cmd/compile: apply optimization for readonly globals on wasm

Extend the optimization introduced in CL 141118 to the wasm architecture.

And for reference, the rules trigger 212 times while building std and cmd

$GOOS=js GOARCH=wasm gotip build std cmd
$grep -E "Wasm.rules:44(1|2|3|4)" rulelog | wc -l
212

Updates #26498

Change-Id: I153684a2b98589ae812b42268da08b65679e09d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/185477
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Richard Musiol <neelance@gmail.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/ssa/rewriteWasm.go b/src/cmd/compile/internal/ssa/rewriteWasm.go
index f57305dade..f374565327 100644
--- a/src/cmd/compile/internal/ssa/rewriteWasm.go
+++ b/src/cmd/compile/internal/ssa/rewriteWasm.go
@@ -5508,6 +5508,8 @@ func rewriteValueWasm_OpWasmI64Eqz_0(v *Value) bool {
 	return false
 }
 func rewriteValueWasm_OpWasmI64Load_0(v *Value) bool {
+	b := v.Block
+	config := b.Func.Config
 	// match: (I64Load [off] (I64AddConst [off2] ptr) mem)
 	// cond: isU32Bit(off+off2)
 	// result: (I64Load [off+off2] ptr mem)
@@ -5529,6 +5531,29 @@ func rewriteValueWasm_OpWasmI64Load_0(v *Value) bool {
 		v.AddArg(mem)
 		return true
 	}
+	// match: (I64Load [off] (LoweredAddr {sym} [off2] (SB)) _)
+	// cond: symIsRO(sym) && isU32Bit(off+off2)
+	// result: (I64Const [int64(read64(sym, off+off2, config.BigEndian))])
+	for {
+		off := v.AuxInt
+		_ = v.Args[1]
+		v_0 := v.Args[0]
+		if v_0.Op != OpWasmLoweredAddr {
+			break
+		}
+		off2 := v_0.AuxInt
+		sym := v_0.Aux
+		v_0_0 := v_0.Args[0]
+		if v_0_0.Op != OpSB {
+			break
+		}
+		if !(symIsRO(sym) && isU32Bit(off+off2)) {
+			break
+		}
+		v.reset(OpWasmI64Const)
+		v.AuxInt = int64(read64(sym, off+off2, config.BigEndian))
+		return true
+	}
 	return false
 }
 func rewriteValueWasm_OpWasmI64Load16S_0(v *Value) bool {
@@ -5556,6 +5581,8 @@ func rewriteValueWasm_OpWasmI64Load16S_0(v *Value) bool {
 	return false
 }
 func rewriteValueWasm_OpWasmI64Load16U_0(v *Value) bool {
+	b := v.Block
+	config := b.Func.Config
 	// match: (I64Load16U [off] (I64AddConst [off2] ptr) mem)
 	// cond: isU32Bit(off+off2)
 	// result: (I64Load16U [off+off2] ptr mem)
@@ -5577,6 +5604,29 @@ func rewriteValueWasm_OpWasmI64Load16U_0(v *Value) bool {
 		v.AddArg(mem)
 		return true
 	}
+	// match: (I64Load16U [off] (LoweredAddr {sym} [off2] (SB)) _)
+	// cond: symIsRO(sym) && isU32Bit(off+off2)
+	// result: (I64Const [int64(read16(sym, off+off2, config.BigEndian))])
+	for {
+		off := v.AuxInt
+		_ = v.Args[1]
+		v_0 := v.Args[0]
+		if v_0.Op != OpWasmLoweredAddr {
+			break
+		}
+		off2 := v_0.AuxInt
+		sym := v_0.Aux
+		v_0_0 := v_0.Args[0]
+		if v_0_0.Op != OpSB {
+			break
+		}
+		if !(symIsRO(sym) && isU32Bit(off+off2)) {
+			break
+		}
+		v.reset(OpWasmI64Const)
+		v.AuxInt = int64(read16(sym, off+off2, config.BigEndian))
+		return true
+	}
 	return false
 }
 func rewriteValueWasm_OpWasmI64Load32S_0(v *Value) bool {
@@ -5604,6 +5654,8 @@ func rewriteValueWasm_OpWasmI64Load32S_0(v *Value) bool {
 	return false
 }
 func rewriteValueWasm_OpWasmI64Load32U_0(v *Value) bool {
+	b := v.Block
+	config := b.Func.Config
 	// match: (I64Load32U [off] (I64AddConst [off2] ptr) mem)
 	// cond: isU32Bit(off+off2)
 	// result: (I64Load32U [off+off2] ptr mem)
@@ -5625,6 +5677,29 @@ func rewriteValueWasm_OpWasmI64Load32U_0(v *Value) bool {
 		v.AddArg(mem)
 		return true
 	}
+	// match: (I64Load32U [off] (LoweredAddr {sym} [off2] (SB)) _)
+	// cond: symIsRO(sym) && isU32Bit(off+off2)
+	// result: (I64Const [int64(read32(sym, off+off2, config.BigEndian))])
+	for {
+		off := v.AuxInt
+		_ = v.Args[1]
+		v_0 := v.Args[0]
+		if v_0.Op != OpWasmLoweredAddr {
+			break
+		}
+		off2 := v_0.AuxInt
+		sym := v_0.Aux
+		v_0_0 := v_0.Args[0]
+		if v_0_0.Op != OpSB {
+			break
+		}
+		if !(symIsRO(sym) && isU32Bit(off+off2)) {
+			break
+		}
+		v.reset(OpWasmI64Const)
+		v.AuxInt = int64(read32(sym, off+off2, config.BigEndian))
+		return true
+	}
 	return false
 }
 func rewriteValueWasm_OpWasmI64Load8S_0(v *Value) bool {
@@ -5673,6 +5748,29 @@ func rewriteValueWasm_OpWasmI64Load8U_0(v *Value) bool {
 		v.AddArg(mem)
 		return true
 	}
+	// match: (I64Load8U [off] (LoweredAddr {sym} [off2] (SB)) _)
+	// cond: symIsRO(sym) && isU32Bit(off+off2)
+	// result: (I64Const [int64(read8(sym, off+off2))])
+	for {
+		off := v.AuxInt
+		_ = v.Args[1]
+		v_0 := v.Args[0]
+		if v_0.Op != OpWasmLoweredAddr {
+			break
+		}
+		off2 := v_0.AuxInt
+		sym := v_0.Aux
+		v_0_0 := v_0.Args[0]
+		if v_0_0.Op != OpSB {
+			break
+		}
+		if !(symIsRO(sym) && isU32Bit(off+off2)) {
+			break
+		}
+		v.reset(OpWasmI64Const)
+		v.AuxInt = int64(read8(sym, off+off2))
+		return true
+	}
 	return false
 }
 func rewriteValueWasm_OpWasmI64Mul_0(v *Value) bool {