Revert of [ic] [stubs] Don't use Code::flags in megamorphic stub cache hash computations.

src/ic/mips64/stub-cache-mips64.cc

Index: src/ic/mips64/stub-cache-mips64.cc
diff --git a/src/ic/mips64/stub-cache-mips64.cc b/src/ic/mips64/stub-cache-mips64.cc
index d8c2716a67bc2988c3c55c1e5a3a9f84fdc54f6c..41c3aa4969fcccc2cc162693122f5c087810b91f 100644
--- a/src/ic/mips64/stub-cache-mips64.cc
+++ b/src/ic/mips64/stub-cache-mips64.cc
@@ -15,7 +15,8 @@
 #define __ ACCESS_MASM(masm)
 
 static void ProbeTable(StubCache* stub_cache, MacroAssembler* masm,
-                       StubCache::Table table, Register receiver, Register name,
+                       Code::Flags flags, StubCache::Table table,
+                       Register receiver, Register name,
                        // Number of the cache entry, not scaled.
                        Register offset, Register scratch, Register scratch2,
                        Register offset_scratch) {
@@ -62,16 +63,14 @@
   __ ld(code, MemOperand(base_addr,
                          static_cast<int32_t>(value_off_addr - key_off_addr)));
 
-#ifdef DEBUG
   // Check that the flags match what we're looking for.
-  Code::Flags flags = Code::RemoveHolderFromFlags(
-      Code::ComputeHandlerFlags(stub_cache->ic_kind()));
   Register flags_reg = base_addr;
   base_addr = no_reg;
   __ lw(flags_reg, FieldMemOperand(code, Code::kFlagsOffset));
   __ And(flags_reg, flags_reg, Operand(~Code::kFlagsNotUsedInLookup));
-  __ Check(eq, kUnexpectedValue, flags_reg, Operand(flags));
+  __ Branch(&miss, ne, flags_reg, Operand(flags));
 
+#ifdef DEBUG
   if (FLAG_test_secondary_stub_cache && table == StubCache::kPrimary) {
     __ jmp(&miss);
   } else if (FLAG_test_primary_stub_cache && table == StubCache::kSecondary) {
@@ -90,6 +89,9 @@
 void StubCache::GenerateProbe(MacroAssembler* masm, Register receiver,
                               Register name, Register scratch, Register extra,
                               Register extra2, Register extra3) {
+  Code::Flags flags =
+      Code::RemoveHolderFromFlags(Code::ComputeHandlerFlags(ic_kind_));
+
   Label miss;
 
   // Make sure that code is valid. The multiplying code relies on the
@@ -139,21 +141,23 @@
   // We shift out the last two bits because they are not part of the hash and
   // they are always 01 for maps.
   __ dsrl(scratch, scratch, kCacheIndexShift);
+  __ Xor(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask));
   __ And(scratch, scratch, Operand(mask));
 
   // Probe the primary table.
-  ProbeTable(this, masm, kPrimary, receiver, name, scratch, extra, extra2,
-             extra3);
+  ProbeTable(this, masm, flags, kPrimary, receiver, name, scratch, extra,
+             extra2, extra3);
 
   // Primary miss: Compute hash for secondary probe.
   __ dsrl(at, name, kCacheIndexShift);
   __ Dsubu(scratch, scratch, at);
   uint64_t mask2 = kSecondaryTableSize - 1;
+  __ Daddu(scratch, scratch, Operand((flags >> kCacheIndexShift) & mask2));
   __ And(scratch, scratch, Operand(mask2));
 
   // Probe the secondary table.
-  ProbeTable(this, masm, kSecondary, receiver, name, scratch, extra, extra2,
-             extra3);
+  ProbeTable(this, masm, flags, kSecondary, receiver, name, scratch, extra,
+             extra2, extra3);
 
   // Cache miss: Fall-through and let caller handle the miss by
   // entering the runtime system.