[wasm] Introduce special bytecodes for asm.js division/remainder instead of relying on module state.

src/compiler/wasm-compiler.cc

Index: src/compiler/wasm-compiler.cc
diff --git a/src/compiler/wasm-compiler.cc b/src/compiler/wasm-compiler.cc
index b543c80e5722fc7828a65e019371359e0d8a1f01..c985115b8c9e67bdff8e10bc9d7a84d91b878678 100644
--- a/src/compiler/wasm-compiler.cc
+++ b/src/compiler/wasm-compiler.cc
@@ -614,15 +614,20 @@ Node* WasmGraphBuilder::Binop(wasm::WasmOpcode opcode, Node* left, Node* right,
       return BuildF32Max(left, right);
     case wasm::kExprF64Max:
       return BuildF64Max(left, right);
-    case wasm::kExprF64Pow: {
+    case wasm::kExprF64Pow:
       return BuildF64Pow(left, right);
-    }
-    case wasm::kExprF64Atan2: {
+    case wasm::kExprF64Atan2:
       return BuildF64Atan2(left, right);
-    }
-    case wasm::kExprF64Mod: {
+    case wasm::kExprF64Mod:
       return BuildF64Mod(left, right);
-    }
+    case wasm::kExprI32AsmjsDivS:
+      return BuildI32AsmjsDivS(left, right);
+    case wasm::kExprI32AsmjsDivU:
+      return BuildI32AsmjsDivU(left, right);
+    case wasm::kExprI32AsmjsRemS:
+      return BuildI32AsmjsRemS(left, right);
+    case wasm::kExprI32AsmjsRemU:
+      return BuildI32AsmjsRemU(left, right);
     default:
       op = UnsupportedOpcode(opcode);
   }
@@ -1591,34 +1596,6 @@ Node* WasmGraphBuilder::BuildFloatToIntConversionInstruction(
 Node* WasmGraphBuilder::BuildI32DivS(Node* left, Node* right,
                                      wasm::WasmCodePosition position) {
   MachineOperatorBuilder* m = jsgraph()->machine();
-  if (module_ && module_->asm_js()) {
-    // asm.js semantics return 0 on divide or mod by zero.
-    if (m->Int32DivIsSafe()) {
-      // The hardware instruction does the right thing (e.g. arm).
-      return graph()->NewNode(m->Int32Div(), left, right, graph()->start());
-    }
-
-    // Check denominator for zero.
-    Diamond z(
-        graph(), jsgraph()->common(),
-        graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
-        BranchHint::kFalse);
-
-    // Check numerator for -1. (avoid minint / -1 case).
-    Diamond n(
-        graph(), jsgraph()->common(),
-        graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(-1)),
-        BranchHint::kFalse);
-
-    Node* div = graph()->NewNode(m->Int32Div(), left, right, z.if_false);
-    Node* neg =
-        graph()->NewNode(m->Int32Sub(), jsgraph()->Int32Constant(0), left);
-
-    return n.Phi(MachineRepresentation::kWord32, neg,
-                 z.Phi(MachineRepresentation::kWord32,
-                       jsgraph()->Int32Constant(0), div));
-  }
-
   trap_->ZeroCheck32(wasm::kTrapDivByZero, right, position);
   Node* before = *control_;
   Node* denom_is_m1;
@@ -1640,26 +1617,6 @@ Node* WasmGraphBuilder::BuildI32DivS(Node* left, Node* right,
 Node* WasmGraphBuilder::BuildI32RemS(Node* left, Node* right,
                                      wasm::WasmCodePosition position) {
   MachineOperatorBuilder* m = jsgraph()->machine();
-  if (module_ && module_->asm_js()) {
-    // asm.js semantics return 0 on divide or mod by zero.
-    // Explicit check for x % 0.
-    Diamond z(
-        graph(), jsgraph()->common(),
-        graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
-        BranchHint::kFalse);
-
-    // Explicit check for x % -1.
-    Diamond d(
-        graph(), jsgraph()->common(),
-        graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(-1)),
-        BranchHint::kFalse);
-    d.Chain(z.if_false);
-
-    return z.Phi(
-        MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
-        d.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
-              graph()->NewNode(m->Int32Mod(), left, right, d.if_false)));
-  }
 
   trap_->ZeroCheck32(wasm::kTrapRemByZero, right, position);
 
