For simplicity, only recognizes expressions of the exact form
"(x << a) | (x >> b)" where x is a variable and a and b are
integer constant expressions that add to x's bit width.
Fixes#4629.
$ cat rotate.c
unsigned int
rotate(unsigned int x)
{
x = (x << 3) | (x >> (sizeof(x) * 8 - 3));
return x;
}
## BEFORE
$ go tool 6c -S rotate.c
(rotate.c:2) TEXT rotate+0(SB),$0-8
(rotate.c:2) MOVL x+0(FP),!!DX
(rotate.c:4) MOVL DX,!!AX
(rotate.c:4) SALL $3,!!AX
(rotate.c:4) MOVL DX,!!CX
(rotate.c:4) SHRL $29,!!CX
(rotate.c:4) ORL CX,!!AX
(rotate.c:5) RET ,!!
(rotate.c:5) RET ,!!
(rotate.c:5) END ,!!
## AFTER
$ go tool 6c -S rotate.c
(rotate.c:2) TEXT rotate+0(SB),$0-8
(rotate.c:4) MOVL x+0(FP),!!AX
(rotate.c:4) ROLL $3,!!AX
(rotate.c:5) RET ,!!
(rotate.c:5) RET ,!!
(rotate.c:5) END ,!!
R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/7069056
If the scanned block has no typeinfo the garbage collector will attempt
to get the actual type of the block.
R=golang-dev, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/7093045
On Plan 9, only the parent of a given process can enter its wait
queue. When a Go program tries to fork-exec a child process
and subsequently waits for it to finish, the goroutines doing
these two tasks do not necessarily tie themselves to the same
(or any single) OS thread. In the case that the fork and the wait
system calls happen on different OS threads (say, due to a
goroutine being rescheduled somewhere along the way), the
wait() will either return an error or end up waiting for a
completely different child than was intended.
This change forces the fork and wait syscalls to happen in the
same goroutine and ties that goroutine to its OS thread until
the child exits. The PID of the child is recorded upon fork and
exit, and de-queued once the child's wait message has been read.
The Wait API, then, is translated into a synthetic implementation
that simply waits for the requested PID to show up in the queue
and then reads the associated stats.
R=rsc, rminnich, npe, mirtchovski, ality
CC=golang-dev
https://golang.org/cl/6545051
The test case of issue 4585 was not passing due to
miscalculation of memequal args, and the previous fix
does not handle padding at the end of a struct.
Handling of padding at end of structs also fixes the case
of [n]T where T is such a padded struct.
Fixes#4585.
(again)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7133059
Reference the 80386 compiler documentation now that the
documentation for the 68020 is offline.
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7127053
sse2 is a more precise description of the requirement,
and it matches what people will see in, for example
grep sse2 /proc/cpuinfo # linux
sysctl hw.optional.sse2 # os x
R=golang-dev, dsymonds, iant
CC=golang-dev
https://golang.org/cl/7057050
Decode as much as possible of a Huffman symbol in a single table
lookup (much like the zlib implementation), filling more bits
(conservatively, so we don't consume past the end of the stream)
when the code prefix indicates more bits are needed. This
results in about a 50% performance gain in speed benchmarks.
The following set is benchcmp done on a retina MacBook Pro:
benchmark old MB/s new MB/s speedup
BenchmarkDecodeDigitsSpeed1e4 28.41 42.79 1.51x
BenchmarkDecodeDigitsSpeed1e5 30.18 47.62 1.58x
BenchmarkDecodeDigitsSpeed1e6 30.81 48.14 1.56x
BenchmarkDecodeDigitsDefault1e4 30.28 44.61 1.47x
BenchmarkDecodeDigitsDefault1e5 32.18 51.94 1.61x
BenchmarkDecodeDigitsDefault1e6 35.57 53.28 1.50x
BenchmarkDecodeDigitsCompress1e4 30.39 44.83 1.48x
BenchmarkDecodeDigitsCompress1e5 33.05 51.64 1.56x
BenchmarkDecodeDigitsCompress1e6 35.69 53.04 1.49x
BenchmarkDecodeTwainSpeed1e4 25.90 43.04 1.66x
BenchmarkDecodeTwainSpeed1e5 29.97 48.19 1.61x
BenchmarkDecodeTwainSpeed1e6 31.36 49.43 1.58x
BenchmarkDecodeTwainDefault1e4 28.79 45.02 1.56x
BenchmarkDecodeTwainDefault1e5 37.12 55.65 1.50x
BenchmarkDecodeTwainDefault1e6 39.28 58.16 1.48x
BenchmarkDecodeTwainCompress1e4 28.64 44.90 1.57x
BenchmarkDecodeTwainCompress1e5 37.40 55.98 1.50x
BenchmarkDecodeTwainCompress1e6 39.35 58.06 1.48x
R=rsc, dave, minux.ma, bradfitz, nigeltao
CC=golang-dev
https://golang.org/cl/6872063
People keep not reading all the way to the bottom of the doc
and not running hg mail.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/7137057
Calling it will show memory allocation statistics for that
single benchmark (if -test.benchmem is not provided)
R=golang-dev, rsc, kevlar, bradfitz
CC=golang-dev
https://golang.org/cl/7027046
I think that the parser is complete enough to take that warning out.
It passes the test suite.
There may be incompatible API changes, but being in the exp directory
is warning enough for that.
R=nigeltao
CC=golang-dev
https://golang.org/cl/7131050
We need to wait for the handler to actually finish running,
not almost be done running.
This was always a bug, but now that handler output is buffered
it shows up easily on GOMAXPROCS >1 systems.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7109043
- always set the Pkg field in QualifiedIdents
- call Context.Ident for all identifiers in the AST that denote
a types.Object (bug fix)
- added test that Context.Ident is called for all such identifiers
R=adonovan
CC=golang-dev
https://golang.org/cl/7101054
