X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fadt%2Fpdeq.c;h=dcf1143156513b569757c623ae55940f11fff342;hb=b1ac8fe5c7b3b462f66a99e6c780be9826414b7d;hp=e74d82a3953198a54298be665a404c6cf826e1be;hpb=0804355762ef7b45199c73902aaec3016edb1243;p=libfirm

diff --git a/ir/adt/pdeq.c b/ir/adt/pdeq.c
index e74d82a39..dcf114315 100644
--- a/ir/adt/pdeq.c
+++ b/ir/adt/pdeq.c
@@ -1,482 +1,456 @@
 /*
- * Project:     libFIRM
- * File name:   ir/adt/pdeq.c
- * Purpose:     Pdeq --- double ended queue of generic pointers.
- * Author:      Christian von Roques
- * Modified by:
- * Created:     1999 by getting from fiasco
- * CVS-ID:      $Id$
- * Copyright:   (c) 1995, 1996 Christian von Roques
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * This file is part of libFirm.
+ * Copyright (C) 2012 University of Karlsruhe.
  */
 
+/**
+ * @file
+ * @brief       double ended queue of generic pointers.
+ * @author      Christian von Roques
+ * @date        1999 by getting from fiasco
+ */
+#include "config.h"
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <stdbool.h>
-# ifdef HAVE_STRING_H
-#  include <string.h>
-# endif
+#include <string.h>
+#include <assert.h>
 
-#include "cookies.h"
-#include "debug.h"
+#include "fourcc.h"
 #include "pdeq.h"
 #include "xmalloc.h"
 
+/* Pointer Double Ended Queue */
+#define PDEQ_MAGIC1 FOURCC('P','D','E','1')
+#define PDEQ_MAGIC2 FOURCC('P','D','E','2')
 
-/** Size of pdeq block cache */
+/** Size of pdeq block cache. */
 #define TUNE_NSAVED_PDEQS 16
 
-/* # of data items in block */
-#define NDATA ((int)((PREF_MALLOC_SIZE - offsetof (pdeq, data)) / sizeof (void *)))
+/** A size handled efficiently by malloc(), at least 1K.  */
+#define PREF_MALLOC_SIZE 2048
+
+/**
+ * Maximal number of data items in a pdeq chunk.
+ */
+#define NDATA ((PREF_MALLOC_SIZE - offsetof(pdeq, data)) / sizeof(void *))
 
 #ifdef NDEBUG
 # define VRFY(dq) ((void)0)
 #else
-# define VRFY(dq) \
-    (d_(df_vrfy_level,1) ? _pdeq_vrfy ((dq)) : assert ((dq) && ((dq)->cookie == PDEQ_COOKIE1)))
+# define VRFY(dq) assert((dq) && ((dq)->magic == PDEQ_MAGIC1))
 #endif
 
-
+/**
+ * A pointer double ended queue.
+ * This structure is used as a list chunk either.
+ */
 struct pdeq {
 #ifndef NDEBUG
-  unsigned cookie;
+	unsigned magic;       /**< debug magic */
 #endif
-  pdeq *l_end, *r_end;		/* left and right ends of the deque */
-  pdeq *l, *r;			/*  left and right neighbour */
-  int n, p;
-  const void *data[1];
+	pdeq *l_end, *r_end;  /**< left and right ends of the queue */
+	pdeq *l, *r;          /**< left and right neighbor */
+	size_t n;             /**< number of elements in the current chunk */
+	size_t p;             /**< the read/write pointer */
+	const void *data[1];  /**< storage for elements */
 };
 
 
-/* cache of unused, pdeq blocks to speed up new_pdeq and del_pdeq. */
-/* +1 for compilers that can't grok empty arrays */
-pdeq *pdeq_block_cache[TUNE_NSAVED_PDEQS+1];
-unsigned pdeqs_cached;		/* # pdeqs in pdeq_store */
+/**
+ * cache of unused, pdeq blocks to speed up new_pdeq and del_pdeq.
+ */
+static pdeq *pdeq_block_cache[TUNE_NSAVED_PDEQS];
 
+/**
+ * Number of pdeqs in pdeq_store.
+ */
+static unsigned pdeqs_cached;
 
