code[x_, y_, z_, t_, a_, b_, c_, i_] := N[(x * y + N[(z * t + N[(c * i + N[(a * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\left(\left(x \cdot y + z \cdot t\right) + a \cdot b\right) + c \cdot i
↓
\mathsf{fma}\left(x, y, \mathsf{fma}\left(z, t, \mathsf{fma}\left(c, i, a \cdot b\right)\right)\right)
Error
Derivation
Initial program 0.0
\[\left(\left(x \cdot y + z \cdot t\right) + a \cdot b\right) + c \cdot i
\]
Simplified0.0
\[\leadsto \color{blue}{\mathsf{fma}\left(x, y, \mathsf{fma}\left(z, t, \mathsf{fma}\left(c, i, a \cdot b\right)\right)\right)}
\]
Proof
(fma.f64 x y (fma.f64 z t (fma.f64 c i (*.f64 a b)))): 0 points increase in error, 0 points decrease in error
(fma.f64 x y (fma.f64 z t (Rewrite<= fma-def_binary64 (+.f64 (*.f64 c i) (*.f64 a b))))): 0 points increase in error, 0 points decrease in error
(fma.f64 x y (fma.f64 z t (Rewrite<= +-commutative_binary64 (+.f64 (*.f64 a b) (*.f64 c i))))): 0 points increase in error, 0 points decrease in error
(fma.f64 x y (Rewrite<= fma-def_binary64 (+.f64 (*.f64 z t) (+.f64 (*.f64 a b) (*.f64 c i))))): 1 points increase in error, 0 points decrease in error
(Rewrite<= fma-def_binary64 (+.f64 (*.f64 x y) (+.f64 (*.f64 z t) (+.f64 (*.f64 a b) (*.f64 c i))))): 2 points increase in error, 0 points decrease in error
(Rewrite<= associate-+l+_binary64 (+.f64 (+.f64 (*.f64 x y) (*.f64 z t)) (+.f64 (*.f64 a b) (*.f64 c i)))): 0 points increase in error, 0 points decrease in error
(Rewrite<= associate-+l+_binary64 (+.f64 (+.f64 (+.f64 (*.f64 x y) (*.f64 z t)) (*.f64 a b)) (*.f64 c i))): 0 points increase in error, 0 points decrease in error
Final simplification0.0
\[\leadsto \mathsf{fma}\left(x, y, \mathsf{fma}\left(z, t, \mathsf{fma}\left(c, i, a \cdot b\right)\right)\right)
\]
Alternatives
Alternative 1
Error
0.0
Cost
7232
\[\left(a \cdot b + c \cdot i\right) + \mathsf{fma}\left(t, z, x \cdot y\right)
\]
Alternative 2
Error
0.0
Cost
7232
\[\mathsf{fma}\left(x, y, z \cdot t\right) + \left(a \cdot b + c \cdot i\right)
\]
Alternative 3
Error
26.9
Cost
1768
\[\begin{array}{l}
t_1 := c \cdot i + z \cdot t\\
t_2 := a \cdot b + c \cdot i\\
t_3 := x \cdot y + z \cdot t\\
t_4 := c \cdot i + x \cdot y\\
t_5 := a \cdot b + z \cdot t\\
\mathbf{if}\;y \leq -3.6 \cdot 10^{-136}:\\
\;\;\;\;t_4\\
\mathbf{elif}\;y \leq -1.45 \cdot 10^{-244}:\\
\;\;\;\;t_1\\
\mathbf{elif}\;y \leq 2 \cdot 10^{-243}:\\
\;\;\;\;t_5\\
\mathbf{elif}\;y \leq 6.6 \cdot 10^{-178}:\\
\;\;\;\;t_2\\
\mathbf{elif}\;y \leq 2.3 \cdot 10^{-68}:\\
\;\;\;\;t_5\\
\mathbf{elif}\;y \leq 7.5 \cdot 10^{-52}:\\
\;\;\;\;t_1\\
\mathbf{elif}\;y \leq 1.06 \cdot 10^{-13}:\\
\;\;\;\;t_5\\
\mathbf{elif}\;y \leq 1.8 \cdot 10^{+106}:\\
\;\;\;\;t_4\\
\mathbf{elif}\;y \leq 3.3 \cdot 10^{+167}:\\
\;\;\;\;t_3\\
\mathbf{elif}\;y \leq 2.05 \cdot 10^{+210}:\\
\;\;\;\;t_2\\
\mathbf{else}:\\
\;\;\;\;t_3\\
\end{array}
\]
\[\begin{array}{l}
t_1 := a \cdot b + c \cdot i\\
\mathbf{if}\;c \cdot i \leq -7.5 \cdot 10^{+63}:\\
\;\;\;\;t_1\\
\mathbf{elif}\;c \cdot i \leq 4.2 \cdot 10^{+105}:\\
\;\;\;\;a \cdot b + \left(x \cdot y + z \cdot t\right)\\
\mathbf{else}:\\
\;\;\;\;t_1\\
\end{array}
\]
Alternative 10
Error
8.0
Cost
1224
\[\begin{array}{l}
t_1 := x \cdot y + z \cdot t\\
\mathbf{if}\;a \cdot b \leq -9 \cdot 10^{+123}:\\
\;\;\;\;a \cdot b + t_1\\
\mathbf{elif}\;a \cdot b \leq 6.5 \cdot 10^{+74}:\\
\;\;\;\;c \cdot i + t_1\\
\mathbf{else}:\\
\;\;\;\;a \cdot b + c \cdot i\\
\end{array}
\]
Alternative 11
Error
6.2
Cost
1224
\[\begin{array}{l}
t_1 := \left(a \cdot b + c \cdot i\right) + z \cdot t\\
\mathbf{if}\;a \cdot b \leq -6.2 \cdot 10^{+60}:\\
\;\;\;\;t_1\\
\mathbf{elif}\;a \cdot b \leq 2.8 \cdot 10^{+70}:\\
\;\;\;\;c \cdot i + \left(x \cdot y + z \cdot t\right)\\
\mathbf{else}:\\
\;\;\;\;t_1\\
\end{array}
\]
Alternative 12
Error
22.0
Cost
968
\[\begin{array}{l}
t_1 := a \cdot b + c \cdot i\\
\mathbf{if}\;c \cdot i \leq -31500000:\\
\;\;\;\;t_1\\
\mathbf{elif}\;c \cdot i \leq 1.55 \cdot 10^{+19}:\\
\;\;\;\;a \cdot b + z \cdot t\\
\mathbf{else}:\\
\;\;\;\;t_1\\
\end{array}
\]
Alternative 13
Error
0.0
Cost
960
\[c \cdot i + \left(a \cdot b + \left(x \cdot y + z \cdot t\right)\right)
\]
herbie shell --seed 2022337
(FPCore (x y z t a b c i)
:name "Linear.V4:$cdot from linear-1.19.1.3, C"
:precision binary64
(+ (+ (+ (* x y) (* z t)) (* a b)) (* c i)))