PPCJITInfo.cpp revision e7a83dfac62eb01a1dcc71b98363d3bf3a893a6c
1//===-- PPCJITInfo.cpp - Implement the JIT interfaces for the PowerPC -----===//
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 32-bit PowerPC target.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "jit"
15#include "PPCJITInfo.h"
16#include "PPCRelocations.h"
17#include "PPCTargetMachine.h"
18#include "llvm/Function.h"
19#include "llvm/CodeGen/MachineCodeEmitter.h"
20#include "llvm/Config/alloca.h"
21#include "llvm/Support/Debug.h"
22#include <set>
23using namespace llvm;
24
25static TargetJITInfo::JITCompilerFn JITCompilerFunction;
26
27#define BUILD_ADDIS(RD,RS,IMM16) \
28  ((15 << 26) | ((RD) << 21) | ((RS) << 16) | ((IMM16) & 65535))
29#define BUILD_ORI(RD,RS,UIMM16) \
30  ((24 << 26) | ((RS) << 21) | ((RD) << 16) | ((UIMM16) & 65535))
31#define BUILD_ORIS(RD,RS,UIMM16) \
32  ((25 << 26) | ((RS) << 21) | ((RD) << 16) | ((UIMM16) & 65535))
33#define BUILD_RLDICR(RD,RS,SH,ME) \
34  ((30 << 26) | ((RS) << 21) | ((RD) << 16) | (((SH) & 31) << 11) | \
35   (((ME) & 63) << 6) | (1 << 2) | ((((SH) >> 5) & 1) << 1))
36#define BUILD_MTSPR(RS,SPR)      \
37  ((31 << 26) | ((RS) << 21) | ((SPR) << 16) | (467 << 1))
38#define BUILD_BCCTRx(BO,BI,LINK) \
39  ((19 << 26) | ((BO) << 21) | ((BI) << 16) | (528 << 1) | ((LINK) & 1))
40#define BUILD_B(TARGET, LINK) \
41  ((18 << 26) | (((TARGET) & 0x00FFFFFF) << 2) | ((LINK) & 1))
42
43// Pseudo-ops
44#define BUILD_LIS(RD,IMM16)    BUILD_ADDIS(RD,0,IMM16)
45#define BUILD_SLDI(RD,RS,IMM6) BUILD_RLDICR(RD,RS,IMM6,63-IMM6)
46#define BUILD_MTCTR(RS)        BUILD_MTSPR(RS,9)
47#define BUILD_BCTR(LINK)       BUILD_BCCTRx(20,0,LINK)
48
49static void EmitBranchToAt(uint64_t At, uint64_t To, bool isCall, bool is64Bit){
50  intptr_t Offset = ((intptr_t)To - (intptr_t)At) >> 2;
51  unsigned *AtI = (unsigned*)(intptr_t)At;
52
53  if (Offset >= -(1 << 23) && Offset < (1 << 23)) {   // In range?
54    AtI[0] = BUILD_B(Offset, isCall);     // b/bl target
55  } else if (!is64Bit) {
56    AtI[0] = BUILD_LIS(12, To >> 16);     // lis r12, hi16(address)
57    AtI[1] = BUILD_ORI(12, 12, To);       // ori r12, r12, lo16(address)
58    AtI[2] = BUILD_MTCTR(12);             // mtctr r12
59    AtI[3] = BUILD_BCTR(isCall);          // bctr/bctrl
60  } else {
61    AtI[0] = BUILD_LIS(12, To >> 48);      // lis r12, hi16(address)
62    AtI[1] = BUILD_ORI(12, 12, To >> 32);  // ori r12, r12, lo16(address)
63    AtI[2] = BUILD_SLDI(12, 12, 32);       // sldi r12, r12, 32
64    AtI[3] = BUILD_ORIS(12, 12, To >> 16); // oris r12, r12, hi16(address)
65    AtI[4] = BUILD_ORI(12, 12, To);        // ori r12, r12, lo16(address)
66    AtI[5] = BUILD_MTCTR(12);              // mtctr r12
67    AtI[6] = BUILD_BCTR(isCall);           // bctr/bctrl
68  }
69}
70
71extern "C" void PPC32CompilationCallback();
72extern "C" void PPC64CompilationCallback();
73
74#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
75    !(defined(__ppc64__) || defined(__FreeBSD__))
76// CompilationCallback stub - We can't use a C function with inline assembly in
77// it, because we the prolog/epilog inserted by GCC won't work for us.  Instead,
78// write our own wrapper, which does things our way, so we have complete control
79// over register saving and restoring.
