wcc/cgen: extract per-kind helpers from cgexpr/cgstmt (rob pike #5)

selfhost/cmd/w6c/main.combined.ww

@@ -4506,9 +4506,14 @@ fn taggedvariantindex(c: *cgen, tagged: *node, rhs: *node) i32 = {
 // MODULE: wcc
 // selfhost/cmd/wcc/cgen_expr.ww — split out of cgen.ww.
 //
-// Houses cgexpr — the per-expression code generator. The remainder of
+// cgexpr is a thin dispatcher over n.kind; each non-trivial branch
-// the cgen lives in cgen.ww (foundation: types, emit primitives, the
+// lives in a per-kind helper (cgstrlit, cgident, cgindex, cgmatch,
-// collect* tables, FFI/module maps) and cgen_stmt.ww (cgstmt).
+// cgdot, cgun, cgbin, cgcall, cgassign). Trivial literal loads
+// (N_INTLIT, N_RUNELIT, N_TRUE/FALSE/NIL, N_CAST) stay inline.
+//
+// The remainder of cgen lives in cgen.ww (foundation: types, emit
+// primitives, the collect* tables, FFI/module maps) and cgen_stmt.ww
+// (cgstmt).
 //
 // `use cgen_expr;` is unnecessary at consumer sites — cgen.ww imports
 // this file, so any caller of cgen transitively gets cgexpr.
@@ -4541,19 +4546,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 		emitline(", AX\n");
 		return;
 	};
-	if (k == N_STRLIT) {
+	if (k == N_STRLIT) { cgstrlit(c, n); return; };
-		// Result is the (ptr, len) pair: ptr in AX, len in BX. Call
-		// sites that expect a str arg pick these up directly.
-		let nstr: str = n.str;
-		let lab: str = internstrlit(c, nstr);
-		emitline("\tLEAQ\t");
-		os.write(1, lab.ptr, lab.len: u64);
-		emitline("(SB), AX\n");
-		emitline("\tMOVQ\t$");
-		emitint(nstr.len: i64);
-		emitline(", BX\n");
-		return;
-	};
 	if (k == N_TRUE) {
 		emitline("\tMOVQ\t$1, AX\n");
 		return;
@@ -4567,7 +4560,48 @@ fn cgexpr(c: *cgen, n: *node) void = {
 		return;
 	};
 
-	if (k == N_IDENT) {
+	if (k == N_IDENT) { cgident(c, n); return; };
+
+	if (k == N_INDEX) { cgindex(c, n); return; };
+
+	if (k == N_MATCH) { cgmatch(c, n); return; };
+
+	if (k == N_CAST) {
+		// Type casts are mostly no-ops at the asm level for our
+		// integer-shaped operands. Evaluate the source; AX holds
+		// the bits unchanged. (Sign- or zero-extending narrow loads
+		// to wider types is the loader's job, not cast's, in this
+		// minimal cgen.)
+		cgexpr(c, n.lhs);
+		return;
+	};
+
+	if (k == N_DOT) { cgdot(c, n); return; };
+
+	if (k == N_UN) { cgun(c, n); return; };
+
+	if (k == N_BIN) { cgbin(c, n); return; };
+
+	if (k == N_CALL) { cgcall(c, n); return; };
+
+	if (k == N_ASSIGN) { cgassign(c, n); return; };
+};
+
+fn cgstrlit(c: *cgen, n: *node) void = {
+	// Result is the (ptr, len) pair: ptr in AX, len in BX. Call
+	// sites that expect a str arg pick these up directly.
+	let nstr: str = n.str;
+	let lab: str = internstrlit(c, nstr);
+	emitline("\tLEAQ\t");
+	os.write(1, lab.ptr, lab.len: u64);
+	emitline("(SB), AX\n");
+	emitline("\tMOVQ\t$");
+	emitint(nstr.len: i64);
+	emitline(", BX\n");
+	return;
+};
+
+fn cgident(c: *cgen, n: *node) void = {
 	let nm: str = n.str;
 	let lc: *local = localfindnode(c, nm);
 	if (lc != nil) {
@@ -4614,7 +4648,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_INDEX) {
+fn cgindex(c: *cgen, n: *node) void = {
 	// Element-size-aware load: u8-element bases use MOVZBQ,
 	// everything else MOVQ. Fast path when the base is a bare
 	// ident (mem.ww shape).
@@ -4679,7 +4713,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_MATCH) {
+fn cgmatch(c: *cgen, n: *node) void = {
 	// match (e) { case let v: T => stmt; ... }
 	//
 	// Read the tagged-union slot and dispatch by tag. Slot
@@ -4780,17 +4814,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_CAST) {
+fn cgdot(c: *cgen, n: *node) void = {
-		// Type casts are mostly no-ops at the asm level for our
-		// integer-shaped operands. Evaluate the source; AX holds
-		// the bits unchanged. (Sign- or zero-extending narrow loads
-		// to wider types is the loader's job, not cast's, in this
-		// minimal cgen.)
-		cgexpr(c, n.lhs);
-		return;
-	};
-
-	if (k == N_DOT) {
 	let lhs: *node = n.lhs;
 	let fld: str = n.str;
 	if (lhs != nil) {
@@ -5007,7 +5031,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_UN) {
+fn cgun(c: *cgen, n: *node) void = {
 	// Match C cgen ordering: evaluate operand first (load into AX),
 	// then apply the unary op. AMP / STAR override AX with the
 	// address / deref. The wasted load before AMP keeps our asm
@@ -5047,7 +5071,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_BIN) {
+fn cgbin(c: *cgen, n: *node) void = {
 	let unsignd: bool = nodeisunsigned(c, n.lhs);
 	if (!unsignd) { unsignd = nodeisunsigned(c, n.rhs); };
 