@@ -1676,23 +1633,6 @@ Node* WasmGraphBuilder::BuildI32RemS(Node* left, Node* right,
 Node* WasmGraphBuilder::BuildI32DivU(Node* left, Node* right,
                                      wasm::WasmCodePosition position) {
   MachineOperatorBuilder* m = jsgraph()->machine();
-  if (module_ && module_->asm_js()) {
-    // asm.js semantics return 0 on divide or mod by zero.
-    if (m->Uint32DivIsSafe()) {
-      // The hardware instruction does the right thing (e.g. arm).
-      return graph()->NewNode(m->Uint32Div(), left, right, graph()->start());
-    }
-
-    // Explicit check for x % 0.
-    Diamond z(
-        graph(), jsgraph()->common(),
-        graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
-        BranchHint::kFalse);
-
-    return z.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
-                 graph()->NewNode(jsgraph()->machine()->Uint32Div(), left,
-                                  right, z.if_false));
-  }
   return graph()->NewNode(
       m->Uint32Div(), left, right,
       trap_->ZeroCheck32(wasm::kTrapDivByZero, right, position));
@@ -1701,25 +1641,96 @@ Node* WasmGraphBuilder::BuildI32DivU(Node* left, Node* right,
 Node* WasmGraphBuilder::BuildI32RemU(Node* left, Node* right,
                                      wasm::WasmCodePosition position) {
   MachineOperatorBuilder* m = jsgraph()->machine();
-  if (module_ && module_->asm_js()) {
-    // asm.js semantics return 0 on divide or mod by zero.
-    // Explicit check for x % 0.
-    Diamond z(
-        graph(), jsgraph()->common(),
-        graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
-        BranchHint::kFalse);
-
-    Node* rem = graph()->NewNode(jsgraph()->machine()->Uint32Mod(), left, right,
-                                 z.if_false);
-    return z.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
-                 rem);
-  }
-
   return graph()->NewNode(
       m->Uint32Mod(), left, right,
       trap_->ZeroCheck32(wasm::kTrapRemByZero, right, position));
 }
 
+Node* WasmGraphBuilder::BuildI32AsmjsDivS(Node* left, Node* right) {
+  MachineOperatorBuilder* m = jsgraph()->machine();
+  // asm.js semantics return 0 on divide or mod by zero.
+  if (m->Int32DivIsSafe()) {
+    // The hardware instruction does the right thing (e.g. arm).
+    return graph()->NewNode(m->Int32Div(), left, right, graph()->start());
+  }
+
+  // Check denominator for zero.
+  Diamond z(
+      graph(), jsgraph()->common(),
+      graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
+      BranchHint::kFalse);
+
+  // Check numerator for -1. (avoid minint / -1 case).
+  Diamond n(
+      graph(), jsgraph()->common(),
+      graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(-1)),
+      BranchHint::kFalse);
+
+  Node* div = graph()->NewNode(m->Int32Div(), left, right, z.if_false);
+  Node* neg =
+      graph()->NewNode(m->Int32Sub(), jsgraph()->Int32Constant(0), left);
+
+  return n.Phi(
+      MachineRepresentation::kWord32, neg,
+      z.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0), div));
+}
+
+Node* WasmGraphBuilder::BuildI32AsmjsRemS(Node* left, Node* right) {
+  MachineOperatorBuilder* m = jsgraph()->machine();
+  // asm.js semantics return 0 on divide or mod by zero.
+  // Explicit check for x % 0.
+  Diamond z(
+      graph(), jsgraph()->common(),
+      graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
+      BranchHint::kFalse);
+
+  // Explicit check for x % -1.
+  Diamond d(
+      graph(), jsgraph()->common(),
+      graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(-1)),
+      BranchHint::kFalse);
+  d.Chain(z.if_false);
+
+  return z.Phi(
+      MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
+      d.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
+            graph()->NewNode(m->Int32Mod(), left, right, d.if_false)));
+}
+
+Node* WasmGraphBuilder::BuildI32AsmjsDivU(Node* left, Node* right) {
+  MachineOperatorBuilder* m = jsgraph()->machine();
+  // asm.js semantics return 0 on divide or mod by zero.
+  if (m->Uint32DivIsSafe()) {
+    // The hardware instruction does the right thing (e.g. arm).
+    return graph()->NewNode(m->Uint32Div(), left, right, graph()->start());
+  }
+
+  // Explicit check for x % 0.
+  Diamond z(
+      graph(), jsgraph()->common(),
+      graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
+      BranchHint::kFalse);
+
+  return z.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
+               graph()->NewNode(jsgraph()->machine()->Uint32Div(), left, right,
+                                z.if_false));
+}
+
+Node* WasmGraphBuilder::BuildI32AsmjsRemU(Node* left, Node* right) {
+  MachineOperatorBuilder* m = jsgraph()->machine();
+  // asm.js semantics return 0 on divide or mod by zero.
+  // Explicit check for x % 0.
+  Diamond z(
+      graph(), jsgraph()->common(),
+      graph()->NewNode(m->Word32Equal(), right, jsgraph()->Int32Constant(0)),
+      BranchHint::kFalse);
+
+  Node* rem = graph()->NewNode(jsgraph()->machine()->Uint32Mod(), left, right,
+                               z.if_false);
+  return z.Phi(MachineRepresentation::kWord32, jsgraph()->Int32Constant(0),
+               rem);
+}
+
 Node* WasmGraphBuilder::BuildI64DivS(Node* left, Node* right,
                                      wasm::WasmCodePosition position) {
   if (jsgraph()->machine()->Is32()) {