80asm(
81    ".text\n"
82    ".align 2\n"
83    ".globl _PPC32CompilationCallback\n"
84"_PPC32CompilationCallback:\n"
85    // Make space for 8 ints r[3-10] and 13 doubles f[1-13] and the
86    // FIXME: need to save v[0-19] for altivec?
87    // FIXME: could shrink frame
88    // Set up a proper stack frame
89    // FIXME Layout
90    //   PowerPC64 ABI linkage    -  24 bytes
91    //                 parameters -  32 bytes
92    //   13 double registers      - 104 bytes
93    //   8 int registers          -  32 bytes
94    "mflr r0\n"
95    "stw r0,  8(r1)\n"
96    "stwu r1, -208(r1)\n"
97    // Save all int arg registers
98    "stw r10, 204(r1)\n"    "stw r9,  200(r1)\n"
99    "stw r8,  196(r1)\n"    "stw r7,  192(r1)\n"
100    "stw r6,  188(r1)\n"    "stw r5,  184(r1)\n"
101    "stw r4,  180(r1)\n"    "stw r3,  176(r1)\n"
102    // Save all call-clobbered FP regs.
103    "stfd f13, 168(r1)\n"   "stfd f12, 160(r1)\n"
104    "stfd f11, 152(r1)\n"   "stfd f10, 144(r1)\n"
105    "stfd f9,  136(r1)\n"   "stfd f8,  128(r1)\n"
106    "stfd f7,  120(r1)\n"   "stfd f6,  112(r1)\n"
107    "stfd f5,  104(r1)\n"   "stfd f4,   96(r1)\n"
108    "stfd f3,   88(r1)\n"   "stfd f2,   80(r1)\n"
109    "stfd f1,   72(r1)\n"
110    // Arguments to Compilation Callback:
111    // r3 - our lr (address of the call instruction in stub plus 4)
112    // r4 - stub's lr (address of instruction that called the stub plus 4)
113    // r5 - is64Bit - always 0.
114    "mr   r3, r0\n"
115    "lwz  r2, 208(r1)\n" // stub's frame
116    "lwz  r4, 8(r2)\n" // stub's lr
117    "li   r5, 0\n"       // 0 == 32 bit
118    "bl _PPCCompilationCallbackC\n"
119    "mtctr r3\n"
120    // Restore all int arg registers
121    "lwz r10, 204(r1)\n"    "lwz r9,  200(r1)\n"
122    "lwz r8,  196(r1)\n"    "lwz r7,  192(r1)\n"
123    "lwz r6,  188(r1)\n"    "lwz r5,  184(r1)\n"
124    "lwz r4,  180(r1)\n"    "lwz r3,  176(r1)\n"
125    // Restore all FP arg registers
126    "lfd f13, 168(r1)\n"    "lfd f12, 160(r1)\n"
127    "lfd f11, 152(r1)\n"    "lfd f10, 144(r1)\n"
128    "lfd f9,  136(r1)\n"    "lfd f8,  128(r1)\n"
129    "lfd f7,  120(r1)\n"    "lfd f6,  112(r1)\n"
130    "lfd f5,  104(r1)\n"    "lfd f4,   96(r1)\n"
131    "lfd f3,   88(r1)\n"    "lfd f2,   80(r1)\n"
132    "lfd f1,   72(r1)\n"
133    // Pop 3 frames off the stack and branch to target
134    "lwz  r1, 208(r1)\n"
135    "lwz  r2, 8(r1)\n"
136    "mtlr r2\n"
137    "bctr\n"
138    );
139
140#elif defined(__PPC__) && !defined(__ppc64__)
141// Linux & FreeBSD / PPC 32 support
142
143// CompilationCallback stub - We can't use a C function with inline assembly in
144// it, because we the prolog/epilog inserted by GCC won't work for us.  Instead,
145// write our own wrapper, which does things our way, so we have complete control
146// over register saving and restoring.
147asm(
148    ".text\n"
149    ".align 2\n"
150    ".globl PPC32CompilationCallback\n"
151"PPC32CompilationCallback:\n"
152    // Make space for 8 ints r[3-10] and 8 doubles f[1-8] and the
153    // FIXME: need to save v[0-19] for altivec?
154    // FIXME: could shrink frame
155    // Set up a proper stack frame
156    // FIXME Layout
157    //   8 double registers       -  64 bytes
158    //   8 int registers          -  32 bytes
159    "mflr 0\n"
160    "stw 0,  4(1)\n"
161    "stwu 1, -104(1)\n"
162    // Save all int arg registers
163    "stw 10, 100(1)\n"   "stw 9,  96(1)\n"
164    "stw 8,  92(1)\n"    "stw 7,  88(1)\n"
165    "stw 6,  84(1)\n"    "stw 5,  80(1)\n"
166    "stw 4,  76(1)\n"    "stw 3,  72(1)\n"
167    // Save all call-clobbered FP regs.
168    "stfd 8,  64(1)\n"
169    "stfd 7,  56(1)\n"   "stfd 6,  48(1)\n"
170    "stfd 5,  40(1)\n"   "stfd 4,  32(1)\n"
171    "stfd 3,  24(1)\n"   "stfd 2,  16(1)\n"
172    "stfd 1,  8(1)\n"
173    // Arguments to Compilation Callback:
174    // r3 - our lr (address of the call instruction in stub plus 4)
175    // r4 - stub's lr (address of instruction that called the stub plus 4)
176    // r5 - is64Bit - always 0.
177    "mr   3, 0\n"
178    "lwz  5, 104(1)\n" // stub's frame
179    "lwz  4, 4(5)\n" // stub's lr
180    "li   5, 0\n"       // 0 == 32 bit
181    "bl PPCCompilationCallbackC\n"
182    "mtctr 3\n"
183    // Restore all int arg registers
184    "lwz 10, 100(1)\n"   "lwz 9,  96(1)\n"
185    "lwz 8,  92(1)\n"    "lwz 7,  88(1)\n"
186    "lwz 6,  84(1)\n"    "lwz 5,  80(1)\n"
187    "lwz 4,  76(1)\n"    "lwz 3,  72(1)\n"
188    // Restore all FP arg registers
189    "lfd 8,  64(1)\n"
190    "lfd 7,  56(1)\n"    "lfd 6,  48(1)\n"
191    "lfd 5,  40(1)\n"    "lfd 4,  32(1)\n"
192    "lfd 3,  24(1)\n"    "lfd 2,  16(1)\n"
193    "lfd 1,  8(1)\n"
194    // Pop 3 frames off the stack and branch to target
195    "lwz  1, 104(1)\n"
196    "lwz  0, 4(1)\n"
197    "mtlr 0\n"
198    "bctr\n"
199    );
200#else
201void PPC32CompilationCallback() {
202  assert(0 && "This is not a power pc, you can't execute this!");
203  abort();
204}
205#endif
206
207#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
208    defined(__ppc64__)
209asm(
210    ".text\n"
211    ".align 2\n"
212    ".globl _PPC64CompilationCallback\n"
213"_PPC64CompilationCallback:\n"
214    // Make space for 8 ints r[3-10] and 13 doubles f[1-13] and the
215    // FIXME: need to save v[0-19] for altivec?
