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unwind-dw2-fde.c (frame_downheap): Split out from...

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* unwind-dw2-fde.c (frame_downheap): Split out from...
        (frame_heapsort): Here.

From-SVN: r60253
This commit is contained in:
Jason Merrill 2002-12-18 11:27:56 -05:00 committed by Jason Merrill
parent a15791b0c9
commit 80d83b160f
2 changed files with 46 additions and 46 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
2002-12-18 Jason Merrill <jason@redhat.com>
* unwind-dw2-fde.c (frame_downheap): Split out from...
(frame_heapsort): Here.
2002-12-17 Jason Merrill <jason@redhat.com>
* tree.c (make_node): Don't set TREE_TYPE on 's' class nodes.

87
gcc/unwind-dw2-fde.c
View File

@ -467,6 +467,34 @@ fde_split (struct object *ob, fde_compare_t fde_compare,
erratic->count = k;
}
#define SWAP(x,y) do { fde * tmp = x; x = y; y = tmp; } while (0)
/* Convert a semi-heap to a heap. A semi-heap is a heap except possibly
for the first (root) node; push it down to its rightful place. */
static void
frame_downheap (struct object *ob, fde_compare_t fde_compare, fde **a,
int lo, int hi)
{
int i, j;
for (i = lo, j = 2*i+1;
j < hi;
j = 2*i+1)
{
if (j+1 < hi && fde_compare (ob, a[j], a[j+1]) < 0)
++j;
if (fde_compare (ob, a[i], a[j]) < 0)
{
SWAP (a[i], a[j]);
i = j;
}
else
break;
}
}
/* This is O(n log(n)). BSD/OS defines heapsort in stdlib.h, so we must
use a name that does not conflict. */
@ -481,55 +509,22 @@ frame_heapsort (struct object *ob, fde_compare_t fde_compare,
/* A portion of the array is called a "heap" if for all i>=0:
If i and 2i+1 are valid indices, then a[i] >= a[2i+1].
If i and 2i+2 are valid indices, then a[i] >= a[2i+2]. */
#define SWAP(x,y) do { fde * tmp = x; x = y; y = tmp; } while (0)
size_t n = erratic->count;
size_t m = n;
size_t i;
int m;
while (m > 0)
/* Expand our heap incrementally from the end of the array, heapifying
each resulting semi-heap as we go. After each step, a[m] is the top
of a heap. */
for (m = n/2-1; m >= 0; --m)
frame_downheap (ob, fde_compare, a, m, n);
/* Shrink our heap incrementally from the end of the array, first
swapping out the largest element a[0] and then re-heapifying the
resulting semi-heap. After each step, a[0..m) is a heap. */
for (m = n-1; m >= 1; --m)
{
/* Invariant: a[m..n-1] is a heap. */
m--;
for (i = m; 2*i+1 < n; )
{
if (2*i+2 < n
&& fde_compare (ob, a[2*i+2], a[2*i+1]) > 0
&& fde_compare (ob, a[2*i+2], a[i]) > 0)
{
SWAP (a[i], a[2*i+2]);
i = 2*i+2;
}
else if (fde_compare (ob, a[2*i+1], a[i]) > 0)
{
SWAP (a[i], a[2*i+1]);
i = 2*i+1;
}
else
break;
}
}
while (n > 1)
{
/* Invariant: a[0..n-1] is a heap. */
n--;
SWAP (a[0], a[n]);
for (i = 0; 2*i+1 < n; )
{
if (2*i+2 < n
&& fde_compare (ob, a[2*i+2], a[2*i+1]) > 0
&& fde_compare (ob, a[2*i+2], a[i]) > 0)
{
SWAP (a[i], a[2*i+2]);
i = 2*i+2;
}
else if (fde_compare (ob, a[2*i+1], a[i]) > 0)
{
SWAP (a[i], a[2*i+1]);
i = 2*i+1;
}
else
break;
}
SWAP (a[0], a[m]);
frame_downheap (ob, fde_compare, a, 0, m);
}
#undef SWAP
}