1 /*
2 * Copyright (C) 2011 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 #include "context_x86_64.h"
18
19 #include "base/bit_utils.h"
20 #include "quick/quick_method_frame_info.h"
21
22 namespace art {
23 namespace x86_64 {
24
25 static constexpr uintptr_t gZero = 0;
26
Reset()27 void X86_64Context::Reset() {
28 std::fill_n(gprs_, arraysize(gprs_), nullptr);
29 std::fill_n(fprs_, arraysize(fprs_), nullptr);
30 gprs_[RSP] = &rsp_;
31 gprs_[RDI] = &arg0_;
32 // Initialize registers with easy to spot debug values.
33 rsp_ = X86_64Context::kBadGprBase + RSP;
34 rip_ = X86_64Context::kBadGprBase + kNumberOfCpuRegisters;
35 arg0_ = 0;
36 }
37
FillCalleeSaves(uint8_t * frame,const QuickMethodFrameInfo & frame_info)38 void X86_64Context::FillCalleeSaves(uint8_t* frame, const QuickMethodFrameInfo& frame_info) {
39 int spill_pos = 0;
40
41 // Core registers come first, from the highest down to the lowest.
42 uint32_t core_regs =
43 frame_info.CoreSpillMask() & ~(static_cast<uint32_t>(-1) << kNumberOfCpuRegisters);
44 DCHECK_EQ(1, POPCOUNT(frame_info.CoreSpillMask() & ~core_regs)); // Return address spill.
45 for (uint32_t core_reg : HighToLowBits(core_regs)) {
46 gprs_[core_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
47 ++spill_pos;
48 }
49 DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()) - 1);
50
51 // FP registers come second, from the highest down to the lowest.
52 uint32_t fp_regs = frame_info.FpSpillMask();
53 DCHECK_EQ(0u, fp_regs & (static_cast<uint32_t>(-1) << kNumberOfFloatRegisters));
54 for (uint32_t fp_reg : HighToLowBits(fp_regs)) {
55 fprs_[fp_reg] = reinterpret_cast<uint64_t*>(
56 CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes()));
57 ++spill_pos;
58 }
59 DCHECK_EQ(spill_pos,
60 POPCOUNT(frame_info.CoreSpillMask()) - 1 + POPCOUNT(frame_info.FpSpillMask()));
61 }
62
SmashCallerSaves()63 void X86_64Context::SmashCallerSaves() {
64 // This needs to be 0 because we want a null/zero return value.
65 gprs_[RAX] = const_cast<uintptr_t*>(&gZero);
66 gprs_[RDX] = const_cast<uintptr_t*>(&gZero);
67 gprs_[RCX] = nullptr;
68 gprs_[RSI] = nullptr;
69 gprs_[RDI] = nullptr;
70 gprs_[R8] = nullptr;
71 gprs_[R9] = nullptr;
72 gprs_[R10] = nullptr;
73 gprs_[R11] = nullptr;
74 fprs_[XMM0] = nullptr;
75 fprs_[XMM1] = nullptr;
76 fprs_[XMM2] = nullptr;
77 fprs_[XMM3] = nullptr;
78 fprs_[XMM4] = nullptr;
79 fprs_[XMM5] = nullptr;
80 fprs_[XMM6] = nullptr;
81 fprs_[XMM7] = nullptr;
82 fprs_[XMM8] = nullptr;
83 fprs_[XMM9] = nullptr;
84 fprs_[XMM10] = nullptr;
85 fprs_[XMM11] = nullptr;
86 }
87
SetGPR(uint32_t reg,uintptr_t value)88 void X86_64Context::SetGPR(uint32_t reg, uintptr_t value) {
89 CHECK_LT(reg, static_cast<uint32_t>(kNumberOfCpuRegisters));
90 DCHECK(IsAccessibleGPR(reg));
91 CHECK_NE(gprs_[reg], &gZero);
92 *gprs_[reg] = value;
93 }
94
SetFPR(uint32_t reg,uintptr_t value)95 void X86_64Context::SetFPR(uint32_t reg, uintptr_t value) {
96 CHECK_LT(reg, static_cast<uint32_t>(kNumberOfFloatRegisters));
97 DCHECK(IsAccessibleFPR(reg));
98 CHECK_NE(fprs_[reg], reinterpret_cast<const uint64_t*>(&gZero));
99 *fprs_[reg] = value;
100 }
101
102 extern "C" NO_RETURN void art_quick_do_long_jump(uintptr_t*, uintptr_t*);
103
DoLongJump()104 void X86_64Context::DoLongJump() {
105 #if defined(__x86_64__)
106 uintptr_t gprs[kNumberOfCpuRegisters + 1];
107 uintptr_t fprs[kNumberOfFloatRegisters];
108
109 for (size_t i = 0; i < kNumberOfCpuRegisters; ++i) {
110 gprs[kNumberOfCpuRegisters - i - 1] = gprs_[i] != nullptr ? *gprs_[i] : X86_64Context::kBadGprBase + i;
111 }
112 for (size_t i = 0; i < kNumberOfFloatRegisters; ++i) {
113 fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : X86_64Context::kBadFprBase + i;
114 }
115
116 // We want to load the stack pointer one slot below so that the ret will pop eip.
117 uintptr_t rsp = gprs[kNumberOfCpuRegisters - RSP - 1] - sizeof(intptr_t);
118 gprs[kNumberOfCpuRegisters] = rsp;
119 *(reinterpret_cast<uintptr_t*>(rsp)) = rip_;
120
121 art_quick_do_long_jump(gprs, fprs);
122 #else
123 UNIMPLEMENTED(FATAL);
124 UNREACHABLE();
125 #endif
126 }
127
128 } // namespace x86_64
129 } // namespace art
130