[PATCH] Fix SRA crash

[Devang Patel <dpatel at apple dot com>]

decide_block_copy () does not disable scalarization of sub-elements  
when it encounters an element that is marked as cannot_scalarize.  
This triggers assert later on when generate_copy_inout () receives an  
element that is not instantiated and at the same time use_block_copy  
is not set. I ran into this while building large project here at  
Apple with GCC-4.0.

       * tree-sra.c (decide_block_copy): Disable scalarization of  
sub-elements.
       * g++.dg/tree-sra/ss-sra-3.C: New test.

Bootstrapped and tested on powerpc-darwin.

OK for mainline ?
OK for GCC 4.0 ?

Thanks,
-
Devang


Index: tree-sra.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-sra.c,v
retrieving revision 2.54
diff -Idpatel.pbxuser -c -3 -p -r2.54 tree-sra.c
*** tree-sra.c  9 Mar 2005 11:35:34 -0000       2.54
--- tree-sra.c  29 Mar 2005 18:59:55 -0000
*************** decide_block_copy (struct sra_elt *elt)
*** 1299,1304 ****
--- 1299,1310 ----
          fputc ('\n', dump_file);
        }

+       /* Disable scalarization of sub-elements */
+       for (c = elt->children; c; c = c->sibling)
+       {
+         c->cannot_scalarize = 1;
+         decide_block_copy (c);
+       }
        return false;
      }

Index: testsuite/g++.dg/tree-ssa/ssa-sra-3.C
===================================================================
RCS file: testsuite/g++.dg/tree-ssa/ssa-sra-3.C
diff -N testsuite/g++.dg/tree-ssa/ssa-sra-3.C
*** /dev/null   1 Jan 1970 00:00:00 -0000
--- testsuite/g++.dg/tree-ssa/ssa-sra-3.C       29 Mar 2005 18:59:58  
-0000
***************
*** 0 ****
--- 1,85 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O2" } */
+ /* Test to check use_block_copy bit propagation in sra element  
hierarchy.  */
+
+ typedef unsigned char UINT8 ;
+ typedef unsigned int UINT ;
+ class C4
+ {
+ public:
+   int xy[2];
+ };
+
+ class C3
+ {
+ public:
+   inline void
+   Reset()
+   {
+     C4 const mvMax = {0x7fff, 0x7fff};
+
+     m42(0,mvMax);
+     m42(1,mvMax);
+     m43(0);
+   };
+
+   inline void m42 (UINT  i, C4 mv)
+   {
+     mMv[i] = mv;
+   };
+
+
+
+   inline void  m43(UINT j)
+   {
+     m44 (j);
+     d41 = j + 1;
+   };
+
+ private:
+
+   C4 mMv[2];
+   UINT8 d41;
+   inline void m44 (UINT j) const {};
+ };
+
+ class C2
+ {
+ private:
+   bool valid;
+ };
+
+ class C1
+ {
+ public:
+   void m1(C3 *c);
+
+ private:
+   const C2 * d1[2];
+   void m2(C3 *m);
+ };
+
+ void C1::m1 (C3 *r)
+ {
+   C3 x;
+   m2(&x);
+ }
+ void C1::m2(C3 *x)
+ {
+   C3 m3;
+   int i;
+   m3.Reset ();
+   for(i=0; i<2; i++)
+     {
+       const C2 * r = d1[i];
+       if (r!=__null)
+         {
+         C4 const c400 = {0,0};
+           m3.m42 (i, c400);
+
+         }
+     }
+ }
+
+
+