-static INLINE void
-free_pdeq_block (pdeq *p)
+/**
+ * Free a pdeq chunk, put in into the cache if possible.
+ *
+ * @param p   The pdeq chunk.
+ */
+static inline void free_pdeq_block (pdeq *p)
 {
 #ifndef NDEBUG
-  p->cookie = 0xbadf00d1;
+	p->magic = 0xbadf00d1;
 #endif
-  if (pdeqs_cached < TUNE_NSAVED_PDEQS) {
-    if (d_ (df_pdeq, 2)) printf ("[%p ==> pdeq_block_cache] ", p);
-    pdeq_block_cache[pdeqs_cached++] = p;
-  } else {
-    if (d_ (df_pdeq, 2)) printf ("[%p ==> free] ", p);
-    xfree (p);
-  }
+	if (pdeqs_cached < TUNE_NSAVED_PDEQS) {
+		pdeq_block_cache[pdeqs_cached++] = p;
+	} else {
+		xfree (p);
+	}
 }
 
-
-static INLINE pdeq *
-alloc_pdeq_block (void)
-{
-  pdeq *p;
-  if (TUNE_NSAVED_PDEQS && pdeqs_cached) {
-    p = pdeq_block_cache[--pdeqs_cached];
-    if (d_ (df_pdeq, 2)) printf ("[pdeq_block_cache ==> %p] ", p);
-  } else {
-    p = xmalloc (PREF_MALLOC_SIZE);
-    if (d_ (df_pdeq, 2)) printf ("[malloc ==> %p] ", p);
-  }
-  return p;
-}
-
-
-#ifndef NDEBUG
-void
-_pdeq_vrfy (pdeq *dq)
+/**
+ * Allocate a new pdeq chunk, get it from the cache if possible.
+ *
+ * @return A new pdeq chunk.
+ */
+static inline pdeq *alloc_pdeq_block (void)
 {
-  pdeq *q;
-
-  if (d_ (df_pdeq, 5)) printf ("[pdeq_vrfy %p] ", dq);
-
-  assert (   dq
-	  && (dq->cookie == PDEQ_COOKIE1)
-	  && (dq->l_end && dq->r_end));
-  q = dq->l_end;
-  while (q) {
-    assert (   ((q == dq) || (q->cookie == PDEQ_COOKIE2))
-	    && ((q == dq->l_end) ^ (q->l!=0))
-	    && ((q == dq->r_end) ^ (q->r!=0))
-	    && (!q->l || (q == q->l->r))
-	    && ((q->n>=0) && (q->n<=NDATA))
-	    && ((q == dq->l_end) || (q == dq->r_end) || (q->n == NDATA))
-	    && ((q->p>=0) && (q->p<NDATA)));
-    q = q->r;
-  }
+	pdeq *p;
+	if (pdeqs_cached > 0) {
+		p = pdeq_block_cache[--pdeqs_cached];
+	} else {
+		p = (pdeq*) xmalloc(PREF_MALLOC_SIZE);
+	}
+	return p;
 }
-#endif
-
 
-pdeq *
-new_pdeq (void)
+/* Creates a new double ended pointer list. */
+pdeq *new_pdeq(void)
 {
-  pdeq *dq;
+	pdeq *dq;
 
-  dq = alloc_pdeq_block();
+	dq = alloc_pdeq_block();
 
 #ifndef NDEBUG
-  dq->cookie = PDEQ_COOKIE1;
+	dq->magic = PDEQ_MAGIC1;
 #endif
-  dq->l_end = dq->r_end = dq;
-  dq->l = dq->r = NULL;
-  dq->n = dq->p = 0;
+	dq->l_end = dq->r_end = dq;
+	dq->l = dq->r = NULL;
+	dq->n = dq->p = 0;
 
-  VRFY (dq);
-  if (d_ (df_pdeq, 1)) printf ("(new_pdeq ==> %p)\n", dq);
-  return dq;
+	VRFY(dq);
+	return dq;
 }
 
-
-pdeq *
-new_pdeq1 (const void *x)
+/* Creates a new double ended pointer list and puts an initial pointer element in. */
+pdeq *new_pdeq1(const void *x)
 {
-  return pdeq_putr (new_pdeq(), x);
+	return pdeq_putr(new_pdeq(), x);
 }
 
-
-void
-del_pdeq (pdeq *dq)
+/* Delete a double ended pointer list. */
+void del_pdeq(pdeq *dq)
 {
-  pdeq *q, *qq;
-
-  VRFY (dq);
+	pdeq *q, *qq;
 
