Reland "Handle non-power-of-2 divisors in division-like operations".

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 95f17247a975896330620d443d7069d154018194..3191199271613443a6dfe3ebdff826e22c28da5c 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -4979,6 +4979,18 @@ void MacroAssembler::JumpIfDictionaryInPrototypeChain(
 }
 
 
+void MacroAssembler::FlooringDiv(Register dividend, int32_t divisor) {
+  ASSERT(!dividend.is(rax));
+  ASSERT(!dividend.is(rdx));
+  MultiplierAndShift ms(divisor);
+  movl(rax, Immediate(ms.multiplier()));
+  imull(dividend);
+  if (divisor > 0 && ms.multiplier() < 0) addl(rdx, dividend);
+  if (divisor < 0 && ms.multiplier() > 0) subl(rdx, dividend);
+  if (ms.shift() > 0) sarl(rdx, Immediate(ms.shift()));
+}
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64