Don't pre-sort the temp swap buffer

This is a close call.  On the one hand, this buffer will get jumbled when
used for merging adjacent blocks, so we'll need to sort it again before
distributing it.  On the other hand, by sorting it early, we know that we
won't have to distribute it very far.

In testing, pre-sorting seems to lose out overall.

1 files changed, 5 insertions, 4 deletions

diff --git a/grailsort.c b/grailsort.c
index 6e360dc..67528ca 100644
--- a/grailsort.c
+++ b/grailsort.c
@@ -61,12 +61,12 @@ void grailsort(void *unsorted, size_t nmel, size_t width, cmpfun cmp)
 	char *a = base + bufnmel * width;
 	char *b = a    + acount  * bwidth;
 
-	/* sort the buffer as if it were part of the a array */
-	grailsort(base, bufnmel + acount * blknmel, width, cmp);
-	grailsort(b,              bcount * blknmel, width, cmp);
+	grailsort(a, acount * blknmel, width, cmp);
+	grailsort(b, bcount * blknmel, width, cmp);
 
 	/* if already sorted, nothing to do */
-	if (cmp(TAIL(a, acount * blknmel, width), b) <= 0) return;
+	if (cmp(TAIL(a, acount * blknmel, width), b) <= 0)
+		goto distribute;
 
 	/* sort all the a and b blocks together by their head elements */
 	grailsort(a, blocks, bwidth, cmp);
@@ -80,6 +80,7 @@ void grailsort(void *unsorted, size_t nmel, size_t width, cmpfun cmp)
 		blocks  = overlap;
 	}
 
+distribute:
 	grailsort(base, bufnmel, width, cmp);
 	distribute_buffer(base, bufnmel, nmel - bufnmel, width, cmp);
 }