ARM: testsuite gcc.c-torture/execute/20020307-2.c failure

[jeroen dobbelaere <jeroen dot dobbelaere at acunia dot com>]

Looking at testcase
	gcc.c-torture/execute/20020307-2.c

It seems that there is a problem with putting the arguments in the right place.
Following peace of code

void foo3()
{
#ifdef USE_DEFINE
# define zzz 2
#else
  int zzz=2;
#endif
  struct {
    int a[zzz];
  } t;

  t.a[0]=1;
  t.a[1]=2;

  foo4(t);
}


results, depending on the definition of 'USE_DEFINE' in completely different output :
 - for structures with a fixed array length, we get following (correct) code : (-O2)

foo3:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 0, uses_anonymous_args = 0
	str	lr, [sp, #-4]!
	adr	r0, .L25
	ldmia	r0, {r0-r1}
	@ Sibcall epilogue
	ldr	lr, [sp], #4
	b	foo4
.L26:
	.align	2
.L25:
	.word	1
	.word	2

 - for structures with a variable array length, we get following (incorrect) code :

	.size	foo,.Lfe2-foo
	.global	memcpy
	.align	2
	.global	foo3
	.type	foo3,function
foo3:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 1, uses_anonymous_args = 0
	mov	ip, sp
	stmfd	sp!, {r4, r5, fp, ip, lr, pc}
	mov	r3, #1
	mov	r5, sp
	mov	r2, #2
	sub	sp, sp, #8
	str	r3, [sp, #0]
	str	r2, [sp, #4]
	mov	r4, sp
	sub	sp, sp, #8
	mov	r0, sp
	sub	fp, ip, #4
	mov	r2, r2, asl r2
	mov	r1, r4
	bl	memcpy
	bl	foo4
	mov	sp, r4
	mov	sp, r5
	ldmea	fp, {r4, r5, fp, sp, pc}


Between the 'bl memcpy' and 'bl foo4' there is no loading of r0-r1...

(in the case of 20020307-2 : this results in no loading of r1-r3, while the
target function expects to see data in those registers...)

Any idea where this different behavior is triggered ?

Greetings,
--
Jeroen Dobbelaere
Embedded Software Engineer

ACUNIA Embedded Solutions
http://www.acunia.com/aes