@@ -5112,7 +5136,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_CALL) {
+fn cgcall(c: *cgen, n: *node) void = {
 	let nargs: i32 = pushargsrev(c, n.list);
 	let i: i32 = 0;
 	for (i < nargs) {
@@ -5216,7 +5240,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_ASSIGN) {
+fn cgassign(c: *cgen, n: *node) void = {
 	let lhs: *node = n.lhs;
 	// `*p = v` — deref-assign. Element width comes from the
 	// pointer's declared type. Mirrors C cgen: eval rhs (AX,
@@ -5579,17 +5603,19 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	};
 	return;
 };
-};
+
 
 
 // MODULE: wcc
 // selfhost/cmd/wcc/cgen_stmt.ww — split out of cgen.ww.
 //
-// Houses cgstmt — statements + control flow (N_BLOCK, N_IF, N_FOR,
+// cgstmt is a thin dispatcher over n.kind; each branch defers to a
-// N_BREAK/N_CONTINUE, N_RETURN, N_LET, N_ASSIGN, etc.). The
+// per-kind helper: cgblock, cgreturn, cgexprstmt, cglet, cgif, cgfor,
-// expression generator (cgexpr) lives in cgen_expr.ww; the foundation
+// cgmassign, cgbreak, cgcontinue.
-// (types, emit primitives, collect* tables, FFI/module maps) lives in
+//
-// cgen.ww.
+// The expression generator (cgexpr) lives in cgen_expr.ww; the
+// foundation (types, emit primitives, collect* tables, FFI/module
+// maps) lives in cgen.ww.
 
 use os;
 use mem;
@@ -5605,7 +5631,27 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	if (n == nil) { return; };
 	let k: i32 = n.kind;
 
-	if (k == N_BLOCK) {
+	if (k == N_BLOCK) { cgblock(c, n); return; };
+
+	if (k == N_RETURN) { cgreturn(c, n); return; };
+
+	if (k == N_EXPRSTMT) { cgexprstmt(c, n); return; };
+
+	if (k == N_LET) { cglet(c, n); return; };
+
+	if (k == N_IF) { cgif(c, n); return; };
+
+	if (k == N_FOR) { cgfor(c, n); return; };
+
+	if (k == N_MASSIGN) { cgmassign(c, n); return; };
+
+	if (k == N_BREAK) { cgbreak(c, n); return; };
+	if (k == N_CONTINUE) { cgcontinue(c, n); return; };
+
+	c.last_was_return = 0;
+};
+
+fn cgblock(c: *cgen, n: *node) void = {
 	let s: *node = n.list;
 	for (s != nil) {
 		cgstmt(c, s);
@@ -5614,7 +5660,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_RETURN) {
+fn cgreturn(c: *cgen, n: *node) void = {
 	let rhs: *node = n.lhs;
 	if (rhs != nil) {
 		// Tuple return `return a, b;` — pack as (AX=v0, DX=v1).
@@ -5681,13 +5727,13 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_EXPRSTMT) {
+fn cgexprstmt(c: *cgen, n: *node) void = {
 	if (n.lhs != nil) { cgexpr(c, n.lhs); };
 	c.last_was_return = 0;
 	return;
 };
 
