diff options
Diffstat (limited to 'src/buildvm_asm.c')
| -rw-r--r-- | src/buildvm_asm.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/src/buildvm_asm.c b/src/buildvm_asm.c new file mode 100644 index 00000000..e6972bd5 --- /dev/null +++ b/src/buildvm_asm.c @@ -0,0 +1,220 @@ +/* +** LuaJIT VM builder: Assembler source code emitter. +** Copyright (C) 2005-2009 Mike Pall. See Copyright Notice in luajit.h +*/ + +#include "buildvm.h" +#include "lj_bc.h" + +/* ------------------------------------------------------------------------ */ + +/* Emit bytes piecewise as assembler text. */ +static void emit_asm_bytes(BuildCtx *ctx, uint8_t *p, int n) +{ + int i; + for (i = 0; i < n; i++) { + if ((i & 15) == 0) + fprintf(ctx->fp, "\t.byte %d", p[i]); + else + fprintf(ctx->fp, ",%d", p[i]); + if ((i & 15) == 15) putc('\n', ctx->fp); + } + if ((n & 15) != 0) putc('\n', ctx->fp); +} + +/* Emit relocation */ +static void emit_asm_reloc(BuildCtx *ctx, BuildReloc *r) +{ + const char *sym = ctx->extnames[r->sym]; + switch (ctx->mode) { + case BUILD_elfasm: + if (r->type) + fprintf(ctx->fp, "\t.long %s-.-4\n", sym); + else + fprintf(ctx->fp, "\t.long %s\n", sym); + break; + case BUILD_coffasm: + fprintf(ctx->fp, "\t.def _%s; .scl 3; .type 32; .endef\n", sym); + if (r->type) + fprintf(ctx->fp, "\t.long _%s-.-4\n", sym); + else + fprintf(ctx->fp, "\t.long _%s\n", sym); + break; + default: /* BUILD_machasm for relative relocations handled below. */ + fprintf(ctx->fp, "\t.long _%s\n", sym); + break; + } +} + +static const char *const jccnames[] = { + "jo", "jno", "jb", "jnb", "jz", "jnz", "jbe", "ja", + "js", "jns", "jpe", "jpo", "jl", "jge", "jle", "jg" +}; + +/* Emit relocation for the incredibly stupid OSX assembler. */ +static void emit_asm_reloc_mach(BuildCtx *ctx, uint8_t *cp, int n, + const char *sym) +{ + const char *opname = NULL; + if (--n < 0) goto err; + if (cp[n] == 0xe8) { + opname = "call"; + } else if (cp[n] == 0xe9) { + opname = "jmp"; + } else if (cp[n] >= 0x80 && cp[n] <= 0x8f && n > 0 && cp[n-1] == 0x0f) { + opname = jccnames[cp[n]-0x80]; + n--; + } else { +err: + fprintf(stderr, "Error: unsupported opcode for %s symbol relocation.\n", + sym); + exit(1); + } + emit_asm_bytes(ctx, cp, n); + if (!strncmp(sym, LABEL_PREFIX, sizeof(LABEL_PREFIX)-1)) + fprintf(ctx->fp, "\t%s _%s\n", opname, sym); + else + fprintf(ctx->fp, "\t%s _" LABEL_PREFIX "wrapper_%s\n", opname, sym); +} + +/* Emit an assembler label. */ +static void emit_asm_label(BuildCtx *ctx, const char *name, int size, int isfunc) +{ + switch (ctx->mode) { + case BUILD_elfasm: + fprintf(ctx->fp, + "\n\t.globl %s\n" + "\t.hidden %s\n" + "\t.type %s, @%s\n" + "\t.size %s, %d\n" + "%s:\n", + name, name, name, isfunc ? "function" : "object", name, size, name); + break; + case BUILD_coffasm: + fprintf(ctx->fp, "\n\t.globl _%s\n", name); + if (isfunc) + fprintf(ctx->fp, "\t.def _%s; .scl 3; .type 32; .endef\n", name); + fprintf(ctx->fp, "_%s:\n", name); + break; + case BUILD_machasm: + fprintf(ctx->fp, + "\n\t.private_extern _%s\n" + "_%s:\n", name, name); + break; + default: + break; + } +} + +/* Emit alignment. */ +static void emit_asm_align(BuildCtx *ctx, int bits) +{ + switch (ctx->mode) { + case BUILD_elfasm: + case BUILD_coffasm: + fprintf(ctx->fp, "\t.p2align %d\n", bits); + break; + case BUILD_machasm: + fprintf(ctx->fp, "\t.align %d\n", bits); + break; + default: + break; + } +} + +/* ------------------------------------------------------------------------ */ + +/* Emit assembler source code. */ +void emit_asm(BuildCtx *ctx) +{ + char name[80]; + int32_t prev; + int i, pi, rel; + + fprintf(ctx->fp, "\t.file \"buildvm_%s.dasc\"\n", ctx->dasm_arch); + fprintf(ctx->fp, "\t.text\n"); + emit_asm_align(ctx, 4); + + emit_asm_label(ctx, LABEL_ASM_BEGIN, 0, 1); + if (ctx->mode == BUILD_elfasm) + fprintf(ctx->fp, ".Lbegin:\n"); + + i = 0; + do { + pi = ctx->perm[i++]; + prev = ctx->sym_ofs[pi]; + } while (prev < 0); /* Skip the _Z symbols. */ + + for (rel = 0; i <= ctx->nsym; i++) { + int ni = ctx->perm[i]; + int32_t next = ctx->sym_ofs[ni]; + int size = (int)(next - prev); + int32_t stop = next; + if (pi >= ctx->npc) { + sprintf(name, LABEL_PREFIX "%s", ctx->globnames[pi-ctx->npc]); + emit_asm_label(ctx, name, size, 1); +#if LJ_HASJIT + } else { +#else + } else if (!(pi == BC_JFORI || pi == BC_JFORL || pi == BC_JITERL || + pi == BC_JLOOP || pi == BC_IFORL || pi == BC_IITERL || + pi == BC_ILOOP)) { +#endif + sprintf(name, LABEL_PREFIX_BC "%s", bc_names[pi]); + emit_asm_label(ctx, name, size, 1); + } + while (rel < ctx->nreloc && ctx->reloc[rel].ofs < stop) { + int n = ctx->reloc[rel].ofs - prev; + if (ctx->mode == BUILD_machasm && ctx->reloc[rel].type != 0) { + emit_asm_reloc_mach(ctx, ctx->code+prev, n, + ctx->extnames[ctx->reloc[rel].sym]); + } else { + emit_asm_bytes(ctx, ctx->code+prev, n); + emit_asm_reloc(ctx, &ctx->reloc[rel]); + } + prev += n+4; + rel++; + } + emit_asm_bytes(ctx, ctx->code+prev, stop-prev); + prev = next; + pi = ni; + } + + switch (ctx->mode) { + case BUILD_elfasm: + fprintf(ctx->fp, "\n\t.section .rodata\n"); + break; + case BUILD_coffasm: + fprintf(ctx->fp, "\n\t.section .rdata,\"dr\"\n"); + break; + case BUILD_machasm: + fprintf(ctx->fp, "\n\t.const\n"); + break; + default: + break; + } + emit_asm_align(ctx, 5); + + emit_asm_label(ctx, LABEL_OP_OFS, 2*ctx->npc, 0); + for (i = 0; i < ctx->npc; i++) + fprintf(ctx->fp, "\t.short %d\n", ctx->sym_ofs[i]); + + fprintf(ctx->fp, "\n"); + switch (ctx->mode) { + case BUILD_elfasm: + fprintf(ctx->fp, "\t.section .note.GNU-stack,\"\",@progbits\n"); + /* fallthrough */ + case BUILD_coffasm: + fprintf(ctx->fp, "\t.ident \"%s\"\n", ctx->dasm_ident); + break; + case BUILD_machasm: + fprintf(ctx->fp, + "\t.cstring\n" + "\t.ascii \"%s\\0\"\n", ctx->dasm_ident); + break; + default: + break; + } + fprintf(ctx->fp, "\n"); +} + |