MIPS64: Add java.lang.String.equals intrinsic.
Change-Id: I71e41b20ebaf7640b2c72c590455eb0be4cbc5b7
diff --git a/compiler/optimizing/intrinsics_mips64.cc b/compiler/optimizing/intrinsics_mips64.cc
index ff843eb..3654159 100644
--- a/compiler/optimizing/intrinsics_mips64.cc
+++ b/compiler/optimizing/intrinsics_mips64.cc
@@ -1391,6 +1391,108 @@
__ Bind(slow_path->GetExitLabel());
}
+// boolean java.lang.String.equals(Object anObject)
+void IntrinsicLocationsBuilderMIPS64::VisitStringEquals(HInvoke* invoke) {
+ LocationSummary* locations = new (arena_) LocationSummary(invoke,
+ LocationSummary::kNoCall,
+ kIntrinsified);
+ locations->SetInAt(0, Location::RequiresRegister());
+ locations->SetInAt(1, Location::RequiresRegister());
+ locations->SetOut(Location::RequiresRegister());
+
+ // Temporary registers to store lengths of strings and for calculations.
+ locations->AddTemp(Location::RequiresRegister());
+ locations->AddTemp(Location::RequiresRegister());
+ locations->AddTemp(Location::RequiresRegister());
+}
+
+void IntrinsicCodeGeneratorMIPS64::VisitStringEquals(HInvoke* invoke) {
+ Mips64Assembler* assembler = GetAssembler();
+ LocationSummary* locations = invoke->GetLocations();
+
+ GpuRegister str = locations->InAt(0).AsRegister<GpuRegister>();
+ GpuRegister arg = locations->InAt(1).AsRegister<GpuRegister>();
+ GpuRegister out = locations->Out().AsRegister<GpuRegister>();
+
+ GpuRegister temp1 = locations->GetTemp(0).AsRegister<GpuRegister>();
+ GpuRegister temp2 = locations->GetTemp(1).AsRegister<GpuRegister>();
+ GpuRegister temp3 = locations->GetTemp(2).AsRegister<GpuRegister>();
+
+ Label loop;
+ Label end;
+ Label return_true;
+ Label return_false;
+
+ // Get offsets of count, value, and class fields within a string object.
+ const int32_t count_offset = mirror::String::CountOffset().Int32Value();
+ const int32_t value_offset = mirror::String::ValueOffset().Int32Value();
+ const int32_t class_offset = mirror::Object::ClassOffset().Int32Value();
+
+ // Note that the null check must have been done earlier.
+ DCHECK(!invoke->CanDoImplicitNullCheckOn(invoke->InputAt(0)));
+
+ // If the register containing the pointer to "this", and the register
+ // containing the pointer to "anObject" are the same register then
+ // "this", and "anObject" are the same object and we can
+ // short-circuit the logic to a true result.
+ if (str == arg) {
+ __ LoadConst64(out, 1);
+ return;
+ }
+
+ // Check if input is null, return false if it is.
+ __ Beqzc(arg, &return_false);
+
+ // Reference equality check, return true if same reference.
+ __ Beqc(str, arg, &return_true);
+
+ // Instanceof check for the argument by comparing class fields.
+ // All string objects must have the same type since String cannot be subclassed.
+ // Receiver must be a string object, so its class field is equal to all strings' class fields.
+ // If the argument is a string object, its class field must be equal to receiver's class field.
+ __ Lw(temp1, str, class_offset);
+ __ Lw(temp2, arg, class_offset);
+ __ Bnec(temp1, temp2, &return_false);
+
+ // Load lengths of this and argument strings.
+ __ Lw(temp1, str, count_offset);
+ __ Lw(temp2, arg, count_offset);
+ // Check if lengths are equal, return false if they're not.
+ __ Bnec(temp1, temp2, &return_false);
+ // Return true if both strings are empty.
+ __ Beqzc(temp1, &return_true);
+
+ // Don't overwrite input registers
+ __ Move(TMP, str);
+ __ Move(temp3, arg);
+
+ // Assertions that must hold in order to compare strings 4 characters at a time.
+ DCHECK_ALIGNED(value_offset, 8);
+ static_assert(IsAligned<8>(kObjectAlignment), "String of odd length is not zero padded");
+
+ // Loop to compare strings 4 characters at a time starting at the beginning of the string.
+ // Ok to do this because strings are zero-padded to be 8-byte aligned.
+ __ Bind(&loop);
+ __ Ld(out, TMP, value_offset);
+ __ Ld(temp2, temp3, value_offset);
+ __ Bnec(out, temp2, &return_false);
+ __ Daddiu(TMP, TMP, 8);
+ __ Daddiu(temp3, temp3, 8);
+ __ Addiu(temp1, temp1, -4);
+ __ Bgtzc(temp1, &loop);
+
+ // Return true and exit the function.
+ // If loop does not result in returning false, we return true.
+ __ Bind(&return_true);
+ __ LoadConst64(out, 1);
+ __ B(&end);
+
+ // Return false and exit the function.
+ __ Bind(&return_false);
+ __ LoadConst64(out, 0);
+ __ Bind(&end);
+}
+
static void GenerateStringIndexOf(HInvoke* invoke,
Mips64Assembler* assembler,
CodeGeneratorMIPS64* codegen,
@@ -1586,8 +1688,6 @@
UNIMPLEMENTED_INTRINSIC(MathRoundDouble)
UNIMPLEMENTED_INTRINSIC(MathRoundFloat)
-UNIMPLEMENTED_INTRINSIC(StringEquals)
-
UNIMPLEMENTED_INTRINSIC(ReferenceGetReferent)
UNIMPLEMENTED_INTRINSIC(StringGetCharsNoCheck)
UNIMPLEMENTED_INTRINSIC(SystemArrayCopyChar)