src/lj_ccall.h

   1 /*
   2 ** FFI C call handling.
   3 ** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #ifndef _LJ_CCALL_H
   7 #define _LJ_CCALL_H
   8
   9 #include "lj_obj.h"
  10 #include "lj_ctype.h"
  11
  12 #if LJ_HASFFI
  13
  14 /* -- C calling conventions ----------------------------------------------- */
  15
  16 #if LJ_TARGET_X86ORX64
  17
  18 #if LJ_TARGET_X86
  19 #define CCALL_NARG_GPR          2       /* For fastcall arguments. */
  20 #define CCALL_NARG_FPR          0
  21 #define CCALL_NRET_GPR          2
  22 #define CCALL_NRET_FPR          1       /* For FP results on x87 stack. */
  23 #define CCALL_ALIGN_STACKARG    0       /* Don't align argument on stack. */
  24 #elif LJ_ABI_WIN
  25 #define CCALL_NARG_GPR          4
  26 #define CCALL_NARG_FPR          4
  27 #define CCALL_NRET_GPR          1
  28 #define CCALL_NRET_FPR          1
  29 #define CCALL_SPS_EXTRA         4
  30 #else
  31 #define CCALL_NARG_GPR          6
  32 #define CCALL_NARG_FPR          8
  33 #define CCALL_NRET_GPR          2
  34 #define CCALL_NRET_FPR          2
  35 #define CCALL_VECTOR_REG        1       /* Pass vectors in registers. */
  36 #endif
  37
  38 #define CCALL_SPS_FREE          1
  39 #define CCALL_ALIGN_CALLSTATE   16
  40
  41 typedef LJ_ALIGN(16) union FPRArg {
  42   double d[2];
  43   float f[4];
  44   uint8_t b[16];
  45   uint16_t s[8];
  46   int i[4];
  47   int64_t l[2];
  48 } FPRArg;
  49
  50 typedef intptr_t GPRArg;
  51
  52 #elif LJ_TARGET_ARM
  53
  54 #define CCALL_NARG_GPR          4
  55 #define CCALL_NRET_GPR          2       /* For softfp double. */
  56 #if LJ_ABI_SOFTFP
  57 #define CCALL_NARG_FPR          0
  58 #define CCALL_NRET_FPR          0
  59 #else
  60 #define CCALL_NARG_FPR          8
  61 #define CCALL_NRET_FPR          4
  62 #endif
  63 #define CCALL_SPS_FREE          0
  64
  65 typedef intptr_t GPRArg;
  66 typedef union FPRArg {
  67   double d;
  68   float f[2];
  69 } FPRArg;
  70
  71 #elif LJ_TARGET_ARM64
  72
  73 #define CCALL_NARG_GPR          8
  74 #define CCALL_NRET_GPR          2
  75 #define CCALL_NARG_FPR          8
  76 #define CCALL_NRET_FPR          4
  77 #define CCALL_SPS_FREE          0
  78 #if LJ_TARGET_OSX
  79 #define CCALL_PACK_STACKARG     1
  80 #endif
  81
  82 typedef intptr_t GPRArg;
  83 typedef union FPRArg {
  84   double d;
  85   struct { LJ_ENDIAN_LOHI(float f; , float g;) };
  86   struct { LJ_ENDIAN_LOHI(uint32_t lo; , uint32_t hi;) };
  87 } FPRArg;
  88
  89 #elif LJ_TARGET_PPC
  90
  91 #define CCALL_NARG_GPR          8
  92 #define CCALL_NARG_FPR          (LJ_ABI_SOFTFP ? 0 : 8)
  93 #define CCALL_NRET_GPR          4       /* For complex double. */
  94 #define CCALL_NRET_FPR          (LJ_ABI_SOFTFP ? 0 : 1)
  95 #define CCALL_SPS_EXTRA         4
  96 #define CCALL_SPS_FREE          0
  97
  98 typedef intptr_t GPRArg;
  99 typedef double FPRArg;
 100
 101 #elif LJ_TARGET_MIPS32
 102
 103 #define CCALL_NARG_GPR          4
 104 #define CCALL_NARG_FPR          (LJ_ABI_SOFTFP ? 0 : 2)
 105 #define CCALL_NRET_GPR          (LJ_ABI_SOFTFP ? 4 : 2)
 106 #define CCALL_NRET_FPR          (LJ_ABI_SOFTFP ? 0 : 2)
 107 #define CCALL_SPS_EXTRA         7
 108 #define CCALL_SPS_FREE          1
 109
