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authorMike Pall <mike>2009-12-08 19:46:35 +0100
committerMike Pall <mike>2009-12-08 19:46:35 +0100
commit55b16959717084884fd4a0cbae6d19e3786c20c7 (patch)
treec8a07a43c13679751ed25a9d06796e9e7b2134a6 /dynasm/dasm_x86.h
downloadluajit2-55b16959717084884fd4a0cbae6d19e3786c20c7.tar.gz
RELEASE LuaJIT-2.0.0-beta1v2.0.0-beta1
Diffstat (limited to 'dynasm/dasm_x86.h')
-rw-r--r--dynasm/dasm_x86.h467
1 files changed, 467 insertions, 0 deletions
diff --git a/dynasm/dasm_x86.h b/dynasm/dasm_x86.h
new file mode 100644
index 00000000..dab33e5a
--- /dev/null
+++ b/dynasm/dasm_x86.h
@@ -0,0 +1,467 @@
+/*
+** DynASM x86 encoding engine.
+** Copyright (C) 2005-2009 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 "x86"
+
+#ifndef DASM_EXTERN
+#define DASM_EXTERN(a,b,c,d) 0
+#endif
+
+/* Action definitions. DASM_STOP must be 255. */
+enum {
+ DASM_DISP = 233,
+ DASM_IMM_S, DASM_IMM_B, DASM_IMM_W, DASM_IMM_D, DASM_IMM_WB, DASM_IMM_DB,
+ DASM_VREG, DASM_SPACE, DASM_SETLABEL, DASM_REL_A, DASM_REL_LG, DASM_REL_PC,
+ DASM_IMM_LG, DASM_IMM_PC, DASM_LABEL_LG, DASM_LABEL_PC, DASM_ALIGN,
+ DASM_EXTERN, DASM_ESC, DASM_MARK, DASM_SECTION, DASM_STOP
+};
+
+/* 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_VREG 0x15000000
+#define DASM_S_UNDEF_L 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))
+
+/* 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, dasm_ActList actionlist)
+{
+ dasm_State *D = Dst_REF;
+ int i;
+ D->actionlist = 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, mrm = 4;
+ 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) {
+ int action = *p++;
+ if (action < DASM_DISP) {
+ ofs++;
+ } else if (action <= DASM_REL_A) {
+ int n = va_arg(ap, int);
+ b[pos++] = n;
+ switch (action) {
+ case DASM_DISP:
+ if (n == 0) { if ((mrm&7) == 4) mrm = p[-2]; if ((mrm&7) != 5) break; }
+ case DASM_IMM_DB: if (((n+128)&-256) == 0) goto ob;
+ case DASM_REL_A: /* Assumes ptrdiff_t is int. !x64 */
+ case DASM_IMM_D: ofs += 4; break;
+ case DASM_IMM_S: CK(((n+128)&-256) == 0, RANGE_I); goto ob;
+ case DASM_IMM_B: CK((n&-256) == 0, RANGE_I); ob: ofs++; break;
+ case DASM_IMM_WB: if (((n+128)&-256) == 0) goto ob;
+ case DASM_IMM_W: CK((n&-65536) == 0, RANGE_I); ofs += 2; break;
+ case DASM_SPACE: p++; ofs += n; break;
+ case DASM_SETLABEL: b[pos-2] = -0x40000000; break; /* Neg. label ofs. */
+ case DASM_VREG: CK((n&-8) == 0 && (n != 4 || (*p&1) == 0), RANGE_VREG);
+ if (*p++ == 1 && *p == DASM_DISP) mrm = n; continue;
+ }
+ mrm = 4;
+ } else {
+ int *pl, n;
+ switch (action) {
+ case DASM_REL_LG:
+ case DASM_IMM_LG:
+ n = *p++; pl = D->lglabels + n;
+ if (n <= 246) { CKPL(lg, LG); goto putrel; } /* Bkwd rel or global. */
+ pl -= 246; n = *pl;
+ if (n < 0) n = 0; /* Start new chain for fwd rel if label exists. */
