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* math: Add examples for Copysign, Dim, Exp* and TruncJavier2019-09-171-0/+46
| | | | | | Change-Id: I95921a8a55b243600aaec24ddca74b7040107dca Reviewed-on: https://go-review.googlesource.com/c/go/+/195203 Reviewed-by: Robert Griesemer <gri@golang.org>
* all: fix typosAinar Garipov2019-09-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the following (suboptimal) script to obtain a list of possible typos: #!/usr/bin/env sh set -x git ls-files |\ grep -e '\.\(c\|cc\|go\)$' |\ xargs -n 1\ awk\ '/\/\// { gsub(/.*\/\//, ""); print; } /\/\*/, /\*\// { gsub(/.*\/\*/, ""); gsub(/\*\/.*/, ""); }' |\ hunspell -d en_US -l |\ grep '^[[:upper:]]\{0,1\}[[:lower:]]\{1,\}$' |\ grep -v -e '^.\{1,4\}$' -e '^.\{16,\}$' |\ sort -f |\ uniq -c |\ awk '$1 == 1 { print $2; }' Then, go through the results manually and fix the most obvious typos in the non-vendored code. Change-Id: I3cb5830a176850e1a0584b8a40b47bde7b260eae Reviewed-on: https://go-review.googlesource.com/c/go/+/193848 Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: fix a duplicate "the" in a commentpeter zhang2019-09-021-1/+1
| | | | | | | | Change-Id: Ib637381ab8a12aeb798576b781e1b3c458ba812d GitHub-Last-Rev: 12994496b6b636d75564e5ae7e938b65bca526df GitHub-Pull-Request: golang/go#34017 Reviewed-on: https://go-review.googlesource.com/c/go/+/192877 Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
* math/big: document that Rat.Denom might modify the receiverEric Lagergren2019-08-281-0/+2
| | | | | | | | Fixes #33792 Change-Id: I306a95883c3db2d674d3294a6feb50adc50ee5d6 Reviewed-on: https://go-review.googlesource.com/c/go/+/192017 Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: fast path for Cmp if sameIllya Yalovyy2019-08-282-0/+16
| | | | | | | | | | | | math/big.Int Cmp method does not have a fast path for the case if x and y are the same. Fixes #30856 Change-Id: Ia9a5b5f72db9d73af1b13ed6ac39ecff87d10393 Reviewed-on: https://go-review.googlesource.com/c/go/+/178957 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* cmd/gofmt: fix normalization of imaginary number literalsRobert Griesemer2019-06-211-1/+1
| | | | | | | | | | | | | | | | | | The old code only normalized decimal integer imaginary number literals. But with the generalized imaginary number syntax, the number value may be decimal, binary, octal, or hexadecimal, integer or floating-point. The new code only looks at the number pattern. Only for decimal integer imaginary literals do we need to strip leading zeroes. The remaining normalization code simply ignore the 'i' suffix. As a result, the new code is both simpler and shorter. Fixes #32718. Change-Id: If43fc962a48ed62002e65d5c81fddbb9bd283984 Reviewed-on: https://go-review.googlesource.com/c/go/+/183378 Reviewed-by: Ian Lance Taylor <iant@golang.org>
* math: add examples for Log, Log2, Mod, and AbsMichael Brandenburg2019-06-191-0/+38
| | | | | | | | Change-Id: I5f57acd5e970b3fec5f33cfceee179235cbf739f Reviewed-on: https://go-review.googlesource.com/c/go/+/182877 Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com> Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
* all: shorten some testsRuss Cox2019-05-225-4/+21
| | | | | | | | | | | | | | | Shorten some of the longest tests that run during all.bash. Removes 7r 50u 21s from all.bash. After this change, all.bash is under 5 minutes again on my laptop. For #26473. Change-Id: Ie0460aa935808d65460408feaed210fbaa1d5d79 Reviewed-on: https://go-review.googlesource.com/c/go/+/177559 Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
* math/bits: document that Add, Sub, Mul, RotateLeft, ReverseBytes are ↵Filippo Valsorda2019-05-211-0/+44
| | | | | | | | | | constant time Fixes #31267 Change-Id: I91e4aa8cf9d797689cb9612d0fe3bf1bb3ad15a6 Reviewed-on: https://go-review.googlesource.com/c/go/+/178177 Reviewed-by: Keith Randall <khr@golang.org>
* math/bits: add example for OnesCount functionadarsh ravichandran2019-05-201-0/+6
| | | | | | | | Change-Id: Id87db9bed5e8715d554c1bf95c063d7d0a03c3e9 Reviewed-on: https://go-review.googlesource.com/c/go/+/178117 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
* math/bits: make Add and Sub fallbacks constant timesmasher1642019-05-201-30/+19
