search for: genreciprocaldiv

...ce the new possible implementation for such optimizations as reciprocal estimation instead of fdiv. In short it's a replacement of fdiv instruction (which is very expensive in most of CPUs) with alternative sequence of instructions which is usually cheaper but has appropriate precision (see genReciprocalDiv in lib/Target/X86/X86InstrInfo.cpp for details). There are other similar optimizations like usage of rsqrt, etc. but at the moment we're dealing with recip estimation only - see https://reviews.llvm.org/D26855 for details. The current version of optimization is done at DAG Combiner level w...

...or such >> optimizations as reciprocal estimation instead of fdiv. In short it's >> a replacement of fdiv instruction (which is very expensive in most of >> CPUs) with alternative sequence of instructions which is usually >> cheaper but has appropriate precision (see genReciprocalDiv in >> lib/Target/X86/X86InstrInfo.cpp for details). There are other similar >> optimizations like usage of rsqrt, etc. but at the moment we're >> dealing with recip estimation only - see >> https://reviews.llvm.org/D26855 for details. >> >> The current ve...