fwprop.c (forward_propagate_and_simplify): Only attach a REG_EQUAL note to an insn if the destination is a register.

* fwprop.c (forward_propagate_and_simplify): Only attach a
        REG_EQUAL note to an insn if the destination is a register.
        * gcse.c (try_replace_reg): Likewise.

        testsuite/
        * gnat.dg/memtrap.adb: New test.

From-SVN: r164245

gcc/ChangeLog

@@ -1,3 +1,9 @@
+2010-09-13  Olivier Hainque  <hainque@adacore.com>
+
+        * fwprop.c (forward_propagate_and_simplify): Only attach a
+	REG_EQUAL note to an insn if the destination is a register.
+        * gcse.c (try_replace_reg): Likewise.
+
 2010-09-13  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/45611

gcc/fwprop.c

@@ -1294,10 +1294,11 @@ forward_propagate_and_simplify (df_ref use, rtx def_insn, rtx def_set)
 	loc = &SET_SRC (use_set);
 
       /* Do not replace an existing REG_EQUAL note if the insn is not
-	 recognized.  Either we're already replacing in the note, or
+	 recognized.  Either we're already replacing in the note, or we'll
-	 we'll separately try plugging the definition in the note and
+	 separately try plugging the definition in the note and simplifying.
-	 simplifying.  */
+	 And only install a REQ_EQUAL note when the destination is a REG,
-      set_reg_equal = (note == NULL_RTX);
+	 as the note would be invalid otherwise.  */
+      set_reg_equal = (note == NULL_RTX && REG_P (SET_DEST (use_set)));
     }
 
   if (GET_MODE (*loc) == VOIDmode)

gcc/gcse.c

@@ -2351,12 +2351,10 @@ try_replace_reg (rtx from, rtx to, rtx insn)
 	  && validate_change (insn, &SET_SRC (set), src, 0))
 	success = 1;
 
-      /* If we've failed to do replacement, have a single SET, don't already
+      /* If we've failed perform the replacement, have a single SET to
-	 have a note, and have no special SET, add a REG_EQUAL note to not
+	 a REG destination and don't yet have a note, add a REG_EQUAL note
-	 lose information.  */
+	 to not lose information.  */
-      if (!success && note == 0 && set != 0
+      if (!success && note == 0 && set != 0 && REG_P (SET_DEST (set)))
-	  && GET_CODE (SET_DEST (set)) != ZERO_EXTRACT
-	  && GET_CODE (SET_DEST (set)) != STRICT_LOW_PART)
 	note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src));
     }
 

gcc/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2010-09-12  Olivier Hainque  <hainque@adacore.com>
+
+	* gnat.dg/memtrap.adb: New test.
+
 2010-09-11  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
 
 	* gfortran.dg/promotion.f90: Fix options.

gcc/testsuite/gnat.dg/memtrap.adb

@@ -0,0 +1,30 @@
+-- { dg-do compile }
+-- { dg-options "-O2" }
+
+with System;
+
+procedure Memtrap is
+  X : integer;
+  for X'address use System.Null_Address;
+begin
+  X := 12;
+exception
+   when others => null;
+end;
+
+-- { dg-final { scan-assembler "__gnat_begin_handler" } }
+-- { dg-do compile }
+-- { dg-options "-O2" }
+
+with System;
+
+procedure Memtrap is
+  X : integer;
+  for X'address use System.Null_Address;
+begin
+  X := 12;
+exception
+   when others => null;
+end;
+
+-- { dg-final { scan-assembler "__gnat_begin_handler|__gnat_raise_nodefer" } }