From patchwork Thu Aug 12 08:10:28 2010
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Subject: Fix VTA ICE (PR debug/45259)
From: Jakub Jelinek <jakub@redhat.com>
X-Patchwork-Id: 61544
Message-Id: <20100812081028.GM702@tyan-ft48-01.lab.bos.redhat.com>
To: gcc-patches@gcc.gnu.org
Date: Thu, 12 Aug 2010 10:10:28 +0200

Hi!

When fixing PR42918, I wasn't aware of reload chain pointing also to
insns before basic block (like jump tables) with ->block number of the
following bb.  The moving of notes in that case is both completely
unnecessary (as the jump tables etc. certainly can't cause any register
saves, therefore there is nothing to restore), but doesn't work (both
in that it tries to move around block notes and that it fails assertion
because it sees CODE_LABEL or BARRIER insns, which is neither a NOTE nor
DEBUG_INSN nor last->insn.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux.
Ok for trunk/4.5?

2010-08-12  Jakub Jelinek  <jakub@redhat.com>

	PR debug/45259
	* caller-save.c (save_call_clobbered_regs): Only swap notes with
	DEBUG_INSNs if n_regs_saved.

	* gcc.dg/pr45259.c: New test.


	Jakub


--- gcc/caller-save.c.jj	2010-08-11 21:08:06.000000000 +0200
+++ gcc/caller-save.c	2010-08-11 22:23:12.000000000 +0200
@@ -868,7 +868,10 @@ save_call_clobbered_regs (void)
 	     remain saved.  If the last insn in the block is a JUMP_INSN, put
 	     the restore before the insn, otherwise, put it after the insn.  */
 
-	  if (DEBUG_INSN_P (insn) && last && last->block == chain->block)
+	  if (n_regs_saved
+	      && DEBUG_INSN_P (insn)
+	      && last
+	      && last->block == chain->block)
 	    {
 	      rtx ins, prev;
 	      basic_block bb = BLOCK_FOR_INSN (insn);
--- gcc/testsuite/gcc.dg/pr45259.c.jj	2010-08-11 22:12:19.000000000 +0200
+++ gcc/testsuite/gcc.dg/pr45259.c	2010-08-11 21:43:24.000000000 +0200
@@ -0,0 +1,42 @@
+/* PR debug/45259 */
+/* { dg-do compile } */
+/* { dg-options "-g -O2 -fpic -w" { target fpic } } */
+
+struct S { void (*bar) (long); };
+struct T { struct S *t; };
+int w;
+extern int baz (int);
+
+void
+foo (int x, int u, char *z)
+{
+  struct T *v;
+  static void *y[256] = { &&l1, &&l2 };
+  for (;;)
+    switch (x)
+      {
+      l2:
+	x = 9;
+      case 9:
+	goto *y[*z++];
+      case 10:
+      case 27:
+      case 54:
+      case 99:
+      case 100:
+      case 120:
+      case 122:
+      case 131:
+      case 132:
+      case 134:
+      case 141:
+      case 142:
+	v->t->bar (u);
+	v->t->bar (u);
+      case 143:
+	continue;
+      l1:
+      default:
+	baz (w);
+      }
+}