Optimize truncated divide (intrinsics and inline).

vm/opt_code_generator_ia32.cc

 // Copyright (c) 2011, 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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/opt_code_generator.h"
 
 #include "vm/assembler_macros.h"
@@ skipping 737 matching lines @@
 // TODO(srdjan): Expand inline caches to detect Smi/double operations, so that
 // we do not have to call the instance method, and therefore could guarantee
 // that the result is a Smi at the end.
 void OptimizingCodeGenerator::GenerateSmiBinaryOp(BinaryOpNode* node) {
   const char* kOptMessage = "Inlines BinaryOp for Smi";
   Label done;
   const Token::Kind kind = node->kind();
   if ((kind == Token::kADD) ||
       (kind == Token::kSUB) ||
       (kind == Token::kMUL) ||
+      (kind == Token::kTRUNCDIV) ||
       (kind == Token::kBIT_AND) ||
       (kind == Token::kBIT_OR) ||
       (kind == Token::kBIT_XOR)) {
     TraceOpt(node, kOptMessage);
     // Check if both arguments are expected to be Smi.
     const ICData& ic_data = node->ICDataAtId(node->id());
     ASSERT(ic_data.NumberOfArgumentsChecked() == 2);
     ASSERT(ic_data.NumberOfChecks() > 0);
     Function& target = Function::Handle();
     GrowableArray<const Class*> classes;
@@ skipping 83 matching lines @@
       case Token::kBIT_OR: {
         // No overflow check.
         __ orl(EAX, EDX);
         break;
       }
       case Token::kBIT_XOR: {
         // No overflow check.
         __ xorl(EAX, EDX);
         break;
       }
+      case Token::kTRUNCDIV: {
+        // Handle Divide by Zero elsewhere
+        __ cmpl(EDX, Immediate(0));
+        __ j(EQUAL, overflow_label);
+        // Move right to ECX, left is in EAX.
+        __ movl(ECX, EDX);
+        __ SmiUntag(ECX);
+        __ SmiUntag(EAX);
+        // Sign extend EAX -> EDX:EAX.
+        __ cdq();
+        __ idivl(ECX);
+        __ SmiTag(EAX);

[sra1, 2011/12/13 21:12:08]

MIN_SMI / -1 is not a Smi.

+        break;
+      }
       default:
         UNREACHABLE();
     }
   } else if (kind == Token::kSHL) {
     GenerateSmiShiftBinaryOp(node);
   } else {
     TraceNotOpt(node, kOptMessage);
     node->left()->Visit(this);
     node->right()->Visit(this);
     CodeGenerator::GenerateBinaryOperatorCall(node->id(),
@@ skipping 1848 matching lines @@
 void OptimizingCodeGenerator::VisitTryCatchNode(TryCatchNode* node) {
   // TODO(srdjan): Set classes for locals.
   classes_for_locals_->Clear();
   CodeGenerator::VisitTryCatchNode(node);
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32