216    // Set up a proper stack frame
217    // Layout
218    //   PowerPC64 ABI linkage    -  48 bytes
219    //                 parameters -  64 bytes
220    //   13 double registers      - 104 bytes
221    //   8 int registers          -  64 bytes
222    "mflr r0\n"
223    "std r0,  16(r1)\n"
224    "stdu r1, -280(r1)\n"
225    // Save all int arg registers
226    "std r10, 272(r1)\n"    "std r9,  264(r1)\n"
227    "std r8,  256(r1)\n"    "std r7,  248(r1)\n"
228    "std r6,  240(r1)\n"    "std r5,  232(r1)\n"
229    "std r4,  224(r1)\n"    "std r3,  216(r1)\n"
230    // Save all call-clobbered FP regs.
231    "stfd f13, 208(r1)\n"    "stfd f12, 200(r1)\n"
232    "stfd f11, 192(r1)\n"    "stfd f10, 184(r1)\n"
233    "stfd f9,  176(r1)\n"    "stfd f8,  168(r1)\n"
234    "stfd f7,  160(r1)\n"    "stfd f6,  152(r1)\n"
235    "stfd f5,  144(r1)\n"    "stfd f4,  136(r1)\n"
236    "stfd f3,  128(r1)\n"    "stfd f2,  120(r1)\n"
237    "stfd f1,  112(r1)\n"
238    // Arguments to Compilation Callback:
239    // r3 - our lr (address of the call instruction in stub plus 4)
240    // r4 - stub's lr (address of instruction that called the stub plus 4)
241    // r5 - is64Bit - always 1.
242    "mr   r3, r0\n"
243    "ld   r2, 280(r1)\n" // stub's frame
244    "ld   r4, 16(r2)\n"  // stub's lr
245    "li   r5, 1\n"       // 1 == 64 bit
246    "bl _PPCCompilationCallbackC\n"
247    "mtctr r3\n"
248    // Restore all int arg registers
249    "ld r10, 272(r1)\n"    "ld r9,  264(r1)\n"
250    "ld r8,  256(r1)\n"    "ld r7,  248(r1)\n"
251    "ld r6,  240(r1)\n"    "ld r5,  232(r1)\n"
252    "ld r4,  224(r1)\n"    "ld r3,  216(r1)\n"
253    // Restore all FP arg registers
254    "lfd f13, 208(r1)\n"    "lfd f12, 200(r1)\n"
255    "lfd f11, 192(r1)\n"    "lfd f10, 184(r1)\n"
256    "lfd f9,  176(r1)\n"    "lfd f8,  168(r1)\n"
257    "lfd f7,  160(r1)\n"    "lfd f6,  152(r1)\n"
258    "lfd f5,  144(r1)\n"    "lfd f4,  136(r1)\n"
259    "lfd f3,  128(r1)\n"    "lfd f2,  120(r1)\n"
260    "lfd f1,  112(r1)\n"
261    // Pop 3 frames off the stack and branch to target
262    "ld  r1, 280(r1)\n"
263    "ld  r2, 16(r1)\n"
264    "mtlr r2\n"
265    "bctr\n"
266    );
267#else
268void PPC64CompilationCallback() {
269  assert(0 && "This is not a power pc, you can't execute this!");
270  abort();
271}
272#endif
273
274extern "C" void *PPCCompilationCallbackC(unsigned *StubCallAddrPlus4,
275                                         unsigned *OrigCallAddrPlus4,
276                                         bool is64Bit) {
277  // Adjust the pointer to the address of the call instruction in the stub
278  // emitted by emitFunctionStub, rather than the instruction after it.
279  unsigned *StubCallAddr = StubCallAddrPlus4 - 1;
280  unsigned *OrigCallAddr = OrigCallAddrPlus4 - 1;
281
282  void *Target = JITCompilerFunction(StubCallAddr);
283
284  // Check to see if *OrigCallAddr is a 'bl' instruction, and if we can rewrite
285  // it to branch directly to the destination.  If so, rewrite it so it does not
286  // need to go through the stub anymore.
