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Unaligned access support for pgm_read_word/dword (#5692)

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* Unaligned access support for pgm_read_word/dword

* Fix pgm_read_ptr_aligned() per #5735

* Allow users to use aligned-only via a #define

Adding -DPGM_READ_UNALIGNED=0 or #define PGM_READ_UNALIGNED 0 will
change the default at compile-time to only aligned (faster, but less
compatible) macro implementations.

Default is still to allow unaligned accesses.
This commit is contained in:
Earle F. Philhower, III 2019-04-11 22:24:49 +03:00 committed by GitHub
parent 882d5ba422
commit 885276e75c
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 51 additions and 10 deletions
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4
tests/host/sys/pgmspace.h
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@ -31,13 +31,13 @@
#define pgm_read_word(addr) (*reinterpret_cast<const uint16_t*>(addr)) #define pgm_read_word(addr) (*reinterpret_cast<const uint16_t*>(addr))
#define pgm_read_dword(addr) (*reinterpret_cast<const uint32_t*>(addr)) #define pgm_read_dword(addr) (*reinterpret_cast<const uint32_t*>(addr))
#define pgm_read_float(addr) (*reinterpret_cast<const float>(addr)) #define pgm_read_float(addr) (*reinterpret_cast<const float>(addr))
#define pgm_read_ptr(addr) (*reinterpret_cast<const void const *>(addr)) #define pgm_read_ptr(addr) (*reinterpret_cast<const void* const *>(addr))
#else #else
#define pgm_read_byte(addr) (*(const uint8_t*)(addr)) #define pgm_read_byte(addr) (*(const uint8_t*)(addr))
#define pgm_read_word(addr) (*(const uint16_t*)(addr)) #define pgm_read_word(addr) (*(const uint16_t*)(addr))
#define pgm_read_dword(addr) (*(const uint32_t*)(addr)) #define pgm_read_dword(addr) (*(const uint32_t*)(addr))
#define pgm_read_float(addr) (*(const float)(addr)) #define pgm_read_float(addr) (*(const float)(addr))
#define pgm_read_ptr(addr) (*(const void const *)(addr)) #define pgm_read_ptr(addr) (*(const void* const *)(addr))
#endif #endif
#define pgm_read_byte_near(addr) pgm_read_byte(addr) #define pgm_read_byte_near(addr) pgm_read_byte(addr)

57
tools/sdk/libc/xtensa-lx106-elf/include/sys/pgmspace.h
View File

@ -68,16 +68,57 @@ static inline uint16_t pgm_read_word_inlined(const void* addr) {
return (uint16_t) res; /* This masks the lower half-word from the returned word */ return (uint16_t) res; /* This masks the lower half-word from the returned word */
} }
#define pgm_read_byte(addr) pgm_read_byte_inlined(addr)
#define pgm_read_word(addr) pgm_read_word_inlined(addr)
#define pgm_read_byte(addr) pgm_read_byte_inlined(addr)
#define pgm_read_word_aligned(addr) pgm_read_word_inlined(addr)
#ifdef __cplusplus #ifdef __cplusplus
#define pgm_read_dword(addr) (*reinterpret_cast<const uint32_t*>(addr)) #define pgm_read_dword_aligned(addr) (*reinterpret_cast<const uint32_t*>(addr))
#define pgm_read_float(addr) (*reinterpret_cast<const float*>(addr)) #define pgm_read_float_aligned(addr) (*reinterpret_cast<const float*>(addr))
#define pgm_read_ptr(addr) (*reinterpret_cast<const void* const *>(addr)) #define pgm_read_ptr_aligned(addr) (*reinterpret_cast<const void* const*>(addr))
#else #else
#define pgm_read_dword(addr) (*(const uint32_t*)(addr)) #define pgm_read_dword_aligned(addr) (*(const uint32_t*)(addr))
#define pgm_read_float(addr) (*(const float*)(addr)) #define pgm_read_float_aligned(addr) (*(const float*)(addr))
#define pgm_read_ptr(addr) (*(const void* const*)(addr)) #define pgm_read_ptr_aligned(addr) (*(const void* const*)(addr))
#endif
__attribute__((optimize("-O3"), always_inline)) static inline uint32_t pgm_read_dword_unaligned(const void *addr) {
if (!(((int)addr)&3)) return *(const uint32_t *)addr;
int off = (((int)addr) & 3) << 3;
const uint32_t *p = (const uint32_t *)((int)addr & (~3));
uint32_t a = *p++;
uint32_t b = *p;
return (a>>off) | (b <<(32-off));
}
__attribute__((optimize("-O3"), always_inline)) static inline float pgm_read_float_unaligned(const void *addr) {
return (float)pgm_read_dword_unaligned(addr);
}
__attribute__((optimize("-O3"), always_inline)) static inline void *pgm_read_ptr_unaligned(const void *addr) {
return (void *)pgm_read_dword_unaligned(addr);
}
__attribute__((optimize("-O3"), always_inline)) static inline uint16_t pgm_read_word_unaligned(const void *addr) {
return pgm_read_dword_unaligned(addr) & 0xffff;
}
// Allow selection of _aligned or _unaligned, but default to _unaligned for Arduino compatibility
// Add -DPGM_READ_UNALIGNED=0 or "#define PGM_READ_UNALIGNED 0" to code to use aligned-only (faster) macros by default
#ifndef PGM_READ_UNALIGNED
#define PGM_READ_UNALIGNED 1
#endif
#if PGM_READ_UNALIGNED
#define pgm_read_word(a) pgm_read_word_unaligned(a)
#define pgm_read_dword(a) pgm_read_dword_unaligned(a)
#define pgm_read_float(a) pgm_read_float_unaligned(a)
#define pgm_read_ptr(a) pgm_read_ptr_unaligned(a)
#else
#define pgm_read_word(a) pgm_read_word_aligned(a)
#define pgm_read_dword(a) pgm_read_dword_aligned(a)
#define pgm_read_float(a) pgm_read_float_aligned(a)
#define pgm_read_ptr(a) pgm_read_ptr_aligned(a)
#endif #endif
#define pgm_read_byte_near(addr) pgm_read_byte(addr) #define pgm_read_byte_near(addr) pgm_read_byte(addr)