diff --git a/lib/ww/typ.ww b/lib/ww/typ.ww
index 5881839d..97603333 100644
--- a/lib/ww/typ.ww
+++ b/lib/ww/typ.ww
@@ -85,6 +85,11 @@ type tinfo = struct {
 	params:   *tparam,
 	ret:      *tinfo,
 	variadic: i32,
+	nullable: i32,	// #61 A.3: TY_TAGGED `(*T | void)` fold collapses to
+				// 8B ptr slot (null is the void variant). Mirrors
+				// cstage Type.nullable (cmd/wcc/ww.h:430-433);
+				// slot sits in variadic's natural pad so amalloc(96)
+				// is unchanged.
 	name:     str,
 	under:    *tinfo,
 };
diff --git a/selfhost/cmd/w6c/main.combined.ww b/selfhost/cmd/w6c/main.combined.ww
index a8664c3f..6e24ace7 100644
--- a/selfhost/cmd/w6c/main.combined.ww
+++ b/selfhost/cmd/w6c/main.combined.ww
@@ -6511,6 +6511,11 @@ type tinfo = struct {
 	params:   *tparam,
 	ret:      *tinfo,
 	variadic: i32,
+	nullable: i32,	// #61 A.3: TY_TAGGED `(*T | void)` fold collapses to
+				// 8B ptr slot (null is the void variant). Mirrors
+				// cstage Type.nullable (cmd/wcc/ww.h:430-433);
+				// slot sits in variadic's natural pad so amalloc(96)
+				// is unchanged.
 	name:     str,
 	under:    *tinfo,
 };
@@ -8037,15 +8042,38 @@ fn tinfofornode(c: *checker, n: *node) *tinfo = {
 		r.align = maxalign;
 	} else { if (k == nkind.N_TTAGGED) {
 		// Cstage cmd/wcc/check.c:347-435: 8B tag + max(variant)
-		// rounded up to 8. Variant dedup / never-strip / nullable-fold
-		// stay in cstage's check.c for now — wwstage cgen only reads
-		// the size today, and the AST-level pre-fold (astsize's
-		// TTAGGED arm) already matches the cstage layout numerically
-		// for the shapes selfhost exercises. Pre-bind for cycle
-		// protection (recursive sum-type shapes through NAMED
-		// variants).
+		// rounded up to 8. Pre-bind for cycle protection (recursive
+		// sum-type shapes through NAMED variants).
 		r = newtype(c.a, tykind.TY_TAGGED);
 		tinfocachebind(c.tc, n, r);
+		// #61 A.3 nullable fold: `(*T | void)` collapses to a single
+		// 8B pointer slot, null is the void variant. Mirrors
+		// cmd/wcc/check.c:412-426 — bare TNAME("void"), not `!void`,
+		// and not NAMED — so wwstage slotsize fast-path can graduate
+		// TY_TAGGED off the AST-walker fallback. Match before counting
+		// variants so the 8B fold lands in tinfo.size directly.
+		let a: *node = n.list;
+		if (a != nil) {
+			let b: *node = a.next;
+			if (b != nil && b.next == nil) {
+				let aptr: bool = (a.kind == nkind.N_TPTR);
+				let bptr: bool = (b.kind == nkind.N_TPTR);
+				let avoid: bool = (a.kind == nkind.N_TNAME);
+				if (avoid) { avoid = streq(a.str, "void"); };
+				let bvoid: bool = (b.kind == nkind.N_TNAME);
+				if (bvoid) { bvoid = streq(b.str, "void"); };
+				let isnull: bool = false;
+				if (aptr) { if (bvoid) { isnull = true; }; };
+				if (avoid) { if (bptr) { isnull = true; }; };
+				if (isnull) {
+					r.size = 8u64;
+					r.align = 8u64;
+					r.nullable = 1;
+					tinfocachebind(c.tc, n, r);
+					return r;
+				};
+			};
+		};
 		let maxsz: u64 = 0u64;
 		let al: u64 = 8u64;
 		let v: *node = n.list;
@@ -10919,30 +10947,39 @@ export fn letslotsize(c: *cgen, n: *node) i32 = {
 };
 
 fn slotsize(c: *cgen, typn: *node) i32 = {
-	// #61 audit §1.8 — A.2 graduation: read tinfo.size off the populated
-	// type-expression node when its kind matches the cstage natural-size
-	// SSoT. Filtered set covers shapes whose tinfo.size already encodes
-	// the cgen slot-size contract: pointer-like (PTR/CHAN/FN), slice
-	// (SLICE), and str (STR). Other kinds flow through the fallback
-	// walker. TAGGED stays out because cstage's resolve_type folds
-	// `(*T | void)` to a single 8B pointer (cmd/wcc/check.c:412-426)
-	// but tinfofornode's TTAGGED arm doesn't yet — graduating TAGGED
-	// would shrink that fold's slot from 16 to 8 on the wwstage side.
