math: optimize math.Abs on mips64x

math: optimize math.Abs on mips64x

This commit optimized math.Abs function implementation on mips64x.
Tested on loongson 3A2000.

goos: linux
goarch: mips64le
pkg: math
                      │    oldmath    │               newmath               │
                      │    sec/op     │    sec/op     vs base               │
Acos-4                   258.0n ± ∞ ¹   257.1n ± ∞ ¹   -0.35% (p=0.008 n=5)
Acosh-4                  417.0n ± ∞ ¹   377.9n ± ∞ ¹   -9.38% (p=0.008 n=5)
Asin-4                   248.0n ± ∞ ¹   259.9n ± ∞ ¹   +4.80% (p=0.008 n=5)
Asinh-4                  439.6n ± ∞ ¹   408.3n ± ∞ ¹   -7.12% (p=0.008 n=5)
Atan-4                   189.6n ± ∞ ¹   188.8n ± ∞ ¹        ~ (p=0.056 n=5)
Atanh-4                  390.0n ± ∞ ¹   356.4n ± ∞ ¹   -8.62% (p=0.008 n=5)
Atan2-4                  279.0n ± ∞ ¹   263.9n ± ∞ ¹   -5.41% (p=0.008 n=5)
Cbrt-4                   314.2n ± ∞ ¹   322.3n ± ∞ ¹   +2.58% (p=0.008 n=5)
Ceil-4                   139.7n ± ∞ ¹   136.6n ± ∞ ¹   -2.22% (p=0.008 n=5)
Compare-4                21.11n ± ∞ ¹   21.09n ± ∞ ¹        ~ (p=0.405 n=5)
Compare32-4              20.10n ± ∞ ¹   20.12n ± ∞ ¹        ~ (p=0.206 n=5)
Copysign-4               32.17n ± ∞ ¹   35.71n ± ∞ ¹  +11.00% (p=0.008 n=5)
Cos-4                    222.8n ± ∞ ¹   169.8n ± ∞ ¹  -23.79% (p=0.008 n=5)
Cosh-4                   550.2n ± ∞ ¹   477.4n ± ∞ ¹  -13.23% (p=0.008 n=5)
Erf-4                    171.6n ± ∞ ¹   174.5n ± ∞ ¹        ~ (p=0.635 n=5)
Erfc-4                   182.6n ± ∞ ¹   170.2n ± ∞ ¹   -6.79% (p=0.008 n=5)
Erfinv-4                 177.6n ± ∞ ¹   196.6n ± ∞ ¹  +10.70% (p=0.008 n=5)
Erfcinv-4                177.8n ± ∞ ¹   197.8n ± ∞ ¹  +11.25% (p=0.008 n=5)
Exp-4                    422.8n ± ∞ ¹   382.1n ± ∞ ¹   -9.63% (p=0.008 n=5)
ExpGo-4                  416.1n ± ∞ ¹   383.2n ± ∞ ¹   -7.91% (p=0.008 n=5)
Expm1-4                  232.9n ± ∞ ¹   252.2n ± ∞ ¹   +8.29% (p=0.008 n=5)
Exp2-4                   404.8n ± ∞ ¹   389.1n ± ∞ ¹   -3.88% (p=0.008 n=5)
Exp2Go-4                 407.0n ± ∞ ¹   372.3n ± ∞ ¹   -8.53% (p=0.008 n=5)
Abs-4                   30.120n ± ∞ ¹   3.014n ± ∞ ¹  -89.99% (p=0.008 n=5)
Dim-4                    5.021n ± ∞ ¹   5.023n ± ∞ ¹        ~ (p=0.071 n=5)
Floor-4                  127.8n ± ∞ ¹   127.1n ± ∞ ¹   -0.55% (p=0.008 n=5)
Max-4                    77.69n ± ∞ ¹   76.33n ± ∞ ¹   -1.75% (p=0.008 n=5)
Min-4                    83.27n ± ∞ ¹   77.87n ± ∞ ¹   -6.48% (p=0.008 n=5)
Mod-4                    906.2n ± ∞ ¹   692.9n ± ∞ ¹  -23.54% (p=0.008 n=5)
Frexp-4                  150.6n ± ∞ ¹   108.6n ± ∞ ¹  -27.89% (p=0.008 n=5)
Gamma-4                  418.4n ± ∞ ¹   386.1n ± ∞ ¹   -7.72% (p=0.008 n=5)
Hypot-4                 148.20n ± ∞ ¹   93.78n ± ∞ ¹  -36.72% (p=0.008 n=5)
HypotGo-4               148.20n ± ∞ ¹   94.47n ± ∞ ¹  -36.26% (p=0.008 n=5)
Ilogb-4                 135.50n ± ∞ ¹   92.38n ± ∞ ¹  -31.82% (p=0.008 n=5)
J0-4                     937.7n ± ∞ ¹   861.7n ± ∞ ¹   -8.10% (p=0.008 n=5)
J1-4                     915.4n ± ∞ ¹   875.9n ± ∞ ¹   -4.32% (p=0.008 n=5)
Jn-4                     1.974µ ± ∞ ¹   1.863µ ± ∞ ¹   -5.62% (p=0.008 n=5)
