Stack overflow checks and NPE checks for optimizing.

Change-Id: I59e97448bf29778769b79b51ee4ea43f43493d96

5 files changed, 62 insertions, 0 deletions

diff --git a/compiler/utils/stack_checks.h b/compiler/utils/stack_checks.h
new file mode 100644
index 0000000..63adbc2
--- /dev/null
+++ b/compiler/utils/stack_checks.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+#ifndef ART_COMPILER_UTILS_STACK_CHECKS_H_
+#define ART_COMPILER_UTILS_STACK_CHECKS_H_
+
+#include "instruction_set.h"
+
+namespace art {
+
+// Size of a frame that we definitely consider large. Anything larger than this should
+// definitely get a stack overflow check.
+static constexpr size_t kLargeFrameSize = 2 * KB;
+
+// Size of a frame that should be small. Anything leaf method smaller than this should run
+// without a stack overflow check.
+// The constant is from experience with frameworks code.
+static constexpr size_t kSmallFrameSize = 1 * KB;
+
+// Determine whether a frame is small or large, used in the decision on whether to elide a
+// stack overflow check on method entry.
+//
+// A frame is considered large when it's either above kLargeFrameSize, or a quarter of the
+// overflow-usable stack space.
+static inline bool IsLargeFrame(size_t size, InstructionSet isa) {
+  return size >= kLargeFrameSize || size >= GetStackOverflowReservedBytes(isa) / 4;
+}
+
+}  // namespace art
+
+#endif  // ART_COMPILER_UTILS_STACK_CHECKS_H_
diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index 56c6536..b6a5c20 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -806,6 +806,13 @@ void X86Assembler::testl(Register reg1, Register reg2) {
 }
 
 
+void X86Assembler::testl(Register reg, const Address& address) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitUint8(0x85);
+  EmitOperand(reg, address);
+}
+
+
 void X86Assembler::testl(Register reg, const Immediate& immediate) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   // For registers that have a byte variant (EAX, EBX, ECX, and EDX)
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 2fc6049..ce20768 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -346,6 +346,7 @@ class X86Assembler FINAL : public Assembler {
 
   void testl(Register reg1, Register reg2);
   void testl(Register reg, const Immediate& imm);
+  void testl(Register reg1, const Address& address);
 
   void andl(Register dst, const Immediate& imm);
   void andl(Register dst, Register src);
diff --git a/compiler/utils/x86_64/assembler_x86_64.cc b/compiler/utils/x86_64/assembler_x86_64.cc
index 1dbef95..0d14376 100644
--- a/compiler/utils/x86_64/assembler_x86_64.cc
+++ b/compiler/utils/x86_64/assembler_x86_64.cc
@@ -950,6 +950,14 @@ void X86_64Assembler::testl(CpuRegister reg, const Immediate& immediate) {
 }
 
 
+void X86_64Assembler::testq(CpuRegister reg, const Address& address) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  EmitRex64(reg);
+  EmitUint8(0x85);
+  EmitOperand(reg.LowBits(), address);
+}
+
+
 void X86_64Assembler::andl(CpuRegister dst, CpuRegister src) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitOptionalRex32(dst, src);
diff --git a/compiler/utils/x86_64/assembler_x86_64.h b/compiler/utils/x86_64/assembler_x86_64.h
index e988029..1d6655c 100644
--- a/compiler/utils/x86_64/assembler_x86_64.h
+++ b/compiler/utils/x86_64/assembler_x86_64.h
@@ -391,6 +391,8 @@ class X86_64Assembler FINAL : public Assembler {
   void testl(CpuRegister reg1, CpuRegister reg2);
   void testl(CpuRegister reg, const Immediate& imm);
 
+  void testq(CpuRegister reg, const Address& address);
+
   void andl(CpuRegister dst, const Immediate& imm);
   void andl(CpuRegister dst, CpuRegister src);
   void andq(CpuRegister dst, const Immediate& imm);