[wasm] Clean up float to integer conversions

Cleans up the implementation of trapping/saturating operations to
use existing models of types, instead of defining new ones. That is,
it uses MachineType to represent the kind of integer/float value the
conversion is operating on.

It also removes the need to define NumericImplementation by using
the actual opcodes to determine if the instruction is trapping or
saturating.

Finally, it now defines a single method to implement the truncating
(that doesn't use a ccall) conversions. The previous code had two
methods, one for I32 and one for I64.

Bug: v8:7226
Change-Id: Ia869416c8bd1abe76d0583c28a3105102d130b46
Reviewed-on: https://chromium-review.googlesource.com/900558
Commit-Queue: Karl Schimpf <kschimpf@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51129}

src/compiler/wasm-compiler.h

@@ -255,16 +255,6 @@ typedef ZoneVector<Node*> NodeVector;
 class WasmGraphBuilder {
  public:
   enum EnforceBoundsCheck : bool { kNeedsBoundsCheck, kCanOmitBoundsCheck };
-  enum class Type {
-    kInt8s,
-    kInt8u,
-    kInt32s,
-    kInt32u,
-    kInt64s,
-    kInt64u,
-    kFloat32,
-    kFloat64
-  };
 
   WasmGraphBuilder(ModuleEnv* env, Zone* zone, JSGraph* graph,
                    Handle<Code> centry_stub, wasm::FunctionSig* sig,
@@ -459,9 +449,10 @@ class WasmGraphBuilder {
 
   bool use_trap_handler() const { return env_ && env_->use_trap_handler; }
 
- private:
-  enum class NumericImplementation : uint8_t { kTrap, kSaturate };
+  JSGraph* jsgraph() { return jsgraph_; }
+  Graph* graph();
 
+ private:
   static const int kDefaultBufferSize = 16;
 
   Zone* const zone_;
@@ -496,10 +487,6 @@ class WasmGraphBuilder {
 
   compiler::SourcePositionTable* const source_position_table_ = nullptr;
 
-  // Internal helper methods.
-  JSGraph* jsgraph() { return jsgraph_; }
-  Graph* graph();
-
   Node* String(const char* string);
   Node* MemBuffer(uint32_t offset);
   // BoundsCheckMem receives a uint32 {index} node and returns a ptrsize index.
@@ -524,18 +511,8 @@ class WasmGraphBuilder {
   Node* BuildF32CopySign(Node* left, Node* right);
   Node* BuildF64CopySign(Node* left, Node* right);
 
-  Node* BuildI32ConvertFloat(Node* input, wasm::WasmCodePosition position,
-                             NumericImplementation impl, Type int_type,
-                             Type float_type, const Operator* conv_op,
-                             const wasm::WasmOpcode check_op);
-  Node* BuildI32SConvertF32(Node* input, wasm::WasmCodePosition position,
-                            NumericImplementation impl);
-  Node* BuildI32SConvertF64(Node* input, wasm::WasmCodePosition position,
-                            NumericImplementation impl);
-  Node* BuildI32UConvertF32(Node* input, wasm::WasmCodePosition position,
-                            NumericImplementation impl);
-  Node* BuildI32UConvertF64(Node* input, wasm::WasmCodePosition position,
-                            NumericImplementation impl);
+  Node* BuildIntConvertFloat(Node* input, wasm::WasmCodePosition position,
+                             wasm::WasmOpcode);
   Node* BuildI32Ctz(Node* input);
   Node* BuildI32Popcnt(Node* input);
   Node* BuildI64Ctz(Node* input);
@@ -574,15 +551,8 @@ class WasmGraphBuilder {
       Node* input, ExternalReference ref,
       MachineRepresentation parameter_representation,
       const MachineType result_type, wasm::WasmCodePosition position);
-  Node* BuildI64CcallConvertFloat(Node* input, wasm::WasmCodePosition position,
-                                  NumericImplementation impl, Type int_type,
-                                  Type float_type, ExternalReference call_ref);
-  Node* BuildI64TruncConvertFloat(Node* input, wasm::WasmCodePosition position,
-                                  NumericImplementation impl, Type int_type,
-                                  Type float_type, const Operator* trunc_op);
-
-  Node* BuildI64SConvertF32(Node* input, wasm::WasmCodePosition position,
-                            NumericImplementation impl);
+  Node* BuildCcallConvertFloat(Node* input, wasm::WasmCodePosition position,
+                               wasm::WasmOpcode opcode);
   Node* BuildI64UConvertF32(Node* input, wasm::WasmCodePosition position);
   Node* BuildI64SConvertF64(Node* input, wasm::WasmCodePosition position);
   Node* BuildI64UConvertF64(Node* input, wasm::WasmCodePosition position);