PERFORCE change 103978 for review

[John Birrell]

http://perforce.freebsd.org/chv.cgi?CH=103978

Change 103978 by jb at jb_freebsd2 on 2006/08/15 05:02:20

	Change the generated code to use memcpy rather than a structure
	assignment to avoid possible alignment problems on sun4v.

Affected files ...

.. //depot/projects/dtrace/src/lib/libelf/libelf_convert.m4#4 edit

Differences ...

==== //depot/projects/dtrace/src/lib/libelf/libelf_convert.m4#4 (text+ko) ====

@@ -251,19 +251,20 @@
 static void
 libelf_cvt_$1$3_tof(char *dst, char *src, int count, int byteswap)
 {
-	Elf64_$2 t, *s = (Elf64_$2 *) src;
+	Elf64_$2 t;
 	int c;
 
 	if (dst == src && !byteswap)
 		return;
 
 	if (!byteswap) {
-		(void) memcpy(dst, src, count * sizeof(*s));
+		(void) memcpy(dst, src, count * sizeof(t));
 		return;
 	}
 
 	for (c = 0; c < count; c++) {
-		t = *s++;
+		memcpy(&t, src, sizeof(t));
+		src += sizeof(t);
 		SWAP_$1$3(t);
 		WRITE_$1$3(dst,t);
 	}
@@ -274,21 +275,22 @@
 static void
 libelf_cvt_$1$3_tom(char *dst, char *src, int count, int byteswap)
 {
-	Elf64_$2 t, *d = (Elf64_$2 *) dst;
+	Elf64_$2 t;
 	int c;
 
 	if (dst == src && !byteswap)
 		return;
 
 	if (!byteswap) {
-		(void) memcpy(dst, src, count * sizeof(*d));
+		(void) memcpy(dst, src, count * sizeof(t));
 		return;
 	}
 
 	for (c = 0; c < count; c++) {
 		READ_$1$3(src,t);
 		SWAP_$1$3(t);
-		*d++ = t;
+		memcpy(dst, &t, sizeof(t));
+		dst += sizeof(t);
 	}
 }
 ')
@@ -364,12 +366,12 @@
 static void
 libelf_cvt$3_$1_tof(char *dst, char *src, int count, int byteswap)
 {
-	Elf$3_$2	t, *s;
+	Elf$3_$2	t;
 	int c;
 
-	s = (Elf$3_$2 *) src;
 	for (c = 0; c < count; c++) {
-		t = *s++;
+		memcpy(&t, src, sizeof(t));
+		src += sizeof(t);
 		if (byteswap) {
 			SWAP_STRUCT($2,$3)
 		}
@@ -383,21 +385,22 @@
 static void
 libelf_cvt$3_$1_tom(char *dst, char *src, int count, int byteswap)
 {
-	Elf$3_$2	 t, *d;
-	unsigned char	*s,*s0;
+	Elf$3_$2	t;
+	unsigned char	*s;
+	int		i;
 	size_t		fsz;
 
 	fsz = elf$3_fsize(ELF_T_$1, 1, EV_CURRENT);
-	d   = ((Elf$3_$2 *) dst) + (count - 1);
-	s0  = (unsigned char *) src + (count - 1) * fsz;
 
-	while (count--) {
-		s = s0;
+	for (i = 0; i < count; i++) {
+		s = (unsigned char *) src;
 		READ_STRUCT($2,$3)
 		if (byteswap) {
 			SWAP_STRUCT($2,$3)
 		}
-		*d-- = t; s0 -= fsz;
+		memcpy(dst, &t, sizeof(t));
+		dst += sizeof(t);
+		src += fsz;
 	}
 }
 ')')