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authorDavid S. Miller <davem@davemloft.net>2011-08-02 20:23:34 -0700
committerDavid S. Miller <davem@davemloft.net>2011-08-02 21:28:53 -0700
commit56d205cc5c0a3032a605121d4253e111193bf923 (patch)
tree1e37a74fd6df18ec35a9d6a1f70eca2e649e4afb /arch/sparc/lib
parentea5e7447ea9d555558e0f13798f5143dd51a915a (diff)
sparc: Use popc when possible for ffs/__ffs/ffz.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/lib')
-rw-r--r--arch/sparc/lib/Makefile2
-rw-r--r--arch/sparc/lib/ffs.S84
2 files changed, 85 insertions, 1 deletions
diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 11c850a9b66f..a3fc4375a150 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -37,7 +37,7 @@ lib-$(CONFIG_SPARC64) += GENmemcpy.o GENcopy_from_user.o GENcopy_to_user.o
lib-$(CONFIG_SPARC64) += GENpatch.o GENpage.o GENbzero.o
lib-$(CONFIG_SPARC64) += copy_in_user.o user_fixup.o memmove.o
-lib-$(CONFIG_SPARC64) += mcount.o ipcsum.o xor.o hweight.o
+lib-$(CONFIG_SPARC64) += mcount.o ipcsum.o xor.o hweight.o ffs.o
obj-y += iomap.o
obj-$(CONFIG_SPARC32) += atomic32.o
diff --git a/arch/sparc/lib/ffs.S b/arch/sparc/lib/ffs.S
new file mode 100644
index 000000000000..b39389f69899
--- /dev/null
+++ b/arch/sparc/lib/ffs.S
@@ -0,0 +1,84 @@
+#include <linux/linkage.h>
+
+ .register %g2,#scratch
+
+ .text
+ .align 32
+
+ENTRY(ffs)
+ brnz,pt %o0, 1f
+ mov 1, %o1
+ retl
+ clr %o0
+ nop
+ nop
+ENTRY(__ffs)
+ sllx %o0, 32, %g1 /* 1 */
+ srlx %o0, 32, %g2
+
+ clr %o1 /* 2 */
+ movrz %g1, %g2, %o0
+
+ movrz %g1, 32, %o1 /* 3 */
+1: clr %o2
+
+ sllx %o0, (64 - 16), %g1 /* 4 */
+ srlx %o0, 16, %g2
+
+ movrz %g1, %g2, %o0 /* 5 */
+ clr %o3
+
+ movrz %g1, 16, %o2 /* 6 */
+ clr %o4
+
+ and %o0, 0xff, %g1 /* 7 */
+ srlx %o0, 8, %g2
+
+ movrz %g1, %g2, %o0 /* 8 */
+ clr %o5
+
+ movrz %g1, 8, %o3 /* 9 */
+ add %o2, %o1, %o2
+
+ and %o0, 0xf, %g1 /* 10 */
+ srlx %o0, 4, %g2
+
+ movrz %g1, %g2, %o0 /* 11 */
+ add %o2, %o3, %o2
+
+ movrz %g1, 4, %o4 /* 12 */
+
+ and %o0, 0x3, %g1 /* 13 */
+ srlx %o0, 2, %g2
+
+ movrz %g1, %g2, %o0 /* 14 */
+ add %o2, %o4, %o2
+
+ movrz %g1, 2, %o5 /* 15 */
+
+ and %o0, 0x1, %g1 /* 16 */
+
+ add %o2, %o5, %o2 /* 17 */
+ xor %g1, 0x1, %g1
+
+ retl /* 18 */
+ add %o2, %g1, %o0
+ENDPROC(ffs)
+ENDPROC(__ffs)
+
+ .section .popc_6insn_patch, "ax"
+ .word ffs
+ brz,pn %o0, 98f
+ neg %o0, %g1
+ xnor %o0, %g1, %o1
+ popc %o1, %o0
+98: retl
+ nop
+ .word __ffs
+ neg %o0, %g1
+ xnor %o0, %g1, %o1
+ popc %o1, %o0
+ retl
+ sub %o0, 1, %o0
+ nop
+ .previous