What is floating point speculation and how does it differ from the compiler's floating point model

Question

The Intel C++ compiler provides two options for controlling floating point:

-fp-speculation (fast/safe/strict/off) -fp-model (precise/fast/strict and source/double/exten

Answer 1

Out of order execution and speculative execution can result in extraneous exceptions or raise exceptions at the wrong time.

If that matters to you, you can use the fp-speculation option to control speculation of floating-point instructions.

For (a little bit) more information: http://software.intel.com/sites/products/documentation/hpc/compilerpro/en-us/fortran/lin/compiler_f/copts/common_options/option_fp_speculation.htm