One could expect calls like
z.mant.shl(z.mant, shiftAmount)
(or higher-level-functions calls that use lhs/rhs) to be almost free
when shiftAmount = 0; and expect calls like
z.mant.shl(x.mant, 0)
to have the same cost of a x.mant -> z.mant copy. Neither of this
things are currently true.
For an 800 words nat, the first kind of calls cost ~800ns for rigth
shifts and ~3.5µs for left shift; while the second kind of calls are
doing more work than necessary by calling shlVU/shrVU.
This change makes the first kind of calls ({Shl,Shr}Same) almost free,
and the second kind of calls ({Shl,Shr}) about 30% faster.
name old time/op new time/op delta
ZeroShifts/Shl-4 3.64µs ± 3% 2.49µs ± 1% -31.55% (p=0.000 n=10+10)
ZeroShifts/ShlSame-4 3.65µs ± 1% 0.01µs ± 1% -99.85% (p=0.000 n=9+9)
ZeroShifts/Shr-4 3.65µs ± 1% 2.49µs ± 1% -31.91% (p=0.000 n=10+10)
ZeroShifts/ShrSame-4 825ns ± 0% 6ns ± 1% -99.33% (p=0.000 n=9+10)
During go test math/big, the shl zeroshift fastpath is triggered 1380
times; while the shr fastpath is triggered 153334 times(!).
Change-Id: I5f92b304a40638bd8453a86c87c58e54b337bcdf
Reviewed-on: https://go-review.googlesource.com/87660
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Per #11257 all examples should be in external test files.
Additionally, doing so makes this example playable.
Updates #24352. (Albeit tangentially).
Change-Id: I77ab4655107f61db2e9d21a608b73ace3a230fb2
Reviewed-on: https://go-review.googlesource.com/101285
Reviewed-by: Robert Griesemer <gri@golang.org>
And delete them from asm_test.
Change-Id: I3cf0934706a640136cb0f646509174f8c1bf3363
Reviewed-on: https://go-review.googlesource.com/101395
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Replaces " \t" code indentation with "\t".
Issues like this are easy to spot with editor that prints
whitespace charecters.
Change-Id: Ia82877e7c99121bf369fa76e46ba52dff84f36bf
Reviewed-on: https://go-review.googlesource.com/101355
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
By moving exported methods to the front of method lists, filtering
down to only the exported methods just needs a count of how many
exported methods exist, which the compiler can statically
provide. This allows getting rid of the exported method cache.
For #22075.
Change-Id: I8eeb274563a2940e1347c34d673f843ae2569064
Reviewed-on: https://go-review.googlesource.com/100846
Reviewed-by: Ian Lance Taylor <iant@golang.org>
By sorting method sets earlier, we can change the interface
satisfaction problem from taking O(NM) time to O(N+M). This is the
same algorithm already used by runtime and reflect for dynamic
interface satisfaction testing.
For #22075.
Change-Id: I3d889f0227f37704535739bbde11f5107b4eea17
Reviewed-on: https://go-review.googlesource.com/100845
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Add a search box to the top of the user task views that only displays
tasks containing a particular log message.
Change-Id: I92f4aa113f930954e8811416901e37824f0eb884
Reviewed-on: https://go-review.googlesource.com/100843
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Goroutine analysis reports the sum of all overlapping GC intervals as
the GCTime of a goroutine. The computation is done by adding the length
of a completed GC interval to 'active' goroutines when processing the
corresponding EvGCDone event. This change fixes the two corner cases
the current implementation ignores:
1) Goroutine that ends during GC. Previously, this goroutine was ignored
and GC time was undercounted. We handle this case by setting the
gcStartTime only when GC is active and handling non-zero gcStartTime
when processing EvGoStop and EvGoStart.
2) Goroutine that starts during GC. Previously, the entire GC interval
length was added to the Goroutine's GCTime which resulted in overcount
of GC time. We handle this case by computing the length of overlapped
period precisely.
Change-Id: Ifa8e82672ec341b5ff87837209f4311fa7262b7f
Reviewed-on: https://go-review.googlesource.com/100842
Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
And delete them from asm_test.
