Fixed flooring division by -1 on ARM.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index a8536a1841f379a5078e5fc79716f16e9564024f..a28d6c6f4086c6b6eef3f1b2fc9c34e9bfc7a0f8 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -1139,22 +1139,28 @@ void LCodeGen::DoFlooringDivByPowerOf2I(LFlooringDivByPowerOf2I* instr) {
   }
 
   // If the divisor is negative, we have to negate and handle edge cases.
-  Label not_kmin_int, done;
   __ negl(dividend);
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
     DeoptimizeIf(zero, instr->environment());
   }
-  if (instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
-    // Note that we could emit branch-free code, but that would need one more
-    // register.
-    __ j(no_overflow, &not_kmin_int, Label::kNear);
-    if (divisor == -1) {
-      DeoptimizeIf(no_condition, instr->environment());
-    } else {
-      __ movl(dividend, Immediate(kMinInt / divisor));
-      __ jmp(&done, Label::kNear);
-    }
+
+  // If the negation could not overflow, simply shifting is OK.
+  if (!instr->hydrogen()->CheckFlag(HValue::kLeftCanBeMinInt)) {
+    __ sarl(dividend, Immediate(shift));
+    return;
   }
+
+  // Note that we could emit branch-free code, but that would need one more
+  // register.
+  if (divisor == -1) {
+    DeoptimizeIf(overflow, instr->environment());
+    return;
+  }
+
+  Label not_kmin_int, done;
+  __ j(no_overflow, &not_kmin_int, Label::kNear);
+  __ movl(dividend, Immediate(kMinInt / divisor));
+  __ jmp(&done, Label::kNear);
   __ bind(&not_kmin_int);
   __ sarl(dividend, Immediate(shift));
   __ bind(&done);