From: Bernhard Urban <lewurm@gmail.com>
Date: Wed, 19 Jan 2011 11:06:24 +0000 (+0100)
Subject: progs/max: loop unrolling (102->84)
X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=calu.git;a=commitdiff_plain;h=701e1eb018a01b1cc7f13f7005ce97c3307762d5

progs/max: loop unrolling (102->84)
---

diff --git a/progs/max.s b/progs/max.s
index 0008d64..7192ae3 100644
--- a/progs/max.s
+++ b/progs/max.s
@@ -80,12 +80,52 @@ max:
 	; r4 = arr[x]
 	; r0 = x = arr[0]
 	ldw r0, 0(r2)
-	subi r1, r1, 1
+
+	subi r5, r1, 1
+	andx r5, 0x3
+
+	cmpi r5, 0
+	breq+ loop0
+
+	cmpi r5, 1
+	addideq r1, r1, 3-1
+	subideq r2, r2, 12
+	breq+ loop1
+
+	cmpi r5, 2
+	addideq r1, r1, 2-1
+	subideq r2, r2, 8
+	breq+ loop2
+
+	cmpi r5, 3
+	; addideq r1, r1, 1-1
+	subideq r2, r2, 4
+	breq+ loop3
+
+loop0:
+	addi r1, r1, 4-1
 maxloop:
+	subi r1, r1, 4
+	retzs-
+
 	ldw r4, 4(r2)
 	cmp r0, r4
 	movlt r0, r4
-	subi r1, r1, 1
-	addid r2, r2, 4
-	brnq+ maxloop
-	ret+
+
+loop1:
+	ldw r4, 8(r2)
+	cmp r0, r4
+	movlt r0, r4
+
+loop2:
+	ldw r4, 12(r2)
+	cmp r0, r4
+	movlt r0, r4
+
+loop3:
+	ldw r4, 16(r2)
+	cmp r0, r4
+	movlt r0, r4
+
+	addi r2, r2, 4*4
+	br+ maxloop