+ goto linkrel;
+ case DASM_REL_PC:
+ case DASM_IMM_PC: pl = D->pclabels + va_arg(ap, int); 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++;
+ ofs += 4; /* Maximum offset needed. */
+ if (action == DASM_REL_LG || action == DASM_REL_PC)
+ b[pos++] = ofs; /* Store pass1 offset estimate. */
+ break;
+ case DASM_LABEL_LG: pl = D->lglabels + *p++; CKPL(lg, LG); goto putlabel;
+ case DASM_LABEL_PC: pl = D->pclabels + va_arg(ap, int); 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_ALIGN:
+ ofs += *p++; /* Maximum alignment needed (arg is 2**n-1). */
+ b[pos++] = ofs; /* Store pass1 offset estimate. */
+ break;
+ case DASM_EXTERN: p += 2; ofs += 4; break;
+ case DASM_ESC: p++; ofs++; break;
+ case DASM_MARK: mrm = p[-2]; break;
+ case DASM_SECTION:
+ n = *p; CK(n < D->maxsection, RANGE_SEC); D->section = &D->sections[n];
+ case DASM_STOP: goto stop;
+ }
+ }
+ }
+stop:
+ va_end(ap);
+ sec->pos = pos;
+ sec->ofs = ofs;
+}
+#undef CK
+
+/* Pass 2: Link sections, shrink branches/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 = 10; 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) {
+ int op, action = *p++;
+ switch (action) {
+ case DASM_REL_LG: p++; op = p[-3]; goto rel_pc;
+ case DASM_REL_PC: op = p[-2]; rel_pc: {
+ int shrink = op == 0xe9 ? 3 : ((op&0xf0) == 0x80 ? 4 : 0);
+ if (shrink) { /* Shrinkable branch opcode? */
+ int lofs, lpos = b[pos];
+ if (lpos < 0) goto noshrink; /* Ext global? */
+ lofs = *DASM_POS2PTR(D, lpos);
+ if (lpos > pos) { /* Fwd label: add cumulative section offsets. */
+ int i;
+ for (i = secnum; i < DASM_POS2SEC(lpos); i++)
+ lofs += D->sections[i].ofs;
+ } else {
+ lofs -= ofs; /* Bkwd label: unfix offset. */
+ }
+ lofs -= b[pos+1]; /* Short branch ok? */
+ if (lofs >= -128-shrink && lofs <= 127) ofs -= shrink; /* Yes. */
+ else { noshrink: shrink = 0; } /* No, cannot shrink op. */
+ }
+ b[pos+1] = shrink;
+ pos += 2;
+ break;
+ }
+ case DASM_SPACE: case DASM_IMM_LG: case DASM_VREG: p++;
+ case DASM_DISP: case DASM_IMM_S: case DASM_IMM_B: case DASM_IMM_W:
+ case DASM_IMM_D: case DASM_IMM_WB: case DASM_IMM_DB:
+ case DASM_SETLABEL: case DASM_REL_A: case DASM_IMM_PC: pos++; break;
+ case DASM_LABEL_LG: p++;
+ case DASM_LABEL_PC: b[pos++] += ofs; break; /* Fix label offset. */
+ case DASM_ALIGN: ofs -= (b[pos++]+ofs)&*p++; break; /* Adjust ofs. */
+ case DASM_EXTERN: p += 2; break;
+ case DASM_ESC: p++; break;
+ case DASM_MARK: break;
+ case DASM_SECTION: case DASM_STOP: goto stop;
+ }
+ }
+ 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;
+}
+
+#define dasmb(x) *cp++ = (unsigned char)(x)
+#ifndef DASM_ALIGNED_WRITES
+#define dasmw(x) \
+ do { *((unsigned short *)cp) = (unsigned short)(x); cp+=2; } while (0)
+#define dasmd(x) \