-	if (k == N_LET) {
+fn cglet(c: *cgen, n: *node) void = {
 	let nm: str = n.str;
 	let sz: i32 = slotsize(c, n.lhs);
 	let off: i32 = localadd(c, nm, sz, n.lhs);
@@ -5829,7 +5875,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_IF) {
+fn cgif(c: *cgen, n: *node) void = {
 	let els: str = mklabel(c, "else");
 	let endl: str = mklabel(c, "end");
 	cgexpr(c, n.cond);
@@ -5849,7 +5895,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_FOR) {
+fn cgfor(c: *cgen, n: *node) void = {
 	// Match C cgen's label scheme: <fn>_loop_N for the top,
 	// <fn>_endloop_N for the post-body merge. No separate cont
 	// label when there's no post-expression.
@@ -5885,7 +5931,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 // the first lvalue, then pop DX into the second. Mirrors
 // cmd/w6c/cgen.c:2424-2440. Lvalues beyond two are dropped (same
 // as C — no fixture uses >2 today).
-	if (k == N_MASSIGN) {
+fn cgmassign(c: *cgen, n: *node) void = {
 	if (n.rhs != nil) { cgexpr(c, n.rhs); };
 	emitline("\tPUSHQ\tDX\n");
 	let l0: *node = n.list;
@@ -5916,7 +5962,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_BREAK) {
+fn cgbreak(c: *cgen, n: *node) void = {
 	if (c.loop_top > 0) {
 		let lbl: str = c.loop_end_buf[c.loop_top - 1];
 		emitline("\tJMP\t"); emitline(lbl); emitline("\n");
@@ -5924,7 +5970,8 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	c.last_was_return = 0;
 	return;
 };
-	if (k == N_CONTINUE) {
+
+fn cgcontinue(c: *cgen, n: *node) void = {
 	if (c.loop_top > 0) {
 		let lbl: str = c.loop_cont_buf[c.loop_top - 1];
 		emitline("\tJMP\t"); emitline(lbl); emitline("\n");
@@ -5933,8 +5980,6 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	c.last_was_return = 0;
-};
 
 
 // MODULE: wcc

selfhost/cmd/wcc/cgen_expr.ww

@@ -1,8 +1,13 @@
 // selfhost/cmd/wcc/cgen_expr.ww — split out of cgen.ww.
 //
-// Houses cgexpr — the per-expression code generator. The remainder of
+// cgexpr is a thin dispatcher over n.kind; each non-trivial branch
-// the cgen lives in cgen.ww (foundation: types, emit primitives, the
+// lives in a per-kind helper (cgstrlit, cgident, cgindex, cgmatch,
-// collect* tables, FFI/module maps) and cgen_stmt.ww (cgstmt).
+// cgdot, cgun, cgbin, cgcall, cgassign). Trivial literal loads
+// (N_INTLIT, N_RUNELIT, N_TRUE/FALSE/NIL, N_CAST) stay inline.
+//
+// The remainder of cgen lives in cgen.ww (foundation: types, emit
+// primitives, the collect* tables, FFI/module maps) and cgen_stmt.ww
+// (cgstmt).
 //
 // `use cgen_expr;` is unnecessary at consumer sites — cgen.ww imports
 // this file, so any caller of cgen transitively gets cgexpr.
@@ -35,19 +40,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 		emitline(", AX\n");
 		return;
 	};
-	if (k == N_STRLIT) {
+	if (k == N_STRLIT) { cgstrlit(c, n); return; };
-		// Result is the (ptr, len) pair: ptr in AX, len in BX. Call
-		// sites that expect a str arg pick these up directly.
-		let nstr: str = n.str;
-		let lab: str = internstrlit(c, nstr);
-		emitline("\tLEAQ\t");
-		os.write(1, lab.ptr, lab.len: u64);
-		emitline("(SB), AX\n");
-		emitline("\tMOVQ\t$");
-		emitint(nstr.len: i64);
-		emitline(", BX\n");
-		return;
-	};
 	if (k == N_TRUE) {
 		emitline("\tMOVQ\t$1, AX\n");
 		return;
@@ -61,7 +54,48 @@ fn cgexpr(c: *cgen, n: *node) void = {
 		return;
 	};
 
