optimize_mode_switching SEGV'ing on SH

[Jason R Thorpe]

Tonight while building a compiler targeted to shle-netbsdelf (see patches
posted recently), I ran into lcm.c not compiling due to a typo inside
a chunk of code wrapped in #ifdef NORMAL_MODE.

I change the code to what seemed like the obvious intent (lose the "s"
on "last_basic_blocks"), and the resulting compiler croaked building
libgcc.  Looking at the code in question again (with a brain freshly
fuled by some dinner), my "obvious fix" didn't seem so obvious anymore,
so I reverted it.  Attached is a patch that seems more likely to be
correct, but the compiler still fails:

dr-evil:thorpej 189$ gdb ./cc1 ./cc1.core 
GNU gdb 5.0nb1
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GDB is free software, covered by the GNU General Public License, and you are
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Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386--netbsdelf"...
Core was generated by `cc1'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /usr/libexec/ld.elf_so...done.
Loaded symbols for /usr/libexec/ld.elf_so
Reading symbols from /usr/lib/libintl.so.0...done.
Loaded symbols for /usr/lib/libintl.so.0
Reading symbols from /usr/lib/libc.so.12...done.
Loaded symbols for /usr/lib/libc.so.12
#0  0x8222699 in optimize_mode_switching (file=0x0)
    at ../../../gcc/gcc/lcm.c:1168
1168                info[bb->sindex].seginfo->mode = mode;
Breakpoint 1 at 0x80a990f: file ../../../gcc/gcc/diagnostic.c, line 1446.
Breakpoint 2 at 0x482a8829
Breakpoint 3 at 0x482a9164
(gdb) print last_basic_block
$1 = 4
(gdb) print bb->sindex
$2 = 3
(gdb) print info[bb->sindex]
$3 = {seginfo = 0x0, computing = 0}
(gdb) 

In context:

	bb = EXIT_BLOCK_PTR;
	info[bb->sindex].seginfo->mode = mode;

Since I reverted the change I had made earlier, the file corrently
does not compile for any target that defines NORMAL_MODE (seems like
SH is the only target in this category).

-- 
        -- Jason R. Thorpe <thorpej@wasabisystems.com>
-------------- next part --------------
Index: lcm.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/lcm.c,v
retrieving revision 1.41
diff -u -r1.41 lcm.c
--- lcm.c	17 May 2002 01:33:16 -0000	1.41
+++ lcm.c	17 May 2002 01:42:19 -0000
@@ -1065,7 +1065,7 @@
   if (VARRAY_SIZE (basic_block_info) < last_basic_block)
     VARRAY_GROW (basic_block_info, last_basic_block);
   BASIC_BLOCK (last_basic_block - 1) = EXIT_BLOCK_PTR;
-  EXIT_BLOCK_PTR->sindex = last_basic_blocks;
+  EXIT_BLOCK_PTR->sindex = last_basic_block - 1;
 #endif
 
   /* Create the bitmap vectors.  */