PPC: Add DynASM PowerPC encoding engine.

1 files changed, 408 insertions, 0 deletions

diff --git a/dynasm/dasm_ppc.h b/dynasm/dasm_ppc.h
new file mode 100644
index 00000000..85aeccd8
--- /dev/null
+++ b/dynasm/dasm_ppc.h
@@ -0,0 +1,408 @@
+/*
+** DynASM PPC encoding engine.
+** Copyright (C) 2005-2010 Mike Pall. All rights reserved.
+** Released under the MIT/X 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;
+        if (n >= 0) { CKPL(lg, LG); goto putrel; }  /* Bkwd rel or global. */
+        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);
+        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);
+          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>>((ins>>10)&31)) & ((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
+