1 /*
2 ** Instruction dispatch handling.
3 ** Copyright (C) 2005-2021 Mike Pall. See Copyright Notice in luajit.h
4 */
5 
6 #ifndef _LJ_DISPATCH_H
7 #define _LJ_DISPATCH_H
8 
9 #include "lj_obj.h"
10 #include "lj_bc.h"
11 #if LJ_HASJIT
12 #include "lj_jit.h"
13 #endif
14 
15 #if LJ_TARGET_MIPS
16 /* Need our own global offset table for the dreaded MIPS calling conventions. */
17 
18 #ifndef _LJ_VM_H
19 LJ_ASMF int32_t LJ_FASTCALL lj_vm_modi(int32_t a, int32_t b);
20 #endif
21 
22 #if LJ_SOFTFP
23 #ifndef _LJ_IRCALL_H
24 extern double __adddf3(double a, double b);
25 extern double __subdf3(double a, double b);
26 extern double __muldf3(double a, double b);
27 extern double __divdf3(double a, double b);
28 #endif
29 #define SFGOTDEF(_)	_(sqrt) _(__adddf3) _(__subdf3) _(__muldf3) _(__divdf3)
30 #else
31 #define SFGOTDEF(_)
32 #endif
33 #if LJ_HASJIT
34 #define JITGOTDEF(_)	_(lj_err_trace) _(lj_trace_exit) _(lj_trace_hot)
35 #else
36 #define JITGOTDEF(_)
37 #endif
38 #if LJ_HASFFI
39 #define FFIGOTDEF(_) \
40   _(lj_meta_equal_cd) _(lj_ccallback_enter) _(lj_ccallback_leave)
41 #else
42 #define FFIGOTDEF(_)
43 #endif
44 #define GOTDEF(_) \
45   _(floor) _(ceil) _(trunc) _(log) _(log10) _(exp) _(sin) _(cos) _(tan) \
46   _(asin) _(acos) _(atan) _(sinh) _(cosh) _(tanh) _(frexp) _(modf) _(atan2) \
47   _(pow) _(fmod) _(ldexp) _(lj_vm_modi) \
48   _(lj_dispatch_call) _(lj_dispatch_ins) _(lj_dispatch_stitch) \
49   _(lj_dispatch_profile) _(lj_err_throw) \
50   _(lj_ffh_coroutine_wrap_err) _(lj_func_closeuv) _(lj_func_newL_gc) \
51   _(lj_gc_barrieruv) _(lj_gc_step) _(lj_gc_step_fixtop) _(lj_meta_arith) \
52   _(lj_meta_call) _(lj_meta_cat) _(lj_meta_comp) _(lj_meta_equal) \
53   _(lj_meta_for) _(lj_meta_istype) _(lj_meta_len) _(lj_meta_tget) \
54   _(lj_meta_tset) _(lj_state_growstack) _(lj_strfmt_number) \
55   _(lj_str_new) _(lj_tab_dup) _(lj_tab_get) _(lj_tab_getinth) _(lj_tab_len) \
56   _(lj_tab_new) _(lj_tab_newkey) _(lj_tab_next) _(lj_tab_reasize) \
57   _(lj_tab_setinth) _(lj_buf_putstr_reverse) _(lj_buf_putstr_lower) \
58   _(lj_buf_putstr_upper) _(lj_buf_tostr) \
59   JITGOTDEF(_) FFIGOTDEF(_) SFGOTDEF(_)
60 
61 enum {
62 #define GOTENUM(name) LJ_GOT_##name,
63 GOTDEF(GOTENUM)
64 #undef GOTENUM
65   LJ_GOT__MAX
66 };
67 #endif
68 
69 /* Type of hot counter. Must match the code in the assembler VM. */
70 /* 16 bits are sufficient. Only 0.0015% overhead with maximum slot penalty. */
71 typedef uint16_t HotCount;
72 
73 /* Number of hot counter hash table entries (must be a power of two). */
74 #define HOTCOUNT_SIZE		64
75 #define HOTCOUNT_PCMASK		((HOTCOUNT_SIZE-1)*sizeof(HotCount))
76 
77 /* Hotcount decrements. */
78 #define HOTCOUNT_LOOP		2
79 #define HOTCOUNT_CALL		1
80 
81 /* This solves a circular dependency problem -- bump as needed. Sigh. */
82 #define GG_NUM_ASMFF	57
83 
84 #define GG_LEN_DDISP	(BC__MAX + GG_NUM_ASMFF)
85 #define GG_LEN_SDISP	BC_FUNCF
86 #define GG_LEN_DISP	(GG_LEN_DDISP + GG_LEN_SDISP)
87 
88 /* Global state, main thread and extra fields are allocated together. */
89 typedef struct GG_State {
90   lua_State L;				/* Main thread. */
91   global_State g;			/* Global state. */
92 #if LJ_TARGET_ARM
93   /* Make g reachable via K12 encoded DISPATCH-relative addressing. */
94   uint8_t align1[(16-sizeof(global_State))&15];
95 #endif
96 #if LJ_TARGET_MIPS
97   ASMFunction got[LJ_GOT__MAX];		/* Global offset table. */
98 #endif
99 #if LJ_HASJIT
100   jit_State J;				/* JIT state. */
101   HotCount hotcount[HOTCOUNT_SIZE];	/* Hot counters. */
102 #if LJ_TARGET_ARM
103   /* Ditto for J. */
104   uint8_t align2[(16-sizeof(jit_State)-sizeof(HotCount)*HOTCOUNT_SIZE)&15];
105 #endif
106 #endif
107   ASMFunction dispatch[GG_LEN_DISP];	/* Instruction dispatch tables. */
108   BCIns bcff[GG_NUM_ASMFF];		/* Bytecode for ASM fast functions. */
109 } GG_State;
110 
111 #define GG_OFS(field)	((int)offsetof(GG_State, field))
112 #define G2GG(gl)	((GG_State *)((char *)(gl) - GG_OFS(g)))
113 #define J2GG(j)		((GG_State *)((char *)(j) - GG_OFS(J)))
114 #define L2GG(L)		(G2GG(G(L)))
115 #define J2G(J)		(&J2GG(J)->g)
116 #define G2J(gl)		(&G2GG(gl)->J)
117 #define L2J(L)		(&L2GG(L)->J)
118 #define GG_G2J		(GG_OFS(J) - GG_OFS(g))
119 #define GG_G2DISP	(GG_OFS(dispatch) - GG_OFS(g))
120 #define GG_DISP2G	(GG_OFS(g) - GG_OFS(dispatch))
121 #define GG_DISP2J	(GG_OFS(J) - GG_OFS(dispatch))
122 #define GG_DISP2HOT	(GG_OFS(hotcount) - GG_OFS(dispatch))
123 #define GG_DISP2STATIC	(GG_LEN_DDISP*(int)sizeof(ASMFunction))
124 
125 #define hotcount_get(gg, pc) \
126   (gg)->hotcount[(u32ptr(pc)>>2) & (HOTCOUNT_SIZE-1)]
127 #define hotcount_set(gg, pc, val) \
128   (hotcount_get((gg), (pc)) = (HotCount)(val))
129 
130 /* Dispatch table management. */
131 LJ_FUNC void lj_dispatch_init(GG_State *GG);
132 #if LJ_HASJIT
133 LJ_FUNC void lj_dispatch_init_hotcount(global_State *g);
134 #endif
135 LJ_FUNC void lj_dispatch_update(global_State *g);
136 
137 /* Instruction dispatch callback for hooks or when recording. */
138 LJ_FUNCA void LJ_FASTCALL lj_dispatch_ins(lua_State *L, const BCIns *pc);
139 LJ_FUNCA ASMFunction LJ_FASTCALL lj_dispatch_call(lua_State *L, const BCIns*pc);
140 #if LJ_HASJIT
141 LJ_FUNCA void LJ_FASTCALL lj_dispatch_stitch(jit_State *J, const BCIns *pc);
142 #endif
143 #if LJ_HASPROFILE
144 LJ_FUNCA void LJ_FASTCALL lj_dispatch_profile(lua_State *L, const BCIns *pc);
145 #endif
146 
147 #if LJ_HASFFI && !defined(_BUILDVM_H)
148 /* Save/restore errno and GetLastError() around hooks, exits and recording. */
149 #include <errno.h>
150 #if LJ_TARGET_WINDOWS
151 #define WIN32_LEAN_AND_MEAN
152 #include <windows.h>
153 #define ERRNO_SAVE	int olderr = errno; DWORD oldwerr = GetLastError();
154 #define ERRNO_RESTORE	errno = olderr; SetLastError(oldwerr);
155 #else
156 #define ERRNO_SAVE	int olderr = errno;
157 #define ERRNO_RESTORE	errno = olderr;
158 #endif
159 #else
160 #define ERRNO_SAVE
161 #define ERRNO_RESTORE
162 #endif
163 
164 #endif
165