summaryrefslogtreecommitdiffstats
path: root/include/asm-cris/arch-v10/bitops.h
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-cris/arch-v10/bitops.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-cris/arch-v10/bitops.h')
-rw-r--r--include/asm-cris/arch-v10/bitops.h73
1 files changed, 73 insertions, 0 deletions
diff --git a/include/asm-cris/arch-v10/bitops.h b/include/asm-cris/arch-v10/bitops.h
new file mode 100644
index 00000000000..21b7ae8c9bb
--- /dev/null
+++ b/include/asm-cris/arch-v10/bitops.h
@@ -0,0 +1,73 @@
+/* asm/arch/bitops.h for Linux/CRISv10 */
+
+#ifndef _CRIS_ARCH_BITOPS_H
+#define _CRIS_ARCH_BITOPS_H
+
+/*
+ * Helper functions for the core of the ff[sz] functions, wrapping the
+ * syntactically awkward asms. The asms compute the number of leading
+ * zeroes of a bits-in-byte and byte-in-word and word-in-dword-swapped
+ * number. They differ in that the first function also inverts all bits
+ * in the input.
+ */
+extern inline unsigned long cris_swapnwbrlz(unsigned long w)
+{
+ /* Let's just say we return the result in the same register as the
+ input. Saying we clobber the input but can return the result
+ in another register:
+ ! __asm__ ("swapnwbr %2\n\tlz %2,%0"
+ ! : "=r,r" (res), "=r,X" (dummy) : "1,0" (w));
+ confuses gcc (sched.c, gcc from cris-dist-1.14). */
+
+ unsigned long res;
+ __asm__ ("swapnwbr %0 \n\t"
+ "lz %0,%0"
+ : "=r" (res) : "0" (w));
+ return res;
+}
+
+extern inline unsigned long cris_swapwbrlz(unsigned long w)
+{
+ unsigned res;
+ __asm__ ("swapwbr %0 \n\t"
+ "lz %0,%0"
+ : "=r" (res)
+ : "0" (w));
+ return res;
+}
+
+/*
+ * ffz = Find First Zero in word. Undefined if no zero exists,
+ * so code should check against ~0UL first..
+ */
+extern inline unsigned long ffz(unsigned long w)
+{
+ return cris_swapnwbrlz(w);
+}
+
+/**
+ * __ffs - find first bit in word.
+ * @word: The word to search
+ *
+ * Undefined if no bit exists, so code should check against 0 first.
+ */
+extern __inline__ unsigned long __ffs(unsigned long word)
+{
+ return cris_swapnwbrlz(~word);
+}
+
+/**
+ * ffs - find first bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+
+extern inline unsigned long kernel_ffs(unsigned long w)
+{
+ return w ? cris_swapwbrlz (w) + 1 : 0;
+}
+
+#endif