[arm64] We must not overwrite registers for binop results that are used in frame states.

src/compiler/arm64/instruction-selector-arm64.cc

 // 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.
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 342 matching lines @@
                                &inputs[0], &inputs[1], &opcode)) {
     input_count += 2;
   } else if (is_add_sub && can_commute &&
              TryMatchAnyExtend(&g, selector, node, right_node, left_node,
                                &inputs[0], &inputs[1], &opcode)) {
     if (must_commute_cond) cont->Commute();
     input_count += 2;
   } else if (TryMatchAnyShift(selector, node, right_node, &opcode,
                               !is_add_sub)) {
     Matcher m_shift(right_node);
-    inputs[input_count++] = g.UseRegisterOrImmediateZero(left_node);
+    inputs[input_count++] = cont->IsDeoptimize()
+                                ? g.UseRegister(left_node)
+                                : g.UseRegisterOrImmediateZero(left_node);
     inputs[input_count++] = g.UseRegister(m_shift.left().node());
     inputs[input_count++] = g.UseImmediate(m_shift.right().node());
   } else if (can_commute && TryMatchAnyShift(selector, node, left_node, &opcode,
                                              !is_add_sub)) {
     if (must_commute_cond) cont->Commute();
     Matcher m_shift(left_node);
-    inputs[input_count++] = g.UseRegisterOrImmediateZero(right_node);
+    inputs[input_count++] = cont->IsDeoptimize()
+                                ? g.UseRegister(right_node)
+                                : g.UseRegisterOrImmediateZero(right_node);
     inputs[input_count++] = g.UseRegister(m_shift.left().node());
     inputs[input_count++] = g.UseImmediate(m_shift.right().node());
   } else {
-    inputs[input_count++] = g.UseRegisterOrImmediateZero(left_node);
+    inputs[input_count++] = cont->IsDeoptimize()
+                                ? g.UseRegister(left_node)
+                                : g.UseRegisterOrImmediateZero(left_node);
     inputs[input_count++] = g.UseRegister(right_node);
   }
 
   if (cont->IsBranch()) {
     inputs[input_count++] = g.Label(cont->true_block());
     inputs[input_count++] = g.Label(cont->false_block());
   }
 
   if (!IsComparisonField::decode(properties)) {
-    outputs[output_count++] = g.DefineAsRegister(node);
+    if (cont->IsDeoptimize()) {
+      // If we can deoptimize as a result of the binop, we need to make sure
+      // that the deopt inputs are not overwritten by the binop result. One way
+      // to achieve that is to declare the output register as same-as-first.
+      outputs[output_count++] = g.DefineSameAsFirst(node);
+    } else {
+      outputs[output_count++] = g.DefineAsRegister(node);
+    }
   }
 
   if (cont->IsSet()) {
     outputs[output_count++] = g.DefineAsRegister(cont->result());
   }
 
   DCHECK_NE(0u, input_count);
   DCHECK((output_count != 0) || IsComparisonField::decode(properties));
   DCHECK_GE(arraysize(inputs), input_count);
   DCHECK_GE(arraysize(outputs), output_count);
@@ skipping 2154 matching lines @@
 // static
 MachineOperatorBuilder::AlignmentRequirements
 InstructionSelector::AlignmentRequirements() {
   return MachineOperatorBuilder::AlignmentRequirements::
       FullUnalignedAccessSupport();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8