1 //===-- X86TargetMachine.cpp - Define TargetMachine for the X86 -----------===//
3 // This file defines the X86 specific subclass of TargetMachine.
5 //===----------------------------------------------------------------------===//
7 #include "X86TargetMachine.h"
9 #include "llvm/Module.h"
10 #include "llvm/PassManager.h"
11 #include "llvm/Target/TargetMachineImpls.h"
12 #include "llvm/CodeGen/MachineFunction.h"
13 #include "llvm/CodeGen/Passes.h"
14 #include "llvm/Transforms/Scalar.h"
15 #include "Support/CommandLine.h"
16 #include "Support/Statistic.h"
19 cl::opt<bool> PrintCode("print-machineinstrs",
20 cl::desc("Print generated machine code"));
21 cl::opt<bool> NoPatternISel("disable-pattern-isel", cl::init(true),
22 cl::desc("Use the 'simple' X86 instruction selector"));
25 // allocateX86TargetMachine - Allocate and return a subclass of TargetMachine
26 // that implements the X86 backend.
28 TargetMachine *allocateX86TargetMachine(const Module &M) {
29 return new X86TargetMachine(M);
33 /// X86TargetMachine ctor - Create an ILP32 architecture model
35 X86TargetMachine::X86TargetMachine(const Module &M)
36 : TargetMachine("X86", true, 4, 4, 4, 4, 4),
37 FrameInfo(TargetFrameInfo::StackGrowsDown, 8/*16 for SSE*/, 4) {
41 // addPassesToEmitAssembly - We currently use all of the same passes as the JIT
42 // does to emit statically compiled machine code.
43 bool X86TargetMachine::addPassesToEmitAssembly(PassManager &PM,
45 // FIXME: Implement the switch instruction in the instruction selector!
46 PM.add(createLowerSwitchPass());
48 // FIXME: Implement the invoke/unwind instructions!
49 PM.add(createLowerInvokePass());
51 // FIXME: The code generator does not properly handle functions with
52 // unreachable basic blocks.
53 PM.add(createCFGSimplificationPass());
56 PM.add(createX86SimpleInstructionSelector(*this));
58 PM.add(createX86PatternInstructionSelector(*this));
60 // TODO: optional optimizations go here
62 // FIXME: Add SSA based peephole optimizer here.
64 // Print the instruction selected machine code...
66 PM.add(createMachineFunctionPrinterPass());
68 // Perform register allocation to convert to a concrete x86 representation
69 PM.add(createRegisterAllocator());
72 PM.add(createMachineFunctionPrinterPass());
74 PM.add(createX86FloatingPointStackifierPass());
77 PM.add(createMachineFunctionPrinterPass());
79 // Insert prolog/epilog code. Eliminate abstract frame index references...
80 PM.add(createPrologEpilogCodeInserter());
82 PM.add(createX86PeepholeOptimizerPass());
84 if (PrintCode) // Print the register-allocated code
85 PM.add(createX86CodePrinterPass(std::cerr, *this));
87 PM.add(createX86CodePrinterPass(Out, *this));
88 return false; // success!
91 /// addPassesToJITCompile - Add passes to the specified pass manager to
92 /// implement a fast dynamic compiler for this target. Return true if this is
93 /// not supported for this target.
95 bool X86TargetMachine::addPassesToJITCompile(FunctionPassManager &PM) {
96 // FIXME: Implement the switch instruction in the instruction selector!
97 PM.add(createLowerSwitchPass());
99 // FIXME: Implement the invoke/unwind instructions!
100 PM.add(createLowerInvokePass());
102 // FIXME: The code generator does not properly handle functions with
103 // unreachable basic blocks.
104 PM.add(createCFGSimplificationPass());
107 PM.add(createX86SimpleInstructionSelector(*this));
109 PM.add(createX86PatternInstructionSelector(*this));
111 // TODO: optional optimizations go here
113 // FIXME: Add SSA based peephole optimizer here.
115 // Print the instruction selected machine code...
117 PM.add(createMachineFunctionPrinterPass());
119 // Perform register allocation to convert to a concrete x86 representation
120 PM.add(createRegisterAllocator());
123 PM.add(createMachineFunctionPrinterPass());
125 PM.add(createX86FloatingPointStackifierPass());
128 PM.add(createMachineFunctionPrinterPass());
130 // Insert prolog/epilog code. Eliminate abstract frame index references...
131 PM.add(createPrologEpilogCodeInserter());
133 PM.add(createX86PeepholeOptimizerPass());
135 if (PrintCode) // Print the register-allocated code
136 PM.add(createX86CodePrinterPass(std::cerr, *this));
137 return false; // success!
140 bool X86TargetMachine::replaceMachineCodeForFunction (void *Old, void *New) {
141 // FIXME: This code could perhaps live in a more appropriate place.
142 char *OldByte = (char *) Old;
143 *OldByte++ = 0xE9; // Emit JMP opcode.
144 int32_t *OldWord = (int32_t *) OldByte;
145 int32_t NewAddr = (int32_t) New;
146 int32_t OldAddr = (int32_t) OldWord;
147 *OldWord = NewAddr - OldAddr - 4; // Emit PC-relative addr of New code.
148 return false; // success!