-	// Primitive scalars + enums + inline TUPLE / TSTRUCT also keep
-	// flowing through the fallback walker because cgen's slot-pad-to-8
-	// contract (cmd/w6c/cgen.c let_emit_size:691-720 and the per-field
-	// slot rounding in registerstruct/letslotsize) lives there, not in
-	// tinfo.size. Subsequent sub-commits collapse the remaining shapes
-	// onto the same pivot once cstage parity catches up (#61 Phase A —
-	// see the audit doc for the staged plan).
+	// #61 audit §1.8 — A.3 fast-path expansion. Read tinfo.size off the
+	// populated type-expression node when the kind matches the cstage
+	// natural-size SSoT. Coverage:
+	//   - pointer-like (PTR/CHAN/FN), slice, str, tagged
+	//     return ti.size directly (size already encodes the slot).
+	//     TY_TAGGED is safe now that tinfofornode folds `(*T | void)`
+	//     to 8B (#61 A.3 step 1, mirrors cmd/wcc/check.c:412-426).
+	//   - narrow scalars (BOOL/RUNE/I8..I32/U8..U32/ENUM) pad UP to 8 —
+	//     cstage's let_emit_size (cmd/w6c/cgen.c:691-720) spills every
+	//     primitive into an 8B stack slot regardless of tinfo.size.
+	//     Padding lives at the read site, not in tinfo.size, so size(T)
+	//     stays a faithful natural-width SSoT.
+	// TUPLE / TSTRUCT / TARRAY still flow through the AST-walker fallback
+	// because cgen's per-field stride contract (registerstruct.totsize
+	// rounding, [N]T element-size walk) lives there, not in tinfo.size.
 	if (typn != nil && typn.type_ != nil) {
 		let ti: *tinfo = typn.type_: *tinfo;
 		let kk: tykind = ti.kind;
 		if (kk == tykind.TY_PTR    || kk == tykind.TY_SLICE  ||
 		    kk == tykind.TY_CHAN   || kk == tykind.TY_FN     ||
-		    kk == tykind.TY_STR) {
+		    kk == tykind.TY_STR    || kk == tykind.TY_TAGGED) {
 			return ti.size: i32;
 		};
+		if (kk == tykind.TY_BOOL || kk == tykind.TY_RUNE ||
+		    kk == tykind.TY_I8   || kk == tykind.TY_I16  ||
+		    kk == tykind.TY_I32  || kk == tykind.TY_I64  ||
+		    kk == tykind.TY_U8   || kk == tykind.TY_U16  ||
+		    kk == tykind.TY_U32  || kk == tykind.TY_U64  ||
+		    kk == tykind.TY_INT  || kk == tykind.TY_UINT ||
+		    kk == tykind.TY_UINTPTR || kk == tykind.TY_ENUM ||
+		    kk == tykind.TY_F32  || kk == tykind.TY_F64) {
+			return 8;
+		};
 	};
 	if (typn == nil) { return 8; };
 	let k: nkind = typn.kind;
diff --git a/selfhost/cmd/wcc/cgenutil.ww b/selfhost/cmd/wcc/cgenutil.ww
index e46b61da..4213b309 100644
--- a/selfhost/cmd/wcc/cgenutil.ww
+++ b/selfhost/cmd/wcc/cgenutil.ww
@@ -1941,30 +1941,39 @@ export fn letslotsize(c: *cgen, n: *node) i32 = {
 };
 
 fn slotsize(c: *cgen, typn: *node) i32 = {
-	// #61 audit §1.8 — A.2 graduation: read tinfo.size off the populated
-	// type-expression node when its kind matches the cstage natural-size
-	// SSoT. Filtered set covers shapes whose tinfo.size already encodes
-	// the cgen slot-size contract: pointer-like (PTR/CHAN/FN), slice
-	// (SLICE), and str (STR). Other kinds flow through the fallback
-	// walker. TAGGED stays out because cstage's resolve_type folds
-	// `(*T | void)` to a single 8B pointer (cmd/wcc/check.c:412-426)
-	// but tinfofornode's TTAGGED arm doesn't yet — graduating TAGGED
-	// would shrink that fold's slot from 16 to 8 on the wwstage side.
-	// Primitive scalars + enums + inline TUPLE / TSTRUCT also keep
-	// flowing through the fallback walker because cgen's slot-pad-to-8
-	// contract (cmd/w6c/cgen.c let_emit_size:691-720 and the per-field
-	// slot rounding in registerstruct/letslotsize) lives there, not in
-	// tinfo.size. Subsequent sub-commits collapse the remaining shapes
-	// onto the same pivot once cstage parity catches up (#61 Phase A —
-	// see the audit doc for the staged plan).
+	// #61 audit §1.8 — A.3 fast-path expansion. Read tinfo.size off the
+	// populated type-expression node when the kind matches the cstage
+	// natural-size SSoT. Coverage:
+	//   - pointer-like (PTR/CHAN/FN), slice, str, tagged
+	//     return ti.size directly (size already encodes the slot).
+	//     TY_TAGGED is safe now that tinfofornode folds `(*T | void)`
+	//     to 8B (#61 A.3 step 1, mirrors cmd/wcc/check.c:412-426).
+	//   - narrow scalars (BOOL/RUNE/I8..I32/U8..U32/ENUM) pad UP to 8 —
+	//     cstage's let_emit_size (cmd/w6c/cgen.c:691-720) spills every
+	//     primitive into an 8B stack slot regardless of tinfo.size.
+	//     Padding lives at the read site, not in tinfo.size, so size(T)
+	//     stays a faithful natural-width SSoT.
+	// TUPLE / TSTRUCT / TARRAY still flow through the AST-walker fallback
+	// because cgen's per-field stride contract (registerstruct.totsize
+	// rounding, [N]T element-size walk) lives there, not in tinfo.size.
 	if (typn != nil && typn.type_ != nil) {
 		let ti: *tinfo = typn.type_: *tinfo;
 		let kk: tykind = ti.kind;
 		if (kk == tykind.TY_PTR    || kk == tykind.TY_SLICE  ||
 		    kk == tykind.TY_CHAN   || kk == tykind.TY_FN     ||
-		    kk == tykind.TY_STR) {
+		    kk == tykind.TY_STR    || kk == tykind.TY_TAGGED) {
 			return ti.size: i32;
 		};
+		if (kk == tykind.TY_BOOL || kk == tykind.TY_RUNE ||
+		    kk == tykind.TY_I8   || kk == tykind.TY_I16  ||
+		    kk == tykind.TY_I32  || kk == tykind.TY_I64  ||
+		    kk == tykind.TY_U8   || kk == tykind.TY_U16  ||
+		    kk == tykind.TY_U32  || kk == tykind.TY_U64  ||
+		    kk == tykind.TY_INT  || kk == tykind.TY_UINT ||
+		    kk == tykind.TY_UINTPTR || kk == tykind.TY_ENUM ||
+		    kk == tykind.TY_F32  || kk == tykind.TY_F64) {
+			return 8;
+		};
 	};
 	if (typn == nil) { return 8; };
 	let k: nkind = typn.kind;
diff --git a/selfhost/cmd/wcc/check.ww b/selfhost/cmd/wcc/check.ww
index f992e365..ffe71b1f 100644
--- a/selfhost/cmd/wcc/check.ww
+++ b/selfhost/cmd/wcc/check.ww
@@ -1009,15 +1009,38 @@ fn tinfofornode(c: *checker, n: *node) *tinfo = {
 		r.align = maxalign;
 	} else { if (k == nkind.N_TTAGGED) {
 		// Cstage cmd/wcc/check.c:347-435: 8B tag + max(variant)
-		// rounded up to 8. Variant dedup / never-strip / nullable-fold
-		// stay in cstage's check.c for now — wwstage cgen only reads
-		// the size today, and the AST-level pre-fold (astsize's
-		// TTAGGED arm) already matches the cstage layout numerically
-		// for the shapes selfhost exercises. Pre-bind for cycle
-		// protection (recursive sum-type shapes through NAMED
-		// variants).
