cmd/compile: use ANDL for small immediates

We can rewrite ANDQ with an immediate fitting in 32bit with an ANDL, which is shorter to encode.

Looking at Go binary itself, before the change there was:

ANDL: 2337
ANDQ: 4476

After the change:

ANDL: 3790
ANDQ: 3024

So we got rid of 1452 ANDQs

This makes the Linux x86_64 binary 0.03% smaller.

There seems to be an impact on performance.

Intel Cascade Lake benchmarks (with perflock):

name                     old time/op    new time/op    delta
BinaryTree17-8              1.91s ± 1%     1.89s ± 1%  -1.22%  (p=0.000 n=21+18)
Fannkuch11-8                2.34s ± 0%     2.34s ± 0%    ~     (p=0.052 n=20+20)
FmtFprintfEmpty-8          27.7ns ± 1%    27.4ns ± 3%    ~     (p=0.497 n=21+21)
FmtFprintfString-8         53.2ns ± 0%    51.5ns ± 0%  -3.21%  (p=0.000 n=20+19)
FmtFprintfInt-8            57.3ns ± 0%    55.7ns ± 0%  -2.89%  (p=0.000 n=19+19)
FmtFprintfIntInt-8         92.3ns ± 0%    88.4ns ± 1%  -4.23%  (p=0.000 n=20+21)
FmtFprintfPrefixedInt-8     103ns ± 0%     103ns ± 0%  +0.23%  (p=0.000 n=20+21)
FmtFprintfFloat-8           147ns ± 0%     148ns ± 0%  +0.75%  (p=0.000 n=20+21)
FmtManyArgs-8               384ns ± 0%     381ns ± 0%  -0.63%  (p=0.000 n=21+21)
GobDecode-8                3.86ms ± 1%    3.88ms ± 1%  +0.52%  (p=0.000 n=20+21)
GobEncode-8                2.77ms ± 1%    2.77ms ± 0%    ~     (p=0.078 n=21+21)
Gzip-8                      168ms ± 1%     168ms ± 0%  +0.24%  (p=0.000 n=20+20)
Gunzip-8                   25.1ms ± 0%    24.3ms ± 0%  -3.03%  (p=0.000 n=21+21)
HTTPClientServer-8         61.4µs ± 8%    59.1µs ±10%    ~     (p=0.088 n=20+21)
JSONEncode-8               6.86ms ± 0%    6.70ms ± 0%  -2.29%  (p=0.000 n=20+19)
JSONDecode-8               30.8ms ± 1%    30.6ms ± 1%  -0.82%  (p=0.000 n=20+20)
Mandelbrot200-8            3.85ms ± 0%    3.85ms ± 0%    ~     (p=0.191 n=16+17)
GoParse-8                  2.61ms ± 2%    2.60ms ± 1%    ~     (p=0.561 n=21+20)
RegexpMatchEasy0_32-8      48.5ns ± 2%    45.9ns ± 3%  -5.26%  (p=0.000 n=20+21)
RegexpMatchEasy0_1K-8       139ns ± 0%     139ns ± 0%  +0.27%  (p=0.000 n=18+20)
RegexpMatchEasy1_32-8      41.3ns ± 0%    42.1ns ± 4%  +1.95%  (p=0.000 n=17+21)
RegexpMatchEasy1_1K-8       216ns ± 2%     216ns ± 0%  +0.17%  (p=0.020 n=21+19)
RegexpMatchMedium_32-8      790ns ± 7%     803ns ± 8%    ~     (p=0.178 n=21+21)
RegexpMatchMedium_1K-8     23.5µs ± 5%    23.7µs ± 5%    ~     (p=0.421 n=21+21)
RegexpMatchHard_32-8       1.09µs ± 1%    1.09µs ± 1%  -0.53%  (p=0.000 n=19+18)
RegexpMatchHard_1K-8       33.0µs ± 0%    33.0µs ± 0%    ~     (p=0.610 n=21+20)
Revcomp-8                   348ms ± 0%     353ms ± 0%  +1.38%  (p=0.000 n=17+18)
Template-8                 42.0ms ± 1%    41.9ms ± 1%  -0.30%  (p=0.049 n=20+20)
TimeParse-8                 185ns ± 0%     185ns ± 0%    ~     (p=0.387 n=20+18)
TimeFormat-8                237ns ± 1%     241ns ± 1%  +1.57%  (p=0.000 n=21+21)
[Geo mean]                 35.4µs         35.2µs       -0.66%

name                     old speed      new speed      delta
GobDecode-8               199MB/s ± 1%   198MB/s ± 1%  -0.52%  (p=0.000 n=20+21)
GobEncode-8               277MB/s ± 1%   277MB/s ± 0%    ~     (p=0.075 n=21+21)
Gzip-8                    116MB/s ± 1%   115MB/s ± 0%  -0.25%  (p=0.000 n=20+20)
Gunzip-8                  773MB/s ± 0%   797MB/s ± 0%  +3.12%  (p=0.000 n=21+21)
JSONEncode-8              283MB/s ± 0%   290MB/s ± 0%  +2.35%  (p=0.000 n=20+19)
JSONDecode-8             63.0MB/s ± 1%  63.5MB/s ± 1%  +0.82%  (p=0.000 n=20+20)
GoParse-8                22.2MB/s ± 2%  22.3MB/s ± 1%    ~     (p=0.539 n=21+20)
RegexpMatchEasy0_32-8     660MB/s ± 2%   697MB/s ± 3%  +5.57%  (p=0.000 n=20+21)
RegexpMatchEasy0_1K-8    7.36GB/s ± 0%  7.34GB/s ± 0%  -0.26%  (p=0.000 n=18+20)
RegexpMatchEasy1_32-8     775MB/s ± 0%   761MB/s ± 4%  -1.88%  (p=0.000 n=17+21)
RegexpMatchEasy1_1K-8    4.74GB/s ± 2%  4.74GB/s ± 0%  -0.18%  (p=0.020 n=21+19)
RegexpMatchMedium_32-8   40.6MB/s ± 7%  39.9MB/s ± 9%    ~     (p=0.191 n=21+21)
RegexpMatchMedium_1K-8   43.7MB/s ± 5%  43.2MB/s ± 5%    ~     (p=0.435 n=21+21)
RegexpMatchHard_32-8     29.3MB/s ± 1%  29.4MB/s ± 1%  +0.53%  (p=0.000 n=19+18)
RegexpMatchHard_1K-8     31.0MB/s ± 0%  31.0MB/s ± 0%    ~     (p=0.572 n=21+20)
Revcomp-8                 730MB/s ± 0%   720MB/s ± 0%  -1.36%  (p=0.000 n=17+18)
Template-8               46.2MB/s ± 1%  46.3MB/s ± 1%  +0.30%  (p=0.041 n=20+20)
[Geo mean]                204MB/s        205MB/s       +0.30%

Change-Id: Iac75d0ec184a515ce0e65e19559d5fe2e9840514
Reviewed-on: https://go-review.googlesource.com/c/go/+/354970


Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>