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1 //===-- X86JITInfo.cpp - Implement the JIT interfaces for the X86 target --===//
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 // This file implements the JIT interfaces for the X86 target.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #define DEBUG_TYPE "jit"
15 #include "X86JITInfo.h"
16 #include "X86Relocations.h"
17 #include "X86Subtarget.h"
18 #include "X86TargetMachine.h"
19 #include "llvm/Function.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/Valgrind.h"
23 #include <cstdlib>
24 #include <cstring>
25 using namespace llvm;
26 
27 // Determine the platform we're running on
28 #if defined (__x86_64__) || defined (_M_AMD64) || defined (_M_X64)
29 # define X86_64_JIT
30 #elif defined(__i386__) || defined(i386) || defined(_M_IX86)
31 # define X86_32_JIT
32 #endif
33 
replaceMachineCodeForFunction(void * Old,void * New)34 void X86JITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
35   unsigned char *OldByte = (unsigned char *)Old;
36   *OldByte++ = 0xE9;                // Emit JMP opcode.
37   unsigned *OldWord = (unsigned *)OldByte;
38   unsigned NewAddr = (intptr_t)New;
39   unsigned OldAddr = (intptr_t)OldWord;
40   *OldWord = NewAddr - OldAddr - 4; // Emit PC-relative addr of New code.
41 
42   // X86 doesn't need to invalidate the processor cache, so just invalidate
43   // Valgrind's cache directly.
44   sys::ValgrindDiscardTranslations(Old, 5);
45 }
46 
47 
48 /// JITCompilerFunction - This contains the address of the JIT function used to
49 /// compile a function lazily.
50 static TargetJITInfo::JITCompilerFn JITCompilerFunction;
51 
52 // Get the ASMPREFIX for the current host.  This is often '_'.
53 #ifndef __USER_LABEL_PREFIX__
54 #define __USER_LABEL_PREFIX__
55 #endif
56 #define GETASMPREFIX2(X) #X
57 #define GETASMPREFIX(X) GETASMPREFIX2(X)
58 #define ASMPREFIX GETASMPREFIX(__USER_LABEL_PREFIX__)
59 
60 // For ELF targets, use a .size and .type directive, to let tools
61 // know the extent of functions defined in assembler.
62 #if defined(__ELF__)
63 # define SIZE(sym) ".size " #sym ", . - " #sym "\n"
64 # define TYPE_FUNCTION(sym) ".type " #sym ", @function\n"
65 #else
66 # define SIZE(sym)
67 # define TYPE_FUNCTION(sym)
68 #endif
69 
70 // Provide a convenient way for disabling usage of CFI directives.
71 // This is needed for old/broken assemblers (for example, gas on
72 // Darwin is pretty old and doesn't support these directives)
73 #if defined(__APPLE__)
74 # define CFI(x)
75 #else
76 // FIXME: Disable this until we really want to use it. Also, we will
77 //        need to add some workarounds for compilers, which support
78 //        only subset of these directives.
79 # define CFI(x)
80 #endif
81 
82 // Provide a wrapper for X86CompilationCallback2 that saves non-traditional
83 // callee saved registers, for the fastcc calling convention.
84 extern "C" {
85 #if defined(X86_64_JIT)
86 # ifndef _MSC_VER
87   // No need to save EAX/EDX for X86-64.
88   void X86CompilationCallback(void);
89   asm(
90     ".text\n"
91     ".align 8\n"
92     ".globl " ASMPREFIX "X86CompilationCallback\n"
93     TYPE_FUNCTION(X86CompilationCallback)
94   ASMPREFIX "X86CompilationCallback:\n"
95     CFI(".cfi_startproc\n")
96     // Save RBP
97     "pushq   %rbp\n"
98     CFI(".cfi_def_cfa_offset 16\n")
99     CFI(".cfi_offset %rbp, -16\n")
100     // Save RSP
101     "movq    %rsp, %rbp\n"
102     CFI(".cfi_def_cfa_register %rbp\n")
103     // Save all int arg registers
104     "pushq   %rdi\n"
105     CFI(".cfi_rel_offset %rdi, 0\n")
106     "pushq   %rsi\n"
107     CFI(".cfi_rel_offset %rsi, 8\n")
108     "pushq   %rdx\n"
109     CFI(".cfi_rel_offset %rdx, 16\n")
110     "pushq   %rcx\n"
111     CFI(".cfi_rel_offset %rcx, 24\n")
112     "pushq   %r8\n"
113     CFI(".cfi_rel_offset %r8, 32\n")
114     "pushq   %r9\n"
115     CFI(".cfi_rel_offset %r9, 40\n")
116     // Align stack on 16-byte boundary. ESP might not be properly aligned
117     // (8 byte) if this is called from an indirect stub.
