[libre-riscv-dev] [isa-dev] Re: FP transcendentals (trigonometry, root/exp/log) proposal

[lkcl]

On Thursday, September 12, 2019 at 3:23:28 AM UTC+8, Jacob Lifshay wrote:

> https://gpuopen.com/wp-content/uploads/2019/08/RDNA_Shader_ISA_5August2019.pdf

> looking through it again, the sin/cos instructions for Radeon are actually sin(x * 2 * pi) and cos(x * 2 * pi), reinforcing my idea to just implement sinpi/cospi for GPU applications, though there is a V_TRIG_PREOP_F64 instruction to accelerate argument reduction for f64 sin/cos.

Made a quick note of that, by changing "recommended" subsets and noting this in the insights.

Bear in mind Midgard has cos1pi and sin1pi, not cos2pi sin2pi.

L.