-	if (k == N_IDENT) {
+	if (k == N_IDENT) { cgident(c, n); return; };
+
+	if (k == N_INDEX) { cgindex(c, n); return; };
+
+	if (k == N_MATCH) { cgmatch(c, n); return; };
+
+	if (k == N_CAST) {
+		// Type casts are mostly no-ops at the asm level for our
+		// integer-shaped operands. Evaluate the source; AX holds
+		// the bits unchanged. (Sign- or zero-extending narrow loads
+		// to wider types is the loader's job, not cast's, in this
+		// minimal cgen.)
+		cgexpr(c, n.lhs);
+		return;
+	};
+
+	if (k == N_DOT) { cgdot(c, n); return; };
+
+	if (k == N_UN) { cgun(c, n); return; };
+
+	if (k == N_BIN) { cgbin(c, n); return; };
+
+	if (k == N_CALL) { cgcall(c, n); return; };
+
+	if (k == N_ASSIGN) { cgassign(c, n); return; };
+};
+
+fn cgstrlit(c: *cgen, n: *node) void = {
+	// Result is the (ptr, len) pair: ptr in AX, len in BX. Call
+	// sites that expect a str arg pick these up directly.
+	let nstr: str = n.str;
+	let lab: str = internstrlit(c, nstr);
+	emitline("\tLEAQ\t");
+	os.write(1, lab.ptr, lab.len: u64);
+	emitline("(SB), AX\n");
+	emitline("\tMOVQ\t$");
+	emitint(nstr.len: i64);
+	emitline(", BX\n");
+	return;
+};
+
+fn cgident(c: *cgen, n: *node) void = {
 	let nm: str = n.str;
 	let lc: *local = localfindnode(c, nm);
 	if (lc != nil) {
@@ -108,7 +142,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_INDEX) {
+fn cgindex(c: *cgen, n: *node) void = {
 	// Element-size-aware load: u8-element bases use MOVZBQ,
 	// everything else MOVQ. Fast path when the base is a bare
 	// ident (mem.ww shape).
@@ -173,7 +207,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_MATCH) {
+fn cgmatch(c: *cgen, n: *node) void = {
 	// match (e) { case let v: T => stmt; ... }
 	//
 	// Read the tagged-union slot and dispatch by tag. Slot
@@ -274,17 +308,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_CAST) {
+fn cgdot(c: *cgen, n: *node) void = {
-		// Type casts are mostly no-ops at the asm level for our
-		// integer-shaped operands. Evaluate the source; AX holds
-		// the bits unchanged. (Sign- or zero-extending narrow loads
-		// to wider types is the loader's job, not cast's, in this
-		// minimal cgen.)
-		cgexpr(c, n.lhs);
-		return;
-	};
-
-	if (k == N_DOT) {
 	let lhs: *node = n.lhs;
 	let fld: str = n.str;
 	if (lhs != nil) {
@@ -501,7 +525,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_UN) {
+fn cgun(c: *cgen, n: *node) void = {
 	// Match C cgen ordering: evaluate operand first (load into AX),
 	// then apply the unary op. AMP / STAR override AX with the
 	// address / deref. The wasted load before AMP keeps our asm
@@ -541,7 +565,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_BIN) {
+fn cgbin(c: *cgen, n: *node) void = {
 	let unsignd: bool = nodeisunsigned(c, n.lhs);
 	if (!unsignd) { unsignd = nodeisunsigned(c, n.rhs); };
 
