1 //===-------- OrcMCJITReplacement.cpp - Orc-based MCJIT replacement -------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "OrcMCJITReplacement.h"
11 #include "llvm/ExecutionEngine/GenericValue.h"
12 
13 namespace {
14 
15 static struct RegisterJIT {
RegisterJIT__anon4750a8890111::RegisterJIT16   RegisterJIT() { llvm::orc::OrcMCJITReplacement::Register(); }
17 } JITRegistrator;
18 
19 }
20 
LLVMLinkInOrcMCJITReplacement()21 extern "C" void LLVMLinkInOrcMCJITReplacement() {}
22 
23 namespace llvm {
24 namespace orc {
25 
26 GenericValue
runFunction(Function * F,ArrayRef<GenericValue> ArgValues)27 OrcMCJITReplacement::runFunction(Function *F,
28                                  ArrayRef<GenericValue> ArgValues) {
29   assert(F && "Function *F was null at entry to run()");
30 
31   void *FPtr = getPointerToFunction(F);
32   assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
33   FunctionType *FTy = F->getFunctionType();
34   Type *RetTy = FTy->getReturnType();
35 
36   assert((FTy->getNumParams() == ArgValues.size() ||
37           (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
38          "Wrong number of arguments passed into function!");
39   assert(FTy->getNumParams() == ArgValues.size() &&
40          "This doesn't support passing arguments through varargs (yet)!");
41 
42   // Handle some common cases first.  These cases correspond to common `main'
43   // prototypes.
44   if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
45     switch (ArgValues.size()) {
46     case 3:
47       if (FTy->getParamType(0)->isIntegerTy(32) &&
48           FTy->getParamType(1)->isPointerTy() &&
49           FTy->getParamType(2)->isPointerTy()) {
50         int (*PF)(int, char **, const char **) =
51             (int (*)(int, char **, const char **))(intptr_t)FPtr;
52 
53         // Call the function.
54         GenericValue rv;
55         rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
56                                  (char **)GVTOP(ArgValues[1]),
57                                  (const char **)GVTOP(ArgValues[2])));
58         return rv;
59       }
60       break;
61     case 2:
62       if (FTy->getParamType(0)->isIntegerTy(32) &&
63           FTy->getParamType(1)->isPointerTy()) {
64         int (*PF)(int, char **) = (int (*)(int, char **))(intptr_t)FPtr;
65 
66         // Call the function.
67         GenericValue rv;
68         rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
69                                  (char **)GVTOP(ArgValues[1])));
70         return rv;
71       }
72       break;
73     case 1:
74       if (FTy->getNumParams() == 1 && FTy->getParamType(0)->isIntegerTy(32)) {
75         GenericValue rv;
76         int (*PF)(int) = (int (*)(int))(intptr_t)FPtr;
77         rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
78         return rv;
79       }
80       break;
81     }
82   }
83 
84   // Handle cases where no arguments are passed first.
85   if (ArgValues.empty()) {
86     GenericValue rv;
87     switch (RetTy->getTypeID()) {
88     default:
89       llvm_unreachable("Unknown return type for function call!");
90     case Type::IntegerTyID: {
91       unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
92       if (BitWidth == 1)
93         rv.IntVal = APInt(BitWidth, ((bool (*)())(intptr_t)FPtr)());
94       else if (BitWidth <= 8)
95         rv.IntVal = APInt(BitWidth, ((char (*)())(intptr_t)FPtr)());
96       else if (BitWidth <= 16)
97         rv.IntVal = APInt(BitWidth, ((short (*)())(intptr_t)FPtr)());
98       else if (BitWidth <= 32)
99         rv.IntVal = APInt(BitWidth, ((int (*)())(intptr_t)FPtr)());
100       else if (BitWidth <= 64)
101         rv.IntVal = APInt(BitWidth, ((int64_t (*)())(intptr_t)FPtr)());
102       else
103         llvm_unreachable("Integer types > 64 bits not supported");
104       return rv;
105     }
106     case Type::VoidTyID:
107       rv.IntVal = APInt(32, ((int (*)())(intptr_t)FPtr)());
108       return rv;
109     case Type::FloatTyID:
110       rv.FloatVal = ((float (*)())(intptr_t)FPtr)();
111       return rv;
112     case Type::DoubleTyID:
113       rv.DoubleVal = ((double (*)())(intptr_t)FPtr)();
114       return rv;
115     case Type::X86_FP80TyID:
116     case Type::FP128TyID:
117     case Type::PPC_FP128TyID:
118       llvm_unreachable("long double not supported yet");
119     case Type::PointerTyID:
120       return PTOGV(((void *(*)())(intptr_t)FPtr)());
121     }
122   }
123 
124   llvm_unreachable("Full-featured argument passing not supported yet!");
125 }
126 
127 } // End namespace orc.
128 } // End namespace llvm.
129