+		// rounded up to 8. Pre-bind for cycle protection (recursive
+		// sum-type shapes through NAMED variants).
 		r = newtype(c.a, tykind.TY_TAGGED);
 		tinfocachebind(c.tc, n, r);
+		// #61 A.3 nullable fold: `(*T | void)` collapses to a single
+		// 8B pointer slot, null is the void variant. Mirrors
+		// cmd/wcc/check.c:412-426 — bare TNAME("void"), not `!void`,
+		// and not NAMED — so wwstage slotsize fast-path can graduate
+		// TY_TAGGED off the AST-walker fallback. Match before counting
+		// variants so the 8B fold lands in tinfo.size directly.
+		let a: *node = n.list;
+		if (a != nil) {
+			let b: *node = a.next;
+			if (b != nil && b.next == nil) {
+				let aptr: bool = (a.kind == nkind.N_TPTR);
+				let bptr: bool = (b.kind == nkind.N_TPTR);
+				let avoid: bool = (a.kind == nkind.N_TNAME);
+				if (avoid) { avoid = streq(a.str, "void"); };
+				let bvoid: bool = (b.kind == nkind.N_TNAME);
+				if (bvoid) { bvoid = streq(b.str, "void"); };
+				let isnull: bool = false;
+				if (aptr) { if (bvoid) { isnull = true; }; };
+				if (avoid) { if (bptr) { isnull = true; }; };
+				if (isnull) {
+					r.size = 8u64;
+					r.align = 8u64;
+					r.nullable = 1;
+					tinfocachebind(c.tc, n, r);
+					return r;
+				};
+			};
+		};
 		let maxsz: u64 = 0u64;
 		let al: u64 = 8u64;
 		let v: *node = n.list;
diff --git a/selfhost/cmd/wwdump/main.combined.ww b/selfhost/cmd/wwdump/main.combined.ww
index a1c218a7..aaa997ee 100644
--- a/selfhost/cmd/wwdump/main.combined.ww
+++ b/selfhost/cmd/wwdump/main.combined.ww
@@ -6511,6 +6511,11 @@ type tinfo = struct {
 	params:   *tparam,
 	ret:      *tinfo,
 	variadic: i32,
+	nullable: i32,	// #61 A.3: TY_TAGGED `(*T | void)` fold collapses to
+				// 8B ptr slot (null is the void variant). Mirrors
+				// cstage Type.nullable (cmd/wcc/ww.h:430-433);
+				// slot sits in variadic's natural pad so amalloc(96)
+				// is unchanged.
 	name:     str,
 	under:    *tinfo,
 };
@@ -8037,15 +8042,38 @@ fn tinfofornode(c: *checker, n: *node) *tinfo = {
 		r.align = maxalign;
 	} else { if (k == nkind.N_TTAGGED) {
 		// Cstage cmd/wcc/check.c:347-435: 8B tag + max(variant)
-		// rounded up to 8. Variant dedup / never-strip / nullable-fold
-		// stay in cstage's check.c for now — wwstage cgen only reads
-		// the size today, and the AST-level pre-fold (astsize's
-		// TTAGGED arm) already matches the cstage layout numerically
-		// for the shapes selfhost exercises. Pre-bind for cycle
-		// protection (recursive sum-type shapes through NAMED
-		// variants).
+		// rounded up to 8. Pre-bind for cycle protection (recursive
+		// sum-type shapes through NAMED variants).
 		r = newtype(c.a, tykind.TY_TAGGED);
 		tinfocachebind(c.tc, n, r);
+		// #61 A.3 nullable fold: `(*T | void)` collapses to a single
+		// 8B pointer slot, null is the void variant. Mirrors
+		// cmd/wcc/check.c:412-426 — bare TNAME("void"), not `!void`,
+		// and not NAMED — so wwstage slotsize fast-path can graduate
+		// TY_TAGGED off the AST-walker fallback. Match before counting
+		// variants so the 8B fold lands in tinfo.size directly.