118     "andq    $-16, %rsp\n"
119     // Save all XMM arg registers
120     "subq    $128, %rsp\n"
121     "movaps  %xmm0, (%rsp)\n"
122     "movaps  %xmm1, 16(%rsp)\n"
123     "movaps  %xmm2, 32(%rsp)\n"
124     "movaps  %xmm3, 48(%rsp)\n"
125     "movaps  %xmm4, 64(%rsp)\n"
126     "movaps  %xmm5, 80(%rsp)\n"
127     "movaps  %xmm6, 96(%rsp)\n"
128     "movaps  %xmm7, 112(%rsp)\n"
129     // JIT callee
130 #ifdef _WIN64
131     "subq    $32, %rsp\n"
132     "movq    %rbp, %rcx\n"    // Pass prev frame and return address
133     "movq    8(%rbp), %rdx\n"
134     "call    " ASMPREFIX "X86CompilationCallback2\n"
135     "addq    $32, %rsp\n"
136 #else
137     "movq    %rbp, %rdi\n"    // Pass prev frame and return address
138     "movq    8(%rbp), %rsi\n"
139     "call    " ASMPREFIX "X86CompilationCallback2\n"
140 #endif
141     // Restore all XMM arg registers
142     "movaps  112(%rsp), %xmm7\n"
143     "movaps  96(%rsp), %xmm6\n"
144     "movaps  80(%rsp), %xmm5\n"
145     "movaps  64(%rsp), %xmm4\n"
146     "movaps  48(%rsp), %xmm3\n"
147     "movaps  32(%rsp), %xmm2\n"
148     "movaps  16(%rsp), %xmm1\n"
149     "movaps  (%rsp), %xmm0\n"
150     // Restore RSP
151     "movq    %rbp, %rsp\n"
152     CFI(".cfi_def_cfa_register %rsp\n")
153     // Restore all int arg registers
154     "subq    $48, %rsp\n"
155     CFI(".cfi_adjust_cfa_offset 48\n")
156     "popq    %r9\n"
157     CFI(".cfi_adjust_cfa_offset -8\n")
158     CFI(".cfi_restore %r9\n")
159     "popq    %r8\n"
160     CFI(".cfi_adjust_cfa_offset -8\n")
161     CFI(".cfi_restore %r8\n")
162     "popq    %rcx\n"
163     CFI(".cfi_adjust_cfa_offset -8\n")
164     CFI(".cfi_restore %rcx\n")
165     "popq    %rdx\n"
166     CFI(".cfi_adjust_cfa_offset -8\n")
167     CFI(".cfi_restore %rdx\n")
168     "popq    %rsi\n"
169     CFI(".cfi_adjust_cfa_offset -8\n")
170     CFI(".cfi_restore %rsi\n")
171     "popq    %rdi\n"
172     CFI(".cfi_adjust_cfa_offset -8\n")
173     CFI(".cfi_restore %rdi\n")
174     // Restore RBP
175     "popq    %rbp\n"
176     CFI(".cfi_adjust_cfa_offset -8\n")
177     CFI(".cfi_restore %rbp\n")
178     "ret\n"
179     CFI(".cfi_endproc\n")
180     SIZE(X86CompilationCallback)
181   );
182 # else
183   // No inline assembler support on this platform. The routine is in external
184   // file.
