Revert r7288.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
===================================================================
--- src/arm/lithium-codegen-arm.cc	(revision 7289)
+++ src/arm/lithium-codegen-arm.cc	(working copy)
@@ -1013,123 +1013,40 @@
 
 
 void LCodeGen::DoMulI(LMulI* instr) {
-  LOperand* left_op = instr->InputAt(0);
-  LOperand* right_op = instr->InputAt(1);
-
   Register scratch = scratch0();
-  Register left = ToRegister(left_op);
+  Register left = ToRegister(instr->InputAt(0));
+  Register right = EmitLoadRegister(instr->InputAt(1), scratch);
 
-  ASSERT(left_op->Equals(instr->result()));
+  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero) &&
+      !instr->InputAt(1)->IsConstantOperand()) {
+    __ orr(ToRegister(instr->TempAt(0)), left, right);
+  }
 
-  bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
-  bool bailout_on_minus_zero =
-    instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero);
-
-  if (right_op->IsConstantOperand()) {
-    // Use optimized code for specific constants.
-    int32_t constant = ToInteger32(LConstantOperand::cast(right_op));
-    Condition overflow_deopt_cond = kNoCondition;
-    switch (constant) {
-      case -1:
-        overflow_deopt_cond = can_overflow ? vs : kNoCondition;
-        __ rsb(left,
-               left,
-               Operand(0),
-               can_overflow ? SetCC : LeaveCC);
-        break;
-      case 0:
-        if (bailout_on_minus_zero) {
-          // If left is strictly negative and the constant is null, the
-          // result is -0. Deoptimize if required, otherwise return 0.
-          __ cmp(left, Operand(0));
-          DeoptimizeIf(mi, instr->environment());
-        }
-        __ mov(left, Operand(0));
-        break;
-      case 1:
-        // Do nothing.
-        break;
-      default:
-        // Multiplying by powers of two and powers of two plus or minus
-        // one can be done faster with shifted operands.
-        // For other constants we emit standard code.
-        int32_t mask = constant >> 31;
-        uint32_t constant_abs = (constant + mask) ^ mask;
-        if (IsPowerOf2(constant_abs)) {
-          if (!can_overflow) {
-            int32_t shift = WhichPowerOf2(constant_abs);
-            __ mov(left, Operand(left, LSL, shift));
-            if (constant < 0)  __ rsb(left, left, Operand(0));
-          } else {
-            // scratch:left = left * constant.
-            __ mov(ip, Operand(constant));
-            __ smull(left, scratch, left, ip);
-            __ cmp(scratch, Operand(left, ASR, 31));
-            overflow_deopt_cond = ne;
-          }
-        } else if (IsPowerOf2(constant_abs - 1)) {
-          int32_t shift = WhichPowerOf2(constant_abs - 1);
-          __ add(left,
-                 left,
-                 Operand(left, LSL, shift),
-                 can_overflow ? SetCC : LeaveCC);
-          overflow_deopt_cond = can_overflow ? vs : kNoCondition;
-          if (constant < 0)  __ rsb(left, left, Operand(0));
-        } else if (IsPowerOf2(constant_abs + 1)) {
-          int32_t shift = WhichPowerOf2(constant_abs + 1);
-          __ rsb(left,
-                 left,
-                 Operand(left, LSL, shift),
-                 can_overflow ? SetCC : LeaveCC);
-          overflow_deopt_cond = can_overflow ? vs : kNoCondition;
-          if (constant < 0)  __ rsb(left, left, Operand(0));
-        } else {
-          if (!can_overflow) {
-            __ mov(ip, Operand(constant));
-            __ mul(left, left, ip);
-          } else {
-            // scratch:left = left * constant.
-            __ mov(ip, Operand(constant));
-            __ smull(left, scratch, left, ip);
-            __ cmp(scratch, Operand(left, ASR, 31));
-            overflow_deopt_cond = ne;
-          }
-        }
-        break;
-    }
-
-    if (can_overflow && (constant != 0) && (constant != 1)) {
-      ASSERT(overflow_deopt_cond != kNoCondition);
-      DeoptimizeIf(overflow_deopt_cond, instr->environment());
-    }
-    if (bailout_on_minus_zero && (constant < 0)) {
-      // The case of a null constant was handled separately.
-      // If constant is negative and left is null, the result should be -0.
-      __ cmp(left, Operand(0));
-      DeoptimizeIf(eq, instr->environment());
-    }
+  if (instr->hydrogen()->CheckFlag(HValue::kCanOverflow)) {
+    // scratch:left = left * right.
+    __ smull(left, scratch, left, right);
+    __ mov(ip, Operand(left, ASR, 31));
+    __ cmp(ip, Operand(scratch));
+    DeoptimizeIf(ne, instr->environment());
   } else {
-    Register right = EmitLoadRegister(right_op, scratch);
-    if (bailout_on_minus_zero) {
-      __ orr(ToRegister(instr->TempAt(0)), left, right);
-    }
-    if (can_overflow) {
-      // scratch:left = left * right.
-      __ smull(left, scratch, left, right);
-      __ cmp(scratch, Operand(left, ASR, 31));
-      DeoptimizeIf(ne, instr->environment());
+    __ mul(left, left, right);
+  }
+
+  if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
+    // Bail out if the result is supposed to be negative zero.
+    Label done;
+    __ tst(left, Operand(left));
+    __ b(ne, &done);
+    if (instr->InputAt(1)->IsConstantOperand()) {
+      if (ToInteger32(LConstantOperand::cast(instr->InputAt(1))) <= 0) {
+        DeoptimizeIf(al, instr->environment());
+      }
     } else {
-      __ mul(left, left, right);
-    }
-    if (bailout_on_minus_zero) {
-      // Bail out if the result is supposed to be negative zero.
-      Label done;
-      __ cmp(left, Operand(0));
-      __ b(ne, &done);
+      // Test the non-zero operand for negative sign.
       __ cmp(ToRegister(instr->TempAt(0)), Operand(0));
       DeoptimizeIf(mi, instr->environment());
-      __ bind(&done);
     }
+    __ bind(&done);
   }
 }