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src/lj_emit_mips.h - luajit-2.0-src

Data types defined

Functions defined

Macros defined

Source code

  1. /*
  2. ** MIPS instruction emitter.
  3. ** Copyright (C) 2005-2015 Mike Pall. See Copyright Notice in luajit.h
  4. */

  6. /* -- Emit basic instructions --------------------------------------------- */

  8. ‌static void emit_dst(ASMState *as, MIPSIns mi, Reg rd, Reg rs, Reg rt)
  9. {
  10.   *--as->mcp = mi | MIPSF_D(rd) | MIPSF_S(rs) | MIPSF_T(rt);
  11. }

  13. ‌static void emit_dta(ASMState *as, MIPSIns mi, Reg rd, Reg rt, uint32_t a)
  14. {
  15.   *--as->mcp = mi | MIPSF_D(rd) | MIPSF_T(rt) | MIPSF_A(a);
  16. }

  18. ‌#define emit_ds(as, mi, rd, rs)                emit_dst(as, (mi), (rd), (rs), 0)
  19. ‌#define emit_tg(as, mi, rt, rg)                emit_dst(as, (mi), (rg)&31, 0, (rt))

  21. ‌static void emit_tsi(ASMState *as, MIPSIns mi, Reg rt, Reg rs, int32_t i)
  22. {
  23.   *--as->mcp = mi | MIPSF_T(rt) | MIPSF_S(rs) | (i & 0xffff);
  24. }

  26. ‌#define emit_ti(as, mi, rt, i)                emit_tsi(as, (mi), (rt), 0, (i))
  27. ‌#define emit_hsi(as, mi, rh, rs, i)        emit_tsi(as, (mi), (rh) & 31, (rs), (i))

  29. ‌static void emit_fgh(ASMState *as, MIPSIns mi, Reg rf, Reg rg, Reg rh)
  30. {
  31.   *--as->mcp = mi | MIPSF_F(rf&31) | MIPSF_G(rg&31) | MIPSF_H(rh&31);
  32. }

  34. ‌#define emit_fg(as, mi, rf, rg)                emit_fgh(as, (mi), (rf), (rg), 0)

  36. ‌static void emit_rotr(ASMState *as, Reg dest, Reg src, Reg tmp, uint32_t shift)
  37. {
  38.   if ((as->flags & JIT_F_MIPS32R2)) {
  39.     emit_dta(as, MIPSI_ROTR, dest, src, shift);
  40.   } else {
  41.     emit_dst(as, MIPSI_OR, dest, dest, tmp);
  42.     emit_dta(as, MIPSI_SLL, dest, src, (-shift)&31);
  43.     emit_dta(as, MIPSI_SRL, tmp, src, shift);
  44.   }
  45. }

  47. /* -- Emit loads/stores --------------------------------------------------- */

  49. /* Prefer rematerialization of BASE/L from global_State over spills. */
  50. ‌#define emit_canremat(ref)        ((ref) <= REF_BASE)

  52. /* Try to find a one step delta relative to another constant. */
  53. ‌static int emit_kdelta1(ASMState *as, Reg t, int32_t i)
  54. {
  55.   RegSet work = ~as->freeset & RSET_GPR;
  56.   while (work) {
  57.     Reg r = rset_picktop(work);
  58.     IRRef ref = regcost_ref(as->cost[r]);
  59.     lua_assert(r != t);
  60.     if (ref < ASMREF_L) {
  61.       int32_t delta = i - (ra_iskref(ref) ? ra_krefk(as, ref) : IR(ref)->i);
  62.       if (checki16(delta)) {
  63.         emit_tsi(as, MIPSI_ADDIU, t, r, delta);
  64.         return 1;
  65.       }
  66.     }
  67.     rset_clear(work, r);
  68.   }
  69.   return 0;  /* Failed. */
  70. }

  72. /* Load a 32 bit constant into a GPR. */
  73. ‌static void emit_loadi(ASMState *as, Reg r, int32_t i)
  74. {
  75.   if (checki16(i)) {
  76.     emit_ti(as, MIPSI_LI, r, i);
  77.   } else {
  78.     if ((i & 0xffff)) {
  79.       int32_t jgl = i32ptr(J2G(as->J));
  80.       if ((uint32_t)(i-jgl) < 65536) {
  81.         emit_tsi(as, MIPSI_ADDIU, r, RID_JGL, i-jgl-32768);
  82.         return;
  83.       } else if (emit_kdelta1(as, r, i)) {
  84.         return;
  85.       } else if ((i >> 16) == 0) {
  86.         emit_tsi(as, MIPSI_ORI, r, RID_ZERO, i);
  87.         return;
  88.       }
  89.       emit_tsi(as, MIPSI_ORI, r, r, i);
  90.     }
  91.     emit_ti(as, MIPSI_LUI, r, (i >> 16));
  92.   }
  93. }

  95. ‌#define emit_loada(as, r, addr)                emit_loadi(as, (r), i32ptr((addr)))

  97. static Reg ra_allock(ASMState *as, int32_t k, RegSet allow);
  98. static void ra_allockreg(ASMState *as, int32_t k, Reg r);

