wwstage pushargsrev treated a narrower tagged-union argument widened into
a wider tagged param slot as a concrete variant: taggedvariantindex<0
clamped the tag to 0 and pushed word0 only (deref/index/dot silent-wrong;
ident ran correct only by prefix-union tag-index luck). cstage is correct
(cg_widen_tagged_push routes src_is_tagged unconditionally); align ww UP.
Three arms in cgenutil.ww, all mirroring cstage cgen.c:
- slot-gate the ident aistagged short-circuit so a slot-differ tagged
ident falls to the widen path instead of the raw 2-word push;
- route a tagged source in the widensz>0 arm through @tagscr +
cgwidentaggedstore + push high->low (cgen.c cg_widen_tagged_push);
- cgwidentaggedstore cursor arm (<=32B INDEX/DOT) spills by source
width, zero-pads, and tag-remaps (cgen.c 2698-2714) — was dst-slot
spill of stale high regs with no pad and no remap.
Same-slot tagged->tagged is byte-id-neutral by construction (empty pad +
identity remap). cstage untouched; 4 legs x {aligned, misaligned-tag}
converge ww->cs byte-identical. Pin 944_tagged_widen_arg_run.
Hojun-Cho
cc896bd078