4.6.14.1 Short Double Option

The -fshort-double option controls the size of the double type.

When building to the C99 standard, all floating-point types must be the IEEE754 32-bit format. If you are building for C90 standard, you may use this option to explicitly request the 24-bit form of this format for double objects. When using the -fno-short-double form of the option, the double type can be changed to the full 32-bit IEEE754 format. The selection of this option must be consistent across all modules of the program.