riscv64: Fix Shl+Add simplification.

Test: m test-art-host-gtest
Change-Id: I62803340fb308d24120436bca2005eb75d2ccc85

3 files changed, 93 insertions, 1 deletions

diff --git a/compiler/Android.bp b/compiler/Android.bp
index 0bfc8fa7b2..05a599cf4a 100644
--- a/compiler/Android.bp
+++ b/compiler/Android.bp
@@ -511,6 +511,7 @@ art_cc_defaults {
         },
         riscv64: {
             srcs: [
+                "optimizing/instruction_simplifier_riscv64_test.cc",
                 "utils/riscv64/managed_register_riscv64_test.cc",
             ],
         },
diff --git a/compiler/optimizing/instruction_simplifier_riscv64.cc b/compiler/optimizing/instruction_simplifier_riscv64.cc
index b12941b37d..6dc269f8c5 100644
--- a/compiler/optimizing/instruction_simplifier_riscv64.cc
+++ b/compiler/optimizing/instruction_simplifier_riscv64.cc
@@ -57,7 +57,7 @@ class InstructionSimplifierRiscv64Visitor final : public HGraphVisitor {
     DCHECK(shl->GetRight()->IsIntConstant());
 
     const int32_t distance = shl->GetRight()->AsIntConstant()->GetValue();
-    if ((distance & ~0x3) != 0) {
+    if (distance < 1 || distance > 3) {
       return false;
     }
 
diff --git a/compiler/optimizing/instruction_simplifier_riscv64_test.cc b/compiler/optimizing/instruction_simplifier_riscv64_test.cc
new file mode 100644
index 0000000000..15c81c8957
--- /dev/null
+++ b/compiler/optimizing/instruction_simplifier_riscv64_test.cc
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2024 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_riscv64.h"
+
+#include <gtest/gtest.h>
+
+#include "base/globals.h"
+#include "optimizing_unit_test.h"
+
+namespace art HIDDEN {
+namespace riscv64 {
+
+class InstructionSimplifierRiscv64Test : public OptimizingUnitTest {};
+
+TEST_F(InstructionSimplifierRiscv64Test, SimplifyShiftAdd) {
+  HGraph* graph = CreateGraph();
+  HBasicBlock* entry = AddNewBlock();
+  graph->SetEntryBlock(entry);
+  graph->BuildDominatorTree();
+
+  HInstruction* param0 = MakeParam(DataType::Type::kInt64);
+  HInstruction* param1 = MakeParam(DataType::Type::kInt64);
+  HInstruction* c0 = graph->GetIntConstant(0);
+  HInstruction* c1 = graph->GetIntConstant(1);
+  HInstruction* c2 = graph->GetIntConstant(2);
+  HInstruction* c3 = graph->GetIntConstant(3);
+  HInstruction* c4 = graph->GetIntConstant(4);
+
+  HInstruction* shl0 = MakeBinOp<HShl>(entry, DataType::Type::kInt64, param0, c0);
+  HInstruction* add_shl0 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param1, shl0);
+  HInstruction* shl1 = MakeBinOp<HShl>(entry, DataType::Type::kInt64, param0, c1);
+  HInstruction* add_shl1 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param1, shl1);
+  HInstruction* shl2 = MakeBinOp<HShl>(entry, DataType::Type::kInt64, param0, c2);
+  HInstruction* add_shl2 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param1, shl2);
+  HInstruction* shl3 = MakeBinOp<HShl>(entry, DataType::Type::kInt64, param0, c3);
+  HInstruction* add_shl3 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param1, shl3);
+  HInstruction* shl4 = MakeBinOp<HShl>(entry, DataType::Type::kInt64, param0, c4);
+  HInstruction* add_shl4 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param1, shl4);
+
+  InstructionSimplifierRiscv64 simplifier(graph, /*stats=*/ nullptr);
+  simplifier.Run();
+
+  EXPECT_FALSE(add_shl0->GetBlock() == nullptr);
+  EXPECT_TRUE(add_shl1->GetBlock() == nullptr);
+  EXPECT_TRUE(add_shl2->GetBlock() == nullptr);
+  EXPECT_TRUE(add_shl3->GetBlock() == nullptr);
+  EXPECT_FALSE(add_shl4->GetBlock() == nullptr);
+}
+
+TEST_F(InstructionSimplifierRiscv64Test, SimplifyShiftAddReusedShift) {
+  HGraph* graph = CreateGraph();
+  HBasicBlock* entry = AddNewBlock();
+  graph->SetEntryBlock(entry);
+  graph->BuildDominatorTree();
+
+  HInstruction* param0 = MakeParam(DataType::Type::kInt64);
+  HInstruction* param1 = MakeParam(DataType::Type::kInt64);
+  HInstruction* param2 = MakeParam(DataType::Type::kInt64);
+  HInstruction* param3 = MakeParam(DataType::Type::kInt64);
+  HInstruction* c1 = graph->GetIntConstant(1);
+
+  HInstruction* shl1 = MakeBinOp<HShl>(entry, DataType::Type::kInt64, param0, c1);
+  HInstruction* add1 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param1, shl1);
+  HInstruction* add2 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param2, shl1);
+  HInstruction* add3 = MakeBinOp<HAdd>(entry, DataType::Type::kInt64, param3, shl1);
+
+  InstructionSimplifierRiscv64 simplifier(graph, /*stats=*/ nullptr);
+  simplifier.Run();
+
+  EXPECT_TRUE(shl1->GetBlock() == nullptr);
+  EXPECT_TRUE(add1->GetBlock() == nullptr);
+  EXPECT_TRUE(add2->GetBlock() == nullptr);
+  EXPECT_TRUE(add3->GetBlock() == nullptr);
+}
+
+}  // namespace riscv64
+}  // namespace art