+ do { *((unsigned int *)cp) = (unsigned int)(x); cp+=4; } while (0)
+#else
+#define dasmw(x) do { dasmb(x); dasmb((x)>>8); } while (0)
+#define dasmd(x) do { dasmw(x); dasmw((x)>>16); } while (0)
+#endif
+
+/* Pass 3: Encode sections. */
+int dasm_encode(Dst_DECL, void *buffer)
+{
+ dasm_State *D = Dst_REF;
+ unsigned char *base = (unsigned char *)buffer;
+ unsigned char *cp = base;
+ 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++;
+ unsigned char *mark = NULL;
+ while (1) {
+ int action = *p++;
+ int n = (action >= DASM_DISP && action <= DASM_ALIGN) ? *b++ : 0;
+ switch (action) {
+ case DASM_DISP: if (!mark) mark = cp; {
+ unsigned char *mm = mark;
+ if (*p != DASM_IMM_DB && *p != DASM_IMM_WB) mark = NULL;
+ if (n == 0) { int mrm = mm[-1]&7; if (mrm == 4) mrm = mm[0]&7;
+ if (mrm != 5) { mm[-1] -= 0x80; break; } }
+ if (((n+128) & -256) != 0) goto wd; else mm[-1] -= 0x40;
+ }
+ case DASM_IMM_S: case DASM_IMM_B: wb: dasmb(n); break;
+ case DASM_IMM_DB: if (((n+128)&-256) == 0) {
+ db: if (!mark) mark = cp; mark[-2] += 2; mark = NULL; goto wb;
+ } else mark = NULL;
+ case DASM_IMM_D: wd: dasmd(n); break;
+ case DASM_IMM_WB: if (((n+128)&-256) == 0) goto db; else mark = NULL;
+ case DASM_IMM_W: dasmw(n); break;
+ case DASM_VREG: { int t = *p++; if (t >= 2) n<<=3; cp[-1] |= n; break; }
+ case DASM_REL_LG: p++; if (n >= 0) goto rel_pc;
+ b++; n = (int)(ptrdiff_t)D->globals[-n];
+ case DASM_REL_A: rel_a: n -= (int)(ptrdiff_t)(cp+4); goto wd; /* !x64 */
+ case DASM_REL_PC: rel_pc: {
+ int shrink = *b++;
+ int *pb = DASM_POS2PTR(D, n); if (*pb < 0) { n = pb[1]; goto rel_a; }
+ n = *pb - ((int)(cp-base) + 4-shrink);
+ if (shrink == 0) goto wd;
+ if (shrink == 4) { cp--; cp[-1] = *cp-0x10; } else cp[-1] = 0xeb;
+ goto wb;
+ }
+ case DASM_IMM_LG:
+ p++; if (n < 0) { n = (int)(ptrdiff_t)D->globals[-n]; goto wd; }
+ case DASM_IMM_PC: {
+ int *pb = DASM_POS2PTR(D, n);
+ n = *pb < 0 ? pb[1] : (*pb + (int)(ptrdiff_t)base);
+ goto wd;
+ }
+ case DASM_LABEL_LG: {
+ int idx = *p++;
+ if (idx >= 10)
+ D->globals[idx] = (void *)(base + (*p == DASM_SETLABEL ? *b : n));
+ break;
+ }
+ case DASM_LABEL_PC: case DASM_SETLABEL: break;
+ case DASM_SPACE: { int fill = *p++; while (n--) *cp++ = fill; break; }
+ case DASM_ALIGN:
+ n = *p++;
+ while (((cp-base) & n)) *cp++ = 0x90; /* nop */
+ break;
+ case DASM_EXTERN: n = DASM_EXTERN(Dst, cp, p[1], *p); p += 2; goto wd;
+ case DASM_MARK: mark = cp; break;
+ case DASM_ESC: action = *p++;
+ default: *cp++ = action; break;
+ case DASM_SECTION: case DASM_STOP: goto stop;
+ }
+ }
+ stop: (void)0;
+ }
+ }
+
+ if (base + D->codesize != cp) /* Check for phase errors. */
+ return DASM_S_PHASE;
+ return DASM_S_OK;
+}
+
+/* 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_L|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
+