Fixed flooring division by a power of 2, once again...

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/arm/lithium-codegen-arm.h"
 #include "src/arm/lithium-gap-resolver-arm.h"
 #include "src/code-stubs.h"
 #include "src/stub-cache.h"
@@ skipping 1451 matching lines @@
     __ mov(result, Operand(dividend, ASR, shift));
     return;
   }
 
   // If the divisor is negative, we have to negate and handle edge cases.
   __ rsb(result, dividend, Operand::Zero(), SetCC);
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     DeoptimizeIf(eq, instr->environment());
   }
 
+  // Dividing by -1 is basically negation, unless we overflow.
+  if (divisor == -1) {
+    if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
+      DeoptimizeIf(vs, instr->environment());
+    }
+    return;
+  }
+
   // If the negation could not overflow, simply shifting is OK.
   if (!instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
-    __ mov(result, Operand(dividend, ASR, shift));
-    return;
-  }
-
-  // Dividing by -1 is basically negation, unless we overflow.
-  if (divisor == -1) {
-    DeoptimizeIf(vs, instr->environment());
+    __ mov(result, Operand(result, ASR, shift));
     return;
   }
 
   __ mov(result, Operand(kMinInt / divisor), LeaveCC, vs);
-  __ mov(result, Operand(dividend, ASR, shift), LeaveCC, vc);
+  __ mov(result, Operand(result, ASR, shift), LeaveCC, vc);
 }
 
 
 void LCodeGen::DoFlooringDivByConstI(LFlooringDivByConstI* instr) {
   Register dividend = ToRegister(instr->dividend());
   int32_t divisor = instr->divisor();
   Register result = ToRegister(instr->result());
   ASSERT(!dividend.is(result));
 
   if (divisor == 0) {
@@ skipping 4335 matching lines @@
   __ Push(scope_info);
   __ push(ToRegister(instr->function()));
   CallRuntime(Runtime::kHiddenPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal