From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 1 Jan 2004 13:19:41 +0000 (+0100)
Subject: re PR rtl-optimization/13521 ([3.3 only] Endless loop in calculate_global_regs_live)
X-Git-Tag: releases/gcc-3.3.3~132
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a412391c75d020d68b9a87219dd09f12025afaf8;p=thirdparty%2Fgcc.git

re PR rtl-optimization/13521 ([3.3 only] Endless loop in calculate_global_regs_live)

	PR optimization/13521
	Backport from mainline:
		2003-03-22  Richard Henderson <rth@redhat.com>

		* cfgcleanup.c (insns_match_p): Do not do EQUIV substitution
		after reload.

	* gcc.c-torture/compile/20031231-1.c: New test.

From-SVN: r75300
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e569f4d122c8..74d16a6c9ea5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2004-01-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR optimization/13521
+	Backport from mainline:
+		2003-03-22  Richard Henderson <rth@redhat.com>
+
+		* cfgcleanup.c (insns_match_p): Do not do EQUIV substitution
+		after reload.
+
 2003-12-31  Roger Sayle  <roger@eyesopen.com>
 
 	PR fortran/12632
diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c
index df914ec0cf27..aa120bd4bec2 100644
--- a/gcc/cfgcleanup.c
+++ b/gcc/cfgcleanup.c
@@ -974,7 +974,15 @@ insns_match_p (mode, i1, i2)
 #endif
 
   if (reload_completed
-      ? ! rtx_renumbered_equal_p (p1, p2) : ! rtx_equal_p (p1, p2))
+      ? rtx_renumbered_equal_p (p1, p2) : rtx_equal_p (p1, p2))
+    return true;
+
+  /* Do not do EQUIV substitution after reload.  First, we're undoing the
+     work of reload_cse.  Second, we may be undoing the work of the post-
+     reload splitting pass.  */
+  /* ??? Possibly add a new phase switch variable that can be used by
+     targets to disallow the troublesome insns after splitting.  */
+  if (!reload_completed)
     {
       /* The following code helps take care of G++ cleanups.  */
       rtx equiv1 = find_reg_equal_equiv_note (i1);
@@ -1001,11 +1009,9 @@ insns_match_p (mode, i1, i2)
 		return true;
 	    }
 	}
-
-      return false;
     }
 
-  return true;
+  return false;
 }
 
 /* Look through the insns at the end of BB1 and BB2 and find the longest
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3b58c492f1d9..e34dc4a4ca44 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2004-01-01  Jakub Jelinek  <jakub@redhat.com>
+
+	PR optimization/13521
+	* gcc.c-torture/compile/20031231-1.c: New test.
+
 2003-12-31  Roger Sayle  <roger@eyesopen.com>
 
 	PR fortran/12632
diff --git a/gcc/testsuite/gcc.c-torture/compile/20031231-1.c b/gcc/testsuite/gcc.c-torture/compile/20031231-1.c
new file mode 100644
index 000000000000..bbd8e7cb5143
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20031231-1.c
@@ -0,0 +1,51 @@
+extern int f1 (int, void *);
+extern int *f2 (void) __attribute__ ((__const__));
+extern int f3 (int, void *);
+
+int
+test (int x, char *y, int z)
+{
+  int b = 0;
+
+  if (x < 1024)
+    {
+      y[0] = '\0';
+
+      do
+	{
+	  switch (f1 (x, y + b))
+	    {
+	    case -1:
+	      if (b == 0)
+		return -1;
+	      else
+		return b;
+
+	    default:
+	      b++;
+	    }
+	}
+      while (y[b - 1] != '\0' && y[b - 1] != '\n' && b < z);
+    }
+  else
+    {
+      do
+	{
+	  switch (f3 (x, y + b))
+	    {
+	    case -1:
+	      if ((*f2 ()) == 4)
+		continue;
+	      if (b == 0)
+		return -1;
+	      else
+		return b;
+
+	    default:
+	      b++;
+	    }
+	}
+      while (y[b - 1] != '\0' && y[b - 1] != '\n' && b < z);
+    }
+  return b;
+}