tools/wrk/deps/luajit/dynasm/dasm_arm.h
/*
** DynASM ARM encoding engine.
** Copyright (C) 2005-2013 Mike Pall. All rights reserved.
** Released under the MIT license. See dynasm.lua for full copyright notice.
*/
#include <stddef.h>
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#define DASM_ARCH "arm"
#ifndef DASM_EXTERN
#define DASM_EXTERN(a,b,c,d) 0
#endif
/* Action definitions. */
enum {
DASM_STOP, DASM_SECTION, DASM_ESC, DASM_REL_EXT,
/* The following actions need a buffer position. */
DASM_ALIGN, DASM_REL_LG, DASM_LABEL_LG,
/* The following actions also have an argument. */
DASM_REL_PC, DASM_LABEL_PC,
DASM_IMM, DASM_IMM12, DASM_IMM16, DASM_IMML8, DASM_IMML12, DASM_IMMV8,
DASM__MAX
};
/* Maximum number of section buffer positions for a single dasm_put() call. */
#define DASM_MAXSECPOS 25
/* DynASM encoder status codes. Action list offset or number are or'ed in. */
#define DASM_S_OK 0x00000000
#define DASM_S_NOMEM 0x01000000
#define DASM_S_PHASE 0x02000000
#define DASM_S_MATCH_SEC 0x03000000
#define DASM_S_RANGE_I 0x11000000
#define DASM_S_RANGE_SEC 0x12000000
#define DASM_S_RANGE_LG 0x13000000
#define DASM_S_RANGE_PC 0x14000000
#define DASM_S_RANGE_REL 0x15000000
#define DASM_S_UNDEF_LG 0x21000000
#define DASM_S_UNDEF_PC 0x22000000
/* Macros to convert positions (8 bit section + 24 bit index). */
#define DASM_POS2IDX(pos) ((pos)&0x00ffffff)
#define DASM_POS2BIAS(pos) ((pos)&0xff000000)
#define DASM_SEC2POS(sec) ((sec)<<24)
#define DASM_POS2SEC(pos) ((pos)>>24)
#define DASM_POS2PTR(D, pos) (D->sections[DASM_POS2SEC(pos)].rbuf + (pos))
/* Action list type. */
typedef const unsigned int *dasm_ActList;
/* Per-section structure. */
typedef struct dasm_Section {
int *rbuf; /* Biased buffer pointer (negative section bias). */
int *buf; /* True buffer pointer. */
size_t bsize; /* Buffer size in bytes. */
int pos; /* Biased buffer position. */
int epos; /* End of biased buffer position - max single put. */
int ofs; /* Byte offset into section. */
} dasm_Section;
/* Core structure holding the DynASM encoding state. */
struct dasm_State {
size_t psize; /* Allocated size of this structure. */
dasm_ActList actionlist; /* Current actionlist pointer. */
int *lglabels; /* Local/global chain/pos ptrs. */
size_t lgsize;
int *pclabels; /* PC label chains/pos ptrs. */
size_t pcsize;
void **globals; /* Array of globals (bias -10). */
dasm_Section *section; /* Pointer to active section. */
size_t codesize; /* Total size of all code sections. */
int maxsection; /* 0 <= sectionidx < maxsection. */
int status; /* Status code. */
dasm_Section sections[1]; /* All sections. Alloc-extended. */
};
/* The size of the core structure depends on the max. number of sections. */
#define DASM_PSZ(ms) (sizeof(dasm_State)+(ms-1)*sizeof(dasm_Section))
/* Initialize DynASM state. */
void dasm_init(Dst_DECL, int maxsection)
{
dasm_State *D;
size_t psz = 0;
int i;
Dst_REF = NULL;
DASM_M_GROW(Dst, struct dasm_State, Dst_REF, psz, DASM_PSZ(maxsection));
D = Dst_REF;
D->psize = psz;
D->lglabels = NULL;
D->lgsize = 0;
D->pclabels = NULL;
D->pcsize = 0;
D->globals = NULL;
D->maxsection = maxsection;
