[wasm] Int64Lowering of I64XConvertFXX instructions.

src/wasm/wasm-external-refs.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WASM_EXTERNAL_REFS_H
 #define WASM_EXTERNAL_REFS_H
 
 namespace v8 {
 namespace internal {
 namespace wasm {
@@ skipping 74 matching lines @@
   double result = static_cast<double>(high_word);
   result *= shift;
   result += static_cast<double>(low_word);
   *output = result;
 
 #else
   *output = static_cast<double>(*input);
 #endif
 }
 
+static int32_t float32_to_int64_wrapper(float* input, int64_t* output) {
+  // We use "<" here to check the upper bound because of rounding problems: With
+  // "<=" some inputs would be considered within int64 range which are actually
+  // not within int64 range.
+  if (*input >= static_cast<float>(std::numeric_limits<int64_t>::min()) &&
+      *input < static_cast<float>(std::numeric_limits<int64_t>::max())) {
+    *output = static_cast<int64_t>(*input);
+    return 1;
+  }
+  return 0;
+}
+
+static int32_t float32_to_uint64_wrapper(float* input, uint64_t* output) {
+  // We use "<" here to check the upper bound because of rounding problems: With
+  // "<=" some inputs would be considered within uint64 range which are actually
+  // not within uint64 range.
+  if (*input > -1.0 &&
+      *input < static_cast<float>(std::numeric_limits<uint64_t>::max())) {
+    *output = static_cast<uint64_t>(*input);
+    return 1;
+  }
+  return 0;
+}
+
+static int32_t float64_to_int64_wrapper(double* input, int64_t* output) {
+  // We use "<" here to check the upper bound because of rounding problems: With
+  // "<=" some inputs would be considered within int64 range which are actually
+  // not within int64 range.
+  if (*input >= static_cast<double>(std::numeric_limits<int64_t>::min()) &&
+      *input < static_cast<double>(std::numeric_limits<int64_t>::max())) {
+    *output = static_cast<int64_t>(*input);
+    return 1;
+  }
+  return 0;
+}
+
+static int32_t float64_to_uint64_wrapper(double* input, uint64_t* output) {
+  // We use "<" here to check the upper bound because of rounding problems: With
+  // "<=" some inputs would be considered within uint64 range which are actually
+  // not within uint64 range.
+  if (*input > -1.0 &&
+      *input < static_cast<double>(std::numeric_limits<uint64_t>::max())) {
+    *output = static_cast<uint64_t>(*input);
+    return 1;
+  }
+  return 0;
+}
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif