[PATCH 1/4] Internal: Add word.h - word-at-a-time fns / macros

[Nathan McSween <nwmcsween@gmail.com>]

---
 src/internal/word.h | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 src/internal/word.h

diff --git a/src/internal/word.h b/src/internal/word.h
new file mode 100644
index 0000000..395f802
--- /dev/null
+++ b/src/internal/word.h
@@ -0,0 +1,39 @@
+/**
+ * _INTERNAL_WORD_H - various word size functions / macros
+ */
+#ifndef _MYOSIN_WORD_H
+#define _MYOSIN_WORD_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/**
+ * WORD_LSB_ONE - Set low bit of each byte on arch word size to one.
+ */
+#define WORD_LSB_ONE ((size_t)-1 / (unsigned char)-1)
+
+/**
+ * WORD_MSB_ONE - Set high bit of each byte on arch word size to one.
+ */
+#define WORD_MSB_ONE (WORD_LSB_ONE * ((unsigned char)-1 / 2 + 1))
+
+/**
+ * word_has_zero - Word has a zero character
+ * @w: Word
+ */
+static inline char word_has_zero(size_t w)
+{
+	return !!((w - WORD_LSB_ONE) & (~w & WORD_MSB_ONE));
+}
+
+/**
+ * word_has_char - Word has a character
+ * @w: Word
+ */
+static inline char word_has_char(size_t w, char c)
+{
+	return !!((w - WORD_LSB_ONE)
+		  & ((~w & WORD_MSB_ONE)^(WORD_LSB_ONE * c)));
+}
+
+#endif /* !_INTERNAL_WORD_H */
-- 
1.7.11.4