Re: [PATCH v2] bitops.h: add sign_extend8(), 16 and 64 functions
On Mon, Jan 12, 2015 at 06:22:50PM +0100, Martin Kepplinger wrote: > This adds helper functions for sign-extending signed values of any lower > (hardware-)given size to s8, s16 or s64 respectively, just like > sign_extend32() > for s32. > > Signed-off-by: Martin Kepplinger > Suggested-by: Christoph Muellner Reviewed-by: Guenter Roeck Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2] bitops.h: add sign_extend8(), 16 and 64 functions
This adds helper functions for sign-extending signed values of any lower
(hardware-)given size to s8, s16 or s64 respectively, just like sign_extend32()
for s32.
Signed-off-by: Martin Kepplinger
Suggested-by: Christoph Muellner
---
include/linux/bitops.h | 33 +
1 file changed, 33 insertions(+)
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 5d858e0..9c31680 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -161,6 +161,28 @@ static inline __u8 ror8(__u8 word, unsigned int shift)
}
/**
+ * sign_extend8 - sign extend a 8-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0<=index<8) to sign bit
+ */
+static inline __s8 sign_extend8(__u8 value, int index)
+{
+ __u8 shift = 7 - index;
+ return (__s8)(value << shift) >> shift;
+}
+
+/**
+ * sign_extend16 - sign extend a 16-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0<=index<16) to sign bit
+ */
+static inline __s16 sign_extend16(__u16 value, int index)
+{
+ __u8 shift = 15 - index;
+ return (__s16)(value << shift) >> shift;
+}
+
+/**
* sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
* @value: value to sign extend
* @index: 0 based bit index (0<=index<32) to sign bit
@@ -171,6 +193,17 @@ static inline __s32 sign_extend32(__u32 value, int index)
return (__s32)(value << shift) >> shift;
}
+/**
+ * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0<=index<64) to sign bit
+ */
+static inline __s64 sign_extend64(__u64 value, int index)
+{
+ __u8 shift = 63 - index;
+ return (__s64)(value << shift) >> shift;
+}
+
static inline unsigned fls_long(unsigned long l)
{
if (sizeof(l) == 4)
--
2.1.4
--
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Re: [PATCH v2] bitops.h: add sign_extend8(), 16 and 64 functions
On Mon, Jan 12, 2015 at 06:22:50PM +0100, Martin Kepplinger wrote: This adds helper functions for sign-extending signed values of any lower (hardware-)given size to s8, s16 or s64 respectively, just like sign_extend32() for s32. Signed-off-by: Martin Kepplinger mart...@posteo.de Suggested-by: Christoph Muellner christoph.muell...@theobroma-systems.com Reviewed-by: Guenter Roeck li...@roeck-us.net Guenter -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2] bitops.h: add sign_extend8(), 16 and 64 functions
This adds helper functions for sign-extending signed values of any lower
(hardware-)given size to s8, s16 or s64 respectively, just like sign_extend32()
for s32.
Signed-off-by: Martin Kepplinger mart...@posteo.de
Suggested-by: Christoph Muellner christoph.muell...@theobroma-systems.com
---
include/linux/bitops.h | 33 +
1 file changed, 33 insertions(+)
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 5d858e0..9c31680 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -161,6 +161,28 @@ static inline __u8 ror8(__u8 word, unsigned int shift)
}
/**
+ * sign_extend8 - sign extend a 8-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0=index8) to sign bit
+ */
+static inline __s8 sign_extend8(__u8 value, int index)
+{
+ __u8 shift = 7 - index;
+ return (__s8)(value shift) shift;
+}
+
+/**
+ * sign_extend16 - sign extend a 16-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0=index16) to sign bit
+ */
+static inline __s16 sign_extend16(__u16 value, int index)
+{
+ __u8 shift = 15 - index;
+ return (__s16)(value shift) shift;
+}
+
+/**
* sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
* @value: value to sign extend
* @index: 0 based bit index (0=index32) to sign bit
@@ -171,6 +193,17 @@ static inline __s32 sign_extend32(__u32 value, int index)
return (__s32)(value shift) shift;
}
+/**
+ * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0=index64) to sign bit
+ */
+static inline __s64 sign_extend64(__u64 value, int index)
+{
+ __u8 shift = 63 - index;
+ return (__s64)(value shift) shift;
+}
+
static inline unsigned fls_long(unsigned long l)
{
if (sizeof(l) == 4)
--
2.1.4
--
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