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UHDM: a function-local UNPACKED array keeps one value per element -- st[0] ^ st[1] folded to 1 - #4206
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alaindargelas merged 1 commit intoOct 4, 2026
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…`st[0] ^ st[1]` folded to 1 Bumps UHDM for chipsalliance/UHDM#1161: ExprEval's setValueInInstance found a function-local `reg [57:0] st [0:1]` through getObject and took the flat packed-vector path -- the variable's typespec is the ELEMENT's `[57:0]`, so each element assignment wrote ONE bit at position `index` and the element read it back as that bit: `st[0] ^ st[1]` folded to 1 (verilog-ethernet's lfsr_mask, and every constant function that stages a table in a local array). An array_var now stores per element in a param_assign/array_expr, the representation reduceExpr's bit_select case already reads. tests/FuncLocalArrayElemFold: direct, for-loop and while-loop element reads of a local array; every output folds to 64'h0300000000000001. Golden refresh: TfItemUnpackedLocal's `f0` now folds to 64'hC000000180000001, the XOR of its four table entries (was 1). Prepared with the assistance of Claude Code.
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Bumps UHDM to chipsalliance/UHDM#1161 (7c42de4).
ExprEval::setValueInInstancefound a function-localreg [57:0] st [0:1]throughgetObjectand took the flat packed-vector path: the variable's typespec is the ELEMENT's[57:0], so each element assignment wrote one bit at positionindexand the element read it back as that bit.st[0] ^ st[1]folded to 1 (verilog-ethernet'slfsr_mask, and every constant function that stages a table in a local array). Anarray_varnow stores per element in aparam_assign/array_expr, the representationreduceExpr's bit_select case already reads.Test:
tests/FuncLocalArrayElemFoldwith direct, for-loop and while-loop element reads of a local array; every output folds to64'h0300000000000001.Regression: 828 PASS / 1 DIFF / 0 FAIL. The one DIFF is the intended correction:
TfItemUnpackedLocal'sf0now folds to64'hC000000180000001, the XOR of its four table entries (was 1). Both goldens refreshed and${SURELOG_DIR}-normalized.Prepared with the assistance of Claude Code.
🤖 Generated with Claude Code
https://claude.ai/code/session_01XshwvRJtjR5dA48M4b1CLM