[PATCH] Fix ix86_function_regparm with optimize attribute (PR target/60062)

[Jakub Jelinek]

Hi!

Using !!optimize to determine if we should switch local ABI to regparm
convention isn't compatible with optimize attribute, as !!optimize is
whether the current function is being optimized, but for the ABI decisions
we actually need the caller and callee to agree on the calling convention.

Fixed by looking at callee's optimize settings all the time.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2014-02-05  Jakub Jelinek  <ja...@redhat.com>

        PR target/60062
        * config/i386/i386.c (ix86_function_regparm): Use optimize
        from the callee instead of current function's optimize
        to determine if local regparm convention should be used.

        * gcc.c-torture/execute/pr60062.c: New test.
        * gcc.c-torture/execute/pr60072.c: New test.

--- gcc/config/i386/i386.c.jj   2014-02-04 01:36:00.000000000 +0100
+++ gcc/config/i386/i386.c      2014-02-05 09:09:29.603827877 +0100
@@ -5608,11 +5608,22 @@ ix86_function_regparm (const_tree type,
   /* Use register calling convention for local functions when possible.  */
   if (decl
       && TREE_CODE (decl) == FUNCTION_DECL
-      && optimize
       && !(profile_flag && !flag_fentry))
     {
       /* FIXME: remove this CONST_CAST when cgraph.[ch] is constified.  */
       struct cgraph_local_info *i = cgraph_local_info (CONST_CAST_TREE (decl));
+
+      /* Caller and callee must agree on the calling convention, so
+        checking here just optimize means that with
+        __attribute__((optimize (...))) caller could use regparm convention
+        and callee not, or vice versa.  Instead look at whether the callee
+        is optimized or not.  */
+      tree opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (decl);
+      if (opts == NULL_TREE)
+       opts = optimization_default_node;
+      if (!TREE_OPTIMIZATION (opts)->x_optimize)
+       i = NULL;
+
       if (i && i->local && i->can_change_signature)
        {
          int local_regparm, globals = 0, regno;
--- gcc/testsuite/gcc.c-torture/execute/pr60062.c.jj    2014-02-05 
09:02:13.703085235 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr60062.c       2014-02-05 
09:01:54.000000000 +0100
@@ -0,0 +1,25 @@
+/* PR target/60062 */
+
+int a;
+
+static void
+foo (const char *p1, int p2)
+{
+  if (__builtin_strcmp (p1, "hello") != 0)
+    __builtin_abort ();
+}
+
+static void
+bar (const char *p1)
+{
+  if (__builtin_strcmp (p1, "hello") != 0)
+    __builtin_abort ();
+}
+
+__attribute__((optimize (0))) int
+main ()
+{
+  foo ("hello", a);
+  bar ("hello");
+  return 0;
+}
--- gcc/testsuite/gcc.c-torture/execute/pr60072.c.jj    2013-08-25 
18:20:55.717911035 +0200
+++ gcc/testsuite/gcc.c-torture/execute/pr60072.c       2014-02-05 
11:33:07.501748426 +0100
@@ -0,0 +1,16 @@
+/* PR target/60072 */
+
+int c = 1;
+
+__attribute__ ((optimize (1)))
+static int *foo (int *p)
+{
+  return p;
+}
+
+int
+main ()
+{
+  *foo (&c) = 2;
+  return c - 2;
+}

        Jakub