yocto-poky/meta/recipes-devtools/gcc/gcc-5.2/0037-pr65779.patch

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Date: Mon, 20 Apr 2015 12:40:49 +0930
From: Alan Modra <amodra at gmail dot com>
To: gcc-patches at gcc dot gnu dot org
Subject: [Patch] pr65779 - [5/6 Regression] undefined local symbol on powerpc

This patch removes bogus debug info left around by shrink-wrapping,
which on some powerpc targets with just the right register allocation
led to assembly errors.

Bootstrapped and regression tested powerpc64-linux and x86_64-linux.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65779

gcc/
	PR debug/65779
	* shrink-wrap.c (insn_uses_reg): New function.
	(move_insn_for_shrink_wrap): Remove debug insns using regs set
	by the moved insn.
gcc/testsuite/
	* gcc.dg/pr65779.c: New.
	
Upstream-Status: Pending (from mailing list, not merged yet)

Index: a/gcc/shrink-wrap.c
===================================================================
--- a/gcc/shrink-wrap.c.orig
+++ b/gcc/shrink-wrap.c
@@ -182,6 +182,21 @@ live_edge_for_reg (basic_block bb, int r
   return live_edge;
 }
 
+static bool
+insn_uses_reg (rtx_insn *insn, unsigned int regno, unsigned int end_regno)
+{
+  df_ref use;
+
+  FOR_EACH_INSN_USE (use, insn)
+    {
+      rtx reg = DF_REF_REG (use);
+
+      if (REG_P (reg) && REGNO (reg) >= regno && REGNO (reg) < end_regno)
+	return true;
+    }
+  return false;
+}
+
 /* Try to move INSN from BB to a successor.  Return true on success.
    USES and DEFS are the set of registers that are used and defined
    after INSN in BB.  SPLIT_P indicates whether a live edge from BB
@@ -340,10 +355,15 @@ move_insn_for_shrink_wrap (basic_block b
       *split_p = true;
     }
 
+  vec<basic_block> live_bbs;
+  if (MAY_HAVE_DEBUG_INSNS)
+    live_bbs.create (5);
   /* At this point we are committed to moving INSN, but let's try to
      move it as far as we can.  */
   do
     {
+      if (MAY_HAVE_DEBUG_INSNS)
+	live_bbs.safe_push (bb);
       live_out = df_get_live_out (bb);
       live_in = df_get_live_in (next_block);
       bb = next_block;
@@ -426,6 +446,34 @@ move_insn_for_shrink_wrap (basic_block b
 	SET_REGNO_REG_SET (bb_uses, i);
     }
 
+  /* Remove debug insns using regs set by the insn we are moving.  */
+  if (MAY_HAVE_DEBUG_INSNS)
+    {
+      while (!live_bbs.is_empty ())
+	{
+	  rtx_insn *dinsn;
+	  basic_block tmp_bb = live_bbs.pop ();
+
+	  FOR_BB_INSNS_REVERSE (tmp_bb, dinsn)
+	    {
+	      if (dinsn == insn)
+		break;
+	      if (DEBUG_INSN_P (dinsn)
+		  && insn_uses_reg (dinsn, dregno, end_dregno))
+		{
+		  if (*split_p)
+		    /* If split, then we will be moving insn into a
+		       newly created block immediately after the entry
+		       block.  Move the debug info there too.  */
+		    emit_debug_insn_after (PATTERN (dinsn), bb_note (bb));
+		  delete_insn (dinsn);
+		  break;
+		}
+	    }
+	}
+      live_bbs.release ();
+    }
+
   emit_insn_after (PATTERN (insn), bb_note (bb));
   delete_insn (insn);
   return true;
Index: b/gcc/testsuite/gcc.dg/pr65779.c
===================================================================
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr65779.c
@@ -0,0 +1,64 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -g" } */
+/* { dg-additional-options "-mrelocatable" { target powerpc-*-rtems* } } */
+
+unsigned long __attribute__ ((noinline))
+adler32 (unsigned long adler, unsigned char *buf, unsigned int len)
+{
+  unsigned long s1 = adler & 0xffff;
+  unsigned long s2 = (adler >> 16) & 0xffff;
+  int k;
+
+  if (buf == 0)
+    return 1L;
+
+  while (len > 0)
+    {
+      k = len < 5552 ? len : 5552;
+      len -= k;
+      while (k >= 16)
+	{
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  s1 += *buf++; s2 += s1;
+	  k -= 16;
+	}
+      if (k != 0)
+	do
+	  {
+	    s1 += *buf++; s2 += s1;
+	  } while (--k);
+      s1 &= 0xffffffffUL;
+      s2 &= 0xffffffffUL;
+      s1 %= 65521L;
+      s2 %= 65521L;
+    }
+  return (s2 << 16) | s1;
+}
+
+unsigned char buf[] = { 0, 1, 2, 3, 4, 5, 6, 7,
+			8, 9, 10, 11, 12, 13, 14, 15,
+			0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+			0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+			0x55, 0xaa };
+int
+main ()
+{
+  unsigned long x = adler32 (0, buf, sizeof buf);
+  if (x != 0x640409efUL)
+    __builtin_abort ();
+  return 0;
+}