Turbofan: Modify WASM linkage to store floats using only 4 bytes.

src/compiler/wasm-linkage.cc

 // Copyright 2015 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.
 
 #include "src/assembler.h"
 #include "src/macro-assembler.h"
 
 #include "src/wasm/wasm-module.h"
 
 #include "src/compiler/linkage.h"
@@ skipping 181 matching lines @@
         int offset = -1 - stack_offset;
         stack_offset += Words(type);
         return stackloc(offset);
       }
     }
   }
   bool IsFloatingPoint(LocalType type) {
     return type == kAstF32 || type == kAstF64;
   }
   int Words(LocalType type) {
-    // The code generation for pushing parameters on the stack does not
-    // distinguish between float32 and float64. Therefore also float32 needs
-    // two words.
-    if (kPointerSize < 8 &&
-        (type == kAstI64 || type == kAstF64 || type == kAstF32)) {
+    if (kPointerSize < 8 && (type == kAstI64 || type == kAstF64)) {
       return 2;
     }
     return 1;
   }
 };
 }  // namespace
 
 static Allocator GetReturnRegisters() {
 #ifdef GP_RETURN_REGISTERS
   static const Register kGPReturnRegisters[] = {GP_RETURN_REGISTERS};
@@ skipping 162 matching lines @@
       descriptor->CalleeSavedFPRegisters(),  // callee-saved fp regs
       descriptor->flags(),                   // flags
       descriptor->debug_name());
 
   return descriptor;
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8