[libre-riscv-dev] [isa-dev] Re: FP transcendentals (trigonometry, root/exp/log) proposal
allen.baum at esperantotech.com
Wed Sep 11 20:42:14 BST 2019
Argument reduction is a huge pain; maybe even slower than the evaluation
once it's finished?
HP calculators guaranteed accuracy to 1 LSdigit in the *input* argument
(which is much, much larger than 2pi), not in the output
On Wed, Sep 11, 2019 at 12:23 PM Jacob Lifshay <programmerjake at gmail.com>
> On Wed, Sep 11, 2019, 04:43 lkcl <luke.leighton at gmail.com> wrote:
>> someone kindly (privately) pointed out the above - table 22, p44 - and
>> apart from updating to include F16 and in some cases F64, the opcodes
>> provided *have not changed* in 11 years since the R500.
> 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.
> You received this message because you are subscribed to the Google Groups
> "RISC-V ISA Dev" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to isa-dev+unsubscribe at groups.riscv.org.
> To view this discussion on the web visit
More information about the libre-riscv-dev