Change-Id: Ibdaca3496eefc73c731b511ddb9636a1f3dff68c
Reviewed-on: https://go-review.googlesource.com/100915
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Based on decision for #24183. This makes the go/scanner behavior
match cmd/compile behavior. Adjusted a go/printer test that assumed
silent behavior for invalid line directive, and added more scanner
tests verifying the correct error position and message for invalid
line directives.
The filenames in line directives now remain untouched by the scanner;
there is no cleanup or conversion of relative into absolute paths
anymore, in sync with what the compiler's scanner/parser are doing.
Any kind of filename transformation has to be done by a client. This
makes the scanner code simpler and also more predictable.
For #24183.
Change-Id: Ia091548e1d3d89dfdf6e7d82dab50bea05742ce3
Reviewed-on: https://go-review.googlesource.com/100235
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
When there are plugins, there may not be a unique copy of runtime
functions like goexit, mcall, etc. So identifying them by entry
address is problematic. Instead, keep track of each special function
using a field in the symbol table. That way, multiple copies of
the same runtime function will be treated identically.
Fixes#24351Fixes#23133
Change-Id: Iea3232df8a6af68509769d9ca618f530cc0f84fd
Reviewed-on: https://go-review.googlesource.com/100739
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
There is a bug in Octeon III processors where storing an odd floating
point register after it has recently been written to by a double
floating point operation will store the old value from before the double
operation (there are some extra details - the operation and store
must be a certain number of cycles apart). However, this bug does not
occur if the even register is stored first. Currently the bug only
happens on big endian because go always loads the even register first on
little endian.
Workaround the bug by always loading / storing the even floating point
register first. Since this is just an instruction reordering, it should
have no performance penalty. This follows other compilers like GCC which
will always store the even register first (although you do have to set
the ISA level to MIPS I to prevent it from using SDC1).
Change-Id: I5e73daa4d724ca1df7bf5228aab19f53f26a4976
Reviewed-on: https://go-review.googlesource.com/97735
Reviewed-by: Keith Randall <khr@golang.org>
And delete them from asm_test.
Change-Id: I29c8d098a8893e6b669b6272a2f508985ac9d618
Reviewed-on: https://go-review.googlesource.com/100876
Reviewed-by: Cherry Zhang <cherryyz@google.com>
The Android O seccomp policy disallows the stat syscall on amd64, see
https://android.googlesource.com/platform/bionic/+/android-4.2.2_r1.2/libc/SYSCALLS.TXT
Use the fstatat syscall with AT_FDCWD and zero flags instead to achieve
the same behavior.
Fixes#24403
Change-Id: I36fc9ec9bc938cd8e9de30f66c0eb9d2e24debf6
Reviewed-on: https://go-review.googlesource.com/100878
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The struct stores its 64-bit state field in a 12-byte array to
ensure that it can be 64-bit-aligned. This leaves 4 spare bytes,
which we can reuse to store the sema field.
(32-bit alignment is still guaranteed because the array type was
changed to [3]uint32.)
Fixes#19149.
Change-Id: I9bc20e69e45e0e07fbf496080f3650e8be0d6e8d
Reviewed-on: https://go-review.googlesource.com/100515
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When combining adjacent type switch cases with the same type hash, we
failed to actually remove the combined cases, so we would generate
code for them twice.
We use MD5 for type hashes, so collisions are rare, but they do
currently appear in test/fixedbugs/bug248.dir/bug2.go, which is how I
noticed this failure.
Passes toolstash-check.
Change-Id: I66729b3366b96cb8ddc8fa6f3ebea11ef6d74012
Reviewed-on: https://go-review.googlesource.com/100461
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
The main thing is we now eagerly create the ODCLFUNC node for
closures, immediately cross-link them, and assign fields (e.g., Nbody,
Dcl, Parents, Marks) directly on the ODCLFUNC (previously they were
assigned on the OCLOSURE and later moved to the ODCLFUNC).
This allows us to set Curfn to the ODCLFUNC instead of the OCLOSURE,
which makes things more consistent with normal function declarations.
(Notably, this means Cvars now hang off the ODCLFUNC instead of the
OCLOSURE.)
Assignment of xfunc symbol names also now happens before typechecking
their body, which means debugging output now provides a more helpful
name than "<S>".
