cmd/compile/internal: optimize multiplication use new operation 'ADDshiftLLV' on...

cmd/compile/internal: optimize multiplication use new operation 'ADDshiftLLV' on loong64

goos: linux
goarch: loong64
pkg: cmd/compile/internal/test
cpu: Loongson-3A6000-HV @ 2500.00MHz
                  │     old      │                 new                  │
                  │    sec/op    │    sec/op     vs base                │
MulconstI32/3       0.8004n ± 0%   0.4247n ± 2%  -46.94% (p=0.000 n=10)
MulconstI32/5       0.8005n ± 0%   0.4256n ± 1%  -46.83% (p=0.000 n=10)
MulconstI32/12      1.2010n ± 0%   0.8005n ± 0%  -33.35% (p=0.000 n=10)
MulconstI32/120     0.8090n ± 0%   0.8067n ± 0%   -0.28% (p=0.007 n=10)
MulconstI32/-120    0.8109n ± 0%   0.8072n ± 0%   -0.47% (p=0.000 n=10)
MulconstI32/65537   0.8004n ± 0%   0.8004n ± 0%        ~ (p=1.000 n=10)
MulconstI32/65538   0.8005n ± 0%   0.8005n ± 0%        ~ (p=0.265 n=10)
MulconstI64/3       0.8005n ± 0%   0.4241n ± 1%  -47.02% (p=0.000 n=10)
MulconstI64/5       0.8004n ± 0%   0.4249n ± 1%  -46.91% (p=0.000 n=10)
MulconstI64/12      1.2010n ± 0%   0.8004n ± 0%  -33.36% (p=0.000 n=10)
MulconstI64/120     0.8005n ± 0%   0.8005n ± 0%        ~ (p=0.635 n=10)
MulconstI64/-120    0.8005n ± 0%   0.8005n ± 0%        ~ (p=0.837 n=10)
MulconstI64/65537   0.8005n ± 0%   0.8005n ± 0%        ~ (p=0.837 n=10)
MulconstI64/65538   0.8096n ± 0%   0.8004n ± 0%   -1.14% (p=0.000 n=10)
MulconstU32/3       0.8004n ± 0%   0.4263n ± 1%  -46.75% (p=0.000 n=10)
MulconstU32/5       0.8005n ± 0%   0.4262n ± 1%  -46.76% (p=0.000 n=10)
MulconstU32/12      1.2010n ± 0%   0.8005n ± 0%  -33.35% (p=0.000 n=10)
MulconstU32/120     0.8105n ± 0%   0.8096n ± 0%        ~ (p=0.183 n=10)
MulconstU32/65537   0.8004n ± 0%   0.8004n ± 0%        ~ (p=1.000 n=10)
MulconstU32/65538   0.8005n ± 0%   0.8005n ± 0%        ~ (p=1.000 n=10)
MulconstU64/3       0.8004n ± 0%   0.4265n ± 4%  -46.71% (p=0.000 n=10)
MulconstU64/5       0.8004n ± 0%   0.4256n ± 0%  -46.82% (p=0.000 n=10)
MulconstU64/12      1.2010n ± 0%   0.8004n ± 0%  -33.36% (p=0.000 n=10)
MulconstU64/120     0.8005n ± 0%   0.8005n ± 0%        ~ (p=0.387 n=10)
MulconstU64/65537   0.8005n ± 0%   0.8005n ± 0%        ~ (p=0.265 n=10)
MulconstU64/65538   0.8080n ± 0%   0.8004n ± 0%   -0.93% (p=0.000 n=10)
geomean             0.8539n        0.6597n       -22.74%

Change-Id: Ie33e88985d7639f481bbba540bc917b9f185c357
Reviewed-on: https://go-review.googlesource.com/c/go/+/693855
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: sophie zhao <zhaoxiaolin@loongson.cn>
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>