| | | | | | | | | | | | | | | | | | | | | | | | Make the extended precision add-with-carry and sub-with-carry operations take a constant amount of time to execute, regardless of input. name old time/op new time/op delta Add-4 1.16ns ±11% 1.51ns ± 5% +30.52% (p=0.008 n=5+5) Add32-4 1.08ns ± 0% 1.03ns ± 1% -4.86% (p=0.029 n=4+4) Add64-4 1.09ns ± 1% 1.95ns ± 3% +79.23% (p=0.008 n=5+5) Add64multiple-4 4.03ns ± 1% 4.55ns ±11% +13.07% (p=0.008 n=5+5) Sub-4 1.08ns ± 1% 1.50ns ± 0% +38.17% (p=0.016 n=5+4) Sub32-4 1.09ns ± 2% 1.53ns ±10% +40.26% (p=0.008 n=5+5) Sub64-4 1.10ns ± 1% 1.47ns ± 1% +33.39% (p=0.008 n=5+5) Sub64multiple-4 4.30ns ± 2% 4.08ns ± 4% -5.07% (p=0.032 n=5+5) Fixes #31267 Change-Id: I1824b1b3ab8f09902ce8b5fef84ce2fdb8847ed9 Reviewed-on: https://go-review.googlesource.com/c/go/+/170758 Reviewed-by: Filippo Valsorda <filippo@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Run-TryBot: Filippo Valsorda <filippo@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
* math/big: stack allocate scaleDenom return valueJT Olio2019-05-082-15/+27
| | | | | | | | | | benchmark old ns/op new ns/op delta BenchmarkRatCmp-4 154 77.9 -49.42% Change-Id: I932710ad8b6905879e232168b1777927f86ba22a Reviewed-on: https://go-review.googlesource.com/c/go/+/175460 Run-TryBot: Robert Griesemer <gri@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: fix the bug in assembly implementation of shlVU on arm64erifan012019-05-082-47/+128
| | | | | | | | | | | | | | | For the case where the addresses of parameter z and x of the function shlVU overlap and the address of z is greater than x, x (input value) can be polluted during the calculation when the high words of x are overlapped with the low words of z (output value). Fixes #31084 Change-Id: I9bb0266a1d7856b8faa9a9b1975d6f57dece0479 Reviewed-on: https://go-review.googlesource.com/c/go/+/169780 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
* math/big: document Int.StringBrian Kessler2019-05-031-1/+4
| | | | | | | | | Int.String had no documentation and the documentation for Int.Text did not mention the handling of the nil pointer case. Change-Id: I9f21921e431c948545b7cabc7829e4b4e574bbe9 Reviewed-on: https://go-review.googlesource.com/c/go/+/175118 Reviewed-by: Robert Griesemer <gri@golang.org>
* math: consolidate assembly stub implementationsMichael Munday2019-04-2365-1007/+789
| | | | | | | | | | | | | | | | | | | | Where assembly functions are just jumps to the Go implementation put them into a stubs_<arch>.s file. This reduces the number of files considerably and makes it easier to see what is really implemented in assembly. I've also run the stubs files through asmfmt to format them in a more consistent way. Eventually we should replace these 'stub' assembly files with a pure Go implementation now that we have mid-stack inlining (see #31362). Change-Id: If5b2022dcc23e1299f1b7ba79884f1b1263d0f7f Reviewed-on: https://go-review.googlesource.com/c/go/+/173398 Run-TryBot: Michael Munday <mike.munday@ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
* math/big: optimize mulAddVWW on arm64 for better performanceerifan012019-04-222-8/+61
| | | | | | | | | | | | | | | | | | | | | | | Unroll the cycle 4 times to reduce load overhead. Benchmarks: name old time/op new time/op delta MulAddVWW/1-8 15.9ns ± 0% 11.9ns ± 0% -24.92% (p=0.000 n=8+8) MulAddVWW/2-8 16.1ns ± 0% 13.9ns ± 1% -13.82% (p=0.000 n=8+8) MulAddVWW/3-8 18.9ns ± 0% 17.3ns ± 0% -8.47% (p=0.000 n=8+8) MulAddVWW/4-8 21.7ns ± 0% 19.5ns ± 0% -10.14% (p=0.000 n=8+8) MulAddVWW/5-8 25.1ns ± 0% 22.5ns ± 0% -10.27% (p=0.000 n=8+8) MulAddVWW/10-8 41.6ns ± 0% 40.0ns ± 0% -3.79% (p=0.000 n=8+8) MulAddVWW/100-8 368ns ± 0% 363ns ± 0% -1.36% (p=0.000 n=8+8) MulAddVWW/1000-8 3.52µs ± 0% 3.52µs ± 0% -0.14% (p=0.000 n=8+8) MulAddVWW/10000-8 35.1µs ± 0% 35.1µs ± 0% -0.01% (p=0.000 n=7+6) MulAddVWW/100000-8 351µs ± 0% 351µs ± 0% +0.15% (p=0.038 n=8+8) Change-Id: I052a4db286ac6e4f3293289c7e9a82027da0405e Reviewed-on: https://go-review.googlesource.com/c/go/+/155780 Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
* all: s/cancelation/cancellation/Josh Bleecher Snyder2019-04-162-4/+4
| | | | | | | | | | | | | Though there is variation in the spelling of canceled, cancellation is always spelled with a double l. Reference: https://www.grammarly.com/blog/canceled-vs-cancelled/ Change-Id: I240f1a297776c8e27e74f3eca566d2bc4c856f2f Reviewed-on: https://go-review.googlesource.com/c/go/+/170060 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
* math: use new mnemonics for 'rotate then insert' on s390xMichael Munday2019-04-1617-249/+83
| | | | | | | | | | | Mnemonics for these instructions were added to the assembler in CL 159357. Change-Id: Ie11c45ecc9cead9a8850fcc929b0211cfd980fe5 Reviewed-on: https://go-review.googlesource.com/c/go/+/160157 Run-TryBot: Michael Munday <mike.munday@ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
* math/big: don't clobber shared underlying array in pow5 computationRobert Griesemer2019-04-152-18/+28
| | | | | | | | | | | Rearranged code slightly to make lifetime of underlying array of pow5 more explicit in code. Fixes #31184. Change-Id: I063081f0e54097c499988d268a23813746592654 Reviewed-on: https://go-review.googlesource.com/c/go/+/170641 Reviewed-by: Filippo Valsorda <filippo@golang.org>