185   void X86CompilationCallback();
186 
187 # endif
188 #elif defined (X86_32_JIT)
189 # ifndef _MSC_VER
190   void X86CompilationCallback(void);
191   asm(
192     ".text\n"
193     ".align 8\n"
194     ".globl " ASMPREFIX "X86CompilationCallback\n"
195     TYPE_FUNCTION(X86CompilationCallback)
196   ASMPREFIX "X86CompilationCallback:\n"
197     CFI(".cfi_startproc\n")
198     "pushl   %ebp\n"
199     CFI(".cfi_def_cfa_offset 8\n")
200     CFI(".cfi_offset %ebp, -8\n")
201     "movl    %esp, %ebp\n"    // Standard prologue
202     CFI(".cfi_def_cfa_register %ebp\n")
203     "pushl   %eax\n"
204     CFI(".cfi_rel_offset %eax, 0\n")
205     "pushl   %edx\n"          // Save EAX/EDX/ECX
206     CFI(".cfi_rel_offset %edx, 4\n")
207     "pushl   %ecx\n"
208     CFI(".cfi_rel_offset %ecx, 8\n")
209 #  if defined(__APPLE__)
210     "andl    $-16, %esp\n"    // Align ESP on 16-byte boundary
211 #  endif
212     "subl    $16, %esp\n"
213     "movl    4(%ebp), %eax\n" // Pass prev frame and return address
214     "movl    %eax, 4(%esp)\n"
215     "movl    %ebp, (%esp)\n"
216     "call    " ASMPREFIX "X86CompilationCallback2\n"
217     "movl    %ebp, %esp\n"    // Restore ESP
218     CFI(".cfi_def_cfa_register %esp\n")
219     "subl    $12, %esp\n"
220     CFI(".cfi_adjust_cfa_offset 12\n")
221     "popl    %ecx\n"
222     CFI(".cfi_adjust_cfa_offset -4\n")
223     CFI(".cfi_restore %ecx\n")
224     "popl    %edx\n"
225     CFI(".cfi_adjust_cfa_offset -4\n")
226     CFI(".cfi_restore %edx\n")
227     "popl    %eax\n"
228     CFI(".cfi_adjust_cfa_offset -4\n")
229     CFI(".cfi_restore %eax\n")
230     "popl    %ebp\n"
231     CFI(".cfi_adjust_cfa_offset -4\n")
232     CFI(".cfi_restore %ebp\n")
233     "ret\n"
234     CFI(".cfi_endproc\n")
235     SIZE(X86CompilationCallback)
236   );
237 
238   // Same as X86CompilationCallback but also saves XMM argument registers.
239   void X86CompilationCallback_SSE(void);
240   asm(
241     ".text\n"
242     ".align 8\n"
243     ".globl " ASMPREFIX "X86CompilationCallback_SSE\n"
244     TYPE_FUNCTION(X86CompilationCallback_SSE)
245   ASMPREFIX "X86CompilationCallback_SSE:\n"
246     CFI(".cfi_startproc\n")
247     "pushl   %ebp\n"
248     CFI(".cfi_def_cfa_offset 8\n")
249     CFI(".cfi_offset %ebp, -8\n")
250     "movl    %esp, %ebp\n"    // Standard prologue
251     CFI(".cfi_def_cfa_register %ebp\n")
252     "pushl   %eax\n"
253     CFI(".cfi_rel_offset %eax, 0\n")
254     "pushl   %edx\n"          // Save EAX/EDX/ECX
255     CFI(".cfi_rel_offset %edx, 4\n")
256     "pushl   %ecx\n"
257     CFI(".cfi_rel_offset %ecx, 8\n")
258     "andl    $-16, %esp\n"    // Align ESP on 16-byte boundary
259     // Save all XMM arg registers
260     "subl    $64, %esp\n"
261     // FIXME: provide frame move information for xmm registers.
262     // This can be tricky, because CFA register is ebp (unaligned)
263     // and we need to produce offsets relative to it.