+		let a: *node = n.list;
+		if (a != nil) {
+			let b: *node = a.next;
+			if (b != nil && b.next == nil) {
+				let aptr: bool = (a.kind == nkind.N_TPTR);
+				let bptr: bool = (b.kind == nkind.N_TPTR);
+				let avoid: bool = (a.kind == nkind.N_TNAME);
+				if (avoid) { avoid = streq(a.str, "void"); };
+				let bvoid: bool = (b.kind == nkind.N_TNAME);
+				if (bvoid) { bvoid = streq(b.str, "void"); };
+				let isnull: bool = false;
+				if (aptr) { if (bvoid) { isnull = true; }; };
+				if (avoid) { if (bptr) { isnull = true; }; };
+				if (isnull) {
+					r.size = 8u64;
+					r.align = 8u64;
+					r.nullable = 1;
+					tinfocachebind(c.tc, n, r);
+					return r;
+				};
+			};
+		};
 		let maxsz: u64 = 0u64;
 		let al: u64 = 8u64;
 		let v: *node = n.list;
@@ -10919,30 +10947,39 @@ export fn letslotsize(c: *cgen, n: *node) i32 = {
 };
 
 fn slotsize(c: *cgen, typn: *node) i32 = {
-	// #61 audit §1.8 — A.2 graduation: read tinfo.size off the populated
-	// type-expression node when its kind matches the cstage natural-size
-	// SSoT. Filtered set covers shapes whose tinfo.size already encodes
-	// the cgen slot-size contract: pointer-like (PTR/CHAN/FN), slice
-	// (SLICE), and str (STR). Other kinds flow through the fallback
-	// walker. TAGGED stays out because cstage's resolve_type folds
-	// `(*T | void)` to a single 8B pointer (cmd/wcc/check.c:412-426)
-	// but tinfofornode's TTAGGED arm doesn't yet — graduating TAGGED
-	// would shrink that fold's slot from 16 to 8 on the wwstage side.
-	// Primitive scalars + enums + inline TUPLE / TSTRUCT also keep
-	// flowing through the fallback walker because cgen's slot-pad-to-8
-	// contract (cmd/w6c/cgen.c let_emit_size:691-720 and the per-field
-	// slot rounding in registerstruct/letslotsize) lives there, not in
-	// tinfo.size. Subsequent sub-commits collapse the remaining shapes
-	// onto the same pivot once cstage parity catches up (#61 Phase A —
-	// see the audit doc for the staged plan).
+	// #61 audit §1.8 — A.3 fast-path expansion. Read tinfo.size off the
+	// populated type-expression node when the kind matches the cstage
+	// natural-size SSoT. Coverage:
+	//   - pointer-like (PTR/CHAN/FN), slice, str, tagged
+	//     return ti.size directly (size already encodes the slot).
+	//     TY_TAGGED is safe now that tinfofornode folds `(*T | void)`
+	//     to 8B (#61 A.3 step 1, mirrors cmd/wcc/check.c:412-426).
+	//   - narrow scalars (BOOL/RUNE/I8..I32/U8..U32/ENUM) pad UP to 8 —
+	//     cstage's let_emit_size (cmd/w6c/cgen.c:691-720) spills every
+	//     primitive into an 8B stack slot regardless of tinfo.size.
+	//     Padding lives at the read site, not in tinfo.size, so size(T)
+	//     stays a faithful natural-width SSoT.
+	// TUPLE / TSTRUCT / TARRAY still flow through the AST-walker fallback
+	// because cgen's per-field stride contract (registerstruct.totsize
+	// rounding, [N]T element-size walk) lives there, not in tinfo.size.
 	if (typn != nil && typn.type_ != nil) {
 		let ti: *tinfo = typn.type_: *tinfo;
 		let kk: tykind = ti.kind;
 		if (kk == tykind.TY_PTR    || kk == tykind.TY_SLICE  ||
 		    kk == tykind.TY_CHAN   || kk == tykind.TY_FN     ||
-		    kk == tykind.TY_STR) {
+		    kk == tykind.TY_STR    || kk == tykind.TY_TAGGED) {
 			return ti.size: i32;
 		};
+		if (kk == tykind.TY_BOOL || kk == tykind.TY_RUNE ||
+		    kk == tykind.TY_I8   || kk == tykind.TY_I16  ||
+		    kk == tykind.TY_I32  || kk == tykind.TY_I64  ||
+		    kk == tykind.TY_U8   || kk == tykind.TY_U16  ||
+		    kk == tykind.TY_U32  || kk == tykind.TY_U64  ||
+		    kk == tykind.TY_INT  || kk == tykind.TY_UINT ||
+		    kk == tykind.TY_UINTPTR || kk == tykind.TY_ENUM ||
+		    kk == tykind.TY_F32  || kk == tykind.TY_F64) {
+			return 8;
+		};
 	};
 	if (typn == nil) { return 8; };
 	let k: nkind = typn.kind;