-  q = dq->l_end;		/* left end of chain */
-  /* pdeq trunk empty, but !pdeq_empty() ==> trunk not in chain */
-  if (dq->n == 0 && dq->l_end != dq ) {
-    free_pdeq_block (dq);
-  }
+	VRFY(dq);
 
-  /* Free all blocks in the pdeq chain */
-  do {
-    qq = q->r;
-    free_pdeq_block (q);
-  } while ((q = qq));
+	q = dq->l_end; /* left end of chain */
+	/* pdeq trunk empty, but !pdeq_empty() ==> trunk not in chain */
+	if (dq->n == 0 && dq->l_end != dq ) {
+		free_pdeq_block(dq);
+	}
 
-  if (d_ (df_pdeq, 1)) printf ("(del_pdeq %p)\n", dq);
+	/* Free all blocks in the pdeq chain */
+	do {
+		qq = q->r;
+		free_pdeq_block(q);
+	} while ((q = qq));
 }
 
-
-bool
-pdeq_empty (pdeq *dq)
+/* Checks if a list is empty. */
+int pdeq_empty(pdeq *dq)
 {
-  VRFY (dq);
-  if (d_ (df_pdeq, 4)) printf ("(pdeq_empty %p ==> %d)\n", dq, dq->l_end->n == 0);
-  return dq->l_end->n == 0;
+	VRFY(dq);
+	return dq->l_end->n == 0;
 }
 
-
-int
-pdeq_len (pdeq *dq)
+/* Returns the length of a double ended pointer list. */
+size_t pdeq_len(pdeq *dq)
 {
-  int n;
-  pdeq *q;
+	size_t n;
+	pdeq *q;
 
-  VRFY (dq);
+	VRFY(dq);
 
-  n = 0;
-  q = dq->l_end;
-  do {
-    n += q->n;
-    q = q->r;
-  }  while (q);
+	n = 0;
+	q = dq->l_end;
+	do {
+		n += q->n;
+		q = q->r;
+	}  while (q);
 
-  if (d_ (df_pdeq, 4)) printf ("(pdeq_len %p ==> %d)\n", dq, n);
-  return n;
+	return n;
 }
 
-
-pdeq *
-pdeq_putr (pdeq *dq, const void *x)
+/* Add a pointer to the right site of a double ended pointer list. */
+pdeq *pdeq_putr(pdeq *dq, const void *x)
 {
-  pdeq *rdq;
-  int n;
-  bool pr = 0;
+	pdeq *rdq;
+	size_t n;
 
-  VRFY (dq);
+	VRFY(dq);
 
-  rdq = dq->r_end;
-  if (rdq->n >= NDATA) {	/* tailblock full */
-    pdeq *ndq;
+	rdq = dq->r_end;
+	if (rdq->n >= NDATA) {  /* tailblock full */
+		pdeq *ndq;
 
-    ndq = dq;			/* try to reuse trunk, but ... */
-    if (dq->n) {		/* ... if trunk used */
-      /* allocate and init new block */
-      ndq = alloc_pdeq_block ();
-      pr = d_ (df_pdeq, 2);
+		ndq = dq;           /* try to reuse trunk, but ... */
+		if (dq->n) {        /* ... if trunk used */
+			/* allocate and init new block */
+			ndq = alloc_pdeq_block();
 #ifndef NDEBUG
-      ndq->cookie = PDEQ_COOKIE2;
+			ndq->magic = PDEQ_MAGIC2;
 #endif
-      ndq->l_end = ndq->r_end = NULL;
-    }
+			ndq->l_end = ndq->r_end = NULL;
+		}
 
-    ndq->r = NULL;
-    ndq->l = rdq; rdq->r = ndq;
-    ndq->n = 0; ndq->p = 0;
-    dq->r_end = ndq;
-    rdq = ndq;
-  }
+		ndq->r = NULL;
+		ndq->l = rdq; rdq->r = ndq;
+		ndq->n = 0; ndq->p = 0;
+		dq->r_end = ndq;
+		rdq = ndq;
+	}
 
-  n = rdq->n++ + rdq->p;
-  if (n >= NDATA) n -= NDATA;
+	n = rdq->n++ + rdq->p;
+	if (n >= NDATA) n -= NDATA;
 
-  rdq->data[n] = x;
+	rdq->data[n] = x;
 
