Revert r11420 because Win32 compilation was broken.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
===================================================================
--- src/arm/lithium-arm.cc	(revision 11420)
+++ src/arm/lithium-arm.cc	(working copy)
@@ -1315,75 +1315,6 @@
 }
 
 
-bool LChunkBuilder::HasMagicNumberForDivisor(int32_t divisor) {
-  uint32_t divisor_abs = abs(divisor);
-  // Dividing by 0, 1, and powers of 2 is easy.
-  // Note that IsPowerOf2(0) returns true;
-  ASSERT(IsPowerOf2(0) == true);
-  if (IsPowerOf2(divisor_abs)) return true;
-
-  // We have magic numbers for a few specific divisors.
-  // Details and proofs can be found in:
-  // - Hacker's Delight, Henry S. Warren, Jr.
-  // - The PowerPC Compiler Writer’s Guide
-  // and probably many others.
-  //
-  // We handle
-  //   <divisor with magic numbers> * <power of 2>
-  // but not
-  //   <divisor with magic numbers> * <other divisor with magic numbers>
-  int32_t power_of_2_factor =
-    CompilerIntrinsics::CountTrailingZeros(divisor_abs);
-  DivMagicNumbers magic_numbers =
-    DivMagicNumberFor(divisor_abs >> power_of_2_factor);
-  if (magic_numbers.M != InvalidDivMagicNumber.M) return true;
-
-  return false;
-}
-
-
-HValue* LChunkBuilder::SimplifiedDividendForMathFloorOfDiv(HValue* dividend) {
-  // A value with an integer representation does not need to be transformed.
-  if (dividend->representation().IsInteger32()) {
-    return dividend;
-  // A change from an integer32 can be replaced by the integer32 value.
-  } else if (dividend->IsChange() &&
-      HChange::cast(dividend)->from().IsInteger32()) {
-    return HChange::cast(dividend)->value();
-  }
-  return NULL;
-}
-
-
-HValue* LChunkBuilder::SimplifiedDivisorForMathFloorOfDiv(HValue* divisor) {
-  // Only optimize when we have magic numbers for the divisor.
-  // The standard integer division routine is usually slower than transitionning
-  // to VFP.
-  if (divisor->IsConstant() &&
-      HConstant::cast(divisor)->HasInteger32Value()) {
-    HConstant* constant_val = HConstant::cast(divisor);
-    int32_t int32_val = constant_val->Integer32Value();
-    if (LChunkBuilder::HasMagicNumberForDivisor(int32_val)) {
-      return constant_val->CopyToRepresentation(Representation::Integer32());
-    }
-  }
-  return NULL;
-}
-
-
-LInstruction* LChunkBuilder::DoMathFloorOfDiv(HMathFloorOfDiv* instr) {
-    HValue* right = instr->right();
-    LOperand* dividend = UseRegister(instr->left());
-    LOperand* divisor = UseRegisterOrConstant(right);
-    LOperand* remainder = TempRegister();
-    ASSERT(right->IsConstant() &&
-           HConstant::cast(right)->HasInteger32Value() &&
-           HasMagicNumberForDivisor(HConstant::cast(right)->Integer32Value()));
-    return AssignEnvironment(DefineAsRegister(
-          new LMathFloorOfDiv(dividend, divisor, remainder)));
-}
-
-
 LInstruction* LChunkBuilder::DoMod(HMod* instr) {
   if (instr->representation().IsInteger32()) {
     ASSERT(instr->left()->representation().IsInteger32());