[vm] Minor ARM64 code generation improvements discovered during RISC-V port.
TEST=ci
Change-Id: I4bd17df224933f732eb9cef0a9b2da8dfad0a7d4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/227940
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Ryan Macnak <rmacnak@google.com>
diff --git a/runtime/vm/compiler/asm_intrinsifier_arm64.cc b/runtime/vm/compiler/asm_intrinsifier_arm64.cc
index f9c178a..4056cbf 100644
--- a/runtime/vm/compiler/asm_intrinsifier_arm64.cc
+++ b/runtime/vm/compiler/asm_intrinsifier_arm64.cc
@@ -51,9 +51,8 @@
R1);
// Set the length field in the growable array object to 0.
- __ LoadImmediate(R1, 0);
__ StoreCompressedIntoObjectNoBarrier(
- R0, FieldAddress(R0, target::GrowableObjectArray::length_offset()), R1);
+ R0, FieldAddress(R0, target::GrowableObjectArray::length_offset()), ZR);
__ ret(); // Returns the newly allocated object in R0.
__ Bind(normal_ir_body);
diff --git a/runtime/vm/compiler/backend/il_arm64.cc b/runtime/vm/compiler/backend/il_arm64.cc
index 1c5673c..979c8ba 100644
--- a/runtime/vm/compiler/backend/il_arm64.cc
+++ b/runtime/vm/compiler/backend/il_arm64.cc
@@ -5286,10 +5286,16 @@
__ CompareObjectRegisters(result_mod, ZR);
__ b(&done, GE);
// Result is negative, adjust it.
- __ CompareObjectRegisters(right, ZR);
- __ sub(TMP2, result_mod, compiler::Operand(right), compiler::kObjectBytes);
- __ add(TMP, result_mod, compiler::Operand(right), compiler::kObjectBytes);
- __ csel(result_mod, TMP, TMP2, GE);
+ if (RangeUtils::IsNegative(divisor_range())) {
+ __ sub(result_mod, result_mod, compiler::Operand(right));
+ } else if (RangeUtils::IsPositive(divisor_range())) {
+ __ add(result_mod, result_mod, compiler::Operand(right));
+ } else {
+ __ CompareObjectRegisters(right, ZR);
+ __ sub(TMP2, result_mod, compiler::Operand(right), compiler::kObjectBytes);
+ __ add(TMP, result_mod, compiler::Operand(right), compiler::kObjectBytes);
+ __ csel(result_mod, TMP, TMP2, GE);
+ }
__ Bind(&done);
}
@@ -5634,8 +5640,7 @@
// Handle modulo/division by zero exception on slow path.
if (slow_path->has_divide_by_zero()) {
- __ CompareRegisters(right, ZR);
- __ b(slow_path->entry_label(), EQ);
+ __ cbz(slow_path->entry_label(), right);
}
// Perform actual operation
diff --git a/runtime/vm/compiler/backend/range_analysis.cc b/runtime/vm/compiler/backend/range_analysis.cc
index 7d02f87..20c4ba0 100644
--- a/runtime/vm/compiler/backend/range_analysis.cc
+++ b/runtime/vm/compiler/backend/range_analysis.cc
@@ -2082,6 +2082,10 @@
return OnlyGreaterThanOrEqualTo(0);
}
+bool Range::IsNegative() const {
+ return OnlyLessThanOrEqualTo(-1);
+}
+
bool Range::OnlyLessThanOrEqualTo(int64_t val) const {
const RangeBoundary upper_bound = max().UpperBound();
return !upper_bound.IsPositiveInfinity() &&
diff --git a/runtime/vm/compiler/backend/range_analysis.h b/runtime/vm/compiler/backend/range_analysis.h
index b0037f4..aa247c7 100644
--- a/runtime/vm/compiler/backend/range_analysis.h
+++ b/runtime/vm/compiler/backend/range_analysis.h
@@ -413,6 +413,9 @@
// [0, +inf]
bool IsPositive() const;
+ // [-inf, -1]
+ bool IsNegative() const;
+
// [-inf, val].
bool OnlyLessThanOrEqualTo(int64_t val) const;
@@ -560,6 +563,9 @@
static bool IsPositive(Range* range) {
return !Range::IsUnknown(range) && range->IsPositive();
}
+ static bool IsNegative(Range* range) {
+ return !Range::IsUnknown(range) && range->IsNegative();
+ }
static bool Overlaps(Range* range, intptr_t min, intptr_t max) {
return Range::IsUnknown(range) || range->Overlaps(min, max);
diff --git a/runtime/vm/compiler/stub_code_compiler_arm64.cc b/runtime/vm/compiler/stub_code_compiler_arm64.cc
index bcdc1f4..4d22204 100644
--- a/runtime/vm/compiler/stub_code_compiler_arm64.cc
+++ b/runtime/vm/compiler/stub_code_compiler_arm64.cc
@@ -1961,15 +1961,15 @@
Label not_parameterized_case;
const Register kClsIdReg = R4;
- const Register kTypeOffestReg = R5;
+ const Register kTypeOffsetReg = R5;
__ ExtractClassIdFromTags(kClsIdReg, kTagsReg);
// Load class' type_arguments_field offset in words.
- __ LoadClassById(kTypeOffestReg, kClsIdReg);
+ __ LoadClassById(kTypeOffsetReg, kClsIdReg);
__ ldr(
- kTypeOffestReg,
- FieldAddress(kTypeOffestReg,
+ kTypeOffsetReg,
+ FieldAddress(kTypeOffsetReg,
target::Class::
host_type_arguments_field_offset_in_words_offset()),
kFourBytes);
@@ -1977,7 +1977,7 @@
// Set the type arguments in the new object.
__ StoreCompressedIntoObjectNoBarrier(
AllocateObjectABI::kResultReg,
- Address(AllocateObjectABI::kResultReg, kTypeOffestReg, UXTX,
+ Address(AllocateObjectABI::kResultReg, kTypeOffsetReg, UXTX,
Address::Scaled),
AllocateObjectABI::kTypeArgumentsReg);
@@ -3723,9 +3723,7 @@
/* R0: new object start as a tagged pointer. */
/* R1: new object end address. */
/* R2: iterator which initially points to the start of the variable */
- /* R3: scratch register. */
/* data area to be initialized. */
- __ mov(R3, ZR);
__ AddImmediate(R2, R0, target::TypedData::HeaderSize() - 1);
__ StoreInternalPointer(
R0, FieldAddress(R0, target::TypedDataBase::data_field_offset()), R2);
@@ -3733,7 +3731,7 @@
__ Bind(&init_loop);
__ cmp(R2, Operand(R1));
__ b(&done, CS);
- __ str(R3, Address(R2, 0));
+ __ str(ZR, Address(R2, 0));
__ add(R2, R2, Operand(target::kWordSize));
__ b(&init_loop);
__ Bind(&done);
