src/uae_cpu/cpuopti.c

/*
 * UAE - The Un*x Amiga Emulator
 *
 * cpuopti.c - Small optimizer for cpu*.s files
 *             Based on work by Tauno Taipaleenmaki
 *
 * Copyright 1996 Bernd Schmidt
 */

#include <ctype.h>
#include <stdio.h>
#include <string.h>

#include "sysdeps.h"

struct line {
    struct line *next, *prev;
    int delet;
    char *data;
};

struct func {
    struct line *first_line, *last_line;
    int initial_offset;
};

static void oops(void)
{
    fprintf(stderr, "Don't know how to optimize this file.\n");
    abort();
}

static char * match(struct line *l, const char *m)
{
    char *str = l->data;
    int len = strlen(m);
    while (isspace(*str))
        str++;

    if (strncmp(str, m, len) != 0)
        return NULL;
    return str + len;
}

static int insn_references_reg (struct line *l, char *reg)
{
    if (reg[0] != 'e') {
        fprintf(stderr, "Unknown register?!?\n");
        abort();
    }
    if (strstr (l->data, reg) != 0)
        return 1;
    if (strstr (l->data, reg+1) != 0)
        return 1;
    if (strcmp (reg, "eax") == 0
        && (strstr (l->data, "%al") != 0 || strstr (l->data, "%ah") != 0))
        return 1;
    if (strcmp (reg, "ebx") == 0
        && (strstr (l->data, "%bl") != 0 || strstr (l->data, "%bh") != 0))
        return 1;
    if (strcmp (reg, "ecx") == 0
        && (strstr (l->data, "%cl") != 0 || strstr (l->data, "%ch") != 0))
        return 1;
    if (strcmp (reg, "edx") == 0
        && (strstr (l->data, "%dl") != 0 || strstr (l->data, "%dh") != 0))
        return 1;
    return 0;
}

static void do_function(struct func *f)
{
    int v;
    int pops_at_end = 0;
    struct line *l, *l1, *fl, *l2;
    char *s, *s2;
    int in_pop_area = 1;

    f->initial_offset = 0;

    l = f->last_line;
    fl = f->first_line;

    if (match(l,".LFE"))
        l = l->prev;
    if (!match(l,"ret"))
        oops();

    while (!match(fl, "op_"))
        fl = fl->next;
    fl = fl->next;

    /* Try reordering the insns at the end of the function so that the
     * pops are all at the end. */
    l2 = l->prev;
    /* Tolerate one stack adjustment */
    if (match (l2, "addl $") && strstr(l2->data, "esp") != 0)
        l2 = l2->prev;
    for (;;) {
        char *forbidden_reg;
        struct line *l3, *l4;

        while (match (l2, "popl %"))
            l2 = l2->prev;

        l3 = l2;
        for (;;) {
            forbidden_reg = match (l3, "popl %");
            if (forbidden_reg)
                break;
            if (l3 == fl)
                goto reordered;
            /* Jumps and labels put an end to our attempts... */
            if (strstr (l3->data, ".L") != 0)
                goto reordered;
            /* Likewise accesses to the stack pointer... */
            if (strstr (l3->data, "esp") != 0)
                goto reordered;
            /* Function calls... */
            if (strstr (l3->data, "call") != 0)
                goto reordered;
            l3 = l3->prev;
        }
        if (l3 == l2)
            abort();
        for (l4 = l2; l4 != l3; l4 = l4->prev) {
            /* The register may not be referenced by any of the insns that we
             * move the popl past */
            if (insn_references_reg (l4, forbidden_reg))
                goto reordered;
        }
        l3->prev->next = l3->next;
        l3->next->prev = l3->prev;
        l2->next->prev = l3;
        l3->next = l2->next;
        l2->next = l3;
        l3->prev = l2;
    }
reordered:

    l = l->prev;

    s = match (l, "addl $");
    s2 = match (fl, "subl $");

    l1 = l;
    if (s == 0) {
        char *t = match (l, "popl %");
        if (t != 0 && (strcmp (t, "ecx") == 0 || strcmp (t, "edx") == 0)) {
            s = "4,%esp";
            l = l->prev;
            t = match (l, "popl %");
            if (t != 0 && (strcmp (t, "ecx") == 0 || strcmp (t, "edx") == 0)) {
                s = "8,%esp";
                l = l->prev;
            }
        }
    } else {
        l = l->prev;
    }

