calls.c (alloca_call_p): New global function.

	* calls.c (alloca_call_p): New global function.
	* tree.h (alloca_call_p): New.
	* tree-inline.c (inlinable_function_p):  Do not inline when
	function calls alloca.
	(find_alloca_call, find_alloca_call_1): New functions.

From-SVN: r59228

4 files changed, 54 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f323ff1..9bfbfae 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+Sun Nov 17 00:01:28 CET 2002  Jan Hubicka  <jh@suse.cz>
+
+	* calls.c (alloca_call_p): New global function.
+	* tree.h (alloca_call_p): New.
+	* tree-inline.c (inlinable_function_p):  Do not inline when
+	function calls alloca.
+	(find_alloca_call, find_alloca_call_1): New functions.
+
 2002-11-18  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* config/h8300/h8300.md (*andorqi3): Use bor between bld and
diff --git a/gcc/calls.c b/gcc/calls.c
index f2f9c57..99722b5 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -801,6 +801,21 @@ setjmp_call_p (fndecl)
   return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
 }
 
+/* Return true when exp contains alloca call.  */
+bool
+alloca_call_p (exp)
+     tree exp;
+{
+  if (TREE_CODE (exp) == CALL_EXPR
+      && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
+      && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
+	  == FUNCTION_DECL)
+      && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
+			      0) & ECF_MAY_BE_ALLOCA))
+    return true;
+  return false;
+}
+
 /* Detect flags (function attributes) from the function decl or type node.  */
 
 static int
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 362ddd1..73ba48a 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -122,6 +122,8 @@ static void copy_scope_stmt PARAMS ((tree *, int *, inline_data *));
 static tree initialize_inlined_parameters PARAMS ((inline_data *, tree, tree, tree));
 static void remap_block PARAMS ((tree *, tree, inline_data *));
 static tree add_stmt_to_compound PARAMS ((tree, tree, tree));
+static tree find_alloca_call_1 PARAMS ((tree *, int *, void *));
+static tree find_alloca_call PARAMS ((tree));
 #endif /* INLINER_FOR_JAVA */
 
 /* The approximate number of instructions per statement.  This number
@@ -857,6 +859,27 @@ tree_inlinable_function_p (fn)
   return inlinable_function_p (fn, NULL);
 }
 
+/* if *TP is possibly call to alloca, return nonzero.  */
+static tree
+find_alloca_call_1 (tp, walk_subtrees, data)
+     tree *tp;
+     int *walk_subtrees ATTRIBUTE_UNUSED;
+     void *data ATTRIBUTE_UNUSED;
+{
+  if (alloca_call_p (*tp))
+    return *tp;
+  return NULL;
+}
+
+/* Return subexpression representing possible alloca call,
+   if any.  */
+static tree
+find_alloca_call (exp)
+     tree exp;
+{
+  return walk_tree (&exp, find_alloca_call_1, NULL, NULL);
+}
+
 /* Returns nonzero if FN is a function that can be inlined into the
    inlining context ID_.  If ID_ is NULL, check whether the function
    can be inlined at all.  */
@@ -897,6 +920,13 @@ inlinable_function_p (fn, id)
   else if (! (*lang_hooks.tree_inlining.disregard_inline_limits) (fn)
 	   && currfn_insns > MAX_INLINE_INSNS_SINGLE)
     ;
+  /* Refuse to inline alloca call unless user explicitly forced so as this may
+     change program's memory overhead drastically when the function using alloca
+     is called in loop.  In GCC present in SPEC2000 inlining into schedule_block
+     cause it to require 2GB of ram instead of 256MB.  */
+  else if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)) == NULL
+	   && find_alloca_call (DECL_SAVED_TREE (fn)))
+    ;
   /* All is well.  We can inline this function.  Traditionally, GCC
      has refused to inline functions using alloca, or functions whose
      values are returned in a PARALLEL, and a few other such obscure
diff --git a/gcc/tree.h b/gcc/tree.h
index 8e8b168..fc40517 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3018,6 +3018,7 @@ extern rtx emit_line_note		PARAMS ((const char *, int));
 /* In calls.c */
 
 extern int setjmp_call_p		PARAMS ((tree));
+extern bool alloca_call_p		PARAMS ((tree));
 
 /* In attribs.c.  */