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 "base/bit_utils_iterator.h"
21 #include "quick/quick_method_frame_info.h"
22
23 namespace art {
24 namespace x86_64 {
25
26 static constexpr uintptr_t gZero = 0;
27
Reset()28 void X86_64Context::Reset() {
29 std::fill_n(gprs_, arraysize(gprs_), nullptr);
30 std::fill_n(fprs_, arraysize(fprs_), nullptr);
31 gprs_[RSP] = &rsp_;
32 gprs_[RDI] = &arg0_;
33 // Initialize registers with easy to spot debug values.
34 rsp_ = X86_64Context::kBadGprBase + RSP;
35 rip_ = X86_64Context::kBadGprBase + kNumberOfCpuRegisters;
36 arg0_ = 0;
37 }
38
FillCalleeSaves(uint8_t * frame,const QuickMethodFrameInfo & frame_info)39 void X86_64Context::FillCalleeSaves(uint8_t* frame, const QuickMethodFrameInfo& frame_info) {
40 int spill_pos = 0;
41
42 // Core registers come first, from the highest down to the lowest.
43 uint32_t core_regs =
44 frame_info.CoreSpillMask() & ~(static_cast<uint32_t>(-1) << kNumberOfCpuRegisters);
45 DCHECK_EQ(1, POPCOUNT(frame_info.CoreSpillMask() & ~core_regs)); // Return address spill.
46 for (uint32_t core_reg : HighToLowBits(core_regs)) {
47 gprs_[core_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
48 ++spill_pos;
49 }
50 DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()) - 1);
51
52 // FP registers come second, from the highest down to the lowest.
53 uint32_t fp_regs = frame_info.FpSpillMask();
54 DCHECK_EQ(0u, fp_regs & (static_cast<uint32_t>(-1) << kNumberOfFloatRegisters));
55 for (uint32_t fp_reg : HighToLowBits(fp_regs)) {
56 fprs_[fp_reg] = reinterpret_cast<uint64_t*>(
57 CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes()));
58 ++spill_pos;
59 }
60 DCHECK_EQ(spill_pos,
61 POPCOUNT(frame_info.CoreSpillMask()) - 1 + POPCOUNT(frame_info.FpSpillMask()));
62 }
63
SmashCallerSaves()64 void X86_64Context::SmashCallerSaves() {
65 // This needs to be 0 because we want a null/zero return value.
66 gprs_[RAX] = const_cast<uintptr_t*>(&gZero);
67 gprs_[RDX] = const_cast<uintptr_t*>(&gZero);
68 gprs_[RCX] = nullptr;
69 gprs_[RSI] = nullptr;
70 gprs_[RDI] = nullptr;
71 gprs_[R8] = nullptr;
72 gprs_[R9] = nullptr;
73 gprs_[R10] = nullptr;
74 gprs_[R11] = nullptr;
75 fprs_[XMM0] = nullptr;
76 fprs_[XMM1] = nullptr;
77 fprs_[XMM2] = nullptr;
78 fprs_[XMM3] = nullptr;
79 fprs_[XMM4] = nullptr;
80 fprs_[XMM5] = nullptr;
81 fprs_[XMM6] = nullptr;
82 fprs_[XMM7] = nullptr;
83 fprs_[XMM8] = nullptr;
84 fprs_[XMM9] = nullptr;
85 fprs_[XMM10] = nullptr;
86 fprs_[XMM11] = nullptr;
87 }
88
SetGPR(uint32_t reg,uintptr_t value)89 void X86_64Context::SetGPR(uint32_t reg, uintptr_t value) {
90 CHECK_LT(reg, static_cast<uint32_t>(kNumberOfCpuRegisters));
91 DCHECK(IsAccessibleGPR(reg));
92 CHECK_NE(gprs_[reg], &gZero);
93 *gprs_[reg] = value;
94 }
95
SetFPR(uint32_t reg,uintptr_t value)96 void X86_64Context::SetFPR(uint32_t reg, uintptr_t value) {
97 CHECK_LT(reg, static_cast<uint32_t>(kNumberOfFloatRegisters));
98 DCHECK(IsAccessibleFPR(reg));
99 CHECK_NE(fprs_[reg], reinterpret_cast<const uint64_t*>(&gZero));
100 *fprs_[reg] = value;
101 }
102
103 extern "C" NO_RETURN void art_quick_do_long_jump(uintptr_t*, uintptr_t*);
104
DoLongJump()105 void X86_64Context::DoLongJump() {
106 #if defined(__x86_64__)
107 uintptr_t gprs[kNumberOfCpuRegisters + 1];
108 uintptr_t fprs[kNumberOfFloatRegisters];
109
110 for (size_t i = 0; i < kNumberOfCpuRegisters; ++i) {
111 gprs[kNumberOfCpuRegisters - i - 1] = gprs_[i] != nullptr ? *gprs_[i] : X86_64Context::kBadGprBase + i;
112 }
113 for (size_t i = 0; i < kNumberOfFloatRegisters; ++i) {
114 fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : X86_64Context::kBadFprBase + i;
115 }
116
117 // We want to load the stack pointer one slot below so that the ret will pop eip.
118 uintptr_t rsp = gprs[kNumberOfCpuRegisters - RSP - 1] - sizeof(intptr_t);
119 gprs[kNumberOfCpuRegisters] = rsp;
120 *(reinterpret_cast<uintptr_t*>(rsp)) = rip_;
121
122 art_quick_do_long_jump(gprs, fprs);
123 #else
124 UNIMPLEMENTED(FATAL);
125 UNREACHABLE();
126 #endif
127 }
128
129 } // namespace x86_64
130 } // namespace art
131