Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

cmd/compile: add saturating conversions on wasm

Browse source 
This change adds the GOWASM option "satconv" to enable the generation
of experimental saturating (non-trapping) float-to-int conversions.
It improves the performance of the conversion by 42%.

Previously the conversions had already been augmented with helper
functions to have saturating behavior. Now Wasm.rules is always using
the new operation names and wasm/ssa.go is falling back to the helpers
if the feature is not enabled.

The feature is in phase 4 of the WebAssembly proposal process:
https://github.com/WebAssembly/meetings/blob/master/process/phases.md

More information on the feature can be found at:
https://github.com/WebAssembly/nontrapping-float-to-int-conversions/blob/master/proposals/nontrapping-float-to-int-conversion/Overview.md

Change-Id: Ic6c3688017054ede804b02b6b0ffd4a02ef33ad7
Reviewed-on: https://go-review.googlesource.com/c/go/+/170119
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Richard Musiol 2019-03-24 12:14:27 +01:00 • committed by Richard Musiol
parent 1abf3aa55b
commit cf8cc7f63c
12 changed files with 80 additions and 42 deletions
Download patch file Download diff file Expand all files Collapse all files

9
src/cmd/internal/obj/wasm/wasmobj.go
View file

@ -886,7 +886,7 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
}
switch {
case p.As < AUnreachable || p.As >= ALast:
case p.As < AUnreachable:
panic(fmt.Sprintf("unexpected assembler op: %s", p.As))
case p.As < AEnd:
w.WriteByte(byte(p.As - AUnreachable + 0x00))
@ -894,8 +894,13 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
w.WriteByte(byte(p.As - AEnd + 0x0B))
case p.As < AI32Load:
w.WriteByte(byte(p.As - ADrop + 0x1A))
default:
case p.As < AI32TruncSatF32S:
w.WriteByte(byte(p.As - AI32Load + 0x28))
case p.As < ALast:
w.WriteByte(0xFC)
w.WriteByte(byte(p.As - AI32TruncSatF32S + 0x00))
default:
panic(fmt.Sprintf("unexpected assembler op: %s", p.As))
}
switch p.As {