• Martin Möhrmann's avatar
    cmd/compile: generate makechan calls with int arguments · 8a6e51ae
    Martin Möhrmann authored
    Where possible generate calls to runtime makechan with int arguments
    during compile time instead of makechan with int64 arguments.
    
    This eliminates converting arguments for calls to makechan with
    int64 arguments for platforms where int64 values do not fit into
    arguments of type int.
    
    A similar optimization for makeslice was introduced in CL
    golang.org/cl/27851.
    
    386:
    name                old time/op  new time/op  delta
    MakeChan/Byte       52.4ns ± 6%  45.0ns ± 1%  -14.14%  (p=0.000 n=10+10)
    MakeChan/Int        54.5ns ± 1%  49.1ns ± 1%   -9.87%  (p=0.000 n=10+10)
    MakeChan/Ptr         150ns ± 1%   143ns ± 0%   -4.38%  (p=0.000 n=9+7)
    MakeChan/Struct/0   49.2ns ± 2%  43.2ns ± 2%  -12.27%  (p=0.000 n=10+10)
    MakeChan/Struct/32  81.7ns ± 2%  76.2ns ± 1%   -6.71%  (p=0.000 n=10+10)
    MakeChan/Struct/40  88.4ns ± 2%  82.5ns ± 2%   -6.60%  (p=0.000 n=10+10)
    
    AMD64:
    name                old time/op  new time/op  delta
    MakeChan/Byte       83.4ns ± 8%  80.8ns ± 3%    ~     (p=0.171 n=10+10)
    MakeChan/Int         101ns ± 3%   101ns ± 2%    ~     (p=0.412 n=10+10)
    MakeChan/Ptr         128ns ± 1%   128ns ± 1%    ~     (p=0.191 n=10+10)
    MakeChan/Struct/0   67.6ns ± 3%  68.7ns ± 4%    ~     (p=0.224 n=10+10)
    MakeChan/Struct/32   138ns ± 1%   139ns ± 1%    ~     (p=0.185 n=10+9)
    MakeChan/Struct/40   154ns ± 1%   154ns ± 1%  -0.55%  (p=0.027 n=10+9)
    
    Change-Id: Ie854cb066007232c5e9f71ea7d6fe27e81a9c050
    Reviewed-on: https://go-review.googlesource.com/55140
    Run-TryBot: Martin Möhrmann <moehrmann@google.com>
    TryBot-Result: Gobot Gobot <gobot@golang.org>
    Reviewed-by: 's avatarKeith Randall <khr@golang.org>
    8a6e51ae
makechan.go 1.29 KB