@@ -606,7 +630,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_CALL) {
+fn cgcall(c: *cgen, n: *node) void = {
 	let nargs: i32 = pushargsrev(c, n.list);
 	let i: i32 = 0;
 	for (i < nargs) {
@@ -710,7 +734,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_ASSIGN) {
+fn cgassign(c: *cgen, n: *node) void = {
 	let lhs: *node = n.lhs;
 	// `*p = v` — deref-assign. Element width comes from the
 	// pointer's declared type. Mirrors C cgen: eval rhs (AX,
@@ -1073,5 +1097,5 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	};
 	return;
 };
-};
+
 

selfhost/cmd/wcc/cgen_stmt.ww

@@ -1,10 +1,12 @@
 // selfhost/cmd/wcc/cgen_stmt.ww — split out of cgen.ww.
 //
-// Houses cgstmt — statements + control flow (N_BLOCK, N_IF, N_FOR,
+// cgstmt is a thin dispatcher over n.kind; each branch defers to a
-// N_BREAK/N_CONTINUE, N_RETURN, N_LET, N_ASSIGN, etc.). The
+// per-kind helper: cgblock, cgreturn, cgexprstmt, cglet, cgif, cgfor,
-// expression generator (cgexpr) lives in cgen_expr.ww; the foundation
+// cgmassign, cgbreak, cgcontinue.
-// (types, emit primitives, collect* tables, FFI/module maps) lives in
+//
-// cgen.ww.
+// The expression generator (cgexpr) lives in cgen_expr.ww; the
+// foundation (types, emit primitives, collect* tables, FFI/module
+// maps) lives in cgen.ww.
 
 use os;
 use mem;
@@ -20,7 +22,27 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	if (n == nil) { return; };
 	let k: i32 = n.kind;
 
-	if (k == N_BLOCK) {
+	if (k == N_BLOCK) { cgblock(c, n); return; };
+
+	if (k == N_RETURN) { cgreturn(c, n); return; };
+
+	if (k == N_EXPRSTMT) { cgexprstmt(c, n); return; };
+
+	if (k == N_LET) { cglet(c, n); return; };
+
+	if (k == N_IF) { cgif(c, n); return; };
+
+	if (k == N_FOR) { cgfor(c, n); return; };
+
+	if (k == N_MASSIGN) { cgmassign(c, n); return; };
+
+	if (k == N_BREAK) { cgbreak(c, n); return; };
+	if (k == N_CONTINUE) { cgcontinue(c, n); return; };
+
+	c.last_was_return = 0;
+};
+
+fn cgblock(c: *cgen, n: *node) void = {
 	let s: *node = n.list;
 	for (s != nil) {
 		cgstmt(c, s);
@@ -29,7 +51,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_RETURN) {
+fn cgreturn(c: *cgen, n: *node) void = {
 	let rhs: *node = n.lhs;
 	if (rhs != nil) {
 		// Tuple return `return a, b;` — pack as (AX=v0, DX=v1).
@@ -96,13 +118,13 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_EXPRSTMT) {
+fn cgexprstmt(c: *cgen, n: *node) void = {
 	if (n.lhs != nil) { cgexpr(c, n.lhs); };
 	c.last_was_return = 0;
 	return;
 };
 
