Exception for bug366, discussion (missed optimization)

Math

\[\sqrt{a \cdot a - b \cdot b} \]

FPCore

(FPCore (a b) :precision binary64 (sqrt (- (* a a) (* b b))))

C

double code(double a, double b) {
	return sqrt(((a * a) - (b * b)));
}

Fortran

real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = sqrt(((a * a) - (b * b)))
end function

Java

public static double code(double a, double b) {
	return Math.sqrt(((a * a) - (b * b)));
}

Python

def code(a, b):
	return math.sqrt(((a * a) - (b * b)))

Julia

function code(a, b)
	return sqrt(Float64(Float64(a * a) - Float64(b * b)))
end

MATLAB

function tmp = code(a, b)
	tmp = sqrt(((a * a) - (b * b)));
end

Wolfram

code[a_, b_] := N[Sqrt[N[(N[(a * a), $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2022349 
(FPCore (a b)
  :name "bug366, discussion (missed optimization)"
  :precision binary64

  :herbie-target
  (* (sqrt (+ (fabs a) (fabs b))) (sqrt (- (fabs a) (fabs b))))

  (sqrt (- (* a a) (* b b))))

Backtrace

error writing to stream port system error: Broken pipe; errno=32		L	C
writeln	/usr/share/racket/collects/racket/private/misc.rkt	156	4
run-egglog	/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/egglog/run-egglog.rkt	1301	0
run-simplify-input	/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt	74	0
simplify-batch	/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/core/simplify.rkt	51	0
(unnamed)	/usr/share/racket/collects/racket/contract/private/arrow-higher-order.rkt	379	33
get-swaps	/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/symmetry.rkt	6	0
connected-components	/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/symmetry.rkt	20	0
run-improve!	/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/mainloop.rkt	320	0
(unnamed)	/home/nightlies/nightlies/herbie/oflatt-egglog-ctx/src/sandbox.rkt	55	6
(unnamed)	/usr/share/racket/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/share/racket/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/usr/share/racket/collects/racket/engine.rkt	42	24