[Bug c/21171] Generates wrong code (w/ optimization) when copying data from a table to a table in a structure

["sami dot kantoluoto at embedtronics dot fi" <gcc-bugzilla@gcc.gnu.org>]

------- Additional Comments From sami dot kantoluoto at embedtronics dot fi  2005-04-23 08:45 -------
Created an attachment (id=8714)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8714&action=view)
objdump output of working version when compiled in thumb mode (-mthumb)

Same problems in thumb mode. Attachment shows the objdump output of the
_working_ version. Objdump output of non-working version is here:

test.o:     file format elf32-littlearm

Disassembly of section .text:

00000000 <main>:
   0:	4b03		ldr	r3, [pc, #12]	(10 <.text+0x10>)
   2:	1c1a		mov	r2, r3		(add r2, r3, #0)
   4:	3280		add	r2, #128
   6:	3304		add	r3, #4
   8:	4293		cmp	r3, r2
   a:	d1fc		bne	6 <main+0x6>
   c:	2000		mov	r0, #0
   e:	4770		bx	lr
  10:	0000		lsl	r0, r0, #0
	...
Disassembly of section .comment:

00000000 <.comment>:
   0:	43434700	cmpmi	r3, #0	; 0x0
   4:	4728203a	undefined
   8:	2029554e	eorcs	r5, r9, lr, asr #10
   c:	2e302e34	mrccs	14, 1, r2, cr0, cr4, {1}

As you can see, it does not even access the source table (non-thumb version
does).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21171