cmd/compile: batch write barrier calls

Have the write barrier call return a pointer to a buffer into which
the generated code records pointers that need write barrier treatment.

Change-Id: I7871764298e0aa1513de417010c8d46b296b199e
Reviewed-on: https://go-review.googlesource.com/c/go/+/447781
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Bypass: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This commit is contained in:
Keith Randall 2022-11-01 16:46:43 -07:00
parent f684f3dc43
commit 21d82e6ac8
42 changed files with 712 additions and 395 deletions

View file

@ -934,9 +934,10 @@ func init() {
{name: "LoweredGetCallerSP", argLength: 1, reg: gp01, rematerializeable: true},
//arg0=ptr,arg1=mem, returns void. Faults if ptr is nil.
{name: "LoweredNilCheck", argLength: 2, reg: regInfo{inputs: []regMask{gpsp}}, clobberFlags: true, nilCheck: true, faultOnNilArg0: true},
// LoweredWB invokes runtime.gcWriteBarrier. arg0=destptr, arg1=srcptr, arg2=mem, aux=runtime.gcWriteBarrier
// LoweredWB invokes runtime.gcWriteBarrier{auxint}. arg0=mem, auxint=# of buffer entries needed.
// It saves all GP registers if necessary, but may clobber others.
{name: "LoweredWB", argLength: 3, reg: regInfo{inputs: []regMask{buildReg("DI"), buildReg("AX CX DX BX BP SI R8 R9")}, clobbers: callerSave &^ (gp | g)}, clobberFlags: true, aux: "Sym", symEffect: "None"},
// Returns a pointer to a write barrier buffer in R11.
{name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: callerSave &^ (gp | g), outputs: []regMask{buildReg("R11")}}, clobberFlags: true, aux: "Int64"},
{name: "LoweredHasCPUFeature", argLength: 0, reg: gp01, rematerializeable: true, typ: "UInt64", aux: "Sym", symEffect: "None"},