From: Nathan Sidwell <nathan@acm.org>
Date: Wed, 13 May 2020 20:11:36 +0000 (-0700)
Subject: c++: Simplify canonical_type_parameter
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=833c7b4b5ef071bc3c5c79108baff55f2bcaaac3;p=gcc.git

c++: Simplify canonical_type_parameter

Use a single vec_safe_grow_cleared, rather than that or a vec_alloc.
Use a for loop that returns early.

	* pt.c (canonical_type_parameter): Simplify.
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index b75025f389b..10f212f2e53 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,7 @@
 2020-05-13  Nathan Sidwell  <nathan@acm.org>
 
+	* pt.c (canonical_type_parameter): Simplify.
+
 	Formatting fixups & some simplifications.
 	* pt.c (spec_hash_table): New typedef.
 	(decl_specializations, type_specializations): Use it.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index a732ced2d8d..ec2ca3e19de 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -4417,29 +4417,21 @@ build_template_parm_index (int index,
 static tree
 canonical_type_parameter (tree type)
 {
-  tree list;
   int idx = TEMPLATE_TYPE_IDX (type);
 
   gcc_assert (TREE_CODE (type) != TEMPLATE_TEMPLATE_PARM);
 
-  if (!canonical_template_parms)
-    vec_alloc (canonical_template_parms, idx + 1);
-
-  if (canonical_template_parms->length () <= (unsigned) idx)
+  if (vec_safe_length (canonical_template_parms) <= (unsigned) idx)
     vec_safe_grow_cleared (canonical_template_parms, idx + 1);
 
-  list = (*canonical_template_parms)[idx];
-  while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
-    list = TREE_CHAIN (list);
+  for (tree list = (*canonical_template_parms)[idx];
+       list; list = TREE_CHAIN (list))
+    if (comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
+      return TREE_VALUE (list);
 
-  if (list)
-    return TREE_VALUE (list);
-  else
-    {
-      (*canonical_template_parms)[idx]
-	= tree_cons (NULL_TREE, type, (*canonical_template_parms)[idx]);
-      return type;
-    }
+  (*canonical_template_parms)[idx]
+    = tree_cons (NULL_TREE, type, (*canonical_template_parms)[idx]);
+  return type;
 }
 
 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose