Shrink rotate function a bitHEADmaster

Code size is about 40 bytes smaller on amd64, but performance is unchanged.

1 files changed, 9 insertions, 11 deletions

diff --git a/rotate.c b/rotate.c
index 1815812..6aebf7c 100644
--- a/rotate.c
+++ b/rotate.c
@@ -6,17 +6,15 @@
 /* rotates left */
 void rotate(char *base, size_t size, size_t shift)
 {
-	int dir = 1;
-
-	counts[CURRENT].rotate++;
-	while (shift) {
-		while (2*shift <= size) {
-			swap(base, base + dir*shift, shift);
-			size -= shift;
-			base += shift*dir;
+	size_t a = shift, b = size - shift;
+	while (a && b) {
+		if (a <= b) {
+			swap(base, base + b, a);
+			b -= a;
+		} else {
+			swap(base, base + a, b);
+			base += b;
+			a    -= b;
 		}
-		shift = size - shift;
-		base  = dir > 0 ? base + size - shift : base - shift;
-		dir  *= -1;
 	}
 }