[CR16] Improper register allocation

[Jayant R. Sonar]

I am working on CR16 port.

Found an improper code is being generated for following part of the test 
code:
============================================================================
IeData     = (void *) RAlloc(DataLen);
LAHType* p = (LAHType*)IeData;

ReadFH (DpEntry, &FeData, &p->Table, &p->Masked, &p->NumAH, &p->Len, TData);
============================================================================

Arguments are pushed on to the stack from right to left direction.
Possible working assembly that could be generated for this code:
Case 1:
================================================================
       bal (ra), _RAlloc@c
       stord	(r1,r0), 32(sp)
       addd	$-2, (sp)
.LCFI547:
       movd	$18, (r7,r6)
       addd	(sp), (r7,r6)
       push	$2,r6
.LCFI548:
       addd	$3, (r1,r0)
       push	$2,r0

OR lesser optimized code could be:
Case 2:
============================================================
       bal (ra), _RAlloc@c
       stord	(r1,r0), 32(sp)
       addd	$-2, (sp)
.LCFI547:
       movd	$18, (r7,r6)
       addd	(sp), (r7,r6)
       push	$2,r6
.LCFI548:
       loadd	32(sp), (r1,r0)
       addd	$3, (r1,r0)
       push	$2,r0

However, I am getting following code:
============================================================
       bal (ra), _RAlloc@c
       stord	(r1,r0), 20(sp)
       addd	$-2, (sp)
.LCFI547:
       movd	$18, (r2,r1)
       addd	(sp), (r2,r1)
       push	$2,r1	  
.LCFI548:
       addd	$3, (r1,r0)	<<============== PROBLEM
       push	$2,r0

'R1' being the part of first push already has some value in it. So before 
next push, either (r1,r0) should be loaded with new address value as shown 
in Case 2. Otherwise, as in Case 1, different register pairs should be used 
for these two push operations.

CR16 port did not have REG_ALLOC_ORDER defined.
I am trying to control register allocation order using this. However, it 
looks like this sequence has to be decided very carefully as slightest of 
the alternation in sequence are causing some or other application failures.

Is there any other way, I could address this problem?

Thanks and Regards,
Jayant Sonar
[KPIT Cummins, Pune]