[PATCH RFC 04/10] tools: Add packed struct method for unaligned references

From: H. Peter Anvin
Date: Tue Jun 10 2014 - 19:15:16 EST


gcc can generate code for unaligned references using a packed struct
on nearly all architectures.

Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
---
tools/include/tools/unaligned/be_struct.h | 60 +++++++++++++++++++++++++++++++
tools/include/tools/unaligned/le_struct.h | 60 +++++++++++++++++++++++++++++++
2 files changed, 120 insertions(+)
create mode 100644 tools/include/tools/unaligned/be_struct.h
create mode 100644 tools/include/tools/unaligned/le_struct.h

diff --git a/tools/include/tools/unaligned/be_struct.h b/tools/include/tools/unaligned/be_struct.h
new file mode 100644
index 000000000000..27b73bdf5a86
--- /dev/null
+++ b/tools/include/tools/unaligned/be_struct.h
@@ -0,0 +1,60 @@
+#ifndef _TOOLS_BE_STRUCT_H
+#define _TOOLS_BE_STRUCT_H
+
+#include <stdint.h>
+
+struct _packed_u16_struct {
+ uint16_t v;
+} __attribute__((packed));
+
+struct _packed_u32_struct {
+ uint32_t v;
+} __attribute__((packed));
+
+struct _packed_u64_struct {
+ uint64_t v;
+} __attribute__((packed));
+
+static inline uint16_t get_unaligned_be16(const void *_p)
+{
+ const struct _packed_u16_struct *p = _p;
+
+ return p->v;
+}
+
+static inline uint32_t get_unaligned_be32(const void *_p)
+{
+ const struct _packed_u32_struct *p = _p;
+
+ return p->v;
+}
+
+static inline uint64_t get_unaligned_be64(const void *_p)
+{
+ const struct _packed_u64_struct *p = _p;
+
+ return p->v;
+}
+
+static inline void put_unaligned_be16(uint16_t val, void *_p)
+{
+ struct _packed_u16_struct *p = _p;
+
+ p->v = val;
+}
+
+static inline void put_unaligned_be32(uint32_t val, void *_p)
+{
+ struct _packed_u32_struct *p = _p;
+
+ p->v = val;
+}
+
+static inline void put_unaligned_be64(uint64_t val, void *_p)
+{
+ struct _packed_u64_struct *p = _p;
+
+ p->v = val;
+}
+
+#endif /* _TOOLS_BE_STRUCT_H */
diff --git a/tools/include/tools/unaligned/le_struct.h b/tools/include/tools/unaligned/le_struct.h
new file mode 100644
index 000000000000..281b03b8f316
--- /dev/null
+++ b/tools/include/tools/unaligned/le_struct.h
@@ -0,0 +1,60 @@
+#ifndef _TOOLS_LE_STRUCT_H
+#define _TOOLS_LE_STRUCT_H
+
+#include <stdint.h>
+
+struct _packed_u16_struct {
+ uint16_t v;
+} __attribute__((packed));
+
+struct _packed_u32_struct {
+ uint32_t v;
+} __attribute__((packed));
+
+struct _packed_u64_struct {
+ uint64_t v;
+} __attribute__((packed));
+
+static inline uint16_t get_unaligned_le16(const void *_p)
+{
+ const struct _packed_u16_struct *p = _p;
+
+ return p->v;
+}
+
+static inline uint32_t get_unaligned_le32(const void *_p)
+{
+ const struct _packed_u32_struct *p = _p;
+
+ return p->v;
+}
+
+static inline uint64_t get_unaligned_le64(const void *_p)
+{
+ const struct _packed_u64_struct *p = _p;
+
+ return p->v;
+}
+
+static inline void put_unaligned_le16(uint16_t val, void *_p)
+{
+ struct _packed_u16_struct *p = _p;
+
+ p->v = val;
+}
+
+static inline void put_unaligned_le32(uint32_t val, void *_p)
+{
+ struct _packed_u32_struct *p = _p;
+
+ p->v = val;
+}
+
+static inline void put_unaligned_le64(uint64_t val, void *_p)
+{
+ struct _packed_u64_struct *p = _p;
+
+ p->v = val;
+}
+
+#endif /* _TOOLS_LE_STRUCT_H */
--
1.9.3

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