MIPS: Inline inequality compares of strings into CompareICStub

Port r10988 (c6c9ebb5).

Original commit message:

Inline inequality compares of strings into CompareICStub instead of jumping into the CompareStub that handles the generic case.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/9669026
Patch from Daniel Kalmar <kalmard@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11002 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/code-stubs-mips.cc

@@ -6895,6 +6895,8 @@ void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
   ASSERT(state_ == CompareIC::STRINGS);
   Label miss;
 
+  bool equality = Token::IsEqualityOp(op_);
+
   // Registers containing left and right operands respectively.
   Register left = a1;
   Register right = a0;
@@ -6931,32 +6933,43 @@ void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
 
   // Check that both strings are symbols. If they are, we're done
   // because we already know they are not identical.
-  ASSERT(GetCondition() == eq);
-  STATIC_ASSERT(kSymbolTag != 0);
-  __ And(tmp3, tmp1, Operand(tmp2));
-  __ And(tmp5, tmp3, Operand(kIsSymbolMask));
-  Label is_symbol;
-  __ Branch(&is_symbol, eq, tmp5, Operand(zero_reg), USE_DELAY_SLOT);
-  __ mov(v0, a0);  // In the delay slot.
-  // Make sure a0 is non-zero. At this point input operands are
-  // guaranteed to be non-zero.
-  ASSERT(right.is(a0));
-  __ Ret();
-  __ bind(&is_symbol);
+  if (equality) {
+    ASSERT(GetCondition() == eq);
+    STATIC_ASSERT(kSymbolTag != 0);
+    __ And(tmp3, tmp1, Operand(tmp2));
+    __ And(tmp5, tmp3, Operand(kIsSymbolMask));
+    Label is_symbol;
+    __ Branch(&is_symbol, eq, tmp5, Operand(zero_reg), USE_DELAY_SLOT);
+    __ mov(v0, a0);  // In the delay slot.
+    // Make sure a0 is non-zero. At this point input operands are
+    // guaranteed to be non-zero.
+    ASSERT(right.is(a0));
+    __ Ret();
+    __ bind(&is_symbol);
+  }
 
   // Check that both strings are sequential ASCII.
   Label runtime;
-  __ JumpIfBothInstanceTypesAreNotSequentialAscii(tmp1, tmp2, tmp3, tmp4,
-                                                  &runtime);
+  __ JumpIfBothInstanceTypesAreNotSequentialAscii(
+      tmp1, tmp2, tmp3, tmp4, &runtime);
 
   // Compare flat ASCII strings. Returns when done.
-  StringCompareStub::GenerateFlatAsciiStringEquals(
-      masm, left, right, tmp1, tmp2, tmp3);
+  if (equality) {
+    StringCompareStub::GenerateFlatAsciiStringEquals(
+        masm, left, right, tmp1, tmp2, tmp3);
+  } else {
+    StringCompareStub::GenerateCompareFlatAsciiStrings(
+        masm, left, right, tmp1, tmp2, tmp3, tmp4);
+  }
 
   // Handle more complex cases in runtime.
   __ bind(&runtime);
   __ Push(left, right);
-  __ TailCallRuntime(Runtime::kStringEquals, 2, 1);
+  if (equality) {
+    __ TailCallRuntime(Runtime::kStringEquals, 2, 1);
+  } else {
+    __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
+  }
 
   __ bind(&miss);
   GenerateMiss(masm);