    if (s && s2) {
        int v = 0;
        if (strcmp (s, s2) != 0) {
            fprintf (stderr, "Stack adjustment not matching.\n");
            return;
        }

        while (isdigit(*s)) {
            v = v * 10 + (*s) - '0';
            s++;
        }

        if (strcmp (s, ",%esp") != 0) {
            fprintf (stderr, "Not adjusting the stack pointer.\n");
            return;
        }
        f->initial_offset = v;
        fl->delet = 3;
        fl = fl->next;
        l1->delet = 2;
        l1 = l1->prev;
        while (l1 != l) {
            l1->delet = 1;
            l1 = l1->prev;
        }
    }

    while (in_pop_area) {
        char *popm, *pushm;
        popm = match (l, "popl %");
        pushm = match (fl, "pushl %");
        if (popm && pushm && strcmp(pushm, popm) == 0) {
            pops_at_end++;
            fl->delet = l->delet = 1;
        } else
            in_pop_area = 0;
        l = l->prev;
        fl = fl->next;
    }
    if (f->initial_offset)
        f->initial_offset += 4 * pops_at_end;
}

static void output_function(struct func *f)
{
    struct line *l = f->first_line;

    while (l) {
        switch (l->delet) {
         case 1:
            break;
         case 0:
            printf("%s\n", l->data);
            break;
         case 2:
            if (f->initial_offset)
                printf("\taddl $%d,%%esp\n", f->initial_offset);
            break;
         case 3:
            if (f->initial_offset)
                printf("\tsubl $%d,%%esp\n", f->initial_offset);
            break;
        }
        l = l->next;
    }
}

int main(int argc, char **argv)
{
    FILE *infile = stdin;
    char tmp[4096];

#ifdef __mc68000__
    if(system("perl machdep/cpuopti")==-1) {
       perror("perl machdep/cpuopti");
       return 10;
   } else return 0;
#endif

    /* For debugging... */
    if (argc == 2)
        infile = fopen (argv[1], "r");

    for(;;) {
        char *s;

        if ((fgets(tmp, 4095, infile)) == NULL)
            break;

        s = strchr (tmp, '\n');
        if (s != NULL)
            *s = 0;

        if (strncmp(tmp, ".globl op_", 10) == 0) {
            struct line *first_line = NULL, *prev = NULL;
            struct line **nextp = &first_line;
            struct func f;
            int nr_rets = 0;
            int can_opt = 1;

            do {
                struct line *current;

                if (strcmp (tmp, "#APP") != 0 && strcmp (tmp, "#NO_APP") != 0) {
                    current = *nextp = (struct line *)malloc(sizeof (struct line));
                    nextp = &current->next;
                    current->prev = prev; prev = current;
                    current->next = NULL;
                    current->delet = 0;
                    current->data = strdup (tmp);
                    if (match (current, "movl %esp,%ebp") || match (current, "enter")) {
                        fprintf (stderr, "GCC failed to eliminate fp: %s\n", first_line->data);
                        can_opt = 0;
                    }

                    if (match (current, "ret"))
                        nr_rets++;
                }
                if ((fgets(tmp, 4095, infile)) == NULL)
                    oops();
                s = strchr (tmp, '\n');
                if (s != NULL)
                    *s = 0;
            } while (strncmp (tmp,".Lfe", 4) != 0);

            f.first_line = first_line;
            f.last_line = prev;