* all: change the old assembly style AX:CX to CX, AXNeven Sajko2019-04-092-8/+8
| | | | | | | | | | | | | Assembly files with "/vendor/" or "testdata" in their paths were ignored. Change-Id: I3882ff07eb4426abb9f8ee96f82dff73c81cd61f GitHub-Last-Rev: 51ae8c324d72a12a059272fcf8568e670bfaf21b GitHub-Pull-Request: golang/go#31166 Reviewed-on: https://go-review.googlesource.com/c/go/+/170197 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
* math/big: do not panic in Exp when y < 0 and x doesn't have an inverseFilippo Valsorda2019-04-042-7/+20
| | | | | | | | | | | If x does not have an inverse modulo m, and a negative exponent is used, return nil just like ModInverse does now. Change-Id: I8fa72f7a851e8cf77c5fab529ede88408740626f Reviewed-on: https://go-review.googlesource.com/c/go/+/170757 Run-TryBot: Filippo Valsorda <filippo@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/bits: add gccgo-friendly code for compiler bootstrapThan McIntosh2019-04-043-8/+37
| | | | | | | | | | | | | | | When building as part of the bootstrap process, avoid use of "go:linkname" applied to variables, since this feature is ill-defined/unsupported for gccgo. Updates #30771. Change-Id: Id44d01b5c98d292702e5075674117518cb59e2d0 Reviewed-on: https://go-review.googlesource.com/c/go/+/170737 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
* math/big: simplify shlVU_g and shrVU_gNeven Sajko2019-04-041-12/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrote a few lines to be more idiomatic/less assembly-ish. Benchmarked with `go test -bench Float -tags math_big_pure_go`: name old time/op new time/op delta FloatString/100-8 751ns ± 0% 746ns ± 1% -0.71% (p=0.000 n=10+10) FloatString/1000-8 22.9µs ± 0% 22.9µs ± 0% ~ (p=0.271 n=10+10) FloatString/10000-8 1.89ms ± 0% 1.89ms ± 0% ~ (p=0.481 n=10+10) FloatString/100000-8 184ms ± 0% 184ms ± 0% ~ (p=0.094 n=9+9) FloatAdd/10-8 56.4ns ± 1% 56.5ns ± 0% ~ (p=0.170 n=9+9) FloatAdd/100-8 59.7ns ± 0% 59.3ns ± 0% -0.70% (p=0.000 n=8+9) FloatAdd/1000-8 101ns ± 0% 99ns ± 0% -1.89% (p=0.000 n=8+8) FloatAdd/10000-8 553ns ± 0% 536ns ± 0% -3.00% (p=0.000 n=9+10) FloatAdd/100000-8 4.94µs ± 0% 4.74µs ± 0% -3.94% (p=0.000 n=9+10) FloatSub/10-8 50.3ns ± 0% 50.5ns ± 0% +0.52% (p=0.000 n=8+8) FloatSub/100-8 52.0ns ± 0% 52.2ns ± 1% +0.46% (p=0.012 n=8+10) FloatSub/1000-8 77.9ns ± 0% 77.3ns ± 0% -0.80% (p=0.000 n=7+8) FloatSub/10000-8 371ns ± 0% 362ns ± 0% -2.67% (p=0.000 n=10+10) FloatSub/100000-8 3.20µs ± 0% 3.10µs ± 0% -3.16% (p=0.000 n=10+10) ParseFloatSmallExp-8 7.84µs ± 0% 7.82µs ± 0% -0.17% (p=0.037 n=9+9) ParseFloatLargeExp-8 29.3µs ± 1% 29.5µs ± 0% ~ (p=0.059 n=9+8) FloatSqrt/64-8 516ns ± 0% 519ns ± 0% +0.54% (p=0.000 n=9+9) FloatSqrt/128-8 1.07µs ± 0% 1.07µs ± 0% ~ (p=0.109 n=8+9) FloatSqrt/256-8 1.23µs ± 0% 1.23µs ± 0% +0.50% (p=0.000 n=9+9) FloatSqrt/1000-8 3.43µs ± 0% 3.44µs ± 0% +0.53% (p=0.000 n=9+8) FloatSqrt/10000-8 40.9µs ± 0% 40.7µs ± 0% -0.39% (p=0.000 n=9+8) FloatSqrt/100000-8 1.07ms ± 0% 1.07ms ± 0% -0.10% (p=0.017 n=10+9) FloatSqrt/1000000-8 89.3ms ± 0% 89.2ms ± 0% -0.07% (p=0.015 n=9+8) Change-Id: Ibf07c6142719d11bc7f329246957d87a9f3ba3d2 GitHub-Last-Rev: 870a041ab7bb9c24be083114f53653a5f4eed611 GitHub-Pull-Request: golang/go#31220 Reviewed-on: https://go-review.googlesource.com/c/go/+/170449 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: temporarily disable buggy shlVU assembly for arm64Robert Griesemer2019-03-271-0/+4
| | | | | | | | | | | | | This addresses the failures we have seen in #31084. The correct fix is to find the actual bug in the assembly code. Updates #31084. Change-Id: I437780c53d0c4423d742e2e3b650b899ce845372 Reviewed-on: https://go-review.googlesource.com/c/go/+/169721 Run-TryBot: Robert Griesemer <gri@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
* math/big: implement Rat.SetUint64Brian Kessler2019-03-272-0/+58
| | | | | | | | | | | | | Implemented via the underlying Int.SetUint64. Added tests for Rat.SetInt64 and Rat.SetUint64. Fixes #29579 Change-Id: I03faaffc93e36873b202b58ae72b139dea5c40f9 Reviewed-on: https://go-review.googlesource.com/c/go/+/160682 Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math: use Sincos instead of Sin and Cos in Jn and YnNeven Sajko2019-03-251-10/+10
| | | | | | | | Change-Id: I0da3857013f1d4e90820fb043314d78924113a27 GitHub-Last-Rev: 7c3d813c6e188a4afda54b736db14370e52b6f94 GitHub-Pull-Request: golang/go#31019 Reviewed-on: https://go-review.googlesource.com/c/go/+/169078 Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: accept non-decimal floats with Rat.SetStringRobert Griesemer2019-03-254-38/+133
