[wasm] Int64Lowering of FXXXConvertI64 instructions.

src/assembler.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1129 matching lines @@
       Redirect(isolate, FUNCTION_ADDR(Deoptimizer::New)));
 }
 
 
 ExternalReference ExternalReference::compute_output_frames_function(
     Isolate* isolate) {
   return ExternalReference(
       Redirect(isolate, FUNCTION_ADDR(Deoptimizer::ComputeOutputFrames)));
 }
 
-static void f32_trunc_wrapper(float* param) { *param = truncf(*param); }
+static void wasm_f32_trunc_wrapper(float* param) { *param = truncf(*param); }

[titzer, 2016/02/28 15:26:03]

Can we extract these wrappers to a header/cc file pair in
src/wasm/wasm-external-refs.(h|cc)? Then you can use a namespace instead of a
prefix as well.

[ahaas, 2016/03/02 14:02:56]

Done.
I only extracted the static functions, the other functions need the private
"Redirect" function. I didn't introduce wasm-external-refs.cc because
wasm-external-refs.h is only included in assembler.cc.

[titzer, 2016/03/02 14:06:20]

The goal there is to introduce an interface between the assembler and wasm,
instead of a large number of wasm-only functions directly in the assembler. So,
it's not a problem if it's only included in one place.

 
-ExternalReference ExternalReference::f32_trunc_wrapper_function(
-    Isolate* isolate) {
-  return ExternalReference(Redirect(isolate, FUNCTION_ADDR(f32_trunc_wrapper)));
+ExternalReference ExternalReference::wasm_f32_trunc(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_f32_trunc_wrapper)));
 }
 
-static void f32_floor_wrapper(float* param) { *param = floorf(*param); }
+static void wasm_f32_floor_wrapper(float* param) { *param = floorf(*param); }
 
-ExternalReference ExternalReference::f32_floor_wrapper_function(
-    Isolate* isolate) {
-  return ExternalReference(Redirect(isolate, FUNCTION_ADDR(f32_floor_wrapper)));
+ExternalReference ExternalReference::wasm_f32_floor(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_f32_floor_wrapper)));
 }
 
-static void f32_ceil_wrapper(float* param) { *param = ceilf(*param); }
+static void wasm_f32_ceil_wrapper(float* param) { *param = ceilf(*param); }
 
-ExternalReference ExternalReference::f32_ceil_wrapper_function(
-    Isolate* isolate) {
-  return ExternalReference(Redirect(isolate, FUNCTION_ADDR(f32_ceil_wrapper)));
+ExternalReference ExternalReference::wasm_f32_ceil(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_f32_ceil_wrapper)));
 }
 
-static void f32_nearest_int_wrapper(float* param) {
+static void wasm_f32_nearest_int_wrapper(float* param) {
   *param = nearbyintf(*param);
 }
 
-ExternalReference ExternalReference::f32_nearest_int_wrapper_function(
-    Isolate* isolate) {
+ExternalReference ExternalReference::wasm_f32_nearest_int(Isolate* isolate) {
   return ExternalReference(
-      Redirect(isolate, FUNCTION_ADDR(f32_nearest_int_wrapper)));
+      Redirect(isolate, FUNCTION_ADDR(wasm_f32_nearest_int_wrapper)));
 }
 
-static void f64_trunc_wrapper(double* param) { *param = trunc(*param); }
+static void wasm_f64_trunc_wrapper(double* param) { *param = trunc(*param); }
 
-ExternalReference ExternalReference::f64_trunc_wrapper_function(
-    Isolate* isolate) {
-  return ExternalReference(Redirect(isolate, FUNCTION_ADDR(f64_trunc_wrapper)));
+ExternalReference ExternalReference::wasm_f64_trunc(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_f64_trunc_wrapper)));
 }
 
-static void f64_floor_wrapper(double* param) { *param = floor(*param); }
+static void wasm_f64_floor_wrapper(double* param) { *param = floor(*param); }
 
