1 #include "llvm/ADT/Triple.h"
2 #include "llvm/ExecutionEngine/Orc/OrcTargetSupport.h"
3 #include <array>
4
5 using namespace llvm::orc;
6
7 namespace {
8
executeCompileCallback(JITCompileCallbackManagerBase * JCBM,TargetAddress CallbackID)9 uint64_t executeCompileCallback(JITCompileCallbackManagerBase *JCBM,
10 TargetAddress CallbackID) {
11 return JCBM->executeCompileCallback(CallbackID);
12 }
13
14 }
15
16 namespace llvm {
17 namespace orc {
18
19 const char* OrcX86_64::ResolverBlockName = "orc_resolver_block";
20
insertResolverBlock(Module & M,JITCompileCallbackManagerBase & JCBM)21 void OrcX86_64::insertResolverBlock(
22 Module &M, JITCompileCallbackManagerBase &JCBM) {
23
24 // Trampoline code-sequence length, used to get trampoline address from return
25 // address.
26 const unsigned X86_64_TrampolineLength = 6;
27
28 // List of x86-64 GPRs to save. Note - RBP saved separately below.
29 std::array<const char *, 14> GPRs = {{
30 "rax", "rbx", "rcx", "rdx",
31 "rsi", "rdi", "r8", "r9",
32 "r10", "r11", "r12", "r13",
33 "r14", "r15"
34 }};
35
36 // Address of the executeCompileCallback function.
37 uint64_t CallbackAddr =
38 static_cast<uint64_t>(
39 reinterpret_cast<uintptr_t>(executeCompileCallback));
40
41 std::ostringstream AsmStream;
42 Triple TT(M.getTargetTriple());
43
44 // Switch to text section.
45 if (TT.getOS() == Triple::Darwin)
46 AsmStream << ".section __TEXT,__text,regular,pure_instructions\n"
47 << ".align 4, 0x90\n";
48 else
49 AsmStream << ".text\n"
50 << ".align 16, 0x90\n";
51
52 // Bake in a pointer to the callback manager immediately before the
53 // start of the resolver function.
54 AsmStream << "jit_callback_manager_addr:\n"
55 << " .quad " << &JCBM << "\n";
56
57 // Start the resolver function.
58 AsmStream << ResolverBlockName << ":\n"
59 << " pushq %rbp\n"
60 << " movq %rsp, %rbp\n";
61
62 // Store the GPRs.
63 for (const auto &GPR : GPRs)
64 AsmStream << " pushq %" << GPR << "\n";
65
66 // Store floating-point state with FXSAVE.
67 // Note: We need to keep the stack 16-byte aligned, so if we've emitted an odd
68 // number of 64-bit pushes so far (GPRs.size() plus 1 for RBP) then add
69 // an extra 64 bits of padding to the FXSave area.
70 unsigned Padding = (GPRs.size() + 1) % 2 ? 8 : 0;
71 unsigned FXSaveSize = 512 + Padding;
72 AsmStream << " subq $" << FXSaveSize << ", %rsp\n"
73 << " fxsave (%rsp)\n"
74
75 // Load callback manager address, compute trampoline address, call JIT.
76 << " lea jit_callback_manager_addr(%rip), %rdi\n"
77 << " movq (%rdi), %rdi\n"
78 << " movq 0x8(%rbp), %rsi\n"
79 << " subq $" << X86_64_TrampolineLength << ", %rsi\n"
80 << " movabsq $" << CallbackAddr << ", %rax\n"
81 << " callq *%rax\n"
82
83 // Replace the return to the trampoline with the return address of the
84 // compiled function body.
85 << " movq %rax, 0x8(%rbp)\n"
86
87 // Restore the floating point state.
88 << " fxrstor (%rsp)\n"
89 << " addq $" << FXSaveSize << ", %rsp\n";
90
91 for (const auto &GPR : make_range(GPRs.rbegin(), GPRs.rend()))
92 AsmStream << " popq %" << GPR << "\n";
93
94 // Restore original RBP and return to compiled function body.
95 AsmStream << " popq %rbp\n"
96 << " retq\n";
97
98 M.appendModuleInlineAsm(AsmStream.str());
99 }
100
101 OrcX86_64::LabelNameFtor
insertCompileCallbackTrampolines(Module & M,TargetAddress ResolverBlockAddr,unsigned NumCalls,unsigned StartIndex)102 OrcX86_64::insertCompileCallbackTrampolines(Module &M,
103 TargetAddress ResolverBlockAddr,
104 unsigned NumCalls,
105 unsigned StartIndex) {
106 const char *ResolverBlockPtrName = "Lorc_resolve_block_addr";
107
108 std::ostringstream AsmStream;
109 Triple TT(M.getTargetTriple());
110
111 if (TT.getOS() == Triple::Darwin)
112 AsmStream << ".section __TEXT,__text,regular,pure_instructions\n"
113 << ".align 4, 0x90\n";
114 else
115 AsmStream << ".text\n"
116 << ".align 16, 0x90\n";
117
118 AsmStream << ResolverBlockPtrName << ":\n"
119 << " .quad " << ResolverBlockAddr << "\n";
120
121 auto GetLabelName =
122 [=](unsigned I) {
123 std::ostringstream LabelStream;
124 LabelStream << "orc_jcc_" << (StartIndex + I);
125 return LabelStream.str();
126 };
127
128 for (unsigned I = 0; I < NumCalls; ++I)
129 AsmStream << GetLabelName(I) << ":\n"
130 << " callq *" << ResolverBlockPtrName << "(%rip)\n";
131
132 M.appendModuleInlineAsm(AsmStream.str());
133
134 return GetLabelName;
135 }
136
137 } // End namespace orc.
138 } // End namespace llvm.
139