            if (nr_rets == 1 && can_opt)
                do_function(&f);
            /*else
                fprintf(stderr, "Too many RET instructions: %s\n", first_line->data);*/
            output_function(&f);
        }
        printf("%s\n", tmp);
    }
    return 0;
}
Revision:	1.1
Committed:	1999-10-03T14:16:26Z (25 years, 2 months ago) by cebix
Content type:	text/plain
Branch:	MAIN
Branch point for:	cebix
Log Message:	Initial revision
#	User	Rev	Content
1	cebix	1.1	/*
2			* UAE - The Un*x Amiga Emulator
3			*
4			* cpuopti.c - Small optimizer for cpu*.s files
5			* Based on work by Tauno Taipaleenmaki
6			*
7			* Copyright 1996 Bernd Schmidt
8			*/
9
10			#include <ctype.h>
11			#include <stdio.h>
12			#include <string.h>
13
14			#include "sysdeps.h"
15
16			struct line {
17			struct line next, prev;
18			int delet;
19			char *data;
20			};
21
22			struct func {
23			struct line first_line, last_line;
24			int initial_offset;
25			};
26
27			static void oops(void)
28			{
29			fprintf(stderr, "Don't know how to optimize this file.\n");
30			abort();
31			}
32
33			static char * match(struct line l, const char m)
34			{
35			char *str = l->data;
36			int len = strlen(m);
37			while (isspace(*str))
38			str++;
39
40			if (strncmp(str, m, len) != 0)
41			return NULL;
42			return str + len;
43			}
44
45			static int insn_references_reg (struct line l, char reg)
46			{
47			if (reg[0] != 'e') {
48			fprintf(stderr, "Unknown register?!?\n");
49			abort();
50			}
51			if (strstr (l->data, reg) != 0)
52			return 1;
53			if (strstr (l->data, reg+1) != 0)
54			return 1;
55			if (strcmp (reg, "eax") == 0
56			&& (strstr (l->data, "%al") != 0 \|\| strstr (l->data, "%ah") != 0))
57			return 1;
58			if (strcmp (reg, "ebx") == 0
59			&& (strstr (l->data, "%bl") != 0 \|\| strstr (l->data, "%bh") != 0))
60			return 1;
61			if (strcmp (reg, "ecx") == 0
62			&& (strstr (l->data, "%cl") != 0 \|\| strstr (l->data, "%ch") != 0))
63			return 1;
64			if (strcmp (reg, "edx") == 0
65			&& (strstr (l->data, "%dl") != 0 \|\| strstr (l->data, "%dh") != 0))
66			return 1;
67			return 0;
68			}
69
70			static void do_function(struct func *f)
71			{
72			int v;
73			int pops_at_end = 0;
74			struct line l, l1, fl, l2;
75			char s, s2;
76			int in_pop_area = 1;
77
78			f->initial_offset = 0;
79
80			l = f->last_line;
81			fl = f->first_line;
82
83			if (match(l,".LFE"))
84			l = l->prev;
85			if (!match(l,"ret"))
86			oops();
87
88			while (!match(fl, "op_"))
89			fl = fl->next;
90			fl = fl->next;
91
92			/* Try reordering the insns at the end of the function so that the
93			* pops are all at the end. */
94			l2 = l->prev;
95			/* Tolerate one stack adjustment */
96			if (match (l2, "addl $") && strstr(l2->data, "esp") != 0)
97			l2 = l2->prev;
98			for (;;) {
99			char *forbidden_reg;
100			struct line l3, l4;
101
102			while (match (l2, "popl %"))
103			l2 = l2->prev;
104
105			l3 = l2;
106			for (;;) {
107			forbidden_reg = match (l3, "popl %");
108			if (forbidden_reg)
109			break;
110			if (l3 == fl)
111			goto reordered;
112			/* Jumps and labels put an end to our attempts... */
113			if (strstr (l3->data, ".L") != 0)
114			goto reordered;
115			/* Likewise accesses to the stack pointer... */
116			if (strstr (l3->data, "esp") != 0)
117			goto reordered;
118			/* Function calls... */
119			if (strstr (l3->data, "call") != 0)
120			goto reordered;
121			l3 = l3->prev;
122			}
123			if (l3 == l2)
124			abort();
125			for (l4 = l2; l4 != l3; l4 = l4->prev) {
126			/* The register may not be referenced by any of the insns that we
127			* move the popl past */
128			if (insn_references_reg (l4, forbidden_reg))
129			goto reordered;
130			}
131			l3->prev->next = l3->next;
132			l3->next->prev = l3->prev;
133			l2->next->prev = l3;
134			l3->next = l2->next;
