RE: [Bug target/14041] H8300-elf unaligned word/longword access of zero initialized variables

["Dhananjay R. Deshpande" <dhananjayd at KPITCummins dot com>]

> 
> 
> Why not h8300-*?  We should care for the COFF target as long as it's
> there.

Initially the bug occurred only for elf target. Looking at generated code, it was due to linker script alignment. So I have now enabled test for h8300-*-*

> 
> Would the same problem exist on the plain H8/300 then?  IIRC, H8 is
> pretty lenient about alignment, but I don't know how lenient it is.
> Or is it the case that no plain H8/300 supports 16-bit data bus or
> something?
> 

Yes, the problem exists on plain H8/300 too. As I mentioned earlier, the compiler will generate ".align 1" for plain H8/300. I couldn't find how to check for ".align 1" when target is plain H8/300 and ".align 2" for -mh and -ms. So I had added -mh in options and checked for ".align 2"

I think it is better to scan only for ".align". Without this patch, .align is not generated. 

> By the way, which version of GCC did you run the testsuite for?
> 
> Currently, h8300-elf on mainline doesn't build, so I'll apply your
> patch after the build is restored.  Meanwhile, you might want to post
> a complete patch with the testcase and ChangeLog entries to
> gcc-patches for the record.

I tested it with 3.4 snapshot. Currently I am facing problems accessing sources using cvs  so can't use mainline.

Please find updated patch below - 

-Dhananjay

gcc/Changelog -

2004-02-16  Dhananjay Deshpande  <dhananjayd@kpitcummins.com>

        PR target/14041
        * config/h8300/h8300.h (ASM_OUTPUT_ALIGNED_BSS): Define.

==========================================================================
--- config/h8300/h8300.h.old	Tue Feb 10 15:51:47 2004
+++ config/h8300/h8300.h	Tue Feb 10 15:52:31 2004
@@ -1157,6 +1157,9 @@ struct cum_arg
 #define ASM_OUTPUT_BSS(FILE, DECL, NAME, SIZE, ROUNDED)		\
   asm_output_bss ((FILE), (DECL), (NAME), (SIZE), (ROUNDED))
 
+#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
+  asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
+
 /* This says how to output an assembler line
    to define a local common symbol.  */
 
==========================================================================
testsuite/Changelog

2004-02-16  Dhananjay Deshpande  <dhananjayd@kpitcummins.com>

        PR target/14041
        * gcc.dg/h8300-bss-align-1.c : New.


==========================================================================
--- /dev/null	Wed May  6 02:02:27 1998
+++ gcc.dg/h8300-bss-align-1.c	Fri Feb 13 18:10:01 2004
@@ -0,0 +1,13 @@
+/* Make sure that the H8 backend does align zero initialized variables. */
+/* { dg-do compile { target h8300-*-* } } */
+/* { dg-options "" } */
+
+struct s {
+  char a, b;
+  long c;
+};
+
+struct s s = {0};
+
+/* { dg-final { scan-assembler ".align" } } */
+
==========================================================================