-  VRFY (dq);
-  if (d_ (df_pdeq, 3) || pr) printf ("(pdeq_putr %p %p)\n", dq, x);
-  return dq;
+	VRFY(dq);
+	return dq;
 }
 
-
-pdeq *
-pdeq_putl (pdeq *dq, const void *x)
+/* Add a pointer to the left site of a double ended pointer list. */
+pdeq *pdeq_putl(pdeq *dq, const void *x)
 {
-  pdeq *ldq;
-  int p;
-  bool pr = 0;
+	pdeq *ldq;
+	size_t p;
 
-  VRFY (dq);
+	VRFY(dq);
 
-  ldq = dq->l_end;
-  if (ldq->n >= NDATA) {	/* headblock full */
-    pdeq *ndq;
+	ldq = dq->l_end;
+	if (ldq->n >= NDATA) {  /* headblock full */
+		pdeq *ndq;
 
-    ndq = dq;			/* try to reuse trunk, but ... */
-    if (dq->n) {		/* ... if trunk used */
-      /* allocate and init new block */
-      ndq = alloc_pdeq_block ();
-      pr = d_ (df_pdeq, 2);
+		ndq = dq;           /* try to reuse trunk, but ... */
+		if (dq->n) {        /* ... if trunk used */
+			/* allocate and init new block */
+			ndq = alloc_pdeq_block();
 #ifndef NDEBUG
-      ndq->cookie = PDEQ_COOKIE2;
+			ndq->magic = PDEQ_MAGIC2;
 #endif
-      ndq->l_end = ndq->r_end = NULL;
-    }
-
-    ndq->l = NULL;
-    ndq->r = ldq; ldq->l = ndq;
-    ndq->n = 0; ndq->p = 0;
-    dq->l_end = ndq;
-    ldq = ndq;
-  }
-
-  ldq->n++;
-  p = ldq->p - 1;
-  if (p < 0) p += NDATA;
-  ldq->p = p;
-
-  ldq->data[p] = x;
-
-  VRFY (dq);
-  if (d_ (df_pdeq, 3) || pr) printf ("(pdeq_putl %p %p)\n", dq, x);
-  return dq;
+			ndq->l_end = ndq->r_end = NULL;
+		}
+
+		ndq->l = NULL;
+		ndq->r = ldq; ldq->l = ndq;
+		ndq->n = 0; ndq->p = 0;
+		dq->l_end = ndq;
+		ldq = ndq;
+	}
+
+	ldq->n++;
+	if (ldq->p == 0)
+		p = NDATA;
+	else
+		p = ldq->p - 1;
+	ldq->p = p;
+
+	ldq->data[p] = x;
+
+	VRFY(dq);
+	return dq;
 }
 
-
-void *
-pdeq_getr (pdeq *dq)
+/* Retrieve a pointer from the right site of a double ended pointer list. */
+void *pdeq_getr(pdeq *dq)
 {
-  pdeq *rdq;
-  const void *x;
-  int n;
-  bool pr = 0;
-
-  VRFY (dq);
-  assert (dq->l_end->n);
-
-  rdq = dq->r_end;
-  n = rdq->p + --rdq->n;
-  if (n>=NDATA) n -= NDATA;
-  x = rdq->data[n];
-
-  if (rdq->n == 0) {
-    if (rdq->l) {
-      dq->r_end = rdq->l;
-      rdq->l->r = NULL;
-      rdq->l = NULL;
-    } else {
-      dq->r_end = dq->l_end = dq;
-    }
-    if (dq != rdq) {
-      free_pdeq_block (rdq);
-      pr = d_ (df_pdeq, 2);
-    }
-  }
-
-  VRFY (dq);
-  if (d_ (df_pdeq, 3) || pr) printf ("(pdeq_getr %p ==> %p)\n", dq, x);
-  return (void *)x;
+	pdeq *rdq;
+	const void *x;
+	size_t n;
+
+	VRFY(dq);
+	assert(dq->l_end->n);
+
+	rdq = dq->r_end;
+	n = rdq->p + --rdq->n;
+	if (n >= NDATA) n -= NDATA;
+	x = rdq->data[n];
+
+	if (rdq->n == 0) {
+		if (rdq->l) {
+			dq->r_end = rdq->l;
+			rdq->l->r = NULL;
+			rdq->l = NULL;
+		} else {
+			dq->r_end = dq->l_end = dq;
+		}
+		if (dq != rdq) {
+			free_pdeq_block(rdq);
+		}
+	}
+
+	VRFY(dq);
+	return (void *)x;
 }
 