for (i = 0; i < maxsection; i++) {
D->sections[i].buf = NULL; /* Need this for pass3. */
D->sections[i].rbuf = D->sections[i].buf - DASM_SEC2POS(i);
D->sections[i].bsize = 0;
D->sections[i].epos = 0; /* Wrong, but is recalculated after resize. */
}
}
/* Free DynASM state. */
void dasm_free(Dst_DECL)
{
dasm_State *D = Dst_REF;
int i;
for (i = 0; i < D->maxsection; i++)
if (D->sections[i].buf)
DASM_M_FREE(Dst, D->sections[i].buf, D->sections[i].bsize);
if (D->pclabels) DASM_M_FREE(Dst, D->pclabels, D->pcsize);
if (D->lglabels) DASM_M_FREE(Dst, D->lglabels, D->lgsize);
DASM_M_FREE(Dst, D, D->psize);
}
/* Setup global label array. Must be called before dasm_setup(). */
void dasm_setupglobal(Dst_DECL, void **gl, unsigned int maxgl)
{
dasm_State *D = Dst_REF;
D->globals = gl - 10; /* Negative bias to compensate for locals. */
DASM_M_GROW(Dst, int, D->lglabels, D->lgsize, (10+maxgl)*sizeof(int));
}
/* Grow PC label array. Can be called after dasm_setup(), too. */
void dasm_growpc(Dst_DECL, unsigned int maxpc)
{
dasm_State *D = Dst_REF;
size_t osz = D->pcsize;
DASM_M_GROW(Dst, int, D->pclabels, D->pcsize, maxpc*sizeof(int));
memset((void *)(((unsigned char *)D->pclabels)+osz), 0, D->pcsize-osz);
}
/* Setup encoder. */
void dasm_setup(Dst_DECL, const void *actionlist)
{
dasm_State *D = Dst_REF;
int i;
D->actionlist = (dasm_ActList)actionlist;
D->status = DASM_S_OK;
D->section = &D->sections[0];
memset((void *)D->lglabels, 0, D->lgsize);
if (D->pclabels) memset((void *)D->pclabels, 0, D->pcsize);
for (i = 0; i < D->maxsection; i++) {
D->sections[i].pos = DASM_SEC2POS(i);
D->sections[i].ofs = 0;
}
}
#ifdef DASM_CHECKS
#define CK(x, st) \
do { if (!(x)) { \
D->status = DASM_S_##st|(p-D->actionlist-1); return; } } while (0)
#define CKPL(kind, st) \
do { if ((size_t)((char *)pl-(char *)D->kind##labels) >= D->kind##size) { \
D->status = DASM_S_RANGE_##st|(p-D->actionlist-1); return; } } while (0)
#else
#define CK(x, st) ((void)0)
#define CKPL(kind, st) ((void)0)
#endif
static int dasm_imm12(unsigned int n)
{
int i;
for (i = 0; i < 16; i++, n = (n << 2) | (n >> 30))
if (n <= 255) return (int)(n + (i << 8));
return -1;
}
/* Pass 1: Store actions and args, link branches/labels, estimate offsets. */
void dasm_put(Dst_DECL, int start, ...)
{
va_list ap;
dasm_State *D = Dst_REF;
dasm_ActList p = D->actionlist + start;
dasm_Section *sec = D->section;
int pos = sec->pos, ofs = sec->ofs;
int *b;
if (pos >= sec->epos) {
DASM_M_GROW(Dst, int, sec->buf, sec->bsize,
sec->bsize + 2*DASM_MAXSECPOS*sizeof(int));
sec->rbuf = sec->buf - DASM_POS2BIAS(pos);
sec->epos = (int)sec->bsize/sizeof(int) - DASM_MAXSECPOS+DASM_POS2BIAS(pos);
}
b = sec->rbuf;
b[pos++] = start;
va_start(ap, start);
while (1) {
unsigned int ins = *p++;
unsigned int action = (ins >> 16);
if (action >= DASM__MAX) {
ofs += 4;
} else {
int *pl, n = action >= DASM_REL_PC ? va_arg(ap, int) : 0;
switch (action) {
case DASM_STOP: goto stop;
case DASM_SECTION:
n = (ins & 255); CK(n < D->maxsection, RANGE_SEC);
D->section = &D->sections[n]; goto stop;
case DASM_ESC: p++; ofs += 4; break;
case DASM_REL_EXT: break;
case DASM_ALIGN: ofs += (ins & 255); b[pos++] = ofs; break;
