From 700b640cf1f07ae02460b51f006e3416bfb47e6d Mon Sep 17 00:00:00 2001
From: John Alanbrook <john@pockle.world>
Date: Sat, 21 Feb 2026 04:13:21 -0600
Subject: [PATCH] type propagation

---
 mcode.cm | 69 ++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 47 insertions(+), 22 deletions(-)

diff --git a/mcode.cm b/mcode.cm
index beb659f8..c6fae5b3 100644
--- a/mcode.cm
+++ b/mcode.cm
@@ -89,6 +89,8 @@ var mcode = function(ast) {
   var s_filename = null
   var s_has_disruption = false
   var s_slot_types = {}
+  var s_num_err_label = null
+  var s_num_err_emitted = false
 
   // Shared closure vars for binop helpers (avoids >4 param functions)
   var _bp_dest = 0
@@ -118,7 +120,9 @@ var mcode = function(ast) {
       cur_line: s_cur_line,
       cur_col: s_cur_col,
       has_disruption: s_has_disruption,
-      slot_types: s_slot_types
+      slot_types: s_slot_types,
+      num_err_label: s_num_err_label,
+      num_err_emitted: s_num_err_emitted
     }
   }
 
@@ -141,6 +145,8 @@ var mcode = function(ast) {
     s_cur_col = saved.cur_col
     s_has_disruption = saved.has_disruption
     s_slot_types = saved.slot_types
+    s_num_err_label = saved.num_err_label
+    s_num_err_emitted = saved.num_err_emitted
   }
 
   // Slot allocation
@@ -413,29 +419,37 @@ var mcode = function(ast) {
   var emit_numeric_binop = function(op_str) {
     var left_known = is_known_number(_bp_ln) || slot_is_num(_bp_left)
     var right_known = is_known_number(_bp_rn) || slot_is_num(_bp_right)
+    var t0 = null
+    var done = null
     if (left_known && right_known) {
       emit_3(op_str, _bp_dest, _bp_left, _bp_right)
       mark_slot(_bp_dest, "num")
       return null
     }
-    var t0 = alloc_slot()
-    var err = gen_label("num_err")
-    var done = gen_label("num_done")
+    if (s_num_err_label == null) {
+      s_num_err_label = gen_label("num_err")
+    }
+    t0 = alloc_slot()
     if (!left_known) {
       emit_2("is_num", t0, _bp_left)
-      emit_jump_cond("jump_false", t0, err)
+      emit_jump_cond("jump_false", t0, s_num_err_label)
+      mark_slot(_bp_left, "num")
     }
     if (!right_known) {
       emit_2("is_num", t0, _bp_right)
-      emit_jump_cond("jump_false", t0, err)
+      emit_jump_cond("jump_false", t0, s_num_err_label)
+      mark_slot(_bp_right, "num")
     }
     emit_3(op_str, _bp_dest, _bp_left, _bp_right)
-    emit_jump(done)
-
-    emit_label(err)
-    emit_log_error("cannot apply '" + _bp_op_sym + "': operands must be numbers")
-    emit_0("disrupt")
-    emit_label(done)
+    if (!s_num_err_emitted) {
+      done = gen_label("num_done")
+      emit_jump(done)
+      emit_label(s_num_err_label)
+      emit_log_error("operands must be numbers")
+      emit_0("disrupt")
+      emit_label(done)
+      s_num_err_emitted = true
+    }
     mark_slot(_bp_dest, "num")
     return null
   }
@@ -460,23 +474,30 @@ var mcode = function(ast) {
 
   // emit_neg_decomposed: emit type-guarded negate
   var emit_neg_decomposed = function(dest, src, src_node) {
+    var t0 = null
+    var done = null
     if (is_known_number(src_node) || slot_is_num(src)) {
       emit_2("negate", dest, src)
       mark_slot(dest, "num")
       return null
     }
-    var t0 = alloc_slot()
-    var err = gen_label("neg_err")
-    var done = gen_label("neg_done")
+    if (s_num_err_label == null) {
+      s_num_err_label = gen_label("num_err")
+    }
+    t0 = alloc_slot()
     emit_2("is_num", t0, src)
-    emit_jump_cond("jump_false", t0, err)
+    emit_jump_cond("jump_false", t0, s_num_err_label)
+    mark_slot(src, "num")
     emit_2("negate", dest, src)
-    emit_jump(done)
-
-    emit_label(err)
-    emit_log_error("cannot negate: operand must be a number")
-    emit_0("disrupt")
-    emit_label(done)
+    if (!s_num_err_emitted) {
+      done = gen_label("num_done")
+      emit_jump(done)
+      emit_label(s_num_err_label)
+      emit_log_error("operands must be numbers")
+      emit_0("disrupt")
+      emit_label(done)
+      s_num_err_emitted = true
+    }
     mark_slot(dest, "num")
     return null
   }
@@ -2605,6 +2626,8 @@ var mcode = function(ast) {
     s_vars = []
     s_intrinsic_cache = []
     s_slot_types = {}
+    s_num_err_label = null
+    s_num_err_emitted = false
     s_loop_break = null
     s_loop_continue = null
     s_label_map = {}
@@ -2804,6 +2827,8 @@ var mcode = function(ast) {
     s_label_counter = 0
     s_func_counter = 0
     s_slot_types = {}
+    s_num_err_label = null
+    s_num_err_emitted = false
     s_loop_break = null
     s_loop_continue = null
     s_label_map = {}