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[as] Remove Bucket structure

A 2 pass assembler knows the size of the section, so we can
allocate the full buffer for it and avoid linked lists.

--- a/as/as.h

+++ b/as/as.h

@@ -10,7 +10,7 @@

 typedef struct op Op;

 typedef struct arg Arg;

 typedef void Format(Op *, Arg *);

-typedef struct sec Section;

+typedef struct section Section;

 enum {

 	BITS16,

@@ -34,13 +34,12 @@

 	TUINT val;

 };

-struct bucket;

-

-struct sec {

+struct section {

 	char *name;

-	struct bucket *mem;

+	char *mem;

 	int flags;

 	TUINT base;

+	TUINT max;

 	TUINT curpc;

 	TUINT pc;

 };

--- a/as/emit.c

+++ b/as/emit.c

@@ -5,16 +5,6 @@

 #include "../inc/scc.h"

 #include "as.h"

-#define BUCKETSIZ 0x100

-

-typedef struct bucket Bucket;

-

-struct bucket {

-	char mem[BUCKETSIZ];

-	TUINT base;

-	struct bucket *next;

-};

-

 Section text = (Section) {.name = "text", .flags = SRELOC|SEXEC|SFILE};

 Section data = (Section) {.name = "data", .flags = SRELOC|SREAD|SWRITE|SFILE};

 Section bss = (Section) {.name = "bss", .flags = SRELOC|SREAD|SWRITE};

@@ -22,44 +12,22 @@

 int pass;

-void

-isections(void)

+static void

+isec(Section *sec)

 {

-	text.curpc = text.pc = text.base;

-	data.curpc = data.pc = data.base;

-	bss.curpc = bss.pc = bss.base;

+	sec->curpc = sec->pc = sec->base;

+	if (sec->max > 0)

+		sec->mem = xmalloc(sec->max - sec->base);

 }

-static struct bucket *

-alloc(TUINT addr)

+void

+isections(void)

 {

-	struct bucket *bp;

-

-	bp = memset(xmalloc(sizeof(*bp)), 0, sizeof(*bp));

-	bp->base = addr+BUCKETSIZ & BUCKETSIZ-1;

-	return bp;

+	isec(&text);

+	isec(&data);

+	isec(&bss);

 }

-static void

-emitbyte(Section *sec, char byte, TUINT addr)

-{

-	struct bucket *cur, *next;

-	TUINT base;

-

-	for (cur = sec->mem; ; cur = cur->next) {

-		base = cur->base;

-		if (base <= addr && addr < base+BUCKETSIZ)

-			break;

-

-		next = cur->next;

-		if (base < addr && next->base > addr) {

-			cur->next = alloc(addr);

-			cur->next->next = next;

-		}

-	}

-	cur->mem[addr - cur->base] = byte;

-}

-

 void

 emit(Section *sec, char *bytes, int nbytes)

 {

@@ -68,13 +36,8 @@

 	if (pass == 1 || !(sec->flags & SFILE))

 		return;

-	if (!sec->mem) {

-		sec->mem = alloc(sec->base);

-		sec->mem->next = sec->mem;

-	}

-

-	for (addr = sec->pc; nbytes--; addr++)

-		emitbyte(sec, *bytes++, addr);

+	for (addr = sec->pc - sec->base; nbytes--; addr++)

+		sec->mem[addr] = *bytes++;

 }

 void

@@ -81,16 +44,11 @@

 writeout(char *name)

 {

 	FILE *fp;

-	Bucket *bp;

 	if ((fp = fopen(name, "wb")) == NULL)

 		die("error opening output file '%s'\n", name);

-	for (bp = text.mem; ; bp = bp->next) {

-		fwrite(bp->mem, BUCKETSIZ, 1, fp);

-		if (bp->next == text.mem)

-			break;

-	}

+	fwrite(text.mem, text.max - text.base, 1, fp);

 	if (fclose(fp))

 		die("error writing the output file");

--- a/as/main.c

+++ b/as/main.c

@@ -69,8 +69,10 @@

 		return;

 	}

 	(*op->format)(op, args);

-	cursec->pc += op->size;

 	cursec->curpc += op->size;

+	cursec->pc += op->size;

+	if (cursec->pc > cursec->max)

+		cursec->max = cursec->pc;

 }

 int