case DASM_REL_LG:
n = (ins & 2047) - 10; pl = D->lglabels + n;
/* Bkwd rel or global. */
if (n >= 0) { CK(n>=10||*pl<0, RANGE_LG); CKPL(lg, LG); goto putrel; }
pl += 10; n = *pl;
if (n < 0) n = 0; /* Start new chain for fwd rel if label exists. */
goto linkrel;
case DASM_REL_PC:
pl = D->pclabels + n; CKPL(pc, PC);
putrel:
n = *pl;
if (n < 0) { /* Label exists. Get label pos and store it. */
b[pos] = -n;
} else {
linkrel:
b[pos] = n; /* Else link to rel chain, anchored at label. */
*pl = pos;
}
pos++;
break;
case DASM_LABEL_LG:
pl = D->lglabels + (ins & 2047) - 10; CKPL(lg, LG); goto putlabel;
case DASM_LABEL_PC:
pl = D->pclabels + n; CKPL(pc, PC);
putlabel:
n = *pl; /* n > 0: Collapse rel chain and replace with label pos. */
while (n > 0) { int *pb = DASM_POS2PTR(D, n); n = *pb; *pb = pos;
}
*pl = -pos; /* Label exists now. */
b[pos++] = ofs; /* Store pass1 offset estimate. */
break;
case DASM_IMM:
case DASM_IMM16:
#ifdef DASM_CHECKS
CK((n & ((1<<((ins>>10)&31))-1)) == 0, RANGE_I);
if ((ins & 0x8000))
CK(((n + (1<<(((ins>>5)&31)-1)))>>((ins>>5)&31)) == 0, RANGE_I);
else
CK((n>>((ins>>5)&31)) == 0, RANGE_I);
#endif
b[pos++] = n;
break;
case DASM_IMMV8:
CK((n & 3) == 0, RANGE_I);
n >>= 2;
case DASM_IMML8:
case DASM_IMML12:
CK(n >= 0 ? ((n>>((ins>>5)&31)) == 0) :
(((-n)>>((ins>>5)&31)) == 0), RANGE_I);
b[pos++] = n;
break;
case DASM_IMM12:
CK(dasm_imm12((unsigned int)n) != -1, RANGE_I);
b[pos++] = n;
break;
}
}
}
stop:
va_end(ap);
sec->pos = pos;
sec->ofs = ofs;
}
#undef CK
/* Pass 2: Link sections, shrink aligns, fix label offsets. */
int dasm_link(Dst_DECL, size_t *szp)
{
dasm_State *D = Dst_REF;
int secnum;
int ofs = 0;
#ifdef DASM_CHECKS
*szp = 0;
if (D->status != DASM_S_OK) return D->status;
{
int pc;
for (pc = 0; pc*sizeof(int) < D->pcsize; pc++)
if (D->pclabels[pc] > 0) return DASM_S_UNDEF_PC|pc;
}
#endif
{ /* Handle globals not defined in this translation unit. */
int idx;
for (idx = 20; idx*sizeof(int) < D->lgsize; idx++) {
int n = D->lglabels[idx];
/* Undefined label: Collapse rel chain and replace with marker (< 0). */
while (n > 0) { int *pb = DASM_POS2PTR(D, n); n = *pb; *pb = -idx; }
}
}
/* Combine all code sections. No support for data sections (yet). */
for (secnum = 0; secnum < D->maxsection; secnum++) {
dasm_Section *sec = D->sections + secnum;
int *b = sec->rbuf;
int pos = DASM_SEC2POS(secnum);
int lastpos = sec->pos;
while (pos != lastpos) {
dasm_ActList p = D->actionlist + b[pos++];
while (1) {
unsigned int ins = *p++;
unsigned int action = (ins >> 16);
switch (action) {
case DASM_STOP: case DASM_SECTION: goto stop;
case DASM_ESC: p++; break;
case DASM_REL_EXT: break;
case DASM_ALIGN: ofs -= (b[pos++] + ofs) & (ins & 255); break;
case DASM_REL_LG: case DASM_REL_PC: pos++; break;
case DASM_LABEL_LG: case DASM_LABEL_PC: b[pos++] += ofs; break;
case DASM_IMM: case DASM_IMM12: case DASM_IMM16:
case DASM_IMML8: case DASM_IMML12: case DASM_IMMV8: pos++; break;
}
}
stop: (void)0;
}
ofs += sec->ofs; /* Next section starts right after current section. */
}
D->codesize = ofs; /* Total size of all code sections */
*szp = ofs;
return DASM_S_OK;
}