287  unsigned OrigCallInst = *OrigCallAddr;
288  if ((OrigCallInst >> 26) == 18) {     // Direct call.
289    intptr_t Offset = ((intptr_t)Target - (intptr_t)OrigCallAddr) >> 2;
290
291    if (Offset >= -(1 << 23) && Offset < (1 << 23)) {   // In range?
292      // Clear the original target out.
293      OrigCallInst &= (63 << 26) | 3;
294      // Fill in the new target.
295      OrigCallInst |= (Offset & ((1 << 24)-1)) << 2;
296      // Replace the call.
297      *OrigCallAddr = OrigCallInst;
298    }
299  }
300
301  // Assert that we are coming from a stub that was created with our
302  // emitFunctionStub.
303  if ((*StubCallAddr >> 26) == 18)
304    StubCallAddr -= 3;
305  else {
306  assert((*StubCallAddr >> 26) == 19 && "Call in stub is not indirect!");
307    StubCallAddr -= is64Bit ? 9 : 6;
308  }
309
310  // Rewrite the stub with an unconditional branch to the target, for any users
311  // who took the address of the stub.
312  EmitBranchToAt((intptr_t)StubCallAddr, (intptr_t)Target, false, is64Bit);
313
314  // Put the address of the target function to call and the address to return to
315  // after calling the target function in a place that is easy to get on the
316  // stack after we restore all regs.
317  return Target;
318}
319
320
321
322TargetJITInfo::LazyResolverFn
323PPCJITInfo::getLazyResolverFunction(JITCompilerFn Fn) {
324  JITCompilerFunction = Fn;
325  return is64Bit ? PPC64CompilationCallback : PPC32CompilationCallback;
326}
327
328#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
329defined(__APPLE__)
330extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
331#endif
332
333/// SyncICache - On PPC, the JIT emitted code must be explicitly refetched to
334/// ensure correct execution.
335static void SyncICache(const void *Addr, size_t len) {
336#if (defined(__POWERPC__) || defined (__ppc__) || defined(_POWER)) && \
337defined(__APPLE__)
338  sys_icache_invalidate(Addr, len);
339#endif
340}
341
342void *PPCJITInfo::emitFunctionStub(const Function* F, void *Fn,
343                                   MachineCodeEmitter &MCE) {
344  // If this is just a call to an external function, emit a branch instead of a
345  // call.  The code is the same except for one bit of the last instruction.
346  if (Fn != (void*)(intptr_t)PPC32CompilationCallback &&
347      Fn != (void*)(intptr_t)PPC64CompilationCallback) {
348    MCE.startFunctionStub(F, 7*4);
349    intptr_t Addr = (intptr_t)MCE.getCurrentPCValue();
350    MCE.emitWordBE(0);
351    MCE.emitWordBE(0);
352    MCE.emitWordBE(0);
353    MCE.emitWordBE(0);
354    MCE.emitWordBE(0);
355    MCE.emitWordBE(0);
356    MCE.emitWordBE(0);
357    EmitBranchToAt(Addr, (intptr_t)Fn, false, is64Bit);
358    SyncICache((void*)Addr, 7*4);
359    return MCE.finishFunctionStub(F);
360  }
361
362  MCE.startFunctionStub(F, 10*4);
363  intptr_t Addr = (intptr_t)MCE.getCurrentPCValue();
364  if (is64Bit) {
365    MCE.emitWordBE(0xf821ffb1);     // stdu r1,-80(r1)
366    MCE.emitWordBE(0x7d6802a6);     // mflr r11
367    MCE.emitWordBE(0xf9610060);     // std r11, 96(r1)
368  } else if (TM.getSubtargetImpl()->isMachoABI()){
369    MCE.emitWordBE(0x9421ffe0);     // stwu r1,-32(r1)
370    MCE.emitWordBE(0x7d6802a6);     // mflr r11
371    MCE.emitWordBE(0x91610028);     // stw r11, 40(r1)
372  } else {