-	if (k == N_LET) {
+fn cglet(c: *cgen, n: *node) void = {
 	let nm: str = n.str;
 	let sz: i32 = slotsize(c, n.lhs);
 	let off: i32 = localadd(c, nm, sz, n.lhs);
@@ -244,7 +266,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_IF) {
+fn cgif(c: *cgen, n: *node) void = {
 	let els: str = mklabel(c, "else");
 	let endl: str = mklabel(c, "end");
 	cgexpr(c, n.cond);
@@ -264,7 +286,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_FOR) {
+fn cgfor(c: *cgen, n: *node) void = {
 	// Match C cgen's label scheme: <fn>_loop_N for the top,
 	// <fn>_endloop_N for the post-body merge. No separate cont
 	// label when there's no post-expression.
@@ -300,7 +322,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 // the first lvalue, then pop DX into the second. Mirrors
 // cmd/w6c/cgen.c:2424-2440. Lvalues beyond two are dropped (same
 // as C — no fixture uses >2 today).
-	if (k == N_MASSIGN) {
+fn cgmassign(c: *cgen, n: *node) void = {
 	if (n.rhs != nil) { cgexpr(c, n.rhs); };
 	emitline("\tPUSHQ\tDX\n");
 	let l0: *node = n.list;
@@ -331,7 +353,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_BREAK) {
+fn cgbreak(c: *cgen, n: *node) void = {
 	if (c.loop_top > 0) {
 		let lbl: str = c.loop_end_buf[c.loop_top - 1];
 		emitline("\tJMP\t"); emitline(lbl); emitline("\n");
@@ -339,7 +361,8 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	c.last_was_return = 0;
 	return;
 };
-	if (k == N_CONTINUE) {
+
+fn cgcontinue(c: *cgen, n: *node) void = {
 	if (c.loop_top > 0) {
 		let lbl: str = c.loop_cont_buf[c.loop_top - 1];
 		emitline("\tJMP\t"); emitline(lbl); emitline("\n");
@@ -348,6 +371,4 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	c.last_was_return = 0;
-};
 

selfhost/cmd/wwdump/main.combined.ww

@@ -4506,9 +4506,14 @@ fn taggedvariantindex(c: *cgen, tagged: *node, rhs: *node) i32 = {
 // MODULE: wcc
 // selfhost/cmd/wcc/cgen_expr.ww — split out of cgen.ww.
 //
-// Houses cgexpr — the per-expression code generator. The remainder of
+// cgexpr is a thin dispatcher over n.kind; each non-trivial branch
-// the cgen lives in cgen.ww (foundation: types, emit primitives, the
+// lives in a per-kind helper (cgstrlit, cgident, cgindex, cgmatch,
-// collect* tables, FFI/module maps) and cgen_stmt.ww (cgstmt).
+// cgdot, cgun, cgbin, cgcall, cgassign). Trivial literal loads
+// (N_INTLIT, N_RUNELIT, N_TRUE/FALSE/NIL, N_CAST) stay inline.
+//
+// The remainder of cgen lives in cgen.ww (foundation: types, emit
+// primitives, the collect* tables, FFI/module maps) and cgen_stmt.ww
+// (cgstmt).
 //
 // `use cgen_expr;` is unnecessary at consumer sites — cgen.ww imports
 // this file, so any caller of cgen transitively gets cgexpr.
@@ -4541,19 +4546,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 		emitline(", AX\n");
 		return;
 	};
-	if (k == N_STRLIT) {
+	if (k == N_STRLIT) { cgstrlit(c, n); return; };
-		// Result is the (ptr, len) pair: ptr in AX, len in BX. Call
-		// sites that expect a str arg pick these up directly.
-		let nstr: str = n.str;
-		let lab: str = internstrlit(c, nstr);
-		emitline("\tLEAQ\t");
-		os.write(1, lab.ptr, lab.len: u64);
-		emitline("(SB), AX\n");
-		emitline("\tMOVQ\t$");
-		emitint(nstr.len: i64);
-		emitline(", BX\n");
-		return;
-	};
 	if (k == N_TRUE) {
 		emitline("\tMOVQ\t$1, AX\n");
 		return;
@@ -4567,7 +4560,48 @@ fn cgexpr(c: *cgen, n: *node) void = {
 		return;
 	};
 
-	if (k == N_IDENT) {
+	if (k == N_IDENT) { cgident(c, n); return; };
+
+	if (k == N_INDEX) { cgindex(c, n); return; };
+
+	if (k == N_MATCH) { cgmatch(c, n); return; };
+
+	if (k == N_CAST) {
+		// Type casts are mostly no-ops at the asm level for our
+		// integer-shaped operands. Evaluate the source; AX holds
+		// the bits unchanged. (Sign- or zero-extending narrow loads
+		// to wider types is the loader's job, not cast's, in this
+		// minimal cgen.)
+		cgexpr(c, n.lhs);
+		return;
+	};
+
+	if (k == N_DOT) { cgdot(c, n); return; };
+
+	if (k == N_UN) { cgun(c, n); return; };
+
+	if (k == N_BIN) { cgbin(c, n); return; };
+
+	if (k == N_CALL) { cgcall(c, n); return; };
+
+	if (k == N_ASSIGN) { cgassign(c, n); return; };
+};
+
+fn cgstrlit(c: *cgen, n: *node) void = {
+	// Result is the (ptr, len) pair: ptr in AX, len in BX. Call
+	// sites that expect a str arg pick these up directly.
+	let nstr: str = n.str;
+	let lab: str = internstrlit(c, nstr);
+	emitline("\tLEAQ\t");
+	os.write(1, lab.ptr, lab.len: u64);
+	emitline("(SB), AX\n");
+	emitline("\tMOVQ\t$");
+	emitint(nstr.len: i64);
+	emitline(", BX\n");
+	return;
+};
+
+fn cgident(c: *cgen, n: *node) void = {
 	let nm: str = n.str;
 	let lc: *local = localfindnode(c, nm);
 	if (lc != nil) {
@@ -4614,7 +4648,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_INDEX) {
+fn cgindex(c: *cgen, n: *node) void = {
 	// Element-size-aware load: u8-element bases use MOVZBQ,
 	// everything else MOVQ. Fast path when the base is a bare
 	// ident (mem.ww shape).
@@ -4679,7 +4713,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_MATCH) {
+fn cgmatch(c: *cgen, n: *node) void = {
 	// match (e) { case let v: T => stmt; ... }
 	//
 	// Read the tagged-union slot and dispatch by tag. Slot
@@ -4780,17 +4814,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_CAST) {
+fn cgdot(c: *cgen, n: *node) void = {
-		// Type casts are mostly no-ops at the asm level for our
-		// integer-shaped operands. Evaluate the source; AX holds
-		// the bits unchanged. (Sign- or zero-extending narrow loads
-		// to wider types is the loader's job, not cast's, in this
-		// minimal cgen.)
-		cgexpr(c, n.lhs);
-		return;
-	};
-
-	if (k == N_DOT) {
 	let lhs: *node = n.lhs;
 	let fld: str = n.str;
 	if (lhs != nil) {
@@ -5007,7 +5031,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_UN) {
+fn cgun(c: *cgen, n: *node) void = {
 	// Match C cgen ordering: evaluate operand first (load into AX),
 	// then apply the unary op. AMP / STAR override AX with the
 	// address / deref. The wasted load before AMP keeps our asm
@@ -5047,7 +5071,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_BIN) {
+fn cgbin(c: *cgen, n: *node) void = {
 	let unsignd: bool = nodeisunsigned(c, n.lhs);
 	if (!unsignd) { unsignd = nodeisunsigned(c, n.rhs); };
 
@@ -5112,7 +5136,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_CALL) {
+fn cgcall(c: *cgen, n: *node) void = {
 	let nargs: i32 = pushargsrev(c, n.list);
 	let i: i32 = 0;
 	for (i < nargs) {
@@ -5216,7 +5240,7 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_ASSIGN) {
+fn cgassign(c: *cgen, n: *node) void = {
 	let lhs: *node = n.lhs;
 	// `*p = v` — deref-assign. Element width comes from the
 	// pointer's declared type. Mirrors C cgen: eval rhs (AX,
@@ -5579,17 +5603,19 @@ fn cgexpr(c: *cgen, n: *node) void = {
 	};
 	return;
 };
-};
+
 
 
 // MODULE: wcc
 // selfhost/cmd/wcc/cgen_stmt.ww — split out of cgen.ww.
 //
-// Houses cgstmt — statements + control flow (N_BLOCK, N_IF, N_FOR,
+// cgstmt is a thin dispatcher over n.kind; each branch defers to a
-// N_BREAK/N_CONTINUE, N_RETURN, N_LET, N_ASSIGN, etc.). The
+// per-kind helper: cgblock, cgreturn, cgexprstmt, cglet, cgif, cgfor,
-// expression generator (cgexpr) lives in cgen_expr.ww; the foundation
+// cgmassign, cgbreak, cgcontinue.
-// (types, emit primitives, collect* tables, FFI/module maps) lives in
+//
-// cgen.ww.
+// The expression generator (cgexpr) lives in cgen_expr.ww; the
+// foundation (types, emit primitives, collect* tables, FFI/module
+// maps) lives in cgen.ww.
 
