cmd/compile, reflect: further allow inlining of TypeFor
Previous CLs optimized direct use of abi.Type, but reflect.Type is
indirected, so was not benefiting.
For TypeFor, we can use toRType directly without a nil check because the
types are statically known.
Normally, I'd think SSA would remove the nil check, but due to some
oddity (specifically, late fuse being required to remove the nil check,
but opt doesn't run that late) means that the nil check persists and
gets in the way.
Manually writing the code in this instance seems to fix the problem.
It also exposed another problem; depending on the ordering, writeType
could get to a type symbol before SSA, thereby preventing Extra from
being created on the symbol for later lookups that don't go through
TypeLinksym directly. In writeType, for non-shape types, call
TypeLinksym to ensure that the type is set up for later callers. That
change itself passed toolstash -cmp.
All up, this stack put through compilecmp shows a lot of improvement in
various reflect-using packages, and reflect itself. It is too big to fit
in the commit message but here's some info:
compilecmp master -> HEAD
master (
d767064170): cmd/compile: mark abi.PtrType.Elem sym as used
HEAD (
846a94c568): cmd/compile, reflect: further allow inlining of TypeFor
file before after Δ %
addr2line
3735911 3735391 -520 -0.014%
asm
6382235 6382091 -144 -0.002%
buildid
3608568 3608360 -208 -0.006%
cgo
5951816 5951480 -336 -0.006%
compile
28362080 28339772 -22308 -0.079%
cover
6668686 6661414 -7272 -0.109%
dist
4311961 4311425 -536 -0.012%
fix
3771706 3771474 -232 -0.006%
link
8686073 8684993 -1080 -0.012%
nm
3715923 3715459 -464 -0.012%
objdump
6074366 6073774 -592 -0.010%
pack
3025653 3025277 -376 -0.012%
pprof
18269485 18261653 -7832 -0.043%
test2json
3442726 3438390 -4336 -0.126%
trace
16984831 16981767 -3064 -0.018%
vet
10701931 10696355 -5576 -0.052%
total
133693951 133639075 -54876 -0.041%
runtime
runtime.stkobjinit 240 -> 165 (-31.25%)
runtime [cmd/compile]
runtime.stkobjinit 240 -> 165 (-31.25%)
reflect
reflect.Value.Seq2.func3 309 -> 245 (-20.71%)
reflect.Value.Seq2.func1.1 281 -> 198 (-29.54%)
reflect.Value.Seq.func1.1 242 -> 165 (-31.82%)
reflect.Value.Seq2.func2 360 -> 285 (-20.83%)
reflect.Value.Seq.func4 281 -> 239 (-14.95%)
reflect.Value.Seq2.func4 399 -> 284 (-28.82%)
reflect.Value.Seq.func2 271 -> 230 (-15.13%)
reflect.TypeFor[go.shape.uint64] 33 -> 18 (-45.45%)
reflect.Value.Seq.func3 219 -> 178 (-18.72%)
reflect [cmd/compile]
reflect.Value.Seq2.func2 360 -> 285 (-20.83%)
reflect.Value.Seq.func4 281 -> 239 (-14.95%)
reflect.Value.Seq.func2 271 -> 230 (-15.13%)
reflect.Value.Seq.func1.1 242 -> 165 (-31.82%)
reflect.Value.Seq2.func1.1 281 -> 198 (-29.54%)
reflect.Value.Seq2.func3 309 -> 245 (-20.71%)
reflect.Value.Seq.func3 219 -> 178 (-18.72%)
reflect.TypeFor[go.shape.uint64] 33 -> 18 (-45.45%)
reflect.Value.Seq2.func4 399 -> 284 (-28.82%)
fmt
fmt.(*pp).fmtBytes 1723 -> 1691 (-1.86%)
database/sql/driver
reflect.TypeFor[go.shape.interface 33 -> 18 (-45.45%)
database/sql/driver.init 72 -> 57 (-20.83%)
Change-Id: I9eb750cf0b7ebf532589f939431feb0a899e42ff
Reviewed-on: https://go-review.googlesource.com/c/go/+/701301
Reviewed-by: Mark Freeman <markfreeman@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>