373    MCE.emitWordBE(0x9421ffe0);     // stwu r1,-32(r1)
374    MCE.emitWordBE(0x7d6802a6);     // mflr r11
375    MCE.emitWordBE(0x91610024);     // stw r11, 36(r1)
376  }
377  intptr_t BranchAddr = (intptr_t)MCE.getCurrentPCValue();
378  MCE.emitWordBE(0);
379  MCE.emitWordBE(0);
380  MCE.emitWordBE(0);
381  MCE.emitWordBE(0);
382  MCE.emitWordBE(0);
383  MCE.emitWordBE(0);
384  MCE.emitWordBE(0);
385  EmitBranchToAt(BranchAddr, (intptr_t)Fn, true, is64Bit);
386  SyncICache((void*)Addr, 10*4);
387  return MCE.finishFunctionStub(F);
388}
389
390
391void PPCJITInfo::relocate(void *Function, MachineRelocation *MR,
392                          unsigned NumRelocs, unsigned char* GOTBase) {
393  for (unsigned i = 0; i != NumRelocs; ++i, ++MR) {
394    unsigned *RelocPos = (unsigned*)Function + MR->getMachineCodeOffset()/4;
395    intptr_t ResultPtr = (intptr_t)MR->getResultPointer();
396    switch ((PPC::RelocationType)MR->getRelocationType()) {
397    default: assert(0 && "Unknown relocation type!");
398    case PPC::reloc_pcrel_bx:
399      // PC-relative relocation for b and bl instructions.
400      ResultPtr = (ResultPtr-(intptr_t)RelocPos) >> 2;
401      assert(ResultPtr >= -(1 << 23) && ResultPtr < (1 << 23) &&
402             "Relocation out of range!");
403      *RelocPos |= (ResultPtr & ((1 << 24)-1))  << 2;
404      break;
405    case PPC::reloc_pcrel_bcx:
406      // PC-relative relocation for BLT,BLE,BEQ,BGE,BGT,BNE, or other
407      // bcx instructions.
408      ResultPtr = (ResultPtr-(intptr_t)RelocPos) >> 2;
409      assert(ResultPtr >= -(1 << 13) && ResultPtr < (1 << 13) &&
410             "Relocation out of range!");
411      *RelocPos |= (ResultPtr & ((1 << 14)-1))  << 2;
412      break;
413    case PPC::reloc_absolute_high:     // high bits of ref -> low 16 of instr
414    case PPC::reloc_absolute_low: {    // low bits of ref  -> low 16 of instr
415      ResultPtr += MR->getConstantVal();
416
417      // If this is a high-part access, get the high-part.
418      if (MR->getRelocationType() == PPC::reloc_absolute_high) {
419        // If the low part will have a carry (really a borrow) from the low
420        // 16-bits into the high 16, add a bit to borrow from.
421        if (((int)ResultPtr << 16) < 0)
422          ResultPtr += 1 << 16;
423        ResultPtr >>= 16;
424      }
425
426      // Do the addition then mask, so the addition does not overflow the 16-bit
427      // immediate section of the instruction.
428      unsigned LowBits  = (*RelocPos + ResultPtr) & 65535;
429      unsigned HighBits = *RelocPos & ~65535;
430      *RelocPos = LowBits | HighBits;  // Slam into low 16-bits
431      break;
432    }
433    case PPC::reloc_absolute_low_ix: {  // low bits of ref  -> low 14 of instr
434      ResultPtr += MR->getConstantVal();
435      // Do the addition then mask, so the addition does not overflow the 16-bit
436      // immediate section of the instruction.
437      unsigned LowBits  = (*RelocPos + ResultPtr) & 0xFFFC;
438      unsigned HighBits = *RelocPos & 0xFFFF0003;
439      *RelocPos = LowBits | HighBits;  // Slam into low 14-bits.
440      break;
441    }
442    }
443  }
444}
445
446void PPCJITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
447  EmitBranchToAt((intptr_t)Old, (intptr_t)New, false, is64Bit);
448}
449