1 /* 2 * Copyright (C) 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_ARCH_X86_JNI_FRAME_X86_H_ 18 #define ART_RUNTIME_ARCH_X86_JNI_FRAME_X86_H_ 19 20 #include <string.h> 21 22 #include "arch/instruction_set.h" 23 #include "base/bit_utils.h" 24 #include "base/globals.h" 25 #include "base/logging.h" 26 27 namespace art { 28 namespace x86 { 29 30 constexpr size_t kFramePointerSize = static_cast<size_t>(PointerSize::k32); 31 static_assert(kX86PointerSize == PointerSize::k32, "Unexpected x86 pointer size"); 32 33 static constexpr size_t kNativeStackAlignment = 16; // IA-32 cdecl requires 16 byte alignment. 34 static_assert(kNativeStackAlignment == kStackAlignment); 35 36 // Get the size of "out args" for @CriticalNative method stub. 37 // This must match the size of the frame emitted by the JNI compiler at the native call site. GetCriticalNativeOutArgsSize(const char * shorty,uint32_t shorty_len)38inline size_t GetCriticalNativeOutArgsSize(const char* shorty, uint32_t shorty_len) { 39 DCHECK_EQ(shorty_len, strlen(shorty)); 40 41 size_t num_long_or_double_args = 0u; 42 for (size_t i = 1; i != shorty_len; ++i) { 43 if (shorty[i] == 'J' || shorty[i] == 'D') { 44 num_long_or_double_args += 1u; 45 } 46 } 47 size_t num_arg_words = shorty_len - 1u + num_long_or_double_args; 48 49 // The size of outgoing arguments. 50 size_t size = num_arg_words * static_cast<size_t>(kX86PointerSize); 51 52 // Add return address size. 53 size += kFramePointerSize; 54 // We can make a tail call if there are no stack args and the return type is not 55 // FP type (needs moving from ST0 to MMX0) and we do not need to extend the result. 56 bool return_type_ok = shorty[0] == 'I' || shorty[0] == 'J' || shorty[0] == 'V'; 57 if (return_type_ok && size == kFramePointerSize) { 58 return kFramePointerSize; 59 } 60 61 return RoundUp(size, kNativeStackAlignment); 62 } 63 64 } // namespace x86 65 } // namespace art 66 67 #endif // ART_RUNTIME_ARCH_X86_JNI_FRAME_X86_H_ 68 69