general, this problem is not solvable without
runtime cost but some advanced cooperation from the compiler
might mitigate common cases.
R=golang-dev, rsc, cshapiro
CC=golang-dev
https://golang.org/cl/14430048
Pass as a slice of strings instead. For 2-5 strings, implement
dedicated routines so no slices are needed.
static call counts in the go binary:
2 strings: 342 occurrences
3 strings: 98
4 strings: 30
5 strings: 13
6+ strings: 14
Why? C varags, bad for stack scanning and copying.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/36380043
Now that the map implementation is reading the keys and values from
arbitrary memory (instead of from stack slots), it needs to tell the
race detector when it does so.
Fixes#6875.
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/36360043
and methodValueCall directly. Instead, we inline their behavior
inside of reflect.call.
This change is required because otherwise we have a situation where
reflect.callXX calls makeFuncStub, neither of which knows the
layout of the args passed between them. That's bad for
precise gc & stack copying.
Fixes#6619.
R=golang-dev, dvyukov, rsc, iant, khr
CC=golang-dev
https://golang.org/cl/26970044
This change is part of the plan to get rid of all vararg C calls
which are a pain for getting exact stack scanning.
We allocate a chunk of zero memory to return a pointer to when a
map access doesn't find the key. This is simpler than returning nil
and fixing things up in the caller. Linker magic allocates a single
zero memory area that is shared by all (non-reflect-generated) map
types.
Passing things by reference gets rid of some copies, so it speeds
up code with big keys/values.
benchmark old ns/op new ns/op delta
BenchmarkBigKeyMap 34 31 -8.48%
BenchmarkBigValMap 37 30 -18.62%
BenchmarkSmallKeyMap 26 23 -11.28%
R=golang-dev, dvyukov, khr, rsc
CC=golang-dev
https://golang.org/cl/14794043
They were out of date and should refer to the source installation instructions.
Fixes#6783.
R=golang-dev, rsc, adg, dave
CC=golang-dev
https://golang.org/cl/28500043
Clarify that GOROOT should only be set when using a custom install path.
Remove NetBSD from binary install page (we don't provide binaries).
Remove "What's next" links from installation instructions.
Emphasize "How to Write Go Code" page.
Fixes#6613.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/28700043
This step makes it possible to upload the -osx10.x binaries
separately to their construction (after signing, for example).
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/28160043