In golang.org/cl/66810, we changed "x := y" statements to avoid
creating false closure variables for x, but we still create them for
struct literals like "s{f: x}". Update comment in capturevars
accordingly.
More opportunity for cleanups still, but this makes some substantial
progress, IMO.
Passes toolstash-check.
Change-Id: I65a4efc91886e3dcd1000561348af88297775cd7
Reviewed-on: https://go-review.googlesource.com/100197
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This reverts commit 080187f4f7.
It broke build of golang.org/x/exp/shiny/iconvg
See issue 24395 for details
Change-Id: Ifd6134f6214e6cee40bd3c63c32941d5fc96ae8b
Reviewed-on: https://go-review.googlesource.com/100755
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
User variables that cannot be SSA'd, either because their addresses are
taken or because they are too large for the decomposition heuristic, do
not explicitly appear as operands of SSA values. Instead they are written
to directly via the stack pointer.
This hid them from the location list generation, which is only
interested in the named value table. Fortunately, the lifetime of
stack-only variables is delineated by VarDef/VarKill ops, and it's easy
enough to turn those into location list bounds.
One wrinkle: stack frame information is not explicitly available in the
SSA phases, because it's owned by the frontend in AllocFrame. It would
be easier if the set of live LocalSlots were returned by that, but this
is the minimal change to fix missing variables. Or VarDef/VarKills
could appear in NamedValues, which would make this change even easier.
Change-Id: Ice6654dad6f9babb0286e95c7ec28594561dc91f
Reviewed-on: https://go-review.googlesource.com/100458
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Some rules in PPC64.rules cause an extremely large rewritePPC64.go
file to be generated, due to rules with commutative operations and
many operands. This happens with the existing
rules for combining byte loads in little endian order, and
also happens with the pending change to do the same for bytes
in big endian order.
The change improves the existing rules and reduces the size of
the rewrite file by more than 60%. Once this change is merged,
then the pending change for big endian ordered rules will be
updated to use rules that avoid generating an excessively large
rewrite file.
This also includes a fix to a performance regression for
littleEndian.PutUint16 on ppc64le.
Change-Id: I8d2ea42885fa2b84b30c63aa124b0a9b130564ff
Reviewed-on: https://go-review.googlesource.com/100675
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The syscall package currently declares RawSyscall6 for every GOOS, but
does not define it on Solaris. This leads to code using said function
to compile but it will not link. Fix it by adding RawSyscall6 and make
it panic.
Also remove the obsolete comment above runtime.syscall_syscall as
pointed out by Aram.
Updates #24357
Change-Id: I1b1423121d1c99de2ecc61cd9a935dba9b39e3a4
Reviewed-on: https://go-review.googlesource.com/100655
Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>
This change ports all the remaining tests checking that small memmoves
are replaced with MOVs to the new codegen test harness, and deletes
them from the asm_test file.
Change-Id: I01c94b441e27a5d61518035af62d62779dafeb56
Reviewed-on: https://go-review.googlesource.com/100476
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Thanks to Iskander Sharipov for spotting this in an earlier CL of mine.
Change-Id: Idf45ad266205ff83985367cb38f585badfbed151
Reviewed-on: https://go-review.googlesource.com/100535
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Iskander Sharipov <iskander.sharipov@intel.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
In CL 98015, findnull was rewritten so it uses bytes.IndexByte.
This broke the build on plan9/amd64 because the implementation
of bytes.IndexByte on AMD64 relies on SSE instructions while
floating point instructions are not allowed in the note handler.
This change fixes findnull by using the former implementation
on Plan 9, so it doesn't use bytes.IndexByte.
Fixes#24387.
Change-Id: I084d1a44d38d9f77a6c1ad492773f0a98226be16
Reviewed-on: https://go-review.googlesource.com/100577
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Add tests for the "negative size argument in make.*" and "size argument
too large in make.*" error messages to appear at call sites in case the
size is a const defined on another line.
As suggested by Matthew in a comment on CL 69910.
Change-Id: I5c33d4bec4e3d20bb21fe8019df27999997ddff3
Reviewed-on: https://go-review.googlesource.com/100395
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
