HairBSDF, sample_f, cosTheta

Specification

?
\[\left(10^{-5} \leq u \land u \leq 1\right) \land \left(0 \leq v \land v \leq 109.746574\right)\]
\[\begin{array}{l} \\ 1 + v \cdot \log \left(u + \left(1 - u\right) \cdot e^{\frac{-2}{v}}\right) \end{array} \]
(FPCore (u v)
 :precision binary32
 (+ 1.0 (* v (log (+ u (* (- 1.0 u) (exp (/ -2.0 v))))))))
float code(float u, float v) {
	return 1.0f + (v * logf((u + ((1.0f - u) * expf((-2.0f / v))))));
}
real(4) function code(u, v)
    real(4), intent (in) :: u
    real(4), intent (in) :: v
    code = 1.0e0 + (v * log((u + ((1.0e0 - u) * exp(((-2.0e0) / v))))))
end function
function code(u, v)
	return Float32(Float32(1.0) + Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * exp(Float32(Float32(-2.0) / v)))))))
end
function tmp = code(u, v)
	tmp = single(1.0) + (v * log((u + ((single(1.0) - u) * exp((single(-2.0) / v))))));
end
\begin{array}{l}

\\
1 + v \cdot \log \left(u + \left(1 - u\right) \cdot e^{\frac{-2}{v}}\right)
\end{array}

Reproduce

?
herbie shell --seed 2024238 
(FPCore (u v)
  :name "HairBSDF, sample_f, cosTheta"
  :precision binary32
  :pre (and (and (<= 1e-5 u) (<= u 1.0)) (and (<= 0.0 v) (<= v 109.746574)))
  (+ 1.0 (* v (log (+ u (* (- 1.0 u) (exp (/ -2.0 v))))))))

Please file a bug report with this information.

Backtrace

error: contract violation expected: string? given: '/.f32LC
f345.../match/compiler.rkt55940
loop.../private/map.rkt4019
loop.../private/map.rkt4019
loop.../private/map.rkt4019
compile-expr/home/nightlies/herbie/bhargav-log-space/src/core/explain.rkt700
explain/home/nightlies/herbie/bhargav-log-space/src/core/explain.rkt6140
explain!/home/nightlies/herbie/bhargav-log-space/src/core/mainloop.rkt3210
run-improve!/home/nightlies/herbie/bhargav-log-space/src/core/mainloop.rkt430
get-alternatives/report/home/nightlies/herbie/bhargav-log-space/src/api/sandbox.rkt1840
(unnamed)/home/nightlies/herbie/bhargav-log-space/src/api/sandbox.rkt2806
(unnamed)/usr/local/racket/share/pkgs/profile-lib/main.rkt4010
profile-thunk/usr/local/racket/share/pkgs/profile-lib/main.rkt90
(unnamed)/usr/local/racket/collects/racket/engine.rkt4224