#ifdef DASM_CHECKS
#define CK(x, st) \
do { if (!(x)) return DASM_S_##st|(p-D->actionlist-1); } while (0)
#else
#define CK(x, st) ((void)0)
#endif
/* Pass 3: Encode sections. */
int dasm_encode(Dst_DECL, void *buffer)
{
dasm_State *D = Dst_REF;
char *base = (char *)buffer;
unsigned int *cp = (unsigned int *)buffer;
int secnum;
/* Encode all code sections. No support for data sections (yet). */
for (secnum = 0; secnum < D->maxsection; secnum++) {
dasm_Section *sec = D->sections + secnum;
int *b = sec->buf;
int *endb = sec->rbuf + sec->pos;
while (b != endb) {
dasm_ActList p = D->actionlist + *b++;
while (1) {
unsigned int ins = *p++;
unsigned int action = (ins >> 16);
int n = (action >= DASM_ALIGN && action < DASM__MAX) ? *b++ : 0;
switch (action) {
case DASM_STOP: case DASM_SECTION: goto stop;
case DASM_ESC: *cp++ = *p++; break;
case DASM_REL_EXT:
n = DASM_EXTERN(Dst, (unsigned char *)cp, (ins&2047), !(ins&2048));
goto patchrel;
case DASM_ALIGN:
ins &= 255; while ((((char *)cp - base) & ins)) *cp++ = 0xe1a00000;
break;
case DASM_REL_LG:
CK(n >= 0, UNDEF_LG);
case DASM_REL_PC:
CK(n >= 0, UNDEF_PC);
n = *DASM_POS2PTR(D, n) - (int)((char *)cp - base) - 4;
patchrel:
if ((ins & 0x800) == 0) {
CK((n & 3) == 0 && ((n+0x02000000) >> 26) == 0, RANGE_REL);
cp[-1] |= ((n >> 2) & 0x00ffffff);
} else if ((ins & 0x1000)) {
CK((n & 3) == 0 && -256 <= n && n <= 256, RANGE_REL);
goto patchimml8;
} else if ((ins & 0x2000) == 0) {
CK((n & 3) == 0 && -4096 <= n && n <= 4096, RANGE_REL);
goto patchimml;
} else {
CK((n & 3) == 0 && -1020 <= n && n <= 1020, RANGE_REL);
n >>= 2;
goto patchimml;
}
break;
case DASM_LABEL_LG:
ins &= 2047; if (ins >= 20) D->globals[ins-10] = (void *)(base + n);
break;
case DASM_LABEL_PC: break;
case DASM_IMM:
cp[-1] |= ((n>>((ins>>10)&31)) & ((1<<((ins>>5)&31))-1)) << (ins&31);
break;
case DASM_IMM12:
cp[-1] |= dasm_imm12((unsigned int)n);
break;
case DASM_IMM16:
cp[-1] |= ((n & 0xf000) << 4) | (n & 0x0fff);
break;
case DASM_IMML8: patchimml8:
cp[-1] |= n >= 0 ? (0x00800000 | (n & 0x0f) | ((n & 0xf0) << 4)) :
((-n & 0x0f) | ((-n & 0xf0) << 4));
break;
case DASM_IMML12: case DASM_IMMV8: patchimml:
cp[-1] |= n >= 0 ? (0x00800000 | n) : (-n);
break;
default: *cp++ = ins; break;
}
}
stop: (void)0;
}
}
if (base + D->codesize != (char *)cp) /* Check for phase errors. */
return DASM_S_PHASE;
return DASM_S_OK;
}
#undef CK
/* Get PC label offset. */
int dasm_getpclabel(Dst_DECL, unsigned int pc)
{
dasm_State *D = Dst_REF;
if (pc*sizeof(int) < D->pcsize) {
int pos = D->pclabels[pc];
if (pos < 0) return *DASM_POS2PTR(D, -pos);
if (pos > 0) return -1; /* Undefined. */
}
return -2; /* Unused or out of range. */
}
#ifdef DASM_CHECKS
/* Optional sanity checker to call between isolated encoding steps. */
int dasm_checkstep(Dst_DECL, int secmatch)
{
dasm_State *D = Dst_REF;
if (D->status == DASM_S_OK) {
int i;
for (i = 1; i <= 9; i++) {
if (D->lglabels[i] > 0) { D->status = DASM_S_UNDEF_LG|i; break; }
D->lglabels[i] = 0;
}
}
if (D->status == DASM_S_OK && secmatch >= 0 &&
D->section != &D->sections[secmatch])
D->status = DASM_S_MATCH_SEC|(D->section-D->sections);
return D->status;
}
#endif