-ExternalReference ExternalReference::f64_floor_wrapper_function(
-    Isolate* isolate) {
-  return ExternalReference(Redirect(isolate, FUNCTION_ADDR(f64_floor_wrapper)));
+ExternalReference ExternalReference::wasm_f64_floor(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_f64_floor_wrapper)));
 }
 
-static void f64_ceil_wrapper(double* param) { *param = ceil(*param); }
+static void wasm_f64_ceil_wrapper(double* param) { *param = ceil(*param); }
 
-ExternalReference ExternalReference::f64_ceil_wrapper_function(
-    Isolate* isolate) {
-  return ExternalReference(Redirect(isolate, FUNCTION_ADDR(f64_ceil_wrapper)));
+ExternalReference ExternalReference::wasm_f64_ceil(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_f64_ceil_wrapper)));
 }
 
-static void f64_nearest_int_wrapper(double* param) {
+static void wasm_f64_nearest_int_wrapper(double* param) {
   *param = nearbyint(*param);
 }
 
-ExternalReference ExternalReference::f64_nearest_int_wrapper_function(
-    Isolate* isolate) {
+ExternalReference ExternalReference::wasm_f64_nearest_int(Isolate* isolate) {
   return ExternalReference(
-      Redirect(isolate, FUNCTION_ADDR(f64_nearest_int_wrapper)));
+      Redirect(isolate, FUNCTION_ADDR(wasm_f64_nearest_int_wrapper)));
+}
+
+static void wasm_int64_to_float32_wrapper(int64_t* input, float* output) {
+  *output = static_cast<float>(*input);
+}
+
+ExternalReference ExternalReference::wasm_int64_to_float32(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_int64_to_float32_wrapper)));
+}
+
+static void wasm_uint64_to_float32_wrapper(uint64_t* input, float* output) {
+  uint64_t value = *input;
+
+#if V8_CC_MSVC
+  // static_cast<float> is compiled to static_cast<float>(static_cast<double>)
+  // by MSVC. Since static_cast<double> can loose information which may be
+  // required for correct rounding, we take the OR of the 11 LSB and store them
+  // the resulting value in a bit which is representable in float64 but not
+  // representable in float32 (I picked 30 because it sounded good).
+  if (value & 0x8000000000000000) {
+    value |= (((value & 0x7ff) != 0 ? 1 : 0) << 30);
+  }
+#endif
+  *output = static_cast<float>(value);
+}
+
+ExternalReference ExternalReference::wasm_uint64_to_float32(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_uint64_to_float32_wrapper)));
+}
+
+static void wasm_int64_to_float64_wrapper(int64_t* input, double* output) {
+  *output = static_cast<double>(*input);
+}
+
+ExternalReference ExternalReference::wasm_int64_to_float64(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_int64_to_float64_wrapper)));
+}
+
+static void wasm_uint64_to_float64_wrapper(uint64_t* input, double* output) {
+  *output = static_cast<double>(*input);
+}
+
+ExternalReference ExternalReference::wasm_uint64_to_float64(Isolate* isolate) {
+  return ExternalReference(
+      Redirect(isolate, FUNCTION_ADDR(wasm_uint64_to_float64_wrapper)));
 }
 
 ExternalReference ExternalReference::log_enter_external_function(
     Isolate* isolate) {
   return ExternalReference(
       Redirect(isolate, FUNCTION_ADDR(Logger::EnterExternal)));
 }
 
 
 ExternalReference ExternalReference::log_leave_external_function(
@@ skipping 716 matching lines @@
 
 
 void Assembler::DataAlign(int m) {
   DCHECK(m >= 2 && base::bits::IsPowerOfTwo32(m));
   while ((pc_offset() & (m - 1)) != 0) {
     db(0);
   }
 }
 }  // namespace internal
 }  // namespace v8