`b_width_capped` already exists for preventing arithmetic overflow, limiting the value of `b_width` to 30. This just changes the left shifts to also use it.
The caveat of incorrect results for extremely large values of `a_width` still applies, as does the improbability of that actually happening.
This fixes#4844 (or at least, the floating point exception; the circuit still isn't valid but I think that's fine).
The $div and $mod cells use truncating division semantics (rounding
towards 0), as defined by e.g. Verilog. Another rounding mode, flooring
(rounding towards negative infinity), can be used in e.g. VHDL. The
new $divfloor cell provides this flooring division.
This commit also fixes the handling of $div in opt_expr, which was
previously optimized as if it was $divfloor.
The $div and $mod cells use truncating division semantics (rounding
towards 0), as defined by e.g. Verilog. Another rounding mode, flooring
(rounding towards negative infinity), can be used in e.g. VHDL. The
new $modfloor cell provides this flooring modulo (also known as "remainder"
in several languages, but this name is ambiguous).
This commit also fixes the handling of $mod in opt_expr, which was
previously optimized as if it was $modfloor.
KrystalDelusion
Martin Povišer
Claire Xenia Wolf
N. Engelhardt
Marcelina Kościelnicka
Xiretza
Eddie Hung
Clifford Wolf