[PATCH] Attempt to prevent cross-jumping of noreturn calls with different args sizes (PR debug/51762)

[Jakub Jelinek]

Hi!

The attached testcase on i?86 (32-bit) ICEs, because the csa pass
cross-jumps the two noret calls, eventhough they have different args size
depths.

The following patch attempts to fix that up by forcibly adding REG_ARGS_SIZE
notes to all noreturn calls when not accumulating outgoing args, which works
for this and passed bootstrap/regtest on x86_64-linux and i686-linux.
Ok?

2012-01-05  Jakub Jelinek  <ja...@redhat.com>

        PR debug/51762
        * calls.c (emit_call_1): For noreturn calls force a REG_ARGS_SIZE
        note when !ACCUMULATE_OUTGOING_ARGS.

        * gcc.dg/pr51762.c: New test.

--- gcc/calls.c.jj      2011-12-21 19:24:55.000000000 +0100
+++ gcc/calls.c 2012-01-05 13:56:02.415231434 +0100
@@ -445,6 +445,11 @@ emit_call_1 (rtx funexp, tree fntree ATT
       if (SUPPORTS_STACK_ALIGNMENT)
         crtl->need_drap = true;
     }
+  /* For noreturn calls when not accumulating outgoing args force
+     REG_ARGS_SIZE note to prevent crossjumping of calls with different
+     args sizes.  */
+  else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
+    add_reg_note (call_insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
 
   if (!ACCUMULATE_OUTGOING_ARGS)
     {
--- gcc/testsuite/gcc.dg/pr51762.c.jj   2012-01-05 13:52:53.188328851 +0100
+++ gcc/testsuite/gcc.dg/pr51762.c      2012-01-05 13:28:50.000000000 +0100
@@ -0,0 +1,19 @@
+/* PR debug/51762 */
+/* { dg-do compile } */
+/* { dg-options "-g -Os -fomit-frame-pointer -fno-asynchronous-unwind-tables" 
} */
+
+void noret (void) __attribute__ ((noreturn));
+int bar (void);
+void baz (const char *);
+static int v = -1;
+
+void
+foo (void)
+{
+  if (bar () && v == -1)
+    {
+      baz ("baz");
+      noret ();
+    }
+  noret ();
+}

        Jakub