| | | | | | | | | | | | | This fixes an old oversight. Rat.SetString already permitted fractions a/b where both a and b could independently specify a base prefix. With this CL, it now also accepts non-decimal floating-point numbers. Fixes #29799. Change-Id: I9cc65666a5cebb00f0202da2e4fc5654a02e3234 Reviewed-on: https://go-review.googlesource.com/c/go/+/168237 Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
* math/rand: add example for Intn funcVladimir Kovpak2019-03-251-0/+15
| | | | | | | | | | Change-Id: I831ffb5c3fa2872d71def8d8461f0adbd4ae2c1a GitHub-Last-Rev: 2adfcd2d5a592ef4c63da781240a391da89b5d9e GitHub-Pull-Request: golang/go#30706 Reviewed-on: https://go-review.googlesource.com/c/go/+/166426 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
* cmd/compile: follow up intrinsifying math/bits.Add64 for arm64erifan012019-03-221-2/+2
| | | | | | | | | | This CL deals with the additional comments of CL 159017. Change-Id: I4ad3c60c834646d58dc0c544c741b92bfe83fb8b Reviewed-on: https://go-review.googlesource.com/c/go/+/168857 Reviewed-by: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
* cmd/compile: intrinsify math/bits.Add64 for arm64erifan012019-03-201-0/+25
| | | | | | | | | | | | | | | | | | | This CL instrinsifies Add64 with arm64 instruction sequence ADDS, ADCS and ADC, and optimzes the case of carry chains.The CL also changes the test code so that the intrinsic implementation can be tested. Benchmarks: name old time/op new time/op delta Add-224 2.500000ns +- 0% 2.090000ns +- 4% -16.40% (p=0.000 n=9+10) Add32-224 2.500000ns +- 0% 2.500000ns +- 0% ~ (all equal) Add64-224 2.500000ns +- 0% 1.577778ns +- 2% -36.89% (p=0.000 n=10+9) Add64multiple-224 6.000000ns +- 0% 2.000000ns +- 0% -66.67% (p=0.000 n=10+10) Change-Id: I6ee91c9a85c16cc72ade5fd94868c579f16c7615 Reviewed-on: https://go-review.googlesource.com/c/go/+/159017 Run-TryBot: Ben Shi <powerman1st@163.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
* math: fix math.Remainder(-x,x) (for Inf > x > 0)David Chase2019-03-152-0/+18
| | | | | | | | | | | | Modify the |x| == |y| case to return -0 when x < 0. Fixes #30814. Change-Id: Ic4cd48001e0e894a12b5b813c6a1ddc3a055610b Reviewed-on: https://go-review.googlesource.com/c/go/+/167479 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: add support for underscores '_' in numbersRobert Griesemer2019-03-128-240/+458
| | | | | | | | | | | | | | | | | | | | | | | | The primary change is in nat.scan which now accepts underscores for base 0. While at it, streamlined error handling in that function as well. Also, improved the corresponding test significantly by checking the expected result values also in case of scan errors. The second major change is in scanExponent which now accepts underscores when the new sepOk argument is set. While at it, essentially rewrote that function to match error and underscore handling of nat.scan more closely. Added a new test for scanExponent which until now was only tested indirectly. Finally, updated the documentation for several functions and added many new test cases to clients of nat.scan. A major portion of this CL is due to much better test coverage. Updates #28493. Change-Id: I7f17b361b633fbe6c798619d891bd5e0a045b5c5 Reviewed-on: https://go-review.googlesource.com/c/go/+/166157 Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
* math/big: implement Int.TrailingZeroBitsBrian Kessler2019-03-122-0/+31
| | | | | | | | | | | | Implemented via the underlying nat.trailingZeroBits. Fixes #29578 Change-Id: If9876c5a74b107cbabceb7547bef4e44501f6745 Reviewed-on: https://go-review.googlesource.com/c/go/+/160681 Reviewed-by: Robert Griesemer <gri@golang.org> Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
* math/big: add fast path for amd64 addVW for large zJosh Bleecher Snyder2019-03-091-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This matches the pure Go fast path added in the previous commit. I will leave other architectures to those with ready access to hardware. name old time/op new time/op delta AddVW/1-8 3.60ns ± 3% 3.59ns ± 1% ~ (p=0.147 n=91+86) AddVW/2-8 3.92ns ± 1% 3.91ns ± 2% -0.36% (p=0.000 n=86+92) AddVW/3-8 4.33ns ± 5% 4.46ns ± 5% +2.94% (p=0.000 n=96+97) AddVW/4-8 4.76ns ± 5% 4.82ns ± 5% +1.28% (p=0.000 n=95+92) AddVW/5-8 5.40ns ± 1% 5.42ns ± 0% +0.47% (p=0.000 n=76+71) AddVW/10-8 8.03ns ± 1% 7.80ns ± 5% -2.90% (p=0.000 n=73+96) AddVW/100-8 43.8ns ± 5% 17.9ns ± 1% -59.12% (p=0.000 n=94+81) AddVW/1000-8 428ns ± 4% 85ns ± 6% -80.20% (p=0.000 n=96+99) AddVW/10000-8 4.22µs ± 2% 1.80µs ± 3% -57.32% (p=0.000 n=69+92) AddVW/100000-8 44.8µs ± 8% 31.5µs ± 3% -29.76% (p=0.000 n=99+90) name old time/op new time/op delta SubVW/1-8 3.53ns ± 2% 3.63ns ± 5% +2.97% (p=0.000 n=94+93) SubVW/2-8 4.33ns ± 5% 4.01ns ± 2% -7.36% (p=0.000 