  100. /* Get/set from constant pointer. */
  101. ‌static void emit_lsptr(ASMState *as, MIPSIns mi, Reg r, void *p, RegSet allow)
  102. {
  103.   int32_t jgl = i32ptr(J2G(as->J));
  104.   int32_t i = i32ptr(p);
  105.   Reg base;
  106.   if ((uint32_t)(i-jgl) < 65536) {
  107.     i = i-jgl-32768;
  108.     base = RID_JGL;
  109.   } else {
  110.     base = ra_allock(as, i-(int16_t)i, allow);
  111.   }
  112.   emit_tsi(as, mi, r, base, i);
  113. }

  115. ‌#define emit_loadn(as, r, tv) \
  116.   emit_lsptr(as, MIPSI_LDC1, ((r) & 31), (void *)(tv), RSET_GPR)

  118. /* Get/set global_State fields. */
  119. ‌static void emit_lsglptr(ASMState *as, MIPSIns mi, Reg r, int32_t ofs)
  120. {
  121.   emit_tsi(as, mi, r, RID_JGL, ofs-32768);
  122. }

  124. ‌#define emit_getgl(as, r, field) \
  125.   emit_lsglptr(as, MIPSI_LW, (r), (int32_t)offsetof(global_State, field))
  126. ‌#define emit_setgl(as, r, field) \
  127.   emit_lsglptr(as, MIPSI_SW, (r), (int32_t)offsetof(global_State, field))

  129. /* Trace number is determined from per-trace exit stubs. */
  130. ‌#define emit_setvmstate(as, i)                UNUSED(i)

  132. /* -- Emit control-flow instructions -------------------------------------- */

  134. /* Label for internal jumps. */
  135. ‌typedef MCode *MCLabel;

  137. /* Return label pointing to current PC. */
  138. ‌#define emit_label(as)                ((as)->mcp)

  140. ‌static void emit_branch(ASMState *as, MIPSIns mi, Reg rs, Reg rt, MCode *target)
  141. {
  142.   MCode *p = as->mcp;
  143.   ptrdiff_t delta = target - p;
  144.   lua_assert(((delta + 0x8000) >> 16) == 0);
  145.   *--p = mi | MIPSF_S(rs) | MIPSF_T(rt) | ((uint32_t)delta & 0xffffu);
  146.   as->mcp = p;
  147. }

  149. ‌static void emit_jmp(ASMState *as, MCode *target)
  150. {
  151.   *--as->mcp = MIPSI_NOP;
  152.   emit_branch(as, MIPSI_B, RID_ZERO, RID_ZERO, (target));
  153. }

  155. ‌static void emit_call(ASMState *as, void *target)
  156. {
  157.   MCode *p = as->mcp;
  158.   *--p = MIPSI_NOP;
  159.   if ((((uintptr_t)target ^ (uintptr_t)p) >> 28) == 0)
  160.     *--p = MIPSI_JAL | (((uintptr_t)target >>2) & 0x03ffffffu);
  161.   else  /* Target out of range: need indirect call. */
  162.     *--p = MIPSI_JALR | MIPSF_S(RID_CFUNCADDR);
  163.   as->mcp = p;
  164.   ra_allockreg(as, i32ptr(target), RID_CFUNCADDR);
  165. }

  167. /* -- Emit generic operations --------------------------------------------- */

  169. ‌#define emit_move(as, dst, src) \
  170.   emit_ds(as, MIPSI_MOVE, (dst), (src))

  172. /* Generic move between two regs. */
  173. ‌static void emit_movrr(ASMState *as, IRIns *ir, Reg dst, Reg src)
  174. {
  175.   if (dst < RID_MAX_GPR)
  176.     emit_move(as, dst, src);
  177.   else
  178.     emit_fg(as, irt_isnum(ir->t) ? MIPSI_MOV_D : MIPSI_MOV_S, dst, src);
  179. }

  181. /* Generic load of register with base and (small) offset address. */
  182. ‌static void emit_loadofs(ASMState *as, IRIns *ir, Reg r, Reg base, int32_t ofs)
  183. {
  184.   if (r < RID_MAX_GPR)
  185.     emit_tsi(as, MIPSI_LW, r, base, ofs);
  186.   else
  187.     emit_tsi(as, irt_isnum(ir->t) ? MIPSI_LDC1 : MIPSI_LWC1,
  188.              (r & 31), base, ofs);
  189. }

  191. /* Generic store of register with base and (small) offset address. */
  192. ‌static void emit_storeofs(ASMState *as, IRIns *ir, Reg r, Reg base, int32_t ofs)
  193. {
  194.   if (r < RID_MAX_GPR)
  195.     emit_tsi(as, MIPSI_SW, r, base, ofs);
  196.   else
  197.     emit_tsi(as, irt_isnum(ir->t) ? MIPSI_SDC1 : MIPSI_SWC1,
  198.              (r&31), base, ofs);
  199. }

  201. /* Add offset to pointer. */
  202. ‌static void emit_addptr(ASMState *as, Reg r, int32_t ofs)
  203. {
  204.   if (ofs) {
  205.     lua_assert(checki16(ofs));
  206.     emit_tsi(as, MIPSI_ADDIU, r, r, ofs);
  207.   }
  208. }

  210. ‌#define emit_spsub(as, ofs)        emit_addptr(as, RID_SP, -(ofs))

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