 110 typedef intptr_t GPRArg;
 111 typedef union FPRArg {
 112   double d;
 113   struct { LJ_ENDIAN_LOHI(float f; , float g;) };
 114 } FPRArg;
 115
 116 #elif LJ_TARGET_MIPS64
 117
 118 /* FP args are positional and overlay the GPR array. */
 119 #define CCALL_NARG_GPR          8
 120 #define CCALL_NARG_FPR          0
 121 #define CCALL_NRET_GPR          2
 122 #define CCALL_NRET_FPR          (LJ_ABI_SOFTFP ? 0 : 2)
 123 #define CCALL_SPS_EXTRA         3
 124 #define CCALL_SPS_FREE          1
 125
 126 typedef intptr_t GPRArg;
 127 typedef union FPRArg {
 128   double d;
 129   struct { LJ_ENDIAN_LOHI(float f; , float g;) };
 130 } FPRArg;
 131
 132 #else
 133 #error "Missing calling convention definitions for this architecture"
 134 #endif
 135
 136 #ifndef CCALL_SPS_EXTRA
 137 #define CCALL_SPS_EXTRA         0
 138 #endif
 139 #ifndef CCALL_VECTOR_REG
 140 #define CCALL_VECTOR_REG        0
 141 #endif
 142 #ifndef CCALL_ALIGN_STACKARG
 143 #define CCALL_ALIGN_STACKARG    1
 144 #endif
 145 #ifndef CCALL_PACK_STACKARG
 146 #define CCALL_PACK_STACKARG     0
 147 #endif
 148 #ifndef CCALL_ALIGN_CALLSTATE
 149 #define CCALL_ALIGN_CALLSTATE   8
 150 #endif
 151
 152 #define CCALL_NUM_GPR \
 153   (CCALL_NARG_GPR > CCALL_NRET_GPR ? CCALL_NARG_GPR : CCALL_NRET_GPR)
 154 #define CCALL_NUM_FPR \
 155   (CCALL_NARG_FPR > CCALL_NRET_FPR ? CCALL_NARG_FPR : CCALL_NRET_FPR)
 156
 157 /* Check against constants in lj_ctype.h. */
 158 LJ_STATIC_ASSERT(CCALL_NUM_GPR <= CCALL_MAX_GPR);
 159 LJ_STATIC_ASSERT(CCALL_NUM_FPR <= CCALL_MAX_FPR);
 160
 161 #define CCALL_NUM_STACK         31
 162 #define CCALL_SIZE_STACK        (CCALL_NUM_STACK * CTSIZE_PTR)
 163
 164 /* -- C call state -------------------------------------------------------- */
 165
 166 typedef LJ_ALIGN(CCALL_ALIGN_CALLSTATE) struct CCallState {
 167   void (*func)(void);           /* Pointer to called function. */
 168   uint32_t spadj;               /* Stack pointer adjustment. */
 169   uint8_t nsp;                  /* Number of bytes on stack. */
 170   uint8_t retref;               /* Return value by reference. */
 171 #if LJ_TARGET_X64
 172   uint8_t ngpr;                 /* Number of arguments in GPRs. */
 173   uint8_t nfpr;                 /* Number of arguments in FPRs. */
 174 #elif LJ_TARGET_X86
 175   uint8_t resx87;               /* Result on x87 stack: 1:float, 2:double. */
 176 #elif LJ_TARGET_ARM64
 177   void *retp;                   /* Aggregate return pointer in x8. */
 178 #elif LJ_TARGET_PPC
 179   uint8_t nfpr;                 /* Number of arguments in FPRs. */
 180 #endif
 181 #if LJ_32
 182   int32_t align1;
 183 #endif
 184 #if CCALL_NUM_FPR
 185   FPRArg fpr[CCALL_NUM_FPR];    /* Arguments/results in FPRs. */
 186 #endif
 187   GPRArg gpr[CCALL_NUM_GPR];    /* Arguments/results in GPRs. */
 188   GPRArg stack[CCALL_NUM_STACK];        /* Stack slots. */
 189 } CCallState;
 190
 191 /* -- C call handling ----------------------------------------------------- */
 192
 193 /* Really belongs to lj_vm.h. */
 194 LJ_ASMF void LJ_FASTCALL lj_vm_ffi_call(CCallState *cc);
 195
 196 LJ_FUNC CTypeID lj_ccall_ctid_vararg(CTState *cts, cTValue *o);
 197 LJ_FUNC int lj_ccall_func(lua_State *L, GCcdata *cd);
 198
 199 #endif
 200
 201 #endif