n=90+85) SubVW/3-8 4.32ns ± 2% 4.32ns ± 5% ~ (p=0.084 n=87+97) SubVW/4-8 4.70ns ± 2% 4.83ns ± 6% +2.77% (p=0.000 n=85+96) SubVW/5-8 5.84ns ± 1% 5.35ns ± 1% -8.35% (p=0.000 n=87+87) SubVW/10-8 8.01ns ± 4% 7.54ns ± 4% -5.84% (p=0.000 n=98+97) SubVW/100-8 43.9ns ± 5% 17.9ns ± 1% -59.20% (p=0.000 n=98+76) SubVW/1000-8 426ns ± 2% 85ns ± 3% -80.13% (p=0.000 n=90+98) SubVW/10000-8 4.24µs ± 2% 1.81µs ± 3% -57.28% (p=0.000 n=74+91) SubVW/100000-8 44.5µs ± 4% 31.5µs ± 2% -29.33% (p=0.000 n=84+91) Change-Id: I10dd361cbaca22197c27e7734c0f50065292afbb Reviewed-on: https://go-review.googlesource.com/c/go/+/164969 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: add fast path for pure Go addVW for large zJosh Bleecher Snyder2019-03-092-4/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the normal case, only a few words have to be updated when adding a word to a vector. When that happens, we can simply copy the rest of the words, which is much faster. However, the overhead of that makes it prohibitive for small vectors, so we check the size at the beginning. The implementation is a bit weird to allow addVW to continued to be inlined; see #30548. The AddVW benchmarks are surprising, but fully repeatable. The SubVW benchmarks are more or less as expected. I expect that removing the indirect function call will help both and make them a bit more normal. name old time/op new time/op delta AddVW/1-8 4.27ns ± 2% 3.81ns ± 3% -10.83% (p=0.000 n=89+90) AddVW/2-8 4.91ns ± 2% 4.34ns ± 1% -11.60% (p=0.000 n=83+90) AddVW/3-8 5.77ns ± 4% 5.76ns ± 2% ~ (p=0.365 n=91+87) AddVW/4-8 6.03ns ± 1% 6.03ns ± 1% ~ (p=0.392 n=80+76) AddVW/5-8 6.48ns ± 2% 6.63ns ± 1% +2.27% (p=0.000 n=76+74) AddVW/10-8 9.56ns ± 2% 9.56ns ± 1% -0.02% (p=0.002 n=69+76) AddVW/100-8 90.6ns ± 0% 18.1ns ± 4% -79.99% (p=0.000 n=72+94) AddVW/1000-8 865ns ± 0% 85ns ± 6% -90.14% (p=0.000 n=66+96) AddVW/10000-8 8.57µs ± 2% 1.82µs ± 3% -78.73% (p=0.000 n=99+94) AddVW/100000-8 84.4µs ± 2% 31.8µs ± 4% -62.29% (p=0.000 n=93+98) name old time/op new time/op delta SubVW/1-8 3.90ns ± 2% 4.13ns ± 4% +6.02% (p=0.000 n=92+95) SubVW/2-8 4.15ns ± 1% 5.20ns ± 1% +25.22% (p=0.000 n=83+85) SubVW/3-8 5.50ns ± 2% 6.22ns ± 6% +13.21% (p=0.000 n=91+97) SubVW/4-8 5.99ns ± 1% 6.63ns ± 1% +10.63% (p=0.000 n=79+61) SubVW/5-8 6.75ns ± 4% 6.88ns ± 2% +1.82% (p=0.000 n=98+73) SubVW/10-8 9.57ns ± 1% 9.56ns ± 1% -0.13% (p=0.000 n=77+64) SubVW/100-8 90.3ns ± 1% 18.1ns ± 2% -80.00% (p=0.000 n=75+94) SubVW/1000-8 860ns ± 4% 85ns ± 7% -90.14% (p=0.000 n=97+99) SubVW/10000-8 8.51µs ± 3% 1.77µs ± 6% -79.21% (p=0.000 n=100+97) SubVW/100000-8 84.4µs ± 3% 31.5µs ± 3% -62.66% (p=0.000 n=92+92) Change-Id: I721d7031d40f245b4a284f5bdd93e7bb85e7e937 Reviewed-on: https://go-review.googlesource.com/c/go/+/164968 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: remove bounds checks in pure Go implementationsJosh Bleecher Snyder2019-03-091-6/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These routines are quite sensitive to BCE. This change eliminates bounds checks from loops. It does so at the cost of a bit of safety: malformed input will now return incorrect answers instead of panicking. This isn't as bad as it sounds: math/big has very good test coverage, and the alternative implementations are in assembly, which could do much worse things with malformed input. If the compiler's BCE improves, so could these routines. Notable BCE improvements for these routines would be: * Allowing and propagating more cross-slice length hints. Then hints like _ = y[:len(z)] would eliminate bounds checks for y[i]. * Propagating enough information so that we could do n := len(x) if len(z) < n { n = len(z) } and then have i < n eliminate the same bounds checks as i < len(x) && i < len(z) currently does. * Providing some way to do BCE for unrolled loops. Now that we have math/bits implementations, it is possible to write things like ADC chains in pure Go, if you can reasonably unroll loops. Benchmarks below are for amd64, using -tags=math_big_pure_go. name old time/op new time/op delta AddVV/1-8 5.15ns ± 3% 4.65ns ± 4% -9.81% (p=0.000 n=93+86) AddVV/2-8 6.40ns ± 2% 5.58ns ± 4% -12.78% (p=0.000 n=90+95) AddVV/3-8 7.07ns ± 2% 6.66ns ± 2% -5.88% (p=0.000 n=87+83) AddVV/4-8 7.94ns ± 5% 7.41ns ± 4% -6.65% (p=0.000 n=94+98) AddVV/5-8 8.55ns ± 1% 8.80ns ± 0% +2.92% (p=0.000 n=87+92) AddVV/10-8 12.7ns ± 1% 12.3ns ± 1% -3.12% (p=0.000 n=83+71) AddVV/100-8 119ns ± 5% 117ns ± 4% -1.60% (p=0.000 n=93+90) AddVV/1000-8 1.14µs ± 4% 1.14µs ± 5% ~ (p=0.812 n=95+91) AddVV/10000-8 11.4µs ± 5% 11.3µs ± 5% ~ (p=0.503 n=97+96) AddVV/100000-8 114µs ± 4% 113µs ± 5% -0.98% (p=0.002 n=97+90) name old time/op new time/op delta SubVV/1-8 5.23ns ± 5% 4.65ns ± 3% -11.18% (p=0.000 