The folks at Intel who program FPGA would like to be able to control the FastMathFlag that governs reassociating operations at the source level using pragma's e.g.
#pragma clang fp reassoc(on) // allow reassociation of operations
This patch builds on reviews.llvm.org/D72841
I just realized that I need to update the user manual to describe the syntax, so I owe you an update. Hoping you will take a look