Merge up to 239078.ibm/gcc-4_9-branch

	Upstream FSF 4.9 release branch is now closed.
	* REVISION: Update subversion id.


git-svn-id: https://gcc.gnu.org/svn/gcc/branches/ibm/gcc-4_9-branch@239087 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 45 insertions, 2 deletions

diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c
index 8d99a31d5df..bd6cbe82e82 100644
--- a/gcc/tree-ssa-strlen.c
+++ b/gcc/tree-ssa-strlen.c
@@ -768,6 +768,49 @@ find_equal_ptrs (tree ptr, int idx)
     }
 }
 
+/* Return true if STMT is a call to a builtin function with the right
+   arguments and attributes that should be considered for optimization
+   by this pass.  */
+
+static bool
+valid_builtin_call (gimple stmt)
+{
+  if (!gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
+    return false;
+
+  tree callee = gimple_call_fndecl (stmt);
+  switch (DECL_FUNCTION_CODE (callee))
+    {
+    case BUILT_IN_STRCHR:
+    case BUILT_IN_STRLEN:
+      /* The above functions should be pure.  Punt if they aren't.  */
+      if (gimple_vdef (stmt) || gimple_vuse (stmt) == NULL_TREE)
+	return false;
+      break;
+
+    case BUILT_IN_MEMCPY:
+    case BUILT_IN_MEMCPY_CHK:
+    case BUILT_IN_MEMPCPY:
+    case BUILT_IN_MEMPCPY_CHK:
+    case BUILT_IN_STPCPY:
+    case BUILT_IN_STPCPY_CHK:
+    case BUILT_IN_STRCAT:
+    case BUILT_IN_STRCAT_CHK:
+    case BUILT_IN_STRCPY:
+    case BUILT_IN_STRCPY_CHK:
+      /* The above functions should be neither const nor pure.  Punt if they
+	 aren't.  */
+      if (gimple_vdef (stmt) == NULL_TREE || gimple_vuse (stmt) == NULL_TREE)
+	return false;
+      break;
+
+    default:
+      break;
+    }
+
+  return true;
+}
+
 /* If the last .MEM setter statement before STMT is
    memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT
    and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to
@@ -842,7 +885,7 @@ adjust_last_stmt (strinfo si, gimple stmt, bool is_strcat)
       return;
     }
 
-  if (!gimple_call_builtin_p (last.stmt, BUILT_IN_NORMAL))
+  if (!valid_builtin_call (last.stmt))
     return;
 
   callee = gimple_call_fndecl (last.stmt);
@@ -1827,7 +1870,7 @@ strlen_optimize_stmt (gimple_stmt_iterator *gsi)
   if (is_gimple_call (stmt))
     {
       tree callee = gimple_call_fndecl (stmt);
-      if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
+      if (valid_builtin_call (stmt))
 	switch (DECL_FUNCTION_CODE (callee))
 	  {
 	  case BUILT_IN_STRLEN: