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| author | Richard Musiol <mail@richard-musiol.de> | 2018-03-31 23:14:17 +0200 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2018-05-08 00:17:34 +0000 |
| commit | 35ea62468bf7e3a79011c3ad713e847daa9a45a2 (patch) | |
| tree | 60e4870507f6d9bae6ed07539db29f650a6e10b5 /src/runtime/rt0_js_wasm.s | |
| parent | cc0aaff40e02192356ccb65d8acf571d12f74a95 (diff) | |
| download | go-35ea62468bf7e3a79011c3ad713e847daa9a45a2.tar.gz go-35ea62468bf7e3a79011c3ad713e847daa9a45a2.zip | |
runtime: add js/wasm architecture
This commit adds the js/wasm architecture to the runtime package.
Currently WebAssembly has no support for threads yet, see
https://github.com/WebAssembly/design/issues/1073. Because of that,
there is no preemption of goroutines and no sysmon goroutine.
Design doc: https://docs.google.com/document/d/131vjr4DH6JFnb-blm_uRdaC0_Nv3OUwjEY5qVCxCup4
About WebAssembly assembly files: https://docs.google.com/document/d/1GRmy3rA4DiYtBlX-I1Jr_iHykbX8EixC3Mq0TCYqbKc
Updates #18892
Change-Id: I7f12d21b5180500d55ae9fd2f7e926a1731db391
Reviewed-on: https://go-review.googlesource.com/103877
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Diffstat (limited to 'src/runtime/rt0_js_wasm.s')
| -rw-r--r-- | src/runtime/rt0_js_wasm.s | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/src/runtime/rt0_js_wasm.s b/src/runtime/rt0_js_wasm.s new file mode 100644 index 0000000000..2a878d990c --- /dev/null +++ b/src/runtime/rt0_js_wasm.s @@ -0,0 +1,49 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "go_asm.h" +#include "textflag.h" + +// _rt0_wasm_js does NOT follow the Go ABI. It has two WebAssembly parameters: +// R0: argc (i32) +// R1: argv (i32) +TEXT _rt0_wasm_js(SB),NOSPLIT,$0 + MOVD $runtime·wasmStack+m0Stack__size(SB), SP + + Get SP + Get R0 // argc + I64ExtendUI32 + I64Store $0 + + Get SP + Get R1 // argv + I64ExtendUI32 + I64Store $8 + + I32Const $runtime·rt0_go(SB) + I32Const $16 + I32ShrU + Set PC_F + +// Call the function for the current PC_F. Repeat until SP=0 indicates program end. +// The WebAssembly stack may unwind, e.g. when switching goroutines. +// The Go stack on the linear memory is then used to jump to the correct functions +// with this loop, without having to restore the full WebAssembly stack. +loop: + Loop + Get SP + I32Eqz + If + Return + End + + Get PC_F + CallIndirect $0 + Drop + + Br loop + End + +TEXT _rt0_wasm_js_lib(SB),NOSPLIT,$0 + UNDEF |