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view lwasm/section.c @ 408:0af33282b518
Fix cycle counting for relative branches.
The original creator of the cycle counting code appears to have mangled two
different approaches to counting the cycles for relative branches into the
final product which led to counting too many cycles for the branch
instructions. The comments in the cycle table were correct but the code was
doing some incorrect things.
Also add the missing LBRN entry to the cycle table. The one labelled LBRN
was not, in fact, LBRN, but one of the actual useful branch instructions.
author | William Astle <lost@l-w.ca> |
---|---|
date | Thu, 03 Mar 2016 21:38:21 -0700 |
parents | 8764142b3192 |
children | 58cafa61ab40 |
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/* section.c Copyright © 2010 William Astle This file is part of LWTOOLS. LWTOOLS is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <string.h> #include <ctype.h> #include <lw_string.h> #include <lw_alloc.h> #include "lwasm.h" #include "instab.h" PARSEFUNC(pseudo_parse_section) { char *p2; char *sn; char *opts = NULL; sectiontab_t *s; if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error(as, l, E_SECTION_TARGET); return; } if (!**p) { lwasm_register_error(as, l, E_SECTION_NAME); return; } l -> len = 0; if (as -> csect) { lw_expr_destroy(as -> csect -> offset); as -> csect -> offset = lw_expr_copy(l -> addr); as -> csect = NULL; } for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sn = lw_strndup(*p, p2 - *p); *p = p2; if (**p == ',') { // have opts (*p)++; for (p2 = *p; *p2 && !isspace(*p2); p2++) /* do nothing */ ; opts = lw_strndup(*p, p2 - *p); *p = p2; } for (s = as -> sections; s; s = s -> next) { if (!strcmp(s -> name, sn)) break; } if (s && opts) { lwasm_register_error(as, l, W_DUPLICATE_SECTION); } if (!s) { // create section data structure s = lw_alloc(sizeof(sectiontab_t)); s -> oblen = 0; s -> obsize = 0; s -> obytes = NULL; s -> name = lw_strdup(sn); s -> offset = lw_expr_build(lw_expr_type_special, lwasm_expr_secbase, s); s -> flags = section_flag_none; s -> reloctab = NULL; if (!strcasecmp(sn, "bss") || !strcasecmp(sn, ".bss")) { s -> flags |= section_flag_bss; } if (!strcasecmp(sn, "_constant") || !strcasecmp(sn, "_constants")) { s -> flags |= section_flag_constant; } // parse options if (opts) { // only one option ("bss" or "!bss") if (!strcasecmp(opts, "bss")) { s -> flags |= section_flag_bss; } else if (!strcasecmp(opts, "!bss")) { s -> flags &= ~section_flag_bss; } else if (!strcasecmp(opts, "constant")) { s -> flags |= section_flag_constant; } else if (!strcasecmp(opts, "!constant")) { s -> flags |= section_flag_constant; } else { lwasm_register_error(as, l, E_SECTION_FLAG); lw_free(sn); lw_free(opts); lw_free(s -> name); lw_expr_destroy(s -> offset); lw_free(s); return; } } s -> next = as -> sections; as -> sections = s; } // cause all instances of "constant" sections to start at 0 if (s -> flags & section_flag_constant) s -> offset = lw_expr_build(lw_expr_type_int, 0); lw_expr_destroy(l -> addr); l -> addr = lw_expr_copy(s -> offset); lw_expr_destroy(l -> daddr); l -> daddr = lw_expr_copy(s -> offset); as -> csect = s; as -> context = lwasm_next_context(as); l -> len = 0; lw_free(opts); lw_free(sn); } PARSEFUNC(pseudo_parse_endsection) { if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error(as, l, E_SECTION_TARGET); return; } l -> len = 0; if (!(as -> csect)) { lwasm_register_error(as, l, E_SECTION_END); return; } // save offset in case another instance of the section appears lw_expr_destroy(as -> csect -> offset); as -> csect -> offset = l -> addr; // reset address to 0 l -> addr = lw_expr_build(lw_expr_type_int, 0); as -> csect = NULL; // end of section is a context break as -> context = lwasm_next_context(as); skip_operand(p); } PARSEFUNC(pseudo_parse_export) { int after = 0; char *sym = NULL; exportlist_t *e; if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error2(as, l, E_OBJTARGET_ONLY, "(%s)", "EXPORT"); return; } l -> len = 0; if (l -> sym) { sym = lw_strdup(l -> sym); l -> symset = 1; } if (l -> sym) { skip_operand(p); } again: if (after || !sym) { char *p2; after = 1; for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sym = lw_strndup(*p, p2 - *p); *p = p2; } if (!sym) { lwasm_register_error2(as, l, E_SYMBOL_MISSING, "for %s", "EXPORT"); return; } // add the symbol to the "export" list (which will be resolved // after the parse pass is complete e = lw_alloc(sizeof(exportlist_t)); e -> next = as -> exportlist; e -> symbol = lw_strdup(sym); e -> line = l; e -> se = NULL; as -> exportlist = e; lw_free(sym); if (after && **p == ',') { (*p)++; for (; **p && isspace(**p); (*p)++) /* do nothing */ ; goto again; } } PARSEFUNC(pseudo_parse_extern) { int after = 0; char *sym = NULL; importlist_t *e; if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error2(as, l, E_OBJTARGET_ONLY, "(%s)", "IMPORT"); return; } l -> len = 0; if (l -> sym) { sym = lw_strdup(l -> sym); l -> symset = 1; } if (l -> sym) { skip_operand(p); } again: if (after || !sym) { char *p2; after = 1; for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sym = lw_strndup(*p, p2 - *p); *p = p2; } if (!sym) { lwasm_register_error2(as, l, E_SYMBOL_MISSING, "for %s", "IMPORT"); return; } // add the symbol to the "export" list (which will be resolved // after the parse pass is complete e = lw_alloc(sizeof(importlist_t)); e -> next = as -> importlist; e -> symbol = lw_strdup(sym); as -> importlist = e; lw_free(sym); if (after && **p == ',') { (*p)++; for (; **p && isspace(**p); (*p)++) /* do nothing */ ; goto again; } } PARSEFUNC(pseudo_parse_extdep) { int after = 0; char *sym = NULL; // importlist_t *e; if (as -> output_format != OUTPUT_OBJ) { lwasm_register_error2(as, l, E_OBJTARGET_ONLY, "(%s)", "EXTDEP"); return; } if (!as -> csect) { lwasm_register_error(as, l, E_SECTION_EXTDEP); return; } l -> len = 0; if (l -> sym) sym = lw_strdup(l -> sym); if (l -> sym) { skip_operand(p); } again: if (after || !sym) { char *p2; after = 1; for (p2 = *p; *p2 && *p2 != ',' && !isspace(*p2); p2++) /* do nothing */ ; sym = lw_strndup(*p, p2 - *p); } if (!sym) { lwasm_register_error2(as, l, E_SYMBOL_MISSING, "for %s", "EXTDEP"); return; } // create a zero-width dependency { lw_expr_t e; e = lw_expr_build(lw_expr_type_int, 0); lwasm_emitexpr(l, e, 0); lw_expr_destroy(e); } if (after && **p == ',') { (*p)++; for (; **p && isspace(**p); (*p)++) /* do nothing */ ; goto again; } }