Emit bit manipulation instructions for x86 and x86_64
This patch performs instruction simplification to
generate instructions andn, blsmsk and blsr on
cpus that have avx2.
Test: test.py --host --64, test-art-host-gtest
Change-Id: Ie41a1b99ac2980f1e9f6a831a7d639bc3e248f0f
Signed-off-by: Shalini Salomi Bodapati <shalini.salomi.bodapati@intel.com>
diff --git a/compiler/optimizing/instruction_simplifier_x86_shared.cc b/compiler/optimizing/instruction_simplifier_x86_shared.cc
new file mode 100644
index 0000000..2805abb
--- /dev/null
+++ b/compiler/optimizing/instruction_simplifier_x86_shared.cc
@@ -0,0 +1,137 @@
+/* Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "instruction_simplifier_x86_shared.h"
+#include "nodes_x86.h"
+
+namespace art {
+
+bool TryCombineAndNot(HAnd* instruction) {
+ DataType::Type type = instruction->GetType();
+ if (!DataType::IsIntOrLongType(type)) {
+ return false;
+ }
+ // Replace code looking like
+ // Not tmp, y
+ // And dst, x, tmp
+ // with
+ // AndNot dst, x, y
+ HInstruction* left = instruction->GetLeft();
+ HInstruction* right = instruction->GetRight();
+ // Perform simplication only when either left or right
+ // is Not. When both are Not, instruction should be simplified with
+ // DeMorgan's Laws.
+ if (left->IsNot() ^ right->IsNot()) {
+ bool left_is_not = left->IsNot();
+ HInstruction* other_ins = (left_is_not ? right : left);
+ HNot* not_ins = (left_is_not ? left : right)->AsNot();
+ // Only do the simplification if instruction has only one use
+ // and thus can be safely removed.
+ if (not_ins->HasOnlyOneNonEnvironmentUse()) {
+ ArenaAllocator* arena = instruction->GetBlock()->GetGraph()->GetAllocator();
+ HX86AndNot* and_not = new (arena) HX86AndNot(type,
+ not_ins->GetInput(),
+ other_ins,
+ instruction->GetDexPc());
+ instruction->GetBlock()->ReplaceAndRemoveInstructionWith(instruction, and_not);
+ DCHECK(!not_ins->HasUses());
+ not_ins->GetBlock()->RemoveInstruction(not_ins);
+ return true;
+ }
+ }
+ return false;
+}
+
+bool TryGenerateResetLeastSetBit(HAnd* instruction) {
+ DataType::Type type = instruction->GetType();
+ if (!DataType::IsIntOrLongType(type)) {
+ return false;
+ }
+ // Replace code looking like
+ // Add tmp, x, -1 or Sub tmp, x, 1
+ // And dest x, tmp
+ // with
+ // MaskOrResetLeastSetBit dest, x
+ HInstruction* candidate = nullptr;
+ HInstruction* other = nullptr;
+ HInstruction* left = instruction->GetLeft();
+ HInstruction* right = instruction->GetRight();
+ if (AreLeastSetBitInputs(left, right)) {
+ candidate = left;
+ other = right;
+ } else if (AreLeastSetBitInputs(right, left)) {
+ candidate = right;
+ other = left;
+ }
+ if (candidate != nullptr && candidate->HasOnlyOneNonEnvironmentUse()) {
+ ArenaAllocator* arena = instruction->GetBlock()->GetGraph()->GetAllocator();
+ HX86MaskOrResetLeastSetBit* lsb = new (arena) HX86MaskOrResetLeastSetBit(
+ type, HInstruction::kAnd, other, instruction->GetDexPc());
+ instruction->GetBlock()->ReplaceAndRemoveInstructionWith(instruction, lsb);
+ DCHECK(!candidate->HasUses());
+ candidate->GetBlock()->RemoveInstruction(candidate);
+ return true;
+ }
+ return false;
+}
+
+bool TryGenerateMaskUptoLeastSetBit(HXor* instruction) {
+ DataType::Type type = instruction->GetType();
+ if (!DataType::IsIntOrLongType(type)) {
+ return false;
+ }
+ // Replace code looking like
+ // Add tmp, x, -1 or Sub tmp, x, 1
+ // Xor dest x, tmp
+ // with
+ // MaskOrResetLeastSetBit dest, x
+ HInstruction* left = instruction->GetLeft();
+ HInstruction* right = instruction->GetRight();
+ HInstruction* other = nullptr;
+ HInstruction* candidate = nullptr;
+ if (AreLeastSetBitInputs(left, right)) {
+ candidate = left;
+ other = right;
+ } else if (AreLeastSetBitInputs(right, left)) {
+ candidate = right;
+ other = left;
+ }
+ if (candidate != nullptr && candidate->HasOnlyOneNonEnvironmentUse()) {
+ ArenaAllocator* arena = instruction->GetBlock()->GetGraph()->GetAllocator();
+ HX86MaskOrResetLeastSetBit* lsb = new (arena) HX86MaskOrResetLeastSetBit(
+ type, HInstruction::kXor, other, instruction->GetDexPc());
+ instruction->GetBlock()->ReplaceAndRemoveInstructionWith(instruction, lsb);
+ DCHECK(!candidate->HasUses());
+ candidate->GetBlock()->RemoveInstruction(candidate);
+ return true;
+ }
+ return false;
+}
+
+bool AreLeastSetBitInputs(HInstruction* to_test, HInstruction* other) {
+ if (to_test->IsAdd()) {
+ HAdd* add = to_test->AsAdd();
+ HConstant* cst = add->GetConstantRight();
+ return cst != nullptr && cst->IsMinusOne() && other == add->GetLeastConstantLeft();
+ }
+ if (to_test->IsSub()) {
+ HSub* sub = to_test->AsSub();
+ HConstant* cst = sub->GetConstantRight();
+ return cst != nullptr && cst->IsOne() && other == sub->GetLeastConstantLeft();
+ }
+ return false;
+}
+
+} // namespace art