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view lwcc/cc-gencode.c @ 505:59b8c8b15bd4
Add integer shifts and fix code template errors for mul/div/mod
One needs to remove stuff from the stack after putting it there. Actually do
that in the code output for multiplication, division, and modulus.
Add integer shifting code output which is optimized for constant shift
counts but calls a routine for non-constant shift counts. Shifting by a
negative amount is a no-op. Shifting by more than the size of an integer
results in 0 (for left shifts) or -1 (for right shifts). Both negative shift
counts and shift counts larger than the base type are undefined in the C
standard so this behaviour is allowed.
author | William Astle <lost@l-w.ca> |
---|---|
date | Sat, 26 Oct 2019 22:01:55 -0600 |
parents | 14a40f8bb4eb |
children |
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/* lwcc/cc-gencode.c Copyright © 2019 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 <stdio.h> #include <stdlib.h> #include <string.h> #include <lw_alloc.h> #include <lw_string.h> #include "tree.h" char *generate_nextlabel(void) { static int labelnum = 0; char buf[16]; sprintf(buf, "L%d", labelnum++); return lw_strdup(buf); } void generate_code(node_t *n, FILE *output); void generate_code_shift(node_t *n, FILE *output, int dir) { generate_code(n -> children, output); if (n -> children -> next_child -> type == NODE_CONST_INT) { long ival; int i; ival = strtol(n -> children -> next_child -> strval, NULL, 0); if (ival <= 0) return; if (ival >= 16) { fprintf(output, "\tldd #%d\n", dir == 1 ? 0 : -1); return; } if (ival >= 8) { if (dir == 1) { fprintf(output, "\ttfr b,a\n\tclrb\n"); for (i = ival - 8; i > 0; i--) { fprintf(output, "\tlsla\n"); } } else { fprintf(output, "\ttfr a,b\n\tsex\n"); for (i = ival - 8; i > 0; i--) { fprintf(output, "\tasrb\n"); } } return; } for (i = ival; i > 0; i--) { if (dir == 1) { fprintf(output, "\taslb\n\trola\n"); } else { fprintf(output, "\tasra\n\trorb\n"); } } return; } else { fprintf(output, "\tpshs d\n"); generate_code(n -> children -> next_child, output); fprintf(output, "\tjsr ___%ssh16\n\tpuls d\n", dir == 1 ? "l" : "r"); } } void generate_code(node_t *n, FILE *output) { node_t *nn; char *label1, *label2; switch (n -> type) { // function definition - output prologue, then statements, then epilogue case NODE_FUNDEF: fprintf(output, "\tsection .text\n\texport _%s\n_%s\n", n->children->next_child->strval, n->children->next_child->strval); generate_code(n->children->next_child->next_child->next_child, output); fprintf(output, "\trts\n"); break; case NODE_CONST_INT: fprintf(output, "\tldd #%s\n", n->strval); break; case NODE_OPER_PLUS: generate_code(n->children, output); fprintf(output, "\tpshs d\n"); generate_code(n->children->next_child, output); fprintf(output, "\taddd ,s++\n"); break; case NODE_OPER_MINUS: generate_code(n->children, output); fprintf(output, "\tpshs d,x\n"); generate_code(n->children->next_child, output); fprintf(output, "\tstd 2,s\n\tpuls d\n\tsubd ,s++\n"); break; case NODE_OPER_TIMES: generate_code(n -> children, output); fprintf(output, "\tpshs d\n"); generate_code(n->children->next_child, output); fprintf(output, "\tjsr ___mul16i\n\tpuls d\n"); break; case NODE_OPER_DIVIDE: generate_code(n -> children, output); fprintf(output, "\tpshs d\n"); generate_code(n->children->next_child, output); fprintf(output, "\tjsr ___div16i\n\tpuls d\n"); break; case NODE_OPER_MOD: generate_code(n -> children, output); fprintf(output, "\tpshs d\n"); generate_code(n -> children -> next_child, output); fprintf(output, "\tjsr ___mod16i\n\tpuls d\n"); break; case NODE_OPER_LSH: generate_code_shift(n, output, 1); break; case NODE_OPER_RSH: generate_code_shift(n, output, 0); break; case NODE_OPER_COND: label1 = generate_nextlabel(); label2 = generate_nextlabel(); generate_code(n -> children, output); fprintf(output, "\tsubd #0\n\tbeq %s\n", label1); generate_code(n -> children -> next_child, output); fprintf(output, "\tbra %s\n%s\n", label2, label1); generate_code(n -> children -> next_child -> next_child, output); fprintf(output, "%s\n", label2); lw_free(label1); lw_free(label2); break; case NODE_OPER_COMMA: generate_code(n -> children, output); generate_code(n -> children -> next_child, output); break; case NODE_OPER_BWAND: generate_code(n -> children, output); fprintf(output, "\tpshs d\n"); generate_code(n -> children -> next_child, output); fprintf(output, "\tandb 1,s\n\tanda ,s++\n"); break; case NODE_OPER_BWOR: generate_code(n -> children, output); fprintf(output, "\tpshs d\n"); generate_code(n -> children -> next_child, output); fprintf(output, "\torb 1,s\n\tora ,s++\n"); break; case NODE_OPER_BWXOR: generate_code(n -> children, output); fprintf(output, "\tpshs d\n"); generate_code(n -> children -> next_child, output); fprintf(output, "\teorb 1,s\n\teora ,s++\n"); break; case NODE_OPER_BAND: label1 = generate_nextlabel(); generate_code(n -> children, output); fprintf(output, "\tsubd #0\n\tbeq %s\n", label1); generate_code(n -> children -> next_child, output); fprintf(output, "\tsubd #0\n\tbeq %s\n\tldd #1\n%s\n", label1, label1); lw_free(label1); break; case NODE_OPER_BOR: label1 = generate_nextlabel(); label2 = generate_nextlabel(); generate_code(n -> children, output); fprintf(output, "\tsubd #0\n\tbne %s\n", label1); generate_code(n -> children -> next_child, output); fprintf(output, "\tsubd #0\n\tbeq %s\n%s\tldd #1\n%s\n", label2, label1, label2); lw_free(label1); lw_free(label2); break; case NODE_OPER_NE: case NODE_OPER_EQ: case NODE_OPER_LT: case NODE_OPER_GT: case NODE_OPER_LE: case NODE_OPER_GE: generate_code(n -> children, output); fprintf(output, "\tpshs d\n"); generate_code(n -> children -> next_child, output); fprintf(output, "\tsubd ,s++\n"); label1 = generate_nextlabel(); label2 = generate_nextlabel(); fprintf(output, "\t%s %s\n", ( (n -> type == NODE_OPER_NE ? "bne" : (n -> type == NODE_OPER_EQ ? "beq" : (n -> type == NODE_OPER_LT ? "bge" : (n -> type == NODE_OPER_GT ? "ble" : (n -> type == NODE_OPER_LE ? "bgt" : (n -> type == NODE_OPER_GE ? "blt" : "foobar")))))) ), label1); fprintf(output, "\tldd #0\n\tbra %s\n%s\tldd #1\n%s\n", label2, label1, label2); lw_free(label1); lw_free(label2); break; default: for (nn = n -> children; nn; nn = nn -> next_child) generate_code(nn, output); break; } }