Rip JIT specific stuff out of TargetMachine, as per PR176


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10542 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86CodeEmitter.cpp b/lib/Target/X86/X86CodeEmitter.cpp
index 0b8ac11..1917e62 100644
--- a/lib/Target/X86/X86CodeEmitter.cpp
+++ b/lib/Target/X86/X86CodeEmitter.cpp
@@ -53,13 +53,21 @@
   JITResolver *TheJITResolver;
 }
 
-void *X86TargetMachine::getJITStubForFunction(Function *F,
-                                              MachineCodeEmitter &MCE) {
+void *X86JITInfo::getJITStubForFunction(Function *F, MachineCodeEmitter &MCE) {
   if (TheJITResolver == 0)
     TheJITResolver = new JITResolver(MCE);
   return (void*)((unsigned long)TheJITResolver->getLazyResolver(F));
 }
 
+void X86JITInfo::replaceMachineCodeForFunction (void *Old, void *New) {
+  char *OldByte = (char *) Old;
+  *OldByte++ = 0xE9;                // Emit JMP opcode.
+  int32_t *OldWord = (int32_t *) OldByte;
+  int32_t NewAddr = (intptr_t) New;
+  int32_t OldAddr = (intptr_t) OldWord;
+  *OldWord = NewAddr - OldAddr - 4; // Emit PC-relative addr of New code.
+}
+
 /// addFunctionReference - This method is called when we need to emit the
 /// address of a function that has not yet been emitted, so we don't know the
 /// address.  Instead, we emit a call to the CompilationCallback method, and