The following Intel® Fortran Compiler options enable you to control the compiler optimizations for floating-point computations on ItaniumŪ-based systems.
-IPF_fma[-] enables or disables the contraction of floating-point multiply and add/subtract operations into a single operations. Unless -mp is specified, the compiler tries to contract these operations whenever possible. The -mp option disables the contractions.
-IPF_fma and -IPF_fma- can be used to override the default compiler behavior. For example, a combination of -mp and -IPF_fma enables the compiler to contract operations:
ifort -mp -IPF_fma myprog.f
-IPF_fp_speculationmode sets the compiler to speculate on floating-point operations in one of the following modes:
fast: sets the compiler to speculate on floating-point operations; this is the default.
safe: enables the compiler to speculate on floating-point operations only when it is safe;
strict: enables the compiler's speculation on floating-point operations preserving floating-point status in all situations. In the current version, this mode disables the speculation of floating-point operations (same as off).
off: disables the speculation on floating-point operations.
-IPF_flt_eval_method{0|2} option directs the compiler to evaluate the expressions involving floating-point operands in the following way:
-IPF_flt_eval_method0 directs the compiler to evaluate the expressions involving floating-point operands in the precision indicated by the variable types declared in the program.
-IPF_flt_eval_method2 is not supported in the current version.
-IPF_fltacc disables the optimizations that
affect floating-point accuracy. The default
is
-IPF_fltacc- to enable such optimizations.
The ItaniumŪ compiler may reassociate floating-point expressions to improve application performance. Use -IPF_fltacc or -mp to disable or restrict these floating-point optimizations.