Improved modulo operation in lithium as well as bailout on -0....

src/arm/lithium-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1325 matching lines @@
     return AssignEnvironment(AssignPointerMap(
              DefineFixed(new LDivI(dividend, divisor), r0)));
   } else {
     return DoArithmeticT(Token::DIV, instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoMod(HMod* instr) {
   if (instr->representation().IsInteger32()) {
-    // TODO(1042) The fixed register allocation
-    // is needed because we call GenericBinaryOpStub from
-    // the generated code, which requires registers r0
-    // and r1 to be used. We should remove that
-    // when we provide a native implementation.
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
 
-    LInstruction* result;
+    LModI* mod;
     if (instr->HasPowerOf2Divisor()) {
       ASSERT(!instr->CheckFlag(HValue::kCanBeDivByZero));
       LOperand* value = UseRegisterAtStart(instr->left());
-      LModI* mod = new LModI(value, UseOrConstant(instr->right()));
-      result = DefineSameAsFirst(mod);
-      result = AssignEnvironment(result);
+      mod = new LModI(value, UseOrConstant(instr->right()));
     } else {
-      LOperand* value = UseFixed(instr->left(), r0);
-      LOperand* divisor = UseFixed(instr->right(), r1);
-      result = DefineFixed(new LModI(value, divisor), r0);
-      result = AssignEnvironment(AssignPointerMap(result));
+      LOperand* dividend = UseRegister(instr->left());
+      LOperand* divisor = UseRegisterAtStart(instr->right());
+      mod = new LModI(dividend,
+                      divisor,
+                      TempRegister(),
+                      FixedTemp(d1),
+                      FixedTemp(d2));
     }
 
-    return result;
+    return AssignEnvironment(DefineSameAsFirst(mod));
   } else if (instr->representation().IsTagged()) {
     return DoArithmeticT(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.
     LOperand* left = UseFixedDouble(instr->left(), d1);
     LOperand* right = UseFixedDouble(instr->right(), d2);
     LArithmeticD* result = new LArithmeticD(Token::MOD, left, right);
@@ skipping 690 matching lines @@
 
 
 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   HEnvironment* outer = current_block_->last_environment()->outer();
   current_block_->UpdateEnvironment(outer);
   return NULL;
 }
 
 
 } }  // namespace v8::internal