Inline integer modulo operation.

runtime/vm/intermediate_language_mips.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_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 2382 matching lines @@
     if (RightIsPowerOfTwoConstant()) {
       ConstantInstr* right_constant = right()->definition()->AsConstant();
       summary->set_in(1, Location::Constant(right_constant->value()));
     } else {
       summary->set_in(1, Location::RequiresRegister());
     }
     summary->AddTemp(Location::RequiresRegister());
     summary->set_out(Location::RequiresRegister());
     return summary;
   }
+  if (op_kind() == Token::kMOD) {
+    summary->set_in(0, Location::RequiresRegister());
+    summary->set_in(1, Location::RequiresRegister());
+    summary->AddTemp(Location::RequiresRegister());
+    summary->set_out(Location::RequiresRegister());
+    return summary;
+  }
   summary->set_in(0, Location::RequiresRegister());
   summary->set_in(1, Location::RegisterOrSmiConstant(right()));
   if (((op_kind() == Token::kSHL) && !is_truncating()) ||
       (op_kind() == Token::kSHR)) {
     summary->AddTemp(Location::RequiresRegister());
   } else if (op_kind() == Token::kADD) {
     // Need an extra temp for the overflow detection code.
     summary->set_temp(0, Location::RequiresRegister());
   }
   // We make use of 3-operand instructions by not requiring result register
@@ skipping 220 matching lines @@
       __ sra(temp, left, kSmiTagSize);  // SmiUntag left into temp.
       __ sra(TMP, right, kSmiTagSize);  // SmiUntag right into TMP.
       __ div(temp, TMP);
       __ mflo(result);
       // Check the corner case of dividing the 'MIN_SMI' with -1, in which
       // case we cannot tag the result.
       __ BranchEqual(result, 0x40000000, deopt);
       __ SmiTag(result);
       break;
     }
+    case Token::kMOD: {
+      // Handle divide by zero in runtime.
+      __ beq(right, ZR, deopt);
+      Register temp = locs()->temp(0).reg();
+      __ sra(temp, left, kSmiTagSize);  // SmiUntag left into temp.
+      __ sra(TMP, right, kSmiTagSize);  // SmiUntag right into TMP.
+      __ div(temp, TMP);
+      __ mfhi(result);
+      //  res = left % right;
+      //  if (res < 0) {
+      //    if (right < 0) {
+      //      res = res - right;
+      //    } else {
+      //      res = res + right;
+      //    }
+      //  }
+      Label done, subtract;
+      __ bgez(result, &done);
+      __ bltz(right, &subtract);
+      __ addu(result, result, TMP);
+      __ b(&done);
+      __ Bind(&subtract);
+      __ subu(result, result, TMP);
+      __ Bind(&done);
+      __ SmiTag(result);
+      break;
+    }
     case Token::kSHR: {
       Register temp = locs()->temp(0).reg();
       if (CanDeoptimize()) {
         __ bltz(right, deopt);
       }
       __ sra(temp, right, kSmiTagSize);  // SmiUntag right into temp.
       // sra operation masks the count to 5 bits.
       const intptr_t kCountLimit = 0x1F;
       Range* right_range = this->right()->definition()->range();
       if ((right_range == NULL) ||
           !right_range->IsWithin(RangeBoundary::kMinusInfinity, kCountLimit)) {
         Label ok;
         __ BranchSignedLessEqual(temp, kCountLimit, &ok);
         __ LoadImmediate(temp, kCountLimit);
         __ Bind(&ok);
       }
 
       __ sra(CMPRES1, left, kSmiTagSize);  // SmiUntag left into CMPRES1.
       __ srav(result, CMPRES1, temp);
       __ SmiTag(result);
       break;
     }
     case Token::kDIV: {
       // Dispatches to 'Double./'.
       // TODO(srdjan): Implement as conversion to double and double division.
       UNREACHABLE();
       break;
     }
-    case Token::kMOD: {
-      // TODO(srdjan): Implement.
-      UNREACHABLE();
-      break;
-    }
     case Token::kOR:
     case Token::kAND: {
       // Flow graph builder has dissected this operation to guarantee correct
       // behavior (short-circuit evaluation).
       UNREACHABLE();
       break;
     }
     default:
       UNREACHABLE();
       break;
@@ skipping 1309 matching lines @@
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS