[cfe-dev] [llvm-dev] RFC: change -fp-contract=off to actually disable FMAs

[Stephen Canon via cfe-dev]

> On Jul 12, 2019, at 12:55 PM, Matt Arsenault <arsenm2 at gmail.com> wrote:
> 
> Yes. FMAD is supposed to give the same result as the separate FMUL and FADD with the intermediate rounding step. It exists because most of the combines for FMA still apply, and AMDGPU has an instruction that does this (as long as denormal flushing is OK). I don’t know of any other users.

armv7 also has a non-fused floating-point multiply-add (VMLA as opposed to the fused operation VFMA).

– Steve
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