X87: Turbofan: Modify WASM linkage to store floats using only 4 bytes.

src/compiler/x87/code-generator-x87.cc

 // Copyright 2013 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/compiler/code-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 1646 matching lines @@
         }
       } else {
         __ lea(i.OutputRegister(), i.MemoryOperand());
       }
       break;
     }
     case kX87Push:
       if (instr->InputAt(0)->IsFPRegister()) {
         auto allocated = AllocatedOperand::cast(*instr->InputAt(0));
         if (allocated.representation() == MachineRepresentation::kFloat32) {
-          __ sub(esp, Immediate(kDoubleSize));
+          __ sub(esp, Immediate(kFloatSize));
           __ fst_s(Operand(esp, 0));
+          frame_access_state()->IncreaseSPDelta(kFloatSize / kPointerSize);
         } else {
           DCHECK(allocated.representation() == MachineRepresentation::kFloat64);
           __ sub(esp, Immediate(kDoubleSize));
           __ fst_d(Operand(esp, 0));
+        frame_access_state()->IncreaseSPDelta(kDoubleSize / kPointerSize);
         }
-        frame_access_state()->IncreaseSPDelta(kDoubleSize / kPointerSize);
       } else if (instr->InputAt(0)->IsFPStackSlot()) {
         auto allocated = AllocatedOperand::cast(*instr->InputAt(0));
         if (allocated.representation() == MachineRepresentation::kFloat32) {
-          __ sub(esp, Immediate(kDoubleSize));
+          __ sub(esp, Immediate(kFloatSize));
           __ fld_s(i.InputOperand(0));
           __ fstp_s(MemOperand(esp, 0));
+          frame_access_state()->IncreaseSPDelta(kFloatSize / kPointerSize);
         } else {
           DCHECK(allocated.representation() == MachineRepresentation::kFloat64);
           __ sub(esp, Immediate(kDoubleSize));
           __ fld_d(i.InputOperand(0));
           __ fstp_d(MemOperand(esp, 0));
+        frame_access_state()->IncreaseSPDelta(kDoubleSize / kPointerSize);
         }
-        frame_access_state()->IncreaseSPDelta(kDoubleSize / kPointerSize);
       } else if (HasImmediateInput(instr, 0)) {
         __ push(i.InputImmediate(0));
         frame_access_state()->IncreaseSPDelta(1);
       } else {
         __ push(i.InputOperand(0));
         frame_access_state()->IncreaseSPDelta(1);
       }
       break;
     case kX87Poke: {
       int const slot = MiscField::decode(instr->opcode());
@@ skipping 795 matching lines @@
     int padding_size = last_lazy_deopt_pc_ + space_needed - current_pc;
     __ Nop(padding_size);
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8