lineof.diff

--- compilers/pct/src/PCT/HLLCompiler.pir.orig  2011-08-31 13:29:53.000000000 +0000
+++ compilers/pct/src/PCT/HLLCompiler.pir       2011-08-31 14:59:36.000000000 +0000
@@ -1009,8 +1009,22 @@ memoize the line offsets as a C<!lineof>
     # element is the line number to be returned.
     # (Potential optimization: use a binary search.)
     .local int line, count
+    .local pmc lastpos, lastline
     count = elements linepos
     line = 0
+    unless cache goto line_loop
+    lastpos = getprop '!linepos_lastpos', target
+    lastline = getprop '!linepos_lastline', target
+    unless null lastpos goto line_loop_tstlast
+    lastpos = new ['Integer']
+    lastline = new ['Integer']
+    setprop target, '!linepos_lastpos', lastpos
+    setprop target, '!linepos_lastline', lastline
+    goto line_loop
+  line_loop_tstlast:
+    $I0 = lastpos
+    if $I0 > pos goto line_loop
+    line = lastline
   line_loop:
     if line >= count goto line_done
     $I0 = linepos[line]
@@ -1018,6 +1032,10 @@ memoize the line offsets as a C<!lineof>
     inc line
     goto line_loop
   line_done:
+    unless cache goto line_done2
+    lastpos = pos
+    lastline = line
+  line_done2:
     .return (line)
 .end