[PATCH v4 3/5] sparc64: SPARC optimized fls function

From: Vijay Kumar
Date: Wed Oct 11 2017 - 14:50:56 EST


Defined SPARC optimized fls using lzcnt opcode.

Signed-off-by: Vijay Kumar <vijay.ac.kumar@xxxxxxxxxx>
---
arch/sparc/lib/Makefile | 1 +
arch/sparc/lib/NG4fls.S | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 5380c59..2823b8e 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -18,6 +18,7 @@ lib-$(CONFIG_SPARC32) += muldi3.o bitext.o cmpdi2.o
lib-$(CONFIG_SPARC64) += multi3.o
lib-$(CONFIG_SPARC64) += fls.o
lib-$(CONFIG_SPARC64) += fls64.o
+obj-$(CONFIG_SPARC64) += NG4fls.o

lib-$(CONFIG_SPARC64) += copy_page.o clear_page.o bzero.o
lib-$(CONFIG_SPARC64) += csum_copy.o csum_copy_from_user.o csum_copy_to_user.o
diff --git a/arch/sparc/lib/NG4fls.S b/arch/sparc/lib/NG4fls.S
new file mode 100644
index 0000000..bc17b65
--- /dev/null
+++ b/arch/sparc/lib/NG4fls.S
@@ -0,0 +1,20 @@
+/* NG4fls.S: SPARC optimized fls and __fls for T4 and above.
+ *
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include <linux/linkage.h>
+
+#define LZCNT_O0_G2 \
+ .word 0x85b002e8
+
+ .text
+ .register %g2, #scratch
+ .register %g3, #scratch
+
+ENTRY(NG4fls)
+ LZCNT_O0_G2 !lzcnt %o0, %g2
+ mov 64, %g3
+ retl
+ sub %g3, %g2, %o0
+ENDPROC(NG4fls)
--
1.7.1