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");
        exit(1);
}

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");
        exit(1);
    }
    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)
            exit(1);
        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:	1.2
Committed:	2001-06-28T21:20:02Z (23 years ago) by cebix
Content type:	text/plain
Branch:	MAIN
CVS Tags:	nigel-build-19, nigel-build-12, nigel-build-13, nigel-build-16, nigel-build-17, nigel-build-15, snapshot-15012002
Changes since 1.1:	+3 -3 lines
Log Message:	video_x.cpp supports resolution switching in windowed mode: the available resolutions are 512x384, 640x480, 800x600, 1024x768 and 1280x1024 (the prefs editor has to be updated to reflect this). The resolution selected in the prefs editor is used as the default, but it can be changed in the Monitors control panel. So far only tested with direct addressing.
#	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	cebix	1.2	exit(1);
31	cebix	1.1	}
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	cebix	1.2	exit(1);
50	cebix	1.1	}
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	cebix	1.2	exit(1);
125	cebix	1.1	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			}