Convert BinadryDoubleOp to MathUnaryInstr double-square if both inputs are the same. Uses less regi…

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 4389 matching lines @@
       break;
     case Token::kSUB:
       __ subpl(left, right);
       break;
     default: UNREACHABLE();
   }
 }
 
 
 LocationSummary* MathUnaryInstr::MakeLocationSummary(bool opt) const {
-  if ((kind() == MethodRecognizer::kMathSin) ||
-      (kind() == MethodRecognizer::kMathCos)) {
+  if ((kind() == MathUnaryInstr::kSin) || (kind() == MathUnaryInstr::kCos)) {
     // Calling convention on x64 uses XMM0 and XMM1 to pass the first two
     // double arguments and XMM0 to return the result. Unfortunately
     // currently we can't specify these registers because ParallelMoveResolver
     // assumes that XMM0 is free at all times.
     // TODO(vegorov): allow XMM0 to be used.
     const intptr_t kNumTemps = 1;
     LocationSummary* summary =
         new LocationSummary(InputCount(), kNumTemps, LocationSummary::kCall);
     summary->set_in(0, Location::FpuRegisterLocation(XMM1));
     // R13 is chosen because it is callee saved so we do not need to back it
     // up before calling into the runtime.
     summary->set_temp(0, Location::RegisterLocation(R13));
     summary->set_out(0, Location::FpuRegisterLocation(XMM1));
     return summary;
   }
-  ASSERT(kind() == MethodRecognizer::kMathSqrt);
+  ASSERT((kind() == MathUnaryInstr::kSqrt) ||
+         (kind() == MathUnaryInstr::kDoubleSquare));
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
   LocationSummary* summary =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   summary->set_in(0, Location::RequiresFpuRegister());
-  summary->set_out(0, Location::RequiresFpuRegister());
+  if (kind() == MathUnaryInstr::kDoubleSquare) {
+    summary->set_out(0, Location::SameAsFirstInput());
+  } else {
+    summary->set_out(0, Location::RequiresFpuRegister());
+  }
   return summary;
 }
 
 
 void MathUnaryInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  if (kind() == MethodRecognizer::kMathSqrt) {
+  if (kind() == MathUnaryInstr::kSqrt) {
     __ sqrtsd(locs()->out(0).fpu_reg(), locs()->in(0).fpu_reg());
+  } else if (kind() == MathUnaryInstr::kDoubleSquare) {
+    XmmRegister value_reg = locs()->in(0).fpu_reg();
+    __ mulsd(value_reg, value_reg);
+    ASSERT(value_reg == locs()->out(0).fpu_reg());
   } else {
-    ASSERT((kind() == MethodRecognizer::kMathSin) ||
-           (kind() == MethodRecognizer::kMathCos));
+    ASSERT((kind() == MathUnaryInstr::kSin) ||
+           (kind() == MathUnaryInstr::kCos));
     // Save RSP.
     __ movq(locs()->temp(0).reg(), RSP);
     __ ReserveAlignedFrameSpace(0);
     __ movaps(XMM0, locs()->in(0).fpu_reg());
     __ CallRuntime(TargetFunction(), InputCount());
     __ movaps(locs()->out(0).fpu_reg(), XMM0);
     // Restore RSP.
     __ movq(RSP, locs()->temp(0).reg());
   }
 }
@@ skipping 1146 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64