cmd/compile/internal: intrinsify publicationBarrier on mipsx

This enables publicationBarrier to be used as an intrinsic on mipsx.

Change-Id: Ic199f34b84b3058bcfab79aac8f2399ff21a97ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/674856
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>

src/cmd/compile/internal/mips/ssa.go

@@ -804,6 +804,9 @@ func ssaGenValue(s *ssagen.State, v *ssa.Value) {
 		p := s.Prog(obj.AGETCALLERPC)
 		p.To.Type = obj.TYPE_REG
 		p.To.Reg = v.Reg()
+	case ssa.OpMIPSLoweredPubBarrier:
+		// SYNC
+		s.Prog(v.Op.Asm())
 	case ssa.OpClobber, ssa.OpClobberReg:
 		// TODO: implement for clobberdead experiment. Nop is ok for now.
 	default:

src/cmd/compile/internal/ssa/_gen/MIPS.rules

@@ -420,6 +420,9 @@
 // Write barrier.
 (WB ...) => (LoweredWB ...)
 
+// Publication barrier as intrinsic
+(PubBarrier ...) => (LoweredPubBarrier ...)
+
 (PanicBounds [kind] x y mem) && boundsABI(kind) == 0 => (LoweredPanicBoundsA [kind] x y mem)
 (PanicBounds [kind] x y mem) && boundsABI(kind) == 1 => (LoweredPanicBoundsB [kind] x y mem)
 (PanicBounds [kind] x y mem) && boundsABI(kind) == 2 => (LoweredPanicBoundsC [kind] x y mem)

src/cmd/compile/internal/ssa/_gen/MIPSOps.go

@@ -408,6 +408,9 @@ func init() {
 		// Returns a pointer to a write barrier buffer in R25.
 		{name: "LoweredWB", argLength: 1, reg: regInfo{clobbers: (callerSave &^ gpg) | buildReg("R31"), outputs: []regMask{buildReg("R25")}}, clobberFlags: true, aux: "Int64"},
 
+		// Do data barrier. arg0=memorys
+		{name: "LoweredPubBarrier", argLength: 1, asm: "SYNC", hasSideEffects: true},
+
 		// There are three of these functions so that they can have three different register inputs.
 		// When we check 0 <= c <= cap (A), then 0 <= b <= c (B), then 0 <= a <= b (C), we want the
 		// default registers to match so we don't need to copy registers around unnecessarily.

src/cmd/compile/internal/ssa/opGen.go

@@ -2076,6 +2076,7 @@ const (
 	OpMIPSLoweredGetCallerSP
 	OpMIPSLoweredGetCallerPC
 	OpMIPSLoweredWB
+	OpMIPSLoweredPubBarrier
 	OpMIPSLoweredPanicBoundsA
 	OpMIPSLoweredPanicBoundsB
 	OpMIPSLoweredPanicBoundsC
@@ -27990,6 +27991,13 @@ var opcodeTable = [...]opInfo{
 			},
 		},
 	},
+	{
+		name:           "LoweredPubBarrier",
+		argLen:         1,
+		hasSideEffects: true,
+		asm:            mips.ASYNC,
+		reg:            regInfo{},
+	},
 	{
 		name:    "LoweredPanicBoundsA",
 		auxType: auxInt64,

src/cmd/compile/internal/ssa/rewriteMIPS.go

@@ -450,6 +450,9 @@ func rewriteValueMIPS(v *Value) bool {
 		return rewriteValueMIPS_OpPanicBounds(v)
 	case OpPanicExtend:
 		return rewriteValueMIPS_OpPanicExtend(v)
+	case OpPubBarrier:
+		v.Op = OpMIPSLoweredPubBarrier
+		return true
 	case OpRotateLeft16:
 		return rewriteValueMIPS_OpRotateLeft16(v)
 	case OpRotateLeft32:

src/cmd/compile/internal/ssagen/intrinsics.go

@@ -163,7 +163,7 @@ func initIntrinsics(cfg *intrinsicBuildConfig) {
 			s.vars[memVar] = s.newValue1(ssa.OpPubBarrier, types.TypeMem, s.mem())
 			return nil
 		},
-		sys.ARM64, sys.Loong64, sys.MIPS64, sys.PPC64, sys.RISCV64)
+		sys.ARM64, sys.Loong64, sys.MIPS, sys.MIPS64, sys.PPC64, sys.RISCV64)
 
 	/******** internal/runtime/sys ********/
 	add("internal/runtime/sys", "GetCallerPC",

src/cmd/compile/internal/ssagen/intrinsics_test.go

@@ -554,6 +554,7 @@ var wantIntrinsics = map[testIntrinsicKey]struct{}{
 	{"mips", "math/bits", "TrailingZeros64"}:                           struct{}{},
 	{"mips", "math/bits", "TrailingZeros8"}:                            struct{}{},
 	{"mips", "runtime", "KeepAlive"}:                                   struct{}{},
+	{"mips", "runtime", "publicationBarrier"}:                          struct{}{},
 	{"mips", "runtime", "slicebytetostringtmp"}:                        struct{}{},
 	{"mips", "sync", "runtime_LoadAcquintptr"}:                         struct{}{},
 	{"mips", "sync", "runtime_StoreReluintptr"}:                        struct{}{},
@@ -799,6 +800,7 @@ var wantIntrinsics = map[testIntrinsicKey]struct{}{
 	{"mipsle", "math/bits", "TrailingZeros64"}:                         struct{}{},
 	{"mipsle", "math/bits", "TrailingZeros8"}:                          struct{}{},
 	{"mipsle", "runtime", "KeepAlive"}:                                 struct{}{},
+	{"mipsle", "runtime", "publicationBarrier"}:                        struct{}{},
 	{"mipsle", "runtime", "slicebytetostringtmp"}:                      struct{}{},
 	{"mipsle", "sync", "runtime_LoadAcquintptr"}:                       struct{}{},
 	{"mipsle", "sync", "runtime_StoreReluintptr"}:                      struct{}{},