PSA: floating-point arithmetic

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No, on x86 we only use SSE instructions (80-bit floats are only available with x87 instructions).

Note there are still some ways you might get non-deterministic results:

  • BLAS or LAPACK operations
  • @fastmath: which lets the compiler do a lot of manipulations
  • @simd: which allows re-association of arithmetic operations to exploit SIMD operations.
  • muladd: allows use of either a*b+c or fma(a,b,c) depending on which is faster. This is a tricky one, as we’re increasingly making use of it (such as the recent libm work).
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