135			l2->next = l3;
136			l3->prev = l2;
137			}
138			reordered:
139
140			l = l->prev;
141
142			s = match (l, "addl $");
143			s2 = match (fl, "subl $");
144
145			l1 = l;
146			if (s == 0) {
147			char *t = match (l, "popl %");
148			if (t != 0 && (strcmp (t, "ecx") == 0 \|\| strcmp (t, "edx") == 0)) {
149			s = "4,%esp";
150			l = l->prev;
151			t = match (l, "popl %");
152			if (t != 0 && (strcmp (t, "ecx") == 0 \|\| strcmp (t, "edx") == 0)) {
153			s = "8,%esp";
154			l = l->prev;
155			}
156			}
157			} else {
158			l = l->prev;
159			}
160
161			if (s && s2) {
162			int v = 0;
163			if (strcmp (s, s2) != 0) {
164			fprintf (stderr, "Stack adjustment not matching.\n");
165			return;
166			}
167
168			while (isdigit(*s)) {
169			v = v * 10 + (*s) - '0';
170			s++;
171			}
172
173			if (strcmp (s, ",%esp") != 0) {
174			fprintf (stderr, "Not adjusting the stack pointer.\n");
175			return;
176			}
177			f->initial_offset = v;
178			fl->delet = 3;
179			fl = fl->next;
180			l1->delet = 2;
181			l1 = l1->prev;
182			while (l1 != l) {
183			l1->delet = 1;
184			l1 = l1->prev;
185			}
186			}
187
188			while (in_pop_area) {
189			char popm, pushm;
190			popm = match (l, "popl %");
191			pushm = match (fl, "pushl %");
192			if (popm && pushm && strcmp(pushm, popm) == 0) {
193			pops_at_end++;
194			fl->delet = l->delet = 1;
195			} else
196			in_pop_area = 0;
197			l = l->prev;
198			fl = fl->next;
199			}
200			if (f->initial_offset)
201			f->initial_offset += 4 * pops_at_end;
202			}
203
204			static void output_function(struct func *f)
205			{
206			struct line *l = f->first_line;
207
208			while (l) {
209			switch (l->delet) {
210			case 1:
211			break;
212			case 0:
213			printf("%s\n", l->data);
214			break;
215			case 2:
216			if (f->initial_offset)
217			printf("\taddl $%d,%%esp\n", f->initial_offset);
218			break;
219			case 3:
220			if (f->initial_offset)
221			printf("\tsubl $%d,%%esp\n", f->initial_offset);
222			break;
223			}
224			l = l->next;
225			}
226			}
227
228			int main(int argc, char **argv)
229			{
230			FILE *infile = stdin;
231			char tmp[4096];
232
233			#ifdef __mc68000__
234			if(system("perl machdep/cpuopti")==-1) {
235			perror("perl machdep/cpuopti");
236			return 10;
237			} else return 0;
238			#endif
239
240			/* For debugging... */
241			if (argc == 2)
242			infile = fopen (argv[1], "r");
243
244			for(;;) {
245			char *s;
246
247			if ((fgets(tmp, 4095, infile)) == NULL)
248			break;
249
250			s = strchr (tmp, '\n');
251			if (s != NULL)
252			*s = 0;
253
254			if (strncmp(tmp, ".globl op_", 10) == 0) {
255			struct line first_line = NULL, prev = NULL;
256			struct line **nextp = &first_line;
257			struct func f;
258			int nr_rets = 0;
259			int can_opt = 1;
260
261			do {
262			struct line *current;
263
264			if (strcmp (tmp, "#APP") != 0 && strcmp (tmp, "#NO_APP") != 0) {
265			current = nextp = (struct line )malloc(sizeof (struct line));
266			nextp = &current->next;
267			current->prev = prev; prev = current;
268			current->next = NULL;
269			current->delet = 0;
270			current->data = strdup (tmp);
271			if (match (current, "movl %esp,%ebp") \|\| match (current, "enter")) {
272			fprintf (stderr, "GCC failed to eliminate fp: %s\n", first_line->data);
273			can_opt = 0;
274			}
275
276			if (match (current, "ret"))
277			nr_rets++;
278			}
279			if ((fgets(tmp, 4095, infile)) == NULL)
280			oops();
281			s = strchr (tmp, '\n');
282			if (s != NULL)
283			*s = 0;
284			} while (strncmp (tmp,".Lfe", 4) != 0);
285
286			f.first_line = first_line;
287			f.last_line = prev;
288
289			if (nr_rets == 1 && can_opt)
290			do_function(&f);
291			/*else
292			fprintf(stderr, "Too many RET instructions: %s\n", first_line->data);*/
293			output_function(&f);
294			}
295			printf("%s\n", tmp);
296			}
297			return 0;
298			}