================ @@ -1847,19 +1847,51 @@ floating point semantic models: precise (the default), strict, and fast. * ``16`` - Forces ``_Float16`` operations to be emitted without using excess precision arithmetic. +.. option:: -fcomplex-arithmetic=<value>: + + This option specifies the implementation for complex multiplication and division. + + Valid values are: ``basic``, ``improved``, ``full`` and ``promoted``. + + * ``basic`` Implementation of complex division and multiplication using + algebraic formulas at source precision. No special handling to avoid + overflow. NaN and infinite and values are not handled. + * ``improved`` Implementation of complex division using the Smith algorithm + at source precision. Smith's algorithm for complex division. + See SMITH, R. L. Algorithm 116: Complex division. Commun. ACM 5, 8 (1962). + This value offers improved handling for overflow in intermediate + calculations, but overflow may occur. NaN and infinite and values are not + handled in some cases. + * ``full`` Implementation of complex division and multiplication using a + call to runtime library functions (generally the case, but the BE might + sometimes replace the library call if it knows enough about the potential + range of the inputs). Overflow and non-finite values are handled by the + library implementation. For the case of multiplication overflow will occur in + accordance with normal floating-point rules. + * ``promoted`` Implementation of complex division using algebraic formulas at + higher precision. Overflow is handled. Non-finite values are handled in some + cases. If the target does not have native support for a higher precision + data type, an implementation for the complex operation will be used to provide + improved guards against intermediate overflow, but overflow and underflow may + still occur in some cases. NaN and infinite and values are not handled. + This is the default value. + .. option:: -fcx-limited-range: - This option enables the naive mathematical formulas for complex division and - multiplication with no NaN checking of results. The default is - ``-fno-cx-limited-range``, but this option is enabled by the ``-ffast-math`` + This option is aliased to ``-fcomplex-arithmetic=basic``. It enables the + naive mathematical formulas for complex division and multiplication with no + NaN checking of results. The default is ``-fno-cx-limited-range`` aliased to + ``-fcomplex-arithmetic=full``. This option is enabled by the ``-ffast-math`` ---------------- AaronBallman wrote:
The documentation for `-ffast-math` should mention this option as well. https://github.com/llvm/llvm-project/pull/81514 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits