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

Commit Message

H. Peter Anvin June 10, 2014, 11:13 p.m. UTC

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

Signed-off-by: H. Peter Anvin <[e-mail]>
---
 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

Patch

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 */