n=89+91) SubVV/2-8 6.49ns ± 5% 5.58ns ± 3% -14.04% (p=0.000 n=92+94) SubVV/3-8 7.10ns ± 3% 6.65ns ± 2% -6.28% (p=0.000 n=87+80) SubVV/4-8 8.04ns ± 1% 7.44ns ± 5% -7.49% (p=0.000 n=83+98) SubVV/5-8 8.55ns ± 2% 8.32ns ± 1% -2.75% (p=0.000 n=84+92) SubVV/10-8 12.7ns ± 1% 12.3ns ± 1% -3.09% (p=0.000 n=80+75) SubVV/100-8 119ns ± 0% 116ns ± 3% -1.83% (p=0.000 n=87+98) SubVV/1000-8 1.13µs ± 5% 1.13µs ± 3% ~ (p=0.082 n=96+98) SubVV/10000-8 11.2µs ± 1% 11.3µs ± 3% +0.76% (p=0.000 n=87+97) SubVV/100000-8 112µs ± 2% 113µs ± 3% +0.55% (p=0.000 n=76+88) name old time/op new time/op delta AddVW/1-8 4.30ns ± 4% 3.96ns ± 6% -8.02% (p=0.000 n=89+97) AddVW/2-8 5.15ns ± 2% 4.91ns ± 1% -4.56% (p=0.000 n=87+80) AddVW/3-8 5.59ns ± 3% 5.75ns ± 2% +2.91% (p=0.000 n=91+88) AddVW/4-8 6.20ns ± 1% 6.03ns ± 1% -2.71% (p=0.000 n=75+90) AddVW/5-8 6.93ns ± 3% 6.49ns ± 2% -6.35% (p=0.000 n=100+82) AddVW/10-8 10.0ns ± 7% 9.6ns ± 0% -4.02% (p=0.000 n=98+74) AddVW/100-8 91.1ns ± 1% 90.6ns ± 1% -0.55% (p=0.000 n=84+80) AddVW/1000-8 866ns ± 1% 856ns ± 4% -1.06% (p=0.000 n=69+96) AddVW/10000-8 8.64µs ± 1% 8.53µs ± 4% -1.25% (p=0.000 n=67+99) AddVW/100000-8 84.3µs ± 2% 85.4µs ± 4% +1.22% (p=0.000 n=89+99) name old time/op new time/op delta SubVW/1-8 4.28ns ± 2% 3.82ns ± 3% -10.63% (p=0.000 n=91+89) SubVW/2-8 4.61ns ± 1% 4.48ns ± 3% -2.67% (p=0.000 n=94+96) SubVW/3-8 5.54ns ± 1% 5.81ns ± 4% +4.87% (p=0.000 n=92+97) SubVW/4-8 6.20ns ± 1% 6.08ns ± 2% -1.99% (p=0.000 n=71+88) SubVW/5-8 6.91ns ± 3% 6.64ns ± 1% -3.90% (p=0.000 n=97+70) SubVW/10-8 9.85ns ± 2% 9.62ns ± 0% -2.31% (p=0.000 n=82+62) SubVW/100-8 91.1ns ± 1% 90.9ns ± 3% -0.14% (p=0.010 n=71+93) SubVW/1000-8 859ns ± 3% 867ns ± 1% +0.98% (p=0.000 n=99+78) SubVW/10000-8 8.54µs ± 5% 8.57µs ± 2% +0.38% (p=0.007 n=98+92) SubVW/100000-8 84.5µs ± 3% 84.6µs ± 3% ~ (p=0.334 n=95+94) name old time/op new time/op delta AddMulVVW/1-8 5.43ns ± 3% 4.36ns ± 2% -19.67% (p=0.000 n=95+94) AddMulVVW/2-8 6.56ns ± 4% 6.11ns ± 1% -6.90% (p=0.000 n=91+91) AddMulVVW/3-8 8.00ns ± 1% 7.80ns ± 4% -2.52% (p=0.000 n=83+95) AddMulVVW/4-8 9.81ns ± 2% 9.53ns ± 1% -2.86% (p=0.000 n=77+64) AddMulVVW/5-8 11.4ns ± 3% 11.3ns ± 5% -0.89% (p=0.000 n=95+97) AddMulVVW/10-8 18.9ns ± 5% 19.1ns ± 5% +0.89% (p=0.000 n=91+94) AddMulVVW/100-8 165ns ± 5% 165ns ± 4% ~ (p=0.427 n=97+98) AddMulVVW/1000-8 1.56µs ± 3% 1.56µs ± 4% ~ (p=0.167 n=98+96) AddMulVVW/10000-8 15.7µs ± 5% 15.6µs ± 5% -0.31% (p=0.044 n=95+97) AddMulVVW/100000-8 156µs ± 3% 157µs ± 8% ~ (p=0.373 n=72+99) Change-Id: Ibc720785d5b95f6a797103b1363843205f4d56bf Reviewed-on: https://go-review.googlesource.com/c/go/+/164966 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: support new octal prefixes 0o and 0ORobert Griesemer2019-03-077-58/+112
| | | | | | | | | | | | | | | | | This CL extends the various SetString and Parse methods for Ints, Rats, and Floats to accept the new octal prefixes. The main change is in natconv.go, all other changes are documentation and test updates. Finally, this CL also fixes TestRatSetString which silently dropped certain failures. Updates #12711. Change-Id: I5ee5879e25013ba1e6eda93ff280915f25ab5d55 Reviewed-on: https://go-review.googlesource.com/c/go/+/165898 Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
* math/big: rewrite pure Go implementations to use math/bitsJosh Bleecher Snyder2019-03-042-178/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While we're here, delete addWW_g and subWW_g, per the TODO. They are now obsolete. Benchmarks on amd64 with -tags=math_big_pure_go. name old time/op new time/op delta AddVV/1-8 5.24ns ± 2% 5.12ns ± 1% -2.11% (p=0.000 n=82+87) AddVV/2-8 6.44ns ± 1% 6.33ns ± 2% -1.82% (p=0.000 n=77+82) AddVV/3-8 7.89ns ± 8% 6.97ns ± 4% -11.71% (p=0.000 n=100+96) AddVV/4-8 8.60ns ± 0% 7.72ns ± 4% -10.24% (p=0.000 n=90+96) AddVV/5-8 10.3ns ± 4% 8.5ns ± 1% -17.02% (p=0.000 n=96+91) AddVV/10-8 16.2ns ± 5% 12.8ns ± 1% -21.11% (p=0.000 n=97+86) AddVV/100-8 148ns ± 1% 117ns ± 5% -21.07% (p=0.000 n=66+98) AddVV/1000-8 1.41µs ± 4% 1.13µs ± 3% -19.90% (p=0.000 n=97+97) AddVV/10000-8 14.2µs ± 5% 11.2µs ± 1% -20.82% (p=0.000 n=99+84) AddVV/100000-8 142µs ± 4% 113µs ± 4% -20.40% (p=0.000 n=91+92) SubVV/1-8 5.29ns ± 1% 5.11ns ± 0% -3.30% (p=0.000 n=87+88) SubVV/2-8 6.36ns ± 4% 6.33ns ± 2% -0.56% (p=0.002 n=98+73) SubVV/3-8 7.58ns ± 5% 6.98ns ± 4% -8.01% (p=0.000 n=97+91) SubVV/4-8 8.61ns ± 3% 7.98ns ± 2% -7.31% (p=0.000 n=95+83) SubVV/5-8 10.6ns ± 2% 8.5ns ± 1% -19.56% (p=0.000 n=79+89) SubVV/10-8 16.3ns ± 4% 12.7ns ± 1% -21.97% (p=0.000 n=98+82) SubVV/100-8 124ns ± 1% 118ns ± 1% -4.83% (p=0.000 n=85+81) SubVV/1000-8 1.14µs ± 5% 1.12µs ± 2% -1.17% (p=0.000 n=97+81) SubVV/10000-8 11.6µs ±10% 11.2µs ± 1% -3.39% (p=0.000 n=100+84) SubVV/100000-8 114µs ± 6% 114µs ± 5% ~ (p=0.396 n=83+94) AddVW/1-8 4.04ns ± 4% 4.34ns ± 4% +7.57% (p=0.000 n=96+98) AddVW/2-8 4.34ns ± 5% 4.40ns ± 5% +1.40% (p=0.000 n=99+98) AddVW/3-8 5.43ns ± 0% 5.54ns ± 2% +1.97% (p=0.000 n=85+94) AddVW/4-8 6.23ns ± 1% 6.18ns ± 2% -0.66% (p=0.000 n=77+78) AddVW/5-8 6.78ns ± 2% 6.90ns ± 4% +1.77% (p=0.000 n=80+99) AddVW/10-8 10.5ns ± 4% 9.9ns ± 1% -5.77% (p=0.000 n=97+69) AddVW/100-8 114ns ± 3% 91ns ± 0% -20.38% (p=0.000 n=98+77) AddVW/1000-8 1.12µs ± 1% 0.87µs ± 1% -22.80% (p=0.000 n=82+68) AddVW/10000-8 11.2µs ± 2% 8.5µs ± 5% -23.85% (p=0.000 n=85+100) AddVW/100000-8 112µs ± 2% 85µs ± 5% -24.22% (p=0.000 n=71+96) SubVW/1-8 4.09ns ± 2% 4.18ns ± 4% +2.32% (p=0.000 n=78+96) SubVW/2-8 4.59ns ± 5% 4.52ns ± 7% -1.54% (p=0.000 n=98+94) SubVW/3-8 5.41ns ±10% 5.55ns ± 1% +2.48% (p=0.000 n=100+89) SubVW/4-8 6.51ns ± 2% 6.19ns ± 0% -4.85% (p=0.000 n=97+81) SubVW/5-8 7.25ns ± 3% 6.90ns ± 4% -4.93% (p=0.000 n=97+96) SubVW/10-8 10.6ns ± 4% 9.8ns ± 2% -7.32% (p=0.000 n=95+96) SubVW/100-8 90.4ns ± 0% 90.8ns ± 0% +0.43% (p=0.000 n=83+78) SubVW/1000-8 853ns ± 4% 857ns ± 2% +0.42% (p=0.000 n=100+98) SubVW/10000-8 8.52µs ± 4% 8.53µs ± 2% ~ (p=0.061 n=99+97) SubVW/100000-8 84.8µs ± 5% 84.2µs ± 2% -0.78% (p=0.000 n=99+93) AddMulVVW/1-8 8.73ns ± 0% 5.33ns ± 3% -38.91% (p=0.000 n=91+96) AddMulVVW/2-8 14.8ns ± 3% 6.5ns ± 2% -56.33% (p=0.000 n=100+79) AddMulVVW/3-8 18.6ns ± 2% 7.8ns ± 5% -57.84% (p=0.000 n=89+96) AddMulVVW/4-8 24.0ns ± 2% 9.8ns ± 0% -59.09% (p=0.000 n=95+67) AddMulVVW/5-8 29.0ns ± 2% 11.5ns ± 5% -60.44% (p=0.000 n=90+97) AddMulVVW/10-8 54.1ns ± 0% 18.8ns ± 1% -65.37% (p=0.000 n=82+84) AddMulVVW/100-8 508ns ± 2% 165ns ± 4% -67.62% (p=0.000 n=72+98) AddMulVVW/1000-8 4.96µs ± 3% 1.55µs ± 1% -68.86% (p=0.000 n=99+91) AddMulVVW/10000-8 50.0µs ± 4% 15.5µs ± 4% -68.95% (p=0.000 n=97+97) AddMulVVW/100000-8 491µs ± 1% 156µs ± 8% -68.22% (p=0.000 n=79+95) Change-Id: I4c6ae0b4065f371aea8103f6a85d9e9274bf01d0 Reviewed-on: https://go-review.googlesource.com/c/go/+/164965 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: optimize shlVU_g and shrVU_gJosh Bleecher Snyder2019-03-041-20/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Special case shifts by zero. Provide hints to the compiler that shifts are bounded. There are no existing benchmarks for shifts, but the Float implementation uses shifts, so we can use those. Benchmarks on amd64 with -tags=math_big_pure_go. name old time/op new time/op delta FloatString/100-8 869ns ± 3% 872ns ± 4% +0.40% (p=0.001 n=94+83) FloatString/1000-8 26.5µs ± 1% 26.4µs ± 1% -0.46% (p=0.000 n=87+96) FloatString/10000-8 2.18ms ± 2% 2.18ms ± 2% ~ (p=0.687 n=90+89) FloatString/100000-8 200ms ± 7% 197ms ± 5% -1.47% (p=0.000 n=100+90) FloatAdd/10-8 65.9ns ± 4% 64.0ns ± 4% -2.94% (p=0.000 n=92+93) FloatAdd/100-8 71.3ns ± 4% 67.4ns ± 4% -5.51% (p=0.000 n=96+93) FloatAdd/1000-8 128ns ± 1% 121ns ± 0% -5.69% (p=0.000 n=91+80) FloatAdd/10000-8 718ns ± 4% 626ns ± 4% -12.83% (p=0.000 n=99+99) FloatAdd/100000-8 6.43µs ± 3% 5.50µs ± 1% -14.50% (p=0.000 n=98+83) FloatSub/10-8 57.7ns ± 2% 57.0ns ± 4% -1.20% (p=0.000 n=89+96) FloatSub/100-8 59.9ns ± 3% 58.7ns ± 4% -2.10% (p=0.000 n=100+98) FloatSub/1000-8 94.5ns ± 1% 88.6ns ± 0% -6.16% (p=0.000 n=74+70) FloatSub/10000-8 456ns ± 1% 416ns ± 5% -8.83% (p=0.000 n=87+95) FloatSub/100000-8 4.00µs ± 1% 3.57µs ± 1% -10.87% (p=0.000 n=68+85) FloatSqrt/64-8 585ns ± 1% 579ns ± 1% -0.99% (p=0.000 n=92+90) FloatSqrt/128-8 1.26µs ± 1% 1.23µs ± 2% -2.42% (p=0.000 n=91+81) FloatSqrt/256-8 1.45µs ± 3% 1.40µs ± 1% -3.61% (p=0.000 n=96+90) FloatSqrt/1000-8 4.03µs ± 1% 3.91µs ± 1% -3.05% (p=0.000 n=90+93) FloatSqrt/10000-8 48.0µs ± 0% 47.3µs ± 1% -1.55% (p=0.000 n=90+90) FloatSqrt/100000-8 1.23ms ± 3% 1.22ms ± 4% -1.00% (p=0.000 n=99+99) FloatSqrt/1000000-8 96.7ms ± 4% 98.0ms ±10% ~ (p=0.322 n=89+99) Change-Id: I0f941c05b7c324256d7f0674559b6ba906e92ba8 Reviewed-on: https://go-review.googlesource.com/c/go/+/164967 Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: better initial guess for nat.sqrtJuraj Sukop2019-02-271-1/+1
| | | | | | | | | | | | The proposed change introduces a better initial guess which is closer to the final value and therefore converges in fewer steps. Consider for example sqrt(8): previously the guess was 8, whereas now it is 4 (and the result is 2). All this change does is it computes the division by two more accurately while it keeps the guess ≥ √x. Change-Id: I917248d734a7b0488d14a647a063f674e56c4e30 GitHub-Last-Rev: c06d9d4876c8e7d6739f0e4b687e370fe1e9aad7 GitHub-Pull-Request: golang/go#28981 Reviewed-on: https://go-review.googlesource.com/c/163866 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/cmplx: avoid panic in Pow(x, NaN())Bryan C. Mills2019-02-272-2/+7
| | | | | | | | | | Fixes #30088 Change-Id: I08cec17feddc86bd08532e6b135807e3c8f4c1b2 Reviewed-on: https://go-review.googlesource.com/c/161197 Run-TryBot: Bryan C. Mills <bcmills@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: handle alias of cofactor inputs in GCDBrian Kessler2019-02-272-9/+50
| | | | | | | | | | | | | | | | | | | If the variables passed in to the cofactor arguments of GCD (x, y) aliased the input arguments (a, b), the previous implementation would result in incorrect results for y. This change reorganizes the calculation so that the only case that need to be handled is when y aliases b, which can be handled with a simple check. Tests were added for all of the alias cases for input arguments and and and irrelevant test case for a previous binary GCD calculation was dropped. Fixes #30217 Change-Id: Ibe6137f09b3e1ae3c29e3c97aba85b67f33dc169 Reviewed-on: https://go-review.googlesource.com/c/162517 Run-TryBot: Robert Griesemer <gri@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
* math/big: add %#b and %O integer formatsRuss Cox2019-02-262-4/+14
| | | | | | | | | | | | | | | Matching fmt, %#b now prints an 0b prefix, and %O prints octal with an 0o prefix. See golang.org/design/19308-number-literals for background. For #19308. For #12711. Change-Id: I139c5a9a1dfae15415621601edfa13c6a5f19cfc Reviewed-on: https://go-review.googlesource.com/c/160250 Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: add %x float formatRuss Cox2019-02-262-102/+229
| | | | | | | | | | | | | | | | | | big.Float already had %p for printing hex format, but that format normalizes differently from fmt's %x and ignores precision entirely. This CL adds %x to big.Float, matching fmt's behavior: the verb is spelled 'x' not 'p', the mantissa is normalized to [1, 2), and precision is respected. See golang.org/design/19308-number-literals for background. For #29008. Change-Id: I9c1b9612107094856797e5b0b584c556c1914895 Reviewed-on: https://go-review.googlesource.com/c/160249 Reviewed-by: Robert Griesemer <gri@golang.org>
* math/bits: optimize Reverse32 and Reverse64Michael Munday2019-02-261-5/+2
| | | | | | | | | | | | | | | | Use ReverseBytes32 and ReverseBytes64 to speed up these functions. The byte reversal functions are intrinsics on most platforms and generally compile to a single instruction. name old time/op new time/op delta Reverse32 2.41ns ± 1% 1.94ns ± 3% -19.60% (p=0.000 n=20+19) Reverse64 3.85ns ± 1% 2.56ns ± 1% -33.32% (p=0.000 n=17+19) Change-Id: I160bf59a0c7bd5db94114803ec5a59fae448f096 Reviewed-on: https://go-review.googlesource.com/c/159358 Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* src, misc: apply gofmtRobert Griesemer2019-02-195-41/+41
| | | | | | | | | | This applies the new gofmt literal normalizations to the library. Change-Id: I8c1e8ef62eb556fc568872c9f77a31ef236348e7 Reviewed-on: https://go-review.googlesource.com/c/162539 Run-TryBot: Robert Griesemer <gri@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
* strconv: format hex floatsRuss Cox2019-02-121-3/+3
| | | | | | | | | | | | | | | | This CL updates FormatFloat to format standard hexadecimal floating-point constants, using the 'x' and 'X' verbs. See golang.org/design/19308-number-literals for background. For #29008. Change-Id: I540b8f71d492cfdb7c58af533d357a564591f28b Reviewed-on: https://go-review.googlesource.com/c/160242 Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
* math/big: permit upper-case 'P' binary exponent (not just 'p')Robert Griesemer2019-02-113-6/+8
| | | | | | | | | | | | | | The current implementation accepted binary exponents but restricted them to 'p'. This change permits both 'p' and 'P'. R=Go1.13 Updates #29008. Change-Id: I7a89ccb86af4438f17b0422be7cb630ffcf43272 Reviewed-on: https://go-review.googlesource.com/c/159297 Reviewed-by: Russ Cox <rsc@golang.org> Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
* math/big: document that Rat.SetString accepts _decimal_ float representationsRobert Griesemer2019-01-171-2/+3
| | | | | | | | Updates #29799. Change-Id: I267c2c3ba3964e96903954affc248d0c52c4916c Reviewed-on: https://go-review.googlesource.com/c/158397 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
* math: fix ternary correction statement in Log1pBrian Kessler2019-01-072-2/+5
| | | | | | | | | | | | | | The original port of Log1p incorrectly translated a ternary statement so that a correction was only applied to one of the branches. Fixes #29488 Change-Id: I035b2fc741f76fe7c0154c63da6e298b575e08a4 Reviewed-on: https://go-review.googlesource.com/c/156120 Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Katie Hockman <katie@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
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