264     "movaps  %xmm0, (%esp)\n"
265     "movaps  %xmm1, 16(%esp)\n"
266     "movaps  %xmm2, 32(%esp)\n"
267     "movaps  %xmm3, 48(%esp)\n"
268     "subl    $16, %esp\n"
269     "movl    4(%ebp), %eax\n" // Pass prev frame and return address
270     "movl    %eax, 4(%esp)\n"
271     "movl    %ebp, (%esp)\n"
272     "call    " ASMPREFIX "X86CompilationCallback2\n"
273     "addl    $16, %esp\n"
274     "movaps  48(%esp), %xmm3\n"
275     CFI(".cfi_restore %xmm3\n")
276     "movaps  32(%esp), %xmm2\n"
277     CFI(".cfi_restore %xmm2\n")
278     "movaps  16(%esp), %xmm1\n"
279     CFI(".cfi_restore %xmm1\n")
280     "movaps  (%esp), %xmm0\n"
281     CFI(".cfi_restore %xmm0\n")
282     "movl    %ebp, %esp\n"    // Restore ESP
283     CFI(".cfi_def_cfa_register esp\n")
284     "subl    $12, %esp\n"
285     CFI(".cfi_adjust_cfa_offset 12\n")
286     "popl    %ecx\n"
287     CFI(".cfi_adjust_cfa_offset -4\n")
288     CFI(".cfi_restore %ecx\n")
289     "popl    %edx\n"
290     CFI(".cfi_adjust_cfa_offset -4\n")
291     CFI(".cfi_restore %edx\n")
292     "popl    %eax\n"
293     CFI(".cfi_adjust_cfa_offset -4\n")
294     CFI(".cfi_restore %eax\n")
295     "popl    %ebp\n"
296     CFI(".cfi_adjust_cfa_offset -4\n")
297     CFI(".cfi_restore %ebp\n")
298     "ret\n"
299     CFI(".cfi_endproc\n")
300     SIZE(X86CompilationCallback_SSE)
301   );
302 # else
303   void X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr);
304 
305   _declspec(naked) void X86CompilationCallback(void) {
306     __asm {
307       push  ebp
308       mov   ebp, esp
309       push  eax
310       push  edx
311       push  ecx
312       and   esp, -16
313       sub   esp, 16
314       mov   eax, dword ptr [ebp+4]
315       mov   dword ptr [esp+4], eax
316       mov   dword ptr [esp], ebp
317       call  X86CompilationCallback2
318       mov   esp, ebp
319       sub   esp, 12
320       pop   ecx
321       pop   edx
322       pop   eax
323       pop   ebp
324       ret
325     }
326   }
327 
328 # endif // _MSC_VER
329 
330 #else // Not an i386 host
331   void X86CompilationCallback() {
332     llvm_unreachable("Cannot call X86CompilationCallback() on a non-x86 arch!");
333   }
334 #endif
335 }
336 
337 /// X86CompilationCallback2 - This is the target-specific function invoked by the
338 /// function stub when we did not know the real target of a call.  This function
339 /// must locate the start of the stub or call site and pass it into the JIT
340 /// compiler function.
341 extern "C" {
342 void
X86CompilationCallback2(intptr_t * StackPtr,intptr_t RetAddr)343 X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) {
344   intptr_t *RetAddrLoc = &StackPtr[1];
345   assert(*RetAddrLoc == RetAddr &&
346          "Could not find return address on the stack!");
347 
348   // It's a stub if there is an interrupt marker after the call.
349   bool isStub = ((unsigned char*)RetAddr)[0] == 0xCE;
350 
351   // The call instruction should have pushed the return value onto the stack...
352 #if defined (X86_64_JIT)
353   RetAddr--;     // Backtrack to the reference itself...
354 #else
355   RetAddr -= 4;  // Backtrack to the reference itself...
356 #endif
357 
358 #if 0
359   DEBUG(dbgs() << "In callback! Addr=" << (void*)RetAddr
360                << " ESP=" << (void*)StackPtr
361                << ": Resolving call to function: "
362                << TheVM->getFunctionReferencedName((void*)RetAddr) << "\n");
363 #endif
364 
365   // Sanity check to make sure this really is a call instruction.
366 #if defined (X86_64_JIT)
367   assert(((unsigned char*)RetAddr)[-2] == 0x41 &&"Not a call instr!");
368   assert(((unsigned char*)RetAddr)[-1] == 0xFF &&"Not a call instr!");
369 #else
370   assert(((unsigned char*)RetAddr)[-1] == 0xE8 &&"Not a call instr!");
371 #endif
372 
373   intptr_t NewVal = (intptr_t)JITCompilerFunction((void*)RetAddr);
374 
375   // Rewrite the call target... so that we don't end up here every time we
376   // execute the call.
377 #if defined (X86_64_JIT)
378   assert(isStub &&
379          "X86-64 doesn't support rewriting non-stub lazy compilation calls:"
380          " the call instruction varies too much.");
381 #else
382   *(intptr_t *)RetAddr = (intptr_t)(NewVal-RetAddr-4);
383 #endif
384 
385   if (isStub) {
386     // If this is a stub, rewrite the call into an unconditional branch
387     // instruction so that two return addresses are not pushed onto the stack
388     // when the requested function finally gets called.  This also makes the
389     // 0xCE byte (interrupt) dead, so the marker doesn't effect anything.
390 #if defined (X86_64_JIT)
391     // If the target address is within 32-bit range of the stub, use a
392     // PC-relative branch instead of loading the actual address.  (This is
393     // considerably shorter than the 64-bit immediate load already there.)
394     // We assume here intptr_t is 64 bits.
