qemu/bitops.h: Add extract8 and extract16

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200212130311.127515-3-ysato@users.sourceforge.jp>
Message-Id: <20200225124710.14152-14-alex.bennee@linaro.org>

diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
index 02c1ce6a5d447d8efb31956a08069d66f2329664..f55ce8b320b240aa29e727ecc674e1033f71e589 100644 (file)
--- a/include/qemu/bitops.h
+++ b/include/qemu/bitops.h
@@ -301,6 +301,44 @@ static inline uint32_t extract32(uint32_t value, int start, int length)
     return (value >> start) & (~0U >> (32 - length));
 }
 
+/**
+ * extract8:
+ * @value: the value to extract the bit field from
+ * @start: the lowest bit in the bit field (numbered from 0)
+ * @length: the length of the bit field
+ *
+ * Extract from the 8 bit input @value the bit field specified by the
+ * @start and @length parameters, and return it. The bit field must
+ * lie entirely within the 8 bit word. It is valid to request that
+ * all 8 bits are returned (ie @length 8 and @start 0).
+ *
+ * Returns: the value of the bit field extracted from the input value.
+ */
+static inline uint8_t extract8(uint8_t value, int start, int length)
+{
+    assert(start >= 0 && length > 0 && length <= 8 - start);
+    return extract32(value, start, length);
+}
+
+/**
+ * extract16:
+ * @value: the value to extract the bit field from
+ * @start: the lowest bit in the bit field (numbered from 0)
+ * @length: the length of the bit field
+ *
+ * Extract from the 16 bit input @value the bit field specified by the
+ * @start and @length parameters, and return it. The bit field must
+ * lie entirely within the 16 bit word. It is valid to request that
+ * all 16 bits are returned (ie @length 16 and @start 0).
+ *
+ * Returns: the value of the bit field extracted from the input value.
+ */
+static inline uint16_t extract16(uint16_t value, int start, int length)
+{
+    assert(start >= 0 && length > 0 && length <= 16 - start);
+    return extract32(value, start, length);
+}
+
 /**
  * extract64:
  * @value: the value to extract the bit field from