Surprisingly [sincosf fusion] only happened with -Ofast and not with -O3.
As noted, -Ofast turns on -ffast-math which turns on -funsafe-math-optimizations which "enables optimizations that allow arbitrary reassociations and transformations with no accuracy guarantees."[0] In this case, sincosf by itself is probably more accurate.
Have you seen Curve9767 [0] ? Short-Weierstrass, prime-order, but the implementation does not use the complete formulas. Competitive performance, on the ARM Cortex-M0+ at least.
Not much nuance to this: They were guilty and they are guilty.
From the Armstrong Report:
We believe the inconsistencies contained in the various statements were not such as to destroy their reliability. On the other hand, there was a general consistency that ran through the defendants' descriptions of the attack on the female jogger: she was knocked down on the road, dragged into the woods, hit and molested by several defendants, sexually abused by some while others held her arms and legs, and left semiconscious in a state of undress.
As noted, -Ofast turns on -ffast-math which turns on -funsafe-math-optimizations which "enables optimizations that allow arbitrary reassociations and transformations with no accuracy guarantees."[0] In this case, sincosf by itself is probably more accurate.
[0] https://gcc.gnu.org/wiki/FloatingPointMath