Handle non-power-of-2 divisors in division-like operations

src/ia32/macro-assembler-ia32.cc

 // Copyright 2012 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 3585 matching lines @@
   mov(scratch1, FieldOperand(current, Map::kBitField2Offset));
   and_(scratch1, Map::kElementsKindMask);
   shr(scratch1, Map::kElementsKindShift);
   cmp(scratch1, Immediate(DICTIONARY_ELEMENTS));
   j(equal, found);
   mov(current, FieldOperand(current, Map::kPrototypeOffset));
   cmp(current, Immediate(factory->null_value()));
   j(not_equal, &loop_again);
 }
 
+
+void MacroAssembler::FlooringDiv(Register dividend, int32_t divisor) {
+  ASSERT(!dividend.is(eax));
+  ASSERT(!dividend.is(edx));
+  MultiplierAndShift ms(divisor);
+  mov(eax, Immediate(ms.multiplier()));
+  imul(dividend);
+  if (divisor > 0 && ms.multiplier() < 0) add(edx, dividend);
+  if (divisor < 0 && ms.multiplier() > 0) sub(edx, dividend);
+  if (ms.shift() > 0) sar(edx, ms.shift());
+  mov(eax, dividend);
+  shr(eax, 31);
+  add(edx, eax);
+}
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32