Ldexp-4                  158.5n ± ∞ ¹   129.3n ± ∞ ¹  -18.42% (p=0.008 n=5)
Lgamma-4                 209.0n ± ∞ ¹   211.8n ± ∞ ¹        ~ (p=0.095 n=5)
Log-4                    326.4n ± ∞ ¹   295.2n ± ∞ ¹   -9.56% (p=0.008 n=5)
Logb-4                   147.7n ± ∞ ¹   105.0n ± ∞ ¹  -28.91% (p=0.008 n=5)
Log1p-4                  303.4n ± ∞ ¹   266.3n ± ∞ ¹  -12.23% (p=0.008 n=5)
Log10-4                  329.2n ± ∞ ¹   298.3n ± ∞ ¹   -9.39% (p=0.008 n=5)
Log2-4                   187.4n ± ∞ ¹   153.0n ± ∞ ¹  -18.36% (p=0.008 n=5)
Modf-4                   110.5n ± ∞ ¹   103.5n ± ∞ ¹   -6.33% (p=0.008 n=5)
Nextafter32-4            128.4n ± ∞ ¹   121.5n ± ∞ ¹   -5.37% (p=0.016 n=5)
Nextafter64-4            109.5n ± ∞ ¹   110.5n ± ∞ ¹   +0.91% (p=0.008 n=5)
PowInt-4                 603.3n ± ∞ ¹   516.4n ± ∞ ¹  -14.40% (p=0.008 n=5)
PowFrac-4                1.365µ ± ∞ ¹   1.183µ ± ∞ ¹  -13.33% (p=0.008 n=5)
Pow10Pos-4               15.07n ± ∞ ¹   15.07n ± ∞ ¹        ~ (p=0.738 n=5)
Pow10Neg-4               21.11n ± ∞ ¹   21.10n ± ∞ ¹        ~ (p=0.190 n=5)
Round-4                  44.23n ± ∞ ¹   44.22n ± ∞ ¹        ~ (p=0.635 n=5)
RoundToEven-4            50.25n ± ∞ ¹   46.27n ± ∞ ¹   -7.92% (p=0.008 n=5)
Remainder-4              675.6n ± ∞ ¹   530.4n ± ∞ ¹  -21.49% (p=0.008 n=5)
Signbit-4                17.07n ± ∞ ¹   17.95n ± ∞ ¹   +5.16% (p=0.008 n=5)
Sin-4                    171.6n ± ∞ ¹   189.1n ± ∞ ¹  +10.20% (p=0.008 n=5)
Sincos-4                 201.5n ± ∞ ¹   200.5n ± ∞ ¹        ~ (p=0.421 n=5)
Sinh-4                   529.6n ± ∞ ¹   484.6n ± ∞ ¹   -8.50% (p=0.008 n=5)
SqrtIndirect-4           5.021n ± ∞ ¹   5.023n ± ∞ ¹   +0.04% (p=0.048 n=5)
SqrtLatency-4            8.032n ± ∞ ¹   8.039n ± ∞ ¹   +0.09% (p=0.024 n=5)
SqrtIndirectLatency-4    8.036n ± ∞ ¹   8.038n ± ∞ ¹        ~ (p=0.056 n=5)
SqrtGoLatency-4          338.8n ± ∞ ¹   338.7n ± ∞ ¹        ~ (p=0.841 n=5)
SqrtPrime-4              5.379µ ± ∞ ¹   5.382µ ± ∞ ¹   +0.06% (p=0.048 n=5)
Tan-4                    182.7n ± ∞ ¹   191.8n ± ∞ ¹   +4.98% (p=0.008 n=5)
Tanh-4                   558.7n ± ∞ ¹   497.6n ± ∞ ¹  -10.94% (p=0.008 n=5)
Trunc-4                  122.5n ± ∞ ¹   122.6n ± ∞ ¹        ~ (p=0.405 n=5)
Y0-4                     892.8n ± ∞ ¹   851.7n ± ∞ ¹   -4.60% (p=0.008 n=5)
Y1-4                     887.2n ± ∞ ¹   863.2n ± ∞ ¹   -2.71% (p=0.008 n=5)
Yn-4                     1.889µ ± ∞ ¹   1.832µ ± ∞ ¹   -3.02% (p=0.008 n=5)
Float64bits-4            13.05n ± ∞ ¹   13.06n ± ∞ ¹   +0.08% (p=0.040 n=5)
Float64frombits-4        13.05n ± ∞ ¹   13.06n ± ∞ ¹        ~ (p=0.143 n=5)
Float32bits-4            13.05n ± ∞ ¹   13.06n ± ∞ ¹   +0.08% (p=0.008 n=5)
Float32frombits-4        13.05n ± ∞ ¹   13.08n ± ∞ ¹   +0.23% (p=0.016 n=5)
FMA-4                    445.7n ± ∞ ¹   448.1n ± ∞ ¹   +0.54% (p=0.008 n=5)
geomean                  157.2n         142.8n         -9.17%

Change-Id: I9bf104848b588c9ecf79401a81d483d7fcdb0a79
Reviewed-on: https://go-review.googlesource.com/c/go/+/481575
Reviewed-by: M Zhuo <mzh@golangcn.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Than McIntosh <thanm@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Rong Zhang <rongrong@oss.cipunited.com>