Xform_bitslices bugfix#113
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Fixes a bug that occurs if you have code like this
let wide : bits(1024) = ...;
let r = [wide[0 +: 64], Zeros(64)];
The bug was causing us to generate a zero_extend from 1024 bits "up" to
64 bits.
This patch does not fully fix the bug but it prevents it from happening
when the width of the bitslice is a constant - which fixes the problem
case.
The most general fix would probably be to find the maximum width that
appears anywhere in the transformed expression, widen everything to that
maximum width and then use and/or/mask/etc. in the transformation.
Leaving that to another day.
nikolaykosarev
approved these changes
Jun 1, 2026
| let transform_slices : bool ref = ref true | ||
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| let rec transform_non_slices (loc : Loc.t) (n : AST.expr) (w : AST.expr) (i : AST.expr) (x : AST.expr) : AST.expr = | ||
| let is_constant (x : AST.expr) : bool = |
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Can be reused:
Line 1340 in 11a2e34
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Fixes a bug that occurs if you have code like this
The bug was causing us to generate a zero_extend from 1024 bits "up" to 64 bits.
This patch does not fully fix the bug but it prevents it from happening when the width of the bitslice is a constant - which fixes the problem case.
The most general fix would probably be to find the maximum width that appears anywhere in the transformed expression, widen everything to that maximum width and then use and/or/mask/etc. in the transformation. Leaving that to another day.