[gsubgpos] Also match second component in (Chain)RuleSet::apply()

Another 40% speedup in shaping Gulzar-Regular.

src/hb-ot-layout-gsubgpos.hh

@@ -2170,18 +2170,18 @@ struct RuleSet
       ;
     }
 
-    /* This version is optimized for speed by matching the first component
-     * of the rule here, instead of calling into the matching code.
+    /* This version is optimized for speed by matching the first & second
+     * components of the rule here, instead of calling into the matching code.
      *
      * Replicated from LigatureSet::apply(). */
 
     hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
-    skippy_iter.reset (c->buffer->idx, 1);
+    skippy_iter.reset (c->buffer->idx, 2);
     skippy_iter.set_match_func (match_always, nullptr);
     skippy_iter.set_glyph_data ((HBUINT16 *) nullptr);
-    unsigned unsafe_to;
-    hb_glyph_info_t *first = nullptr;
-    bool matched = skippy_iter.next (&unsafe_to);
+    unsigned unsafe_to = (unsigned) -1, unsafe_to1 = 0, unsafe_to2 = 0;
+    hb_glyph_info_t *first = nullptr, *second = nullptr;
+    bool matched = skippy_iter.next ();
     if (likely (matched))
     {
       first = &c->buffer->info[skippy_iter.idx];
@@ -2207,6 +2207,12 @@ struct RuleSet
       )
       ;
     }
+    matched = skippy_iter.next ();
+    if (likely (matched && !skippy_iter.may_skip (c->buffer->info[skippy_iter.idx])))
+    {
+      second = &c->buffer->info[skippy_iter.idx];
+      unsafe_to2 = skippy_iter.idx + 1;
+    }
 
     bool unsafe_to_concat = false;
 
@@ -2220,15 +2226,34 @@ struct RuleSet
 	  (!lookup_context.funcs.match ||
 	   lookup_context.funcs.match (*first, input.arrayZ[0], lookup_context.match_data)))
       {
-	if (r.apply (c, lookup_context))
+        if (!second ||
+	    (r.inputCount <= 2 ||
+	     (!lookup_context.funcs.match ||
+	      lookup_context.funcs.match (*second, input.arrayZ[1], lookup_context.match_data)))
+	   )
 	{
-	  if (unsafe_to_concat)
-	    c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);
-	  return_trace (true);
+	  if (r.apply (c, lookup_context))
+	  {
+	    if (unsafe_to_concat)
+	      c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);
+	    return_trace (true);
+	  }
+	}
+	else
+	{
+	  if (second)
+	  {
+	    unsafe_to_concat = true;
+	    unsafe_to = unsafe_to2;
+	  }
 	}
       }
       else
-        unsafe_to_concat = true;
+      {
+	unsafe_to_concat = true;
+	if (unsafe_to == (unsigned) -1)
+	  unsafe_to = unsafe_to1;
+      }
     }
     if (likely (unsafe_to_concat))
       c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);
@@ -3324,22 +3349,22 @@ struct ChainRuleSet
       ;
     }
 
-    /* This version is optimized for speed by matching the first component
-     * of the rule here, instead of calling into the matching code.
+    /* This version is optimized for speed by matching the first & second
+     * components of the rule here, instead of calling into the matching code.
      *
      * Replicated from LigatureSet::apply(). */
 
     hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
-    skippy_iter.reset (c->buffer->idx, 1);
+    skippy_iter.reset (c->buffer->idx, 2);
     skippy_iter.set_match_func (match_always, nullptr);
     skippy_iter.set_glyph_data ((HBUINT16 *) nullptr);
-    unsigned unsafe_to;
-    hb_glyph_info_t *first = nullptr;
-    bool matched = skippy_iter.next (&unsafe_to);
+    unsigned unsafe_to = (unsigned) -1, unsafe_to1 = 0, unsafe_to2 = 0;
+    hb_glyph_info_t *first = nullptr, *second = nullptr;
+    bool matched = skippy_iter.next ();
     if (likely (matched))
     {
       first = &c->buffer->info[skippy_iter.idx];
-      unsafe_to = skippy_iter.idx + 1;
+      unsafe_to1 = skippy_iter.idx + 1;
 
       if (skippy_iter.may_skip (c->buffer->info[skippy_iter.idx]))
       {
@@ -3361,6 +3386,12 @@ struct ChainRuleSet
       )
       ;
     }
+    matched = skippy_iter.next ();
+    if (likely (matched && !skippy_iter.may_skip (c->buffer->info[skippy_iter.idx])))
+     {
+      second = &c->buffer->info[skippy_iter.idx];
+      unsafe_to2 = skippy_iter.idx + 1;
+     }
 
     bool unsafe_to_concat = false;
 
@@ -3378,15 +3409,36 @@ struct ChainRuleSet
 	   (!lookahead.len || !lookup_context.funcs.match[2] ||
 	    lookup_context.funcs.match[2] (*first, lookahead.arrayZ[0], lookup_context.match_data[2])))
       {
-	if (r.apply (c, lookup_context))
+        if (!second ||
+	    (input.lenP1 > 2 ?
+	     (!lookup_context.funcs.match[1] ||
+	      lookup_context.funcs.match[1] (*second, input.arrayZ[1], lookup_context.match_data[1]))
+	     :
+	     (lookahead.len <= 2 - input.lenP1 || !lookup_context.funcs.match[2] ||
+	      lookup_context.funcs.match[2] (*second, lookahead.arrayZ[2 - input.lenP1], lookup_context.match_data[2]))))
+	{
+	  if (r.apply (c, lookup_context))
+	  {
+	    if (unsafe_to_concat)
+	      c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);
+	    return_trace (true);
+	  }
+	}
+	else
 	{
-	  if (unsafe_to_concat)
-	    c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);
-	  return_trace (true);
+	  if (second)
+	  {
+	    unsafe_to_concat = true;
+	    unsafe_to = unsafe_to2;
+	  }
 	}
       }
       else
-        unsafe_to_concat = true;
+      {
+	unsafe_to_concat = true;
+	if (unsafe_to == (unsigned) -1)
+	  unsafe_to = unsafe_to1;
+      }
     }
     if (likely (unsafe_to_concat))
       c->buffer->unsafe_to_concat (c->buffer->idx, unsafe_to);