On Fri, Jul 05, 2024 at 07:13:05PM -0700, Michael Cheponis wrote: > sizeof(long double) reports 16 in both amd64 and arm64. I think that amd64 > uses 80-bit long double floats, and arm64 uses 128-bit long double floats. > See enclosed code.
The storage size of a long double is one thing, but the exact format used in calculations may vary. On amd64: > cc -dM -E - < /dev/null | fgrep LDBL_MANT #define __LDBL_MANT_DIG__ 64 On aarch64: > cc -dM -E - < /dev/null | fgrep LDBL_MAN #define __LDBL_MANT_DIG__ 113 (use just LDBL in the fgrep to see more exact limits of the format in use) Martin
