nx_cascade_test.nx

nx_cascade_test.nx -- regression test for the parallel-copy semantic violation bug in nxc2's copy-forward pass. Bug: copy-forward in opt.c walked through single-def OP_COPY chains into multi-def merge values, breaking the cascade emitted by mem2reg's out-of-SSA pass at end of loop bodies. Source while c { h=g; g=f; ...; b=a; a=99 } compiled to mv a, 99 # writes a first mv b, a # b gets NEW a, not OLD a ... cascade collapsed Fixed 2026-05-17 in opt.c::opt_copy_forward_function by skipping forwarding for OP_COPY whose result is multi-def (i.e., parallel- copy glue at end of BB). This file must keep passing. This test covers FOUR cascade shapes: T1: 8-var right-rotation (the original failing case) T2: 3-var swap (a, b, c rotate) T3: single-var redefine (a = a + 1) T4: pair-wise swap via temp (a/b swap) expect_exit: 0 license_tier: ORIGINAL