lib/luajit/dynasm/dasm_ppc.h - trafficserver - Git at Google

 /*
 ** DynASM PPC encoding engine.
 ** Copyright (C) 2005-2015 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		"ppc"

 #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__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

 /* 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:
 #ifdef DASM_CHECKS
 	CK((n & ((1<<((ins>>10)&31))-1)) == 0, RANGE_I);
 #endif
 	n >>= ((ins>>10)&31);
 #ifdef DASM_CHECKS
 	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;
       }
     }
   }
 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: 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), 1) - 4;
 	  goto patchrel;
 	case DASM_ALIGN:
 	  ins &= 255; while ((((char *)cp - base) & ins)) *cp++ = 0x60000000;
 	  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);
 	patchrel:
 	  CK((n & 3) == 0 &&
 	      (((n+4) + ((ins & 2048) ? 0x00008000 : 0x02000000)) >>
 	       ((ins & 2048) ? 16 : 26)) == 0, RANGE_REL);
 	  cp[-1] |= ((n+4) & ((ins & 2048) ? 0x0000fffc: 0x03fffffc));
 	  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 & ((1<<((ins>>5)&31))-1)) << (ins&31);
 	  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
	/*
	** DynASM PPC encoding engine.
	** Copyright (C) 2005-2015 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 "ppc"

	#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__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

	/* 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 + 2DASM_MAXSECPOSsizeof(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:
	#ifdef DASM_CHECKS
	CK((n & ((1<<((ins>>10)&31))-1)) == 0, RANGE_I);
	#endif
	n >>= ((ins>>10)&31);
	#ifdef DASM_CHECKS
	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;
	}
	}
	}
	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: 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), 1) - 4;
	goto patchrel;
	case DASM_ALIGN:
	ins &= 255; while ((((char )cp - base) & ins)) cp++ = 0x60000000;
	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);
	patchrel:
	CK((n & 3) == 0 &&
	(((n+4) + ((ins & 2048) ? 0x00008000 : 0x02000000)) >>
	((ins & 2048) ? 16 : 26)) == 0, RANGE_REL);
	cp[-1] \|= ((n+4) & ((ins & 2048) ? 0x0000fffc: 0x03fffffc));
	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 & ((1<<((ins>>5)&31))-1)) << (ins&31);
	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