[xls][passes] Perform bulk adder and subtractor splits in#4639
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strength reduction. Previously, StrengthReductionPass split adders and subtractors at a single non-propagating carry/borrow bit per pass iteration. For operations with large bit widths (e.g., bits[1593]), chipping away narrow bit slices iteratively caused hundreds of fixed-point optimization pass cycles, resulting in fuzzer timeouts. This change updates adder and subtractor strength reduction to collect all non-propagating carry/borrow split points in a single pass and split the binary operation into multiple sub-adders/sub-subtractors simultaneously via SplitBinOp. Fixes #4411 PiperOrigin-RevId: 953631634
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[xls][passes] Perform bulk adder and subtractor splits in
strength reduction.
Previously, StrengthReductionPass split adders and subtractors at a
single non-propagating carry/borrow bit per pass iteration. For
operations with large bit widths (e.g., bits[1593]), chipping away
narrow bit slices iteratively caused hundreds of fixed-point
optimization pass cycles, resulting in fuzzer timeouts.
This change updates adder and subtractor strength reduction to collect
all non-propagating carry/borrow split points in a single pass and split
the binary operation into multiple sub-adders/sub-subtractors
simultaneously via SplitBinOp.
Fixes #4411