395     intptr_t diff = NewVal-RetAddr+7;
396     if (diff >= -2147483648LL && diff <= 2147483647LL) {
397       *(unsigned char*)(RetAddr-0xc) = 0xE9;
398       *(intptr_t *)(RetAddr-0xb) = diff & 0xffffffff;
399     } else {
400       *(intptr_t *)(RetAddr - 0xa) = NewVal;
401       ((unsigned char*)RetAddr)[0] = (2 | (4 << 3) | (3 << 6));
402     }
403     sys::ValgrindDiscardTranslations((void*)(RetAddr-0xc), 0xd);
404 #else
405     ((unsigned char*)RetAddr)[-1] = 0xE9;
406     sys::ValgrindDiscardTranslations((void*)(RetAddr-1), 5);
407 #endif
408   }
409 
410   // Change the return address to reexecute the call instruction...
411 #if defined (X86_64_JIT)
412   *RetAddrLoc -= 0xd;
413 #else
414   *RetAddrLoc -= 5;
415 #endif
416 }
417 }
418 
419 TargetJITInfo::LazyResolverFn
getLazyResolverFunction(JITCompilerFn F)420 X86JITInfo::getLazyResolverFunction(JITCompilerFn F) {
421   JITCompilerFunction = F;
422 
423 #if defined (X86_32_JIT) && !defined (_MSC_VER)
424   if (Subtarget->hasSSE1())
425     return X86CompilationCallback_SSE;
426 #endif
427 
428   return X86CompilationCallback;
429 }
430 
X86JITInfo(X86TargetMachine & tm)431 X86JITInfo::X86JITInfo(X86TargetMachine &tm) : TM(tm) {
432   Subtarget = &TM.getSubtarget<X86Subtarget>();
433   useGOT = 0;
434   TLSOffset = 0;
435 }
436 
emitGlobalValueIndirectSym(const GlobalValue * GV,void * ptr,JITCodeEmitter & JCE)437 void *X86JITInfo::emitGlobalValueIndirectSym(const GlobalValue* GV, void *ptr,
438                                              JITCodeEmitter &JCE) {
439 #if defined (X86_64_JIT)
440   const unsigned Alignment = 8;
441   uint8_t Buffer[8];
442   uint8_t *Cur = Buffer;
443   MachineCodeEmitter::emitWordLEInto(Cur, (unsigned)(intptr_t)ptr);
444   MachineCodeEmitter::emitWordLEInto(Cur, (unsigned)(((intptr_t)ptr) >> 32));
445 #else
446   const unsigned Alignment = 4;
447   uint8_t Buffer[4];
448   uint8_t *Cur = Buffer;
449   MachineCodeEmitter::emitWordLEInto(Cur, (intptr_t)ptr);
450 #endif
451   return JCE.allocIndirectGV(GV, Buffer, sizeof(Buffer), Alignment);
452 }
453 
getStubLayout()454 TargetJITInfo::StubLayout X86JITInfo::getStubLayout() {
455   // The 64-bit stub contains:
456   //   movabs r10 <- 8-byte-target-address  # 10 bytes
457   //   call|jmp *r10  # 3 bytes
458   // The 32-bit stub contains a 5-byte call|jmp.
459   // If the stub is a call to the compilation callback, an extra byte is added
460   // to mark it as a stub.
461   StubLayout Result = {14, 4};
462   return Result;
463 }
464 
emitFunctionStub(const Function * F,void * Target,JITCodeEmitter & JCE)465 void *X86JITInfo::emitFunctionStub(const Function* F, void *Target,
466                                    JITCodeEmitter &JCE) {
467   // Note, we cast to intptr_t here to silence a -pedantic warning that
468   // complains about casting a function pointer to a normal pointer.
