cmd/compile, cmd/internal/obj: record register maps in binary

This adds FUNCDATA and PCDATA that records the register maps much like
the existing live arguments maps and live locals maps. The register
map is indexed independently from the argument and locals maps since
changes in register liveness tend not to correlate with changes to
argument and local liveness.

This is the final CL toward adding safe-points everywhere. The
following CLs will optimize liveness analysis to bring down the cost.
The effect of this CL is:

name        old time/op       new time/op       delta
Template          195ms ± 2%        197ms ± 1%    ~     (p=0.136 n=9+9)
Unicode          98.4ms ± 2%       99.7ms ± 1%  +1.39%  (p=0.004 n=10+10)
GoTypes           685ms ± 1%        700ms ± 1%  +2.06%  (p=0.000 n=9+9)
Compiler          3.28s ± 1%        3.34s ± 0%  +1.71%  (p=0.000 n=9+8)
SSA               7.79s ± 1%        7.91s ± 1%  +1.55%  (p=0.000 n=10+9)
Flate             133ms ± 2%        133ms ± 2%    ~     (p=0.190 n=10+10)
GoParser          161ms ± 2%        164ms ± 3%  +1.83%  (p=0.015 n=10+10)
Reflect           450ms ± 1%        457ms ± 1%  +1.62%  (p=0.000 n=10+10)
Tar               183ms ± 2%        185ms ± 1%  +0.91%  (p=0.008 n=9+10)
XML               234ms ± 1%        238ms ± 1%  +1.60%  (p=0.000 n=9+9)
[Geo mean]        411ms             417ms       +1.40%

name        old exe-bytes     new exe-bytes     delta
HelloSize         1.47M ± 0%        1.51M ± 0%  +2.79%  (p=0.000 n=10+10)

Compared to just before "cmd/internal/obj: consolidate emitting entry
stack map", the cumulative effect of adding stack maps everywhere and
register maps is:

name        old time/op       new time/op       delta
Template          185ms ± 2%        197ms ± 1%   +6.42%  (p=0.000 n=10+9)
Unicode          96.3ms ± 3%       99.7ms ± 1%   +3.60%  (p=0.000 n=10+10)
GoTypes           658ms ± 0%        700ms ± 1%   +6.37%  (p=0.000 n=10+9)
Compiler          3.14s ± 1%        3.34s ± 0%   +6.53%  (p=0.000 n=9+8)
SSA               7.41s ± 2%        7.91s ± 1%   +6.71%  (p=0.000 n=9+9)
Flate             126ms ± 1%        133ms ± 2%   +6.15%  (p=0.000 n=10+10)
GoParser          153ms ± 1%        164ms ± 3%   +6.89%  (p=0.000 n=10+10)
Reflect           437ms ± 1%        457ms ± 1%   +4.59%  (p=0.000 n=10+10)
Tar               178ms ± 1%        185ms ± 1%   +4.18%  (p=0.000 n=10+10)
XML               223ms ± 1%        238ms ± 1%   +6.39%  (p=0.000 n=10+9)
[Geo mean]        394ms             417ms        +5.78%

name        old alloc/op      new alloc/op      delta
Template         34.5MB ± 0%       38.0MB ± 0%  +10.19%  (p=0.000 n=10+10)
Unicode          29.3MB ± 0%       30.3MB ± 0%   +3.56%  (p=0.000 n=8+9)
GoTypes           113MB ± 0%        125MB ± 0%  +10.89%  (p=0.000 n=10+10)
Compiler          510MB ± 0%        575MB ± 0%  +12.79%  (p=0.000 n=10+10)
SSA              1.46GB ± 0%       1.64GB ± 0%  +12.40%  (p=0.000 n=10+10)
Flate            23.9MB ± 0%       25.9MB ± 0%   +8.56%  (p=0.000 n=10+10)
GoParser         28.0MB ± 0%       30.8MB ± 0%  +10.08%  (p=0.000 n=10+10)
Reflect          77.6MB ± 0%       84.3MB ± 0%   +8.63%  (p=0.000 n=10+10)
Tar              34.1MB ± 0%       37.0MB ± 0%   +8.44%  (p=0.000 n=10+10)
XML              42.7MB ± 0%       47.2MB ± 0%  +10.75%  (p=0.000 n=10+10)
[Geo mean]       76.0MB            83.3MB        +9.60%

name        old allocs/op     new allocs/op     delta
Template           321k ± 0%         337k ± 0%   +4.98%  (p=0.000 n=10+10)
Unicode            337k ± 0%         340k ± 0%   +1.04%  (p=0.000 n=10+9)
GoTypes           1.13M ± 0%        1.18M ± 0%   +4.85%  (p=0.000 n=10+10)
Compiler          4.67M ± 0%        4.96M ± 0%   +6.25%  (p=0.000 n=10+10)
SSA               11.7M ± 0%        12.3M ± 0%   +5.69%  (p=0.000 n=10+10)
Flate              216k ± 0%         226k ± 0%   +4.52%  (p=0.000 n=10+9)
GoParser           271k ± 0%         283k ± 0%   +4.52%  (p=0.000 n=10+10)
Reflect            927k ± 0%         972k ± 0%   +4.78%  (p=0.000 n=10+10)
Tar                318k ± 0%         333k ± 0%   +4.56%  (p=0.000 n=10+10)
XML                376k ± 0%         395k ± 0%   +5.04%  (p=0.000 n=10+10)
[Geo mean]         730k              764k        +4.61%

name        old exe-bytes     new exe-bytes     delta
HelloSize         1.46M ± 0%        1.51M ± 0%   +3.66%  (p=0.000 n=10+10)

For #24543.

Change-Id: I91e003dc64151916b384274884bf02a2d6862547
Reviewed-on: https://go-review.googlesource.com/109353
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go
index c829bfdec1..f730b509d6 100644
--- a/src/runtime/symtab.go
+++ b/src/runtime/symtab.go
@@ -343,9 +343,11 @@ func (f *Func) funcInfo() funcInfo {
 const (
 	_PCDATA_StackMapIndex       = 0
 	_PCDATA_InlTreeIndex        = 1
+	_PCDATA_RegMapIndex         = 2
 	_FUNCDATA_ArgsPointerMaps   = 0
 	_FUNCDATA_LocalsPointerMaps = 1
 	_FUNCDATA_InlTree           = 2
+	_FUNCDATA_RegPointerMaps    = 3
 	_ArgsSizeUnknown            = -0x80000000
 )