Orthogonalize Lithium binary op instructions.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index d3ac5e0dfebf67c4ed54481d8669852b842c1c83..9d25c23178d42157361f53c64924deb16f53e208 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -710,51 +710,44 @@ LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
 
 LInstruction* LChunkBuilder::DoShift(Token::Value op,
                                      HBitwiseBinaryOperation* instr) {
-  if (instr->representation().IsTagged()) {
-    ASSERT(instr->left()->representation().IsTagged());
-    ASSERT(instr->right()->representation().IsTagged());
-
-    LOperand* left = UseFixed(instr->left(), r1);
-    LOperand* right = UseFixed(instr->right(), r0);
-    LArithmeticT* result = new(zone()) LArithmeticT(op, left, right);
-    return MarkAsCall(DefineFixed(result, r0), instr);
-  }
-
-  ASSERT(instr->representation().IsSmiOrInteger32());
-  ASSERT(instr->left()->representation().Equals(instr->representation()));
-  ASSERT(instr->right()->representation().Equals(instr->representation()));
-  LOperand* left = UseRegisterAtStart(instr->left());
+  if (instr->representation().IsSmiOrInteger32()) {
+    ASSERT(instr->left()->representation().Equals(instr->representation()));
+    ASSERT(instr->right()->representation().Equals(instr->representation()));
+    LOperand* left = UseRegisterAtStart(instr->left());
 
-  HValue* right_value = instr->right();
-  LOperand* right = NULL;
-  int constant_value = 0;
-  bool does_deopt = false;
-  if (right_value->IsConstant()) {
-    HConstant* constant = HConstant::cast(right_value);
-    right = chunk_->DefineConstantOperand(constant);
-    constant_value = constant->Integer32Value() & 0x1f;
-    // Left shifts can deoptimize if we shift by > 0 and the result cannot be
-    // truncated to smi.
-    if (instr->representation().IsSmi() && constant_value > 0) {
-      does_deopt = !instr->CheckUsesForFlag(HValue::kTruncatingToSmi);
+    HValue* right_value = instr->right();
+    LOperand* right = NULL;
+    int constant_value = 0;
+    bool does_deopt = false;
+    if (right_value->IsConstant()) {
+      HConstant* constant = HConstant::cast(right_value);
+      right = chunk_->DefineConstantOperand(constant);
+      constant_value = constant->Integer32Value() & 0x1f;
+      // Left shifts can deoptimize if we shift by > 0 and the result cannot be
+      // truncated to smi.
+      if (instr->representation().IsSmi() && constant_value > 0) {
+        does_deopt = !instr->CheckUsesForFlag(HValue::kTruncatingToSmi);
+      }
+    } else {
+      right = UseRegisterAtStart(right_value);
     }
-  } else {
-    right = UseRegisterAtStart(right_value);
-  }
 
-  // Shift operations can only deoptimize if we do a logical shift
-  // by 0 and the result cannot be truncated to int32.
-  if (op == Token::SHR && constant_value == 0) {
-    if (FLAG_opt_safe_uint32_operations) {
-      does_deopt = !instr->CheckFlag(HInstruction::kUint32);
-    } else {
-      does_deopt = !instr->CheckUsesForFlag(HValue::kTruncatingToInt32);
+    // Shift operations can only deoptimize if we do a logical shift
+    // by 0 and the result cannot be truncated to int32.
+    if (op == Token::SHR && constant_value == 0) {
+      if (FLAG_opt_safe_uint32_operations) {
+        does_deopt = !instr->CheckFlag(HInstruction::kUint32);
+      } else {
+        does_deopt = !instr->CheckUsesForFlag(HValue::kTruncatingToInt32);
+      }
     }
-  }
 
-  LInstruction* result =
-      DefineAsRegister(new(zone()) LShiftI(op, left, right, does_deopt));
-  return does_deopt ? AssignEnvironment(result) : result;
+    LInstruction* result =
+        DefineAsRegister(new(zone()) LShiftI(op, left, right, does_deopt));
+    return does_deopt ? AssignEnvironment(result) : result;
+  } else {
+    return DoArithmeticT(op, instr);
+  }
 }
 
 
@@ -763,21 +756,24 @@ LInstruction* LChunkBuilder::DoArithmeticD(Token::Value op,
   ASSERT(instr->representation().IsDouble());
   ASSERT(instr->left()->representation().IsDouble());
   ASSERT(instr->right()->representation().IsDouble());
-  ASSERT(op != Token::MOD);
-  LOperand* left = UseRegisterAtStart(instr->left());
-  LOperand* right = UseRegisterAtStart(instr->right());
+  LOperand* left = (op == Token::MOD)

[Sven Panne, 2013/09/16 13:10:32]

Refactor this into

if (op == Token::MOD) {
...
} else {
...
}

with nothing outside the "if". We basically have 2 different instructions here,
and we should be honest about it. It improves readability, and we shift towards
that style at other places, too.

