1 files changed, 142 insertions, 0 deletions
diff --git a/usr/src/lib/libbc/libc/gen/common/memalign.c b/usr/src/lib/libbc/libc/gen/common/memalign.c
new file mode 100644
index 0000000000..a71c2a06f8
--- /dev/null
+++ b/usr/src/lib/libbc/libc/gen/common/memalign.c
@@ -0,0 +1,142 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 1987 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI" 
+
+#include "mallint.h"
+#include <errno.h>
+
+extern	int errno;
+
+/*
+ * memalign(align,nbytes)
+ *
+ * Description:
+ *	Returns a block of specified size on a specified alignment boundary.
+ *
+ * Algorithm:
+ *	Malloc enough to ensure that a block can be aligned correctly.
+ *	Find the alignment point and return the fragments
+ *	before and after the block.
+ *
+ * Errors:
+ *	Returns NULL and sets errno as follows:
+ *	[EINVAL]
+ *		if nbytes = 0,
+ *		or if alignment is misaligned,
+ *	 	or if the heap has been detectably corrupted.
+ *	[ENOMEM]
+ *		if the requested memory could not be allocated.
+ */
+
+char *
+memalign(align, nbytes)
+	uint	align;
+	uint	nbytes;
+{
+	uint	reqsize;		/* Num of bytes to get from malloc() */
+	register char	*p;		/* Ptr returned from malloc() */
+	register Dblk	blk;		/* For addressing fragment blocks */
+	register uint	blksize;	/* Current (shrinking) block size */
+	register char	*alignedp;	/* Ptr to properly aligned boundary */
+	register Dblk	aligned_blk;	/* The block to be returned */
+	register uint	frag_size;	/* size of fragments fore and aft */
+	uint	x;			/* ccom can't do (char*)(uint/uint) */
+
+	/*
+	 * check for valid size and alignment parameters
+	 */
+	if (nbytes == 0 || misaligned(align)) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	/*
+	 * Malloc enough memory to guarantee that the result can be
+	 * aligned correctly. The worst case is when malloc returns
+	 * a block so close to the next alignment boundary that a
+	 * fragment of minimum size cannot be created.
+	 */
+	nbytes = roundup(nbytes, ALIGNSIZ);
+	reqsize = nbytes + align + SMALLEST_BLK;
+	p = malloc(reqsize);
+	if (p == NULL) {
+		return NULL;
+	}
+
+	/*
+	 * get size of the entire block (overhead and all)
+	 */
+	blk = (Dblk)(p - ALIGNSIZ);	/* back up to get length word */
+	blksize = blk->size;
+
+	/*
+	 * locate the proper alignment boundary within the block.
+	 */
+	x = roundup((uint)p, align);		/* ccom work-around */
+	alignedp = (char *)x;
+	aligned_blk = (Dblk)(alignedp - ALIGNSIZ);
+
+	/*
+	 * Check out the space to the left of the alignment
+	 * boundary, and split off a fragment if necessary.
+	 */
+	frag_size = (uint)aligned_blk - (uint)blk;
+	if (frag_size != 0) {
+		/*
+		 * Create a fragment to the left of the aligned block.
+		 */
+		if ( frag_size < SMALLEST_BLK ) {
+			/*
+			 * Not enough space. So make the split
+			 * at the other end of the alignment unit.
+			 */
+			frag_size += align;
+			aligned_blk = nextblk(aligned_blk,align);
+		}
+		blk->size = frag_size;
+		blksize -= frag_size;
+		aligned_blk->size = blksize;
+		free(blk->data);
+	}
+
+	/*
+	 * Is there a (sufficiently large) fragment to the
+	 * right of the aligned block?
+	 */
+	nbytes += ALIGNSIZ;
+	frag_size = blksize - nbytes;
+	if (frag_size > SMALLEST_BLK) {
+		/*
+		 * split and free a fragment on the right
+		 */
+		blk = nextblk(aligned_blk, nbytes);
+		blk->size = frag_size;
+		aligned_blk->size -= frag_size;
+		free(blk->data);
+	}
+	return(aligned_blk->data);
+}