[wasm] Reuse constrained input for same vreg

src/compiler/instruction-selector-impl.h

 // Copyright 2014 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 V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_
 
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/linkage.h"
@@ skipping 32 matching lines @@
                                      GetVReg(node)));
   }
 
   InstructionOperand DefineSameAsFirst(Node* node) {
     return Define(node,
                   UnallocatedOperand(UnallocatedOperand::SAME_AS_FIRST_INPUT,
                                      GetVReg(node)));
   }
 
   InstructionOperand DefineAsFixed(Node* node, Register reg) {
-    return Define(node, UnallocatedOperand(UnallocatedOperand::FIXED_REGISTER,
-                                           reg.code(), GetVReg(node)));
+    UnallocatedOperand op = DefineAsFixedForVreg(GetVReg(node), reg);
+    return Define(node, op);
+  }
+
+  UnallocatedOperand DefineAsFixedForVreg(int vreg, Register reg) {
+    return UnallocatedOperand(UnallocatedOperand::FIXED_REGISTER, reg.code(),
+                              vreg);
   }
 
   template <typename FPRegType>
   InstructionOperand DefineAsFixed(Node* node, FPRegType reg) {
     return Define(node,
                   UnallocatedOperand(UnallocatedOperand::FIXED_FP_REGISTER,
                                      reg.code(), GetVReg(node)));
   }
 
   InstructionOperand DefineAsConstant(Node* node) {
@@ skipping 116 matching lines @@
                               UnallocatedOperand::USED_AT_START,
                               sequence()->NextVirtualRegister());
   }
 
   int AllocateVirtualRegister() { return sequence()->NextVirtualRegister(); }
 
   InstructionOperand DefineSameAsFirstForVreg(int vreg) {
     return UnallocatedOperand(UnallocatedOperand::SAME_AS_FIRST_INPUT, vreg);
   }
 
-  InstructionOperand DefineAsRegistertForVreg(int vreg) {
+  InstructionOperand DefineAsRegisterForVreg(int vreg) {
     return UnallocatedOperand(UnallocatedOperand::MUST_HAVE_REGISTER, vreg);
   }
 
+  InstructionOperand UseFixedForVreg(int vreg, Register reg) {
+    return UnallocatedOperand(UnallocatedOperand::FIXED_REGISTER, reg.code(),
+                              vreg);
+  }
+
   InstructionOperand UseRegisterForVreg(int vreg) {
     return UnallocatedOperand(UnallocatedOperand::MUST_HAVE_REGISTER,
                               UnallocatedOperand::USED_AT_START, vreg);
   }
 
   InstructionOperand TempDoubleRegister() {
     UnallocatedOperand op = UnallocatedOperand(
         UnallocatedOperand::MUST_HAVE_REGISTER,
         UnallocatedOperand::USED_AT_START, sequence()->NextVirtualRegister());
     sequence()->MarkAsRepresentation(MachineRepresentation::kFloat64,
@@ skipping 282 matching lines @@
   BasicBlock* true_block_;       // Only valid if mode_ == kFlags_branch.
   BasicBlock* false_block_;      // Only valid if mode_ == kFlags_branch.
   Runtime::FunctionId trap_id_;  // Only valid if mode_ == kFlags_trap.
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_IMPL_H_