Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / ipxe / src / arch / x86_64 / include / bits / strings.h

diff --git a/qemu/roms/ipxe/src/arch/x86_64/include/bits/strings.h b/qemu/roms/ipxe/src/arch/x86_64/include/bits/strings.h
new file mode 100644 (file)
index 0000000..6ee99a5
--- /dev/null
+++ b/qemu/roms/ipxe/src/arch/x86_64/include/bits/strings.h
@@ -0,0 +1,42 @@
+#ifndef _BITS_STRINGS_H
+#define _BITS_STRINGS_H
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/**
+ * Find last (i.e. most significant) set bit
+ *
+ * @v value            Value
+ * @ret msb            Most significant bit set in value (LSB=1), or zero
+ */
+static inline __attribute__ (( always_inline )) int __flsll ( long long value ){
+       long long msb_minus_one;
+
+       /* If the input value is zero, the BSR instruction returns
+        * ZF=1 and leaves an undefined value in the output register.
+        * Perform this check in C rather than asm so that it can be
+        * omitted in cases where the compiler is able to prove that
+        * the input is non-zero.
+        */
+       if ( value ) {
+               __asm__ ( "bsrq %1, %0"
+                         : "=r" ( msb_minus_one )
+                         : "rm" ( value ) );
+               return ( msb_minus_one + 1 );
+       } else {
+               return 0;
+       }
+}
+
+/**
+ * Find last (i.e. most significant) set bit
+ *
+ * @v value            Value
+ * @ret msb            Most significant bit set in value (LSB=1), or zero
+ */
+static inline __attribute__ (( always_inline )) int __flsl ( long value ) {
+
+       return __flsll ( value );
+}
+
+#endif /* _BITS_STRINGS_H */