 use os;
 use mem;
@@ -5605,7 +5631,27 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	if (n == nil) { return; };
 	let k: i32 = n.kind;
 
-	if (k == N_BLOCK) {
+	if (k == N_BLOCK) { cgblock(c, n); return; };
+
+	if (k == N_RETURN) { cgreturn(c, n); return; };
+
+	if (k == N_EXPRSTMT) { cgexprstmt(c, n); return; };
+
+	if (k == N_LET) { cglet(c, n); return; };
+
+	if (k == N_IF) { cgif(c, n); return; };
+
+	if (k == N_FOR) { cgfor(c, n); return; };
+
+	if (k == N_MASSIGN) { cgmassign(c, n); return; };
+
+	if (k == N_BREAK) { cgbreak(c, n); return; };
+	if (k == N_CONTINUE) { cgcontinue(c, n); return; };
+
+	c.last_was_return = 0;
+};
+
+fn cgblock(c: *cgen, n: *node) void = {
 	let s: *node = n.list;
 	for (s != nil) {
 		cgstmt(c, s);
@@ -5614,7 +5660,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_RETURN) {
+fn cgreturn(c: *cgen, n: *node) void = {
 	let rhs: *node = n.lhs;
 	if (rhs != nil) {
 		// Tuple return `return a, b;` — pack as (AX=v0, DX=v1).
@@ -5681,13 +5727,13 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_EXPRSTMT) {
+fn cgexprstmt(c: *cgen, n: *node) void = {
 	if (n.lhs != nil) { cgexpr(c, n.lhs); };
 	c.last_was_return = 0;
 	return;
 };
 
-	if (k == N_LET) {
+fn cglet(c: *cgen, n: *node) void = {
 	let nm: str = n.str;
 	let sz: i32 = slotsize(c, n.lhs);
 	let off: i32 = localadd(c, nm, sz, n.lhs);
@@ -5829,7 +5875,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_IF) {
+fn cgif(c: *cgen, n: *node) void = {
 	let els: str = mklabel(c, "else");
 	let endl: str = mklabel(c, "end");
 	cgexpr(c, n.cond);
@@ -5849,7 +5895,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_FOR) {
+fn cgfor(c: *cgen, n: *node) void = {
 	// Match C cgen's label scheme: <fn>_loop_N for the top,
 	// <fn>_endloop_N for the post-body merge. No separate cont
 	// label when there's no post-expression.
@@ -5885,7 +5931,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 // the first lvalue, then pop DX into the second. Mirrors
 // cmd/w6c/cgen.c:2424-2440. Lvalues beyond two are dropped (same
 // as C — no fixture uses >2 today).
-	if (k == N_MASSIGN) {
+fn cgmassign(c: *cgen, n: *node) void = {
 	if (n.rhs != nil) { cgexpr(c, n.rhs); };
 	emitline("\tPUSHQ\tDX\n");
 	let l0: *node = n.list;
@@ -5916,7 +5962,7 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	if (k == N_BREAK) {
+fn cgbreak(c: *cgen, n: *node) void = {
 	if (c.loop_top > 0) {
 		let lbl: str = c.loop_end_buf[c.loop_top - 1];
 		emitline("\tJMP\t"); emitline(lbl); emitline("\n");
@@ -5924,7 +5970,8 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	c.last_was_return = 0;
 	return;
 };
-	if (k == N_CONTINUE) {
+
+fn cgcontinue(c: *cgen, n: *node) void = {
 	if (c.loop_top > 0) {
 		let lbl: str = c.loop_cont_buf[c.loop_top - 1];
 		emitline("\tJMP\t"); emitline(lbl); emitline("\n");
@@ -5933,8 +5980,6 @@ fn cgstmt(c: *cgen, n: *node) void = {
 	return;
 };
 
-	c.last_was_return = 0;
-};
 
 
 // MODULE: wcc