diff options
Diffstat (limited to 'infrastructure/m4/ax_check_nonaligned_access.m4')
-rw-r--r-- | infrastructure/m4/ax_check_nonaligned_access.m4 | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/infrastructure/m4/ax_check_nonaligned_access.m4 b/infrastructure/m4/ax_check_nonaligned_access.m4 new file mode 100644 index 00000000..8a6cd0c6 --- /dev/null +++ b/infrastructure/m4/ax_check_nonaligned_access.m4 @@ -0,0 +1,57 @@ +dnl @synopsis AX_CHECK_NONALIGNED_ACCESS +dnl +dnl This macro will see if non-aligned memory accesses will fail. The following +dnl defines will be made as appropriate: +dnl HAVE_ALIGNED_ONLY_INT16 +dnl HAVE_ALIGNED_ONLY_INT32 +dnl HAVE_ALIGNED_ONLY_INT64 +dnl +dnl @category C +dnl @author Martin Ebourne +dnl @version 2005/07/12 +dnl @license AllPermissive + +AC_DEFUN([AX_CHECK_NONALIGNED_ACCESS], [ + AC_CACHE_CHECK([if non-aligned 16 bit word accesses fail], [have_aligned_only_int16], + [AC_RUN_IFELSE([AC_LANG_PROGRAM([[$ac_includes_default]], [[ + #ifndef HAVE_UINT16_T + #define uint16_t u_int16_t; + #endif + uint16_t scratch[2]; + memset(scratch, 0, sizeof(scratch)); + return *(uint16_t*)((char*)scratch+1); + ]])], + [have_aligned_only_int16=no], [have_aligned_only_int16=yes] + )]) + if test "x$have_aligned_only_int16" = "xyes"; then + AC_DEFINE([HAVE_ALIGNED_ONLY_INT16], 1, [Define to 1 if non-aligned int16 access will fail]) + fi + AC_CACHE_CHECK([if non-aligned 32 bit word accesses fail], [have_aligned_only_int32], + [AC_RUN_IFELSE([AC_LANG_PROGRAM([[$ac_includes_default]], [[ + #ifndef HAVE_UINT32_T + #define uint32_t u_int32_t; + #endif + uint32_t scratch[2]; + memset(scratch, 0, sizeof(scratch)); + return *(uint32_t*)((char*)scratch+1); + ]])], + [have_aligned_only_int32=no], [have_aligned_only_int32=yes] + )]) + if test "x$have_aligned_only_int32" = "xyes"; then + AC_DEFINE([HAVE_ALIGNED_ONLY_INT32], 1, [Define to 1 if non-aligned int32 access will fail]) + fi + AC_CACHE_CHECK([if non-aligned 64 bit word accesses fail], [have_aligned_only_int64], + [AC_RUN_IFELSE([AC_LANG_PROGRAM([[$ac_includes_default]], [[ + #ifndef HAVE_UINT64_T + #define uint64_t u_int64_t; + #endif + uint64_t scratch[2]; + memset(scratch, 0, sizeof(scratch)); + return *(uint64_t*)((char*)scratch+1); + ]])], + [have_aligned_only_int64=no], [have_aligned_only_int64=yes] + )]) + if test "x$have_aligned_only_int64" = "xyes"; then + AC_DEFINE([HAVE_ALIGNED_ONLY_INT64], 1, [Define to 1 if non-aligned int64 access will fail]) + fi + ])dnl |