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[patch] Fix ICE during out-of-SSA


This is a regression present on mainline and 4.7 branch for targets using SJLJ 
exceptions by default in Ada (e.g. ARM).  The error message is:

Unable to coalesce ssa_names 2 and 20 which are marked as MUST COALESCE.
b1_2(ab) and  b1_20(ab)
+===========================GNAT BUG DETECTED==============================+
| 4.8.0 20120716 (experimental) [trunk revision 189525] (x86_64-suse-linux) GCC 
error:|
| SSA corruption                                                           |
| Error detected around p.adb:4:1     

It's the usual case of overlapping live ranges for (ab) SSA names.

Tested on x86_64-suse-linux, OK for the mainline and 4.7 branch?


2012-07-18  Eric Botcazou  <ebotcazou@adacore.com>

	* tree-ssa-forwprop.c (combine_conversions): Punt if the RHS of the
	defining statement is a SSA name that occurs in abnormal PHIs.


2012-07-18  Eric Botcazou  <ebotcazou@adacore.com>

	* gnat.dg/aggr20.ad[sb]: New test.
	* gnat.dg/aggr20_pkg.ads: New helper.


-- 
Eric Botcazou
Index: tree-ssa-forwprop.c
===================================================================
--- tree-ssa-forwprop.c	(revision 189525)
+++ tree-ssa-forwprop.c	(working copy)
@@ -2584,6 +2584,11 @@ combine_conversions (gimple_stmt_iterato
       unsigned int final_prec = TYPE_PRECISION (type);
       int final_unsignedp = TYPE_UNSIGNED (type);
 
+      /* Don't propagate ssa names that occur in abnormal phis.  */
+      if (TREE_CODE (defop0) == SSA_NAME
+	  && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (defop0))
+	return 0;
+
       /* In addition to the cases of two conversions in a row
 	 handled below, if we are converting something to its own
 	 type via an object of identical or wider precision, neither
-- { dg-do compile }

package body Aggr20 is

   procedure Proc (R : out Rec3) is
   begin
      R := (Callback => Nil_Rec2);
   end;

end Aggr20;
with Aggr20_Pkg; use Aggr20_Pkg;
with System;

package Aggr20 is

   type Rec1 is record
      Address : System.Address;
   end record;

   Nil_Rec1 : constant Rec1 := (Address => Default_Nil_Address);

   type Rec2 is record
      Callback : Rec1;
   end record;

   Nil_Rec2 : constant Rec2 := (Callback => Nil_Rec1);

   type Rec3 is record
      Callback : Rec2;
   end record;

   procedure Proc (R : out Rec3);

end Aggr20;
with System;

package Aggr20_Pkg is

   procedure Proc;

   Default_Nil_Address : constant System.Address := Proc'Address;

end Aggr20_Pkg;

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