-
-void *
-pdeq_getl (pdeq *dq)
+/* Retrieve a pointer from the left site of a double ended pointer list. */
+void *pdeq_getl(pdeq *dq)
 {
-  pdeq *ldq;
-  const void *x;
-  int p;
-  bool pr = 0;
-
-  VRFY (dq);
-  assert (dq->l_end->n);
-
-  ldq = dq->l_end;
-  p = ldq->p;
-  x = ldq->data[p];
-  if (++p >= NDATA) p = 0;
-  ldq->p = p;
-
-  if (--ldq->n == 0) {
-    if (ldq->r) {
-      dq->l_end = ldq->r;
-      ldq->r->l = NULL;
-      ldq->r = NULL;
-    } else {
-      dq->l_end = dq->r_end = dq;
-    }
-    if (dq != ldq) {
-      free_pdeq_block (ldq);
-      pr = d_ (df_pdeq, 2);
-    }
-  }
-
-  VRFY (dq);
-  if (d_ (df_pdeq, 3) || pr) printf ("(pdeq_getl %p ==> %p)\n", dq, x);
-  return (void *)x;
+	pdeq *ldq;
+	const void *x;
+	size_t p;
+
+	VRFY(dq);
+	assert(dq->l_end->n);
+
+	ldq = dq->l_end;
+	p = ldq->p;
+	x = ldq->data[p];
+	if (++p >= NDATA) p = 0;
+	ldq->p = p;
+
+	if (--ldq->n == 0) {
+		if (ldq->r) {
+			dq->l_end = ldq->r;
+			ldq->r->l = NULL;
+			ldq->r = NULL;
+		} else {
+			dq->l_end = dq->r_end = dq;
+		}
+		if (dq != ldq) {
+			free_pdeq_block(ldq);
+		}
+	}
+
+	VRFY(dq);
+	return (void *)x;
 }
 
-
-bool
-pdeq_contains (pdeq *dq, const void *x)
+/*
+ * Returns non-zero if a double ended pointer list
+ * contains a pointer x.
+ */
+int pdeq_contains(pdeq *dq, const void *x)
 {
-  pdeq *q;
-
-  VRFY (dq);
+	pdeq *q;
 
-  q = dq->l_end;
-  do {
-    int p, ep;
+	VRFY(dq);
 
-    p = q->p; ep = p + q->n;
+	q = dq->l_end;
+	do {
+		size_t p, ep;
 
-    if (ep > NDATA) {
-      do if (q->data[p] == x) goto found; while (++p < NDATA);
-      p = 0;
-      ep -= NDATA;
-    }
+		p = q->p; ep = p + q->n;
 
-    while (p < ep) if (q->data[p++] == x) goto found;
+		if (ep > NDATA) {
+			do {
+				if (q->data[p] == x) return 1;
+			} while (++p < NDATA);
+			p = 0;
+			ep -= NDATA;
+		}
 
-    q = q->r;
-  } while (q);
+		while (p < ep) {
+			if (q->data[p++] == x) return 1;
+		}
 
-  if (d_ (df_pdeq, 3)) printf ("(pdeq_contains %p %p ==> 0)\n", dq, x);
-  return 0;
+		q = q->r;
+	} while (q);
 
-found:  /* The two gotos can be optimized away, if !DEBUG */
-  if (d_ (df_pdeq, 3)) printf ("(pdeq_contains %p %p ==> 1)\n", dq, x);
-  return 1;
+	return 0;
 }
 
-
-void *
-pdeq_search (pdeq *dq, cmp_fun cmp, const void *key)
+/*
+ * Search a key in a double ended pointer list, the search
+ * is controlled by a compare function.
+ * An element is found, if the compare function returns 0.
+ * The search is started from the left site of the list.
+ */
+void *pdeq_search(pdeq *dq, cmp_fun cmp, const void *key)
 {
-  pdeq *q;
-  int p;
-
-  VRFY (dq);
+	pdeq *q;
+	size_t p;
 
-  q = dq->l_end;
-  do {
-    int ep;
+	VRFY(dq);
 
-    p = q->p; ep = p + q->n;
+	q = dq->l_end;
+	do {
+		size_t ep;
 
-    if (ep > NDATA) {
-      do if (!cmp (q->data[p], key)) goto found; while (++p < NDATA);
-      p = 0;
-      ep -= NDATA;
-    }
+		p = q->p; ep = p + q->n;
 
-    while (p < ep) if (!cmp (q->data[p++], key)) goto found;
+		if (ep > NDATA) {
+			do {
+				if (!cmp(q->data[p], key)) return (void *)q->data[p-1];
+			} while (++p < NDATA);
+			p = 0;
+			ep -= NDATA;
+		}
 
-    q = q->r;
-  } while (q);
+		while (p < ep) {
+			if (!cmp(q->data[p++], key)) return (void *)q->data[p-1];
+		}
 
-  if (d_ (df_pdeq, 3)) printf ("(pdeq_search %p %p %p ==> 0)\n", dq, cmp, key);
-  return NULL;
+		q = q->r;
+	} while (q);
 
-found:  /* The two gotos can be optimized away, if !DEBUG */
-  if (d_ (df_pdeq, 3)) printf ("(pdeq_contains %p %p %p ==> %p)\n",
-			       dq, cmp, key, q->data[p]);
-  return (void *)q->data[p-1];
+	return NULL;
 }
 
-
-void **
-pdeq_copyl (pdeq *dq, const void **dst)
+/*
+ * Convert the double ended pointer list into a linear array beginning from
+ * left, the first element in the linear array will be the left one.
+ */
+void **pdeq_copyl(pdeq *dq, const void **dst)
 {
-  pdeq *q;
-  const void **d = dst;
+	pdeq *q;
+	const void **d = dst;
 
-  VRFY (dq);
+	VRFY(dq);
 
-  q = dq->l_end;
-  while (q) {
-    int p, n;
+	q = dq->l_end;
+	while (q) {
+		size_t p, n;
 
-    p = q->p; n = q->n;
+		p = q->p; n = q->n;
 
-    if (n + p > NDATA) {
-      int nn = NDATA - p;
-      memcpy (d, &q->data[p], nn * sizeof (void *)); d += nn;
-      p = 0; n -= nn;
-    }
+		if (n + p > NDATA) {
+			/* p is always < NDATA */
+			size_t nn = NDATA - p;
+			memcpy((void *) d, &q->data[p], nn * sizeof(void *)); d += nn;
+			p = 0; n -= nn;
+		}
 
-    memcpy (d, &q->data[p], n * sizeof (void *)); d += n;
+		memcpy((void *) d, &q->data[p], n * sizeof(void *)); d += n;
 
-    q = q->r;
-  }
+		q = q->r;
+	}
 
-  if (d_ (df_pdeq, 3)) printf ("(pdeq_copyl %p %p ==> %p)\n", dq, dst, d);
-  return (void **)dst;
+	return (void **)dst;
 }
 
-
-void **
-pdeq_copyr (pdeq *dq, const void **dst)
+/*
+ * Convert the double ended pointer list into a linear array beginning from
+ * right, the first element in the linear array will be the right one.
+ */
+void **pdeq_copyr(pdeq *dq, const void **dst)
 {
-  pdeq *q;
-  const void **d = dst;
-
-  VRFY (dq);
-
-  q = dq->r_end;
-  while (q) {
-    int p, i;
-
-    p = q->p; i = q->n + p - 1;
-    if (i >= NDATA) {
-      i -= NDATA;
-      do *d++ = q->data[i]; while (--i >= 0);
-      i = NDATA - 1;
-    }
-
-    do *d++ = q->data[i]; while (--i >= p);
-
-    q = q->l;
-  }
-
-  if (d_ (df_pdeq, 3)) printf ("(pdeq_copyr %p %p ==> %p)\n", dq, dst, d);
-  return (void **)dst;
+	pdeq *q;
+	const void **d = dst;
+
+	VRFY(dq);
+
+	q = dq->r_end;
+	while (q) {
+		size_t p, i;
+
+		p = q->p; i = q->n + p - 1;
+		if (i >= NDATA) {
+			i -= NDATA;
+			for (;; --i) {
+				*d++ = q->data[i];
+				if (i == 0)
+					break;
+			}
+			i = NDATA - 1;
+		}
+
+		for (;; --i) {
+			*d++ = q->data[i];
+			if (i <= p)
+				break;
+		}
+
+		q = q->l;
+	}
+
+	return (void **)dst;
 }