469 #if defined (X86_32_JIT) && !defined (_MSC_VER)
470   bool NotCC = (Target != (void*)(intptr_t)X86CompilationCallback &&
471                 Target != (void*)(intptr_t)X86CompilationCallback_SSE);
472 #else
473   bool NotCC = Target != (void*)(intptr_t)X86CompilationCallback;
474 #endif
475   JCE.emitAlignment(4);
476   void *Result = (void*)JCE.getCurrentPCValue();
477   if (NotCC) {
478 #if defined (X86_64_JIT)
479     JCE.emitByte(0x49);          // REX prefix
480     JCE.emitByte(0xB8+2);        // movabsq r10
481     JCE.emitWordLE((unsigned)(intptr_t)Target);
482     JCE.emitWordLE((unsigned)(((intptr_t)Target) >> 32));
483     JCE.emitByte(0x41);          // REX prefix
484     JCE.emitByte(0xFF);          // jmpq *r10
485     JCE.emitByte(2 | (4 << 3) | (3 << 6));
486 #else
487     JCE.emitByte(0xE9);
488     JCE.emitWordLE((intptr_t)Target-JCE.getCurrentPCValue()-4);
489 #endif
490     return Result;
491   }
492 
493 #if defined (X86_64_JIT)
494   JCE.emitByte(0x49);          // REX prefix
495   JCE.emitByte(0xB8+2);        // movabsq r10
496   JCE.emitWordLE((unsigned)(intptr_t)Target);
497   JCE.emitWordLE((unsigned)(((intptr_t)Target) >> 32));
498   JCE.emitByte(0x41);          // REX prefix
499   JCE.emitByte(0xFF);          // callq *r10
500   JCE.emitByte(2 | (2 << 3) | (3 << 6));
501 #else
502   JCE.emitByte(0xE8);   // Call with 32 bit pc-rel destination...
503 
504   JCE.emitWordLE((intptr_t)Target-JCE.getCurrentPCValue()-4);
505 #endif
506 
507   // This used to use 0xCD, but that value is used by JITMemoryManager to
508   // initialize the buffer with garbage, which means it may follow a
509   // noreturn function call, confusing X86CompilationCallback2.  PR 4929.
510   JCE.emitByte(0xCE);   // Interrupt - Just a marker identifying the stub!
511   return Result;
512 }
513 
514 /// getPICJumpTableEntry - Returns the value of the jumptable entry for the
515 /// specific basic block.
getPICJumpTableEntry(uintptr_t BB,uintptr_t Entry)516 uintptr_t X86JITInfo::getPICJumpTableEntry(uintptr_t BB, uintptr_t Entry) {
517 #if defined(X86_64_JIT)
518   return BB - Entry;
519 #else
520   return BB - PICBase;
521 #endif
522 }
523 
524 /// relocate - Before the JIT can run a block of code that has been emitted,
525 /// it must rewrite the code to contain the actual addresses of any
526 /// referenced global symbols.
relocate(void * Function,MachineRelocation * MR,unsigned NumRelocs,unsigned char * GOTBase)527 void X86JITInfo::relocate(void *Function, MachineRelocation *MR,
528                           unsigned NumRelocs, unsigned char* GOTBase) {
529   for (unsigned i = 0; i != NumRelocs; ++i, ++MR) {
530     void *RelocPos = (char*)Function + MR->getMachineCodeOffset();
531     intptr_t ResultPtr = (intptr_t)MR->getResultPointer();
532     switch ((X86::RelocationType)MR->getRelocationType()) {
533     case X86::reloc_pcrel_word: {
534       // PC relative relocation, add the relocated value to the value already in
535       // memory, after we adjust it for where the PC is.
536       ResultPtr = ResultPtr -(intptr_t)RelocPos - 4 - MR->getConstantVal();
537       *((unsigned*)RelocPos) += (unsigned)ResultPtr;
538       break;
539     }
540     case X86::reloc_picrel_word: {
541       // PIC base relative relocation, add the relocated value to the value
542       // already in memory, after we adjust it for where the PIC base is.
543       ResultPtr = ResultPtr - ((intptr_t)Function + MR->getConstantVal());
544       *((unsigned*)RelocPos) += (unsigned)ResultPtr;
545       break;
546     }
547     case X86::reloc_absolute_word:
548     case X86::reloc_absolute_word_sext:
549       // Absolute relocation, just add the relocated value to the value already
550       // in memory.
551       *((unsigned*)RelocPos) += (unsigned)ResultPtr;
552       break;
553     case X86::reloc_absolute_dword:
554       *((intptr_t*)RelocPos) += ResultPtr;
555       break;
556     }
557   }
558 }
559 
allocateThreadLocalMemory(size_t size)560 char* X86JITInfo::allocateThreadLocalMemory(size_t size) {
561 #if defined(X86_32_JIT) && !defined(__APPLE__) && !defined(_MSC_VER)
562   TLSOffset -= size;
563   return TLSOffset;
564 #else
565   llvm_unreachable("Cannot allocate thread local storage on this arch!");
566   return 0;
567 #endif
568 }
569