+      ? UseFixedDouble(instr->left(), d1)
+      : UseRegisterAtStart(instr->left());
+  LOperand* right = (op == Token::MOD)
+      ? UseFixedDouble(instr->right(), d2)
+      : UseRegisterAtStart(instr->right());
   LArithmeticD* result = new(zone()) LArithmeticD(op, left, right);
+
+  // We call a C function for double modulo. It can't trigger a GC. We need
+  // to use fixed result register for the call.
+  // TODO(fschneider): Allow any register as input registers.
+  if (op == Token::MOD) return MarkAsCall(DefineFixedDouble(result, d1), instr);
   return DefineAsRegister(result);
 }
 
 
 LInstruction* LChunkBuilder::DoArithmeticT(Token::Value op,
-                                           HArithmeticBinaryOperation* instr) {
-  ASSERT(op == Token::ADD ||
-         op == Token::DIV ||
-         op == Token::MOD ||
-         op == Token::MUL ||
-         op == Token::SUB);
+                                           HBinaryOperation* instr) {
   HValue* left = instr->left();
   HValue* right = instr->right();
   ASSERT(left->representation().IsTagged());
@@ -1347,27 +1343,19 @@ LInstruction* LChunkBuilder::DoBitwise(HBitwise* instr) {
   if (instr->representation().IsSmiOrInteger32()) {
     ASSERT(instr->left()->representation().Equals(instr->representation()));
     ASSERT(instr->right()->representation().Equals(instr->representation()));
+    ASSERT(instr->CheckFlag(HValue::kTruncatingToInt32));
 
     LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand());
     LOperand* right = UseOrConstantAtStart(instr->BetterRightOperand());
     return DefineAsRegister(new(zone()) LBitI(left, right));
   } else {
-    ASSERT(instr->representation().IsTagged());
-    ASSERT(instr->left()->representation().IsTagged());
-    ASSERT(instr->right()->representation().IsTagged());
-
-    LOperand* left = UseFixed(instr->left(), r1);
-    LOperand* right = UseFixed(instr->right(), r0);
-    LArithmeticT* result = new(zone()) LArithmeticT(instr->op(), left, right);
-    return MarkAsCall(DefineFixed(result, r0), instr);
+    return DoArithmeticT(instr->op(), instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoDiv(HDiv* instr) {
-  if (instr->representation().IsDouble()) {
-    return DoArithmeticD(Token::DIV, instr);
-  } else if (instr->representation().IsSmiOrInteger32()) {
+  if (instr->representation().IsSmiOrInteger32()) {
     ASSERT(instr->left()->representation().Equals(instr->representation()));
     ASSERT(instr->right()->representation().Equals(instr->representation()));
     if (instr->HasPowerOf2Divisor()) {
@@ -1381,6 +1369,8 @@ LInstruction* LChunkBuilder::DoDiv(HDiv* instr) {
     LOperand* temp = CpuFeatures::IsSupported(SUDIV) ? NULL : FixedTemp(d4);
     LDivI* div = new(zone()) LDivI(dividend, divisor, temp);
     return AssignEnvironment(DefineAsRegister(div));
+  } else if (instr->representation().IsDouble()) {
+    return DoArithmeticD(Token::DIV, instr);
   } else {
     return DoArithmeticT(Token::DIV, instr);
   }
@@ -1501,17 +1491,10 @@ LInstruction* LChunkBuilder::DoMod(HMod* instr) {
           ? AssignEnvironment(result)
           : result;
     }
-  } else if (instr->representation().IsTagged()) {
-    return DoArithmeticT(Token::MOD, instr);
+  } else if (instr->representation().IsDouble()) {
+    return DoArithmeticD(Token::MOD, instr);
   } else {
-    ASSERT(instr->representation().IsDouble());
-    // We call a C function for double modulo. It can't trigger a GC. We need
-    // to use fixed result register for the call.
-    // TODO(fschneider): Allow any register as input registers.
-    LArithmeticD* mod = new(zone()) LArithmeticD(Token::MOD,
-                                                 UseFixedDouble(left, d1),
-                                                 UseFixedDouble(right, d2));
-    return MarkAsCall(DefineFixedDouble(mod, d1), instr);
+    return DoArithmeticT(Token::MOD, instr);
   }
 }
 
@@ -1678,7 +1661,6 @@ LInstruction* LChunkBuilder::DoAdd(HAdd* instr) {
 
     return DoArithmeticD(Token::ADD, instr);
   } else {
-    ASSERT(instr->representation().IsTagged());
     return DoArithmeticT(Token::ADD, instr);
   }
 }