MIPS: Cleanup some of the range uses in ModI/DivI.

src/mips/lithium-codegen-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.7
 // 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 1077 matching lines @@
   }
 
   __ bind(&dividend_is_not_negative);
   __ And(dividend, dividend, Operand(mask));
   __ bind(&done);
 }
 
 
 void LCodeGen::DoModI(LModI* instr) {
   HMod* hmod = instr->hydrogen();
-  HValue* left = hmod->left();
-  HValue* right = hmod->right();
   const Register left_reg = ToRegister(instr->left());
   const Register right_reg = ToRegister(instr->right());
   const Register result_reg = ToRegister(instr->result());
 
   // div runs in the background while we check for special cases.
   __ div(left_reg, right_reg);
 
   Label done;
   // Check for x % 0, we have to deopt in this case because we can't return a
   // NaN.
-  if (right->CanBeZero()) {
+  if (hmod->CheckFlag(HValue::kCanBeDivByZero)) {
     DeoptimizeIf(eq, instr->environment(), right_reg, Operand(zero_reg));
   }
 
-  // Check for kMinInt % -1, we have to deopt if we care about -0, because we
-  // can't return that.
-  if (left->RangeCanInclude(kMinInt) && right->RangeCanInclude(-1)) {
-    Label left_not_min_int;
-    __ Branch(&left_not_min_int, ne, left_reg, Operand(kMinInt));
-    // TODO(svenpanne) Don't deopt when we don't care about -0.
-    DeoptimizeIf(eq, instr->environment(), right_reg, Operand(-1));
-    __ bind(&left_not_min_int);
+  // Check for kMinInt % -1, div will return kMinInt, which is not what we
+  // want. We have to deopt if we care about -0, because we can't return that.
+  if (hmod->CheckFlag(HValue::kCanOverflow)) {
+    Label no_overflow_possible;
+    __ Branch(&no_overflow_possible, ne, left_reg, Operand(kMinInt));
+    if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
+      DeoptimizeIf(eq, instr->environment(), right_reg, Operand(-1));
+    } else {
+      __ Branch(&no_overflow_possible, ne, right_reg, Operand(-1));
+      __ Branch(USE_DELAY_SLOT, &done);
+      __ mov(result_reg, zero_reg);
+    }
+    __ bind(&no_overflow_possible);
   }
 
-  // TODO(svenpanne) Only emit the test/deopt if we have to.
+  // If we care about -0, test if the dividend is <0 and the result is 0.
   __ Branch(USE_DELAY_SLOT, &done, ge, left_reg, Operand(zero_reg));
   __ mfhi(result_reg);
-
   if (hmod->CheckFlag(HValue::kBailoutOnMinusZero)) {
     DeoptimizeIf(eq, instr->environment(), result_reg, Operand(zero_reg));
   }
   __ bind(&done);
 }
 
 
 void LCodeGen::DoDivI(LDivI* instr) {
+  HBinaryOperation* hdiv = instr->hydrogen();
   const Register left = ToRegister(instr->left());
   const Register right = ToRegister(instr->right());
   const Register result = ToRegister(instr->result());
 
   // On MIPS div is asynchronous - it will run in the background while we
   // check for special cases.
   __ div(left, right);
 
   // Check for x / 0.
-  if (instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
+  if (hdiv->CheckFlag(HValue::kCanBeDivByZero)) {
     DeoptimizeIf(eq, instr->environment(), right, Operand(zero_reg));
   }
 
   // Check for (0 / -x) that will produce negative zero.
-  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
+  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero)) {
     Label left_not_zero;
     __ Branch(&left_not_zero, ne, left, Operand(zero_reg));
     DeoptimizeIf(lt, instr->environment(), right, Operand(zero_reg));
     __ bind(&left_not_zero);
   }
 
   // Check for (kMinInt / -1).
-  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
+  if (hdiv->CheckFlag(HValue::kCanOverflow) &&
+      !hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
     Label left_not_min_int;
     __ Branch(&left_not_min_int, ne, left, Operand(kMinInt));
     DeoptimizeIf(eq, instr->environment(), right, Operand(-1));
     __ bind(&left_not_min_int);
   }
 
-  if (!instr->hydrogen()->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
+  if (!hdiv->CheckFlag(HValue::kAllUsesTruncatingToInt32)) {
     __ mfhi(result);
     DeoptimizeIf(ne, instr->environment(), result, Operand(zero_reg));
   }
   __ mflo(result);
 }
 
 
 void LCodeGen::DoMultiplyAddD(LMultiplyAddD* instr) {
   DoubleRegister addend = ToDoubleRegister(instr->addend());
   DoubleRegister multiplier = ToDoubleRegister(instr->multiplier());
@@ skipping 50 matching lines @@
   Register result = ToRegister(instr->result());
   ASSERT(!dividend.is(result));
 
   if (divisor == 0) {
     DeoptimizeIf(al, instr->environment());
     return;
   }
 
   // Check for (0 / -x) that will produce negative zero.
   HMathFloorOfDiv* hdiv = instr->hydrogen();
-  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) &&
-      hdiv->left()->RangeCanInclude(0) && divisor < 0) {
+  if (hdiv->CheckFlag(HValue::kBailoutOnMinusZero) && divisor < 0) {
     DeoptimizeIf(eq, instr->environment(), dividend, Operand(zero_reg));
   }
 
   __ FlooringDiv(result, dividend, divisor);
 }
 
 
 void LCodeGen::DoMathFloorOfDiv(LMathFloorOfDiv* instr) {
   const Register result = ToRegister(instr->result());
   const Register left = ToRegister(instr->left());
@@ skipping 4468 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal