re PR rtl-optimization/28243 (internal consistency failure when building fontforge with -O3 -fPIC -ftracer)

	PR rtl-optimization/28243
	* combine.c (distribute_notes) <REG_DEAD>: Do not consider SETs past
	the insn to which the note was originally attached.

From-SVN: r116906

4 files changed, 69 insertions, 6 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 35c029b..41aa221 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2006-09-12  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	PR rtl-optimization/28243
+	* combine.c (distribute_notes) <REG_DEAD>: Do not consider SETs past
+	the insn to which the note was originally attached.
+
 2006-09-12  Andrew Pinski  <pinskia@physics.uc.edu>
 	    Roger Sayle  <roger@eyesopen.com>
 
diff --git a/gcc/combine.c b/gcc/combine.c
index 0f4ea02..e85e9d1 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -12165,12 +12165,14 @@ distribute_notes (rtx notes, rtx from_insn, rtx i3, rtx i2, rtx elim_i2,
 		      continue;
 		    }
 
-		  /* If the register is being set at TEM, see if that is all
-		     TEM is doing.  If so, delete TEM.  Otherwise, make this
-		     into a REG_UNUSED note instead. Don't delete sets to
-		     global register vars.  */
-		  if ((REGNO (XEXP (note, 0)) >= FIRST_PSEUDO_REGISTER
-		       || !global_regs[REGNO (XEXP (note, 0))])
+		  /* If TEM is a (reaching) definition of the use to which the
+		     note was attached, see if that is all TEM is doing.  If so,
+		     delete TEM.  Otherwise, make this into a REG_UNUSED note
+		     instead.  Don't delete sets to global register vars.  */
+		  if ((!from_insn
+		       || INSN_CUID (tem) < INSN_CUID (from_insn))
+		      && (REGNO (XEXP (note, 0)) >= FIRST_PSEUDO_REGISTER
+			  || !global_regs[REGNO (XEXP (note, 0))])
 		      && reg_set_p (XEXP (note, 0), PATTERN (tem)))
 		    {
 		      rtx set = single_set (tem);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7764fb0..81f7c7f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2006-09-12  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	* gcc.dg/pr28243.c: New test.
+
 2006-09-12  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/28971
diff --git a/gcc/testsuite/gcc.dg/pr28243.c b/gcc/testsuite/gcc.dg/pr28243.c
new file mode 100644
index 0000000..f74f86e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr28243.c
@@ -0,0 +1,51 @@
+/* PR rtl-optimization/28243 */
+/* Reported by Mike Frysinger <vapier@gentoo.org> */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftracer -fPIC" } */
+
+struct displayfuncs {
+  void (*init) ();
+} funcs;
+
+struct gpsdisplay {
+  struct displayfuncs *funcs;
+};
+
+static void PSMyArc(double cx, double cy, double radx, double rady, double sa,
+		    double ta)
+{
+  double ea;
+  double temp;
+  ea = sa + ta;
+  while (sa < ea) {
+    temp = ((sa + 90) / 90) * 90;
+    PSDoArc(cx, sa, ea < temp ? ea : temp);
+    sa = temp;
+  }
+}
+
+static void PSDrawElipse()
+{
+  float cx;
+  float cy;
+  float radx;
+  float rady;
+  if (radx != rady)
+    PSMyArc(cx, cy, radx, rady, 0, 360);
+}
+
+static void PSDrawFillCircle()
+{
+  PSDrawElipse();
+}
+
+static struct displayfuncs psfuncs[] = {
+  PSDrawFillCircle
+};
+
+void _GPSDraw_CreateDisplay()
+{
+  struct gpsdisplay *gdisp;
+  gdisp->funcs = (void *)&psfuncs;
+}