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authorNicolas Pitre <nico@cam.org>2005-10-31 02:08:03 +0300
committerRussell King <rmk+kernel@arm.linux.org.uk>2005-10-31 02:08:03 +0300
commitf741a1aab5fd7892927208ca37eb86b9ea85784a (patch)
treec4060ea9292f5e8f98e87ef354079bc900d81243 /arch/arm/lib/muldi3.S
parentcb7610d018235653c73ff1fea79b962c16317474 (diff)
downloadlinux-f741a1aab5fd7892927208ca37eb86b9ea85784a.tar.xz
[ARM] 3049/1: More optimized libgcc functions
Patch from Nicolas Pitre This patch gets rid of the last C implementations of needed libgcc functions for the kernel, replacing them with optimized assembly versions. Those functions are: __ashldi3 __ashrdi3 __lshrdi3 __muldi3 __ucmpdi2 The first 3 were lifted from gcc, the other two were written from scratch. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/lib/muldi3.S')
-rw-r--r--arch/arm/lib/muldi3.S44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/lib/muldi3.S b/arch/arm/lib/muldi3.S
new file mode 100644
index 000000000000..c7fbdf005319
--- /dev/null
+++ b/arch/arm/lib/muldi3.S
@@ -0,0 +1,44 @@
+/*
+ * linux/arch/arm/lib/muldi3.S
+ *
+ * Author: Nicolas Pitre
+ * Created: Oct 19, 2005
+ * Copyright: Monta Vista Software, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+
+#ifdef __ARMEB__
+#define xh r0
+#define xl r1
+#define yh r2
+#define yl r3
+#else
+#define xl r0
+#define xh r1
+#define yl r2
+#define yh r3
+#endif
+
+ENTRY(__muldi3)
+
+ mul xh, yl, xh
+ mla xh, xl, yh, xh
+ mov ip, xl, asr #16
+ mov yh, yl, asr #16
+ bic xl, xl, ip, lsl #16
+ bic yl, yl, yh, lsl #16
+ mla xh, yh, ip, xh
+ mul yh, xl, yh
+ mul xl, yl, xl
+ mul ip, yl, ip
+ adds xl, xl, yh, lsl #16
+ adc xh, xh, yh, lsr #16
+ adds xl, xl, ip, lsl #16
+ adc xh, xh, ip, lsr #16
+ mov pc, lr
+