unsigned OptShift2(CodeSeg* S)
/* A call to the asrax1 routines may get replaced by something simpler, if
* X is not used later:
*
* cmp #$80
* ror a
*
*/
{
unsigned Changes = 0;
unsigned I;
/* Walk over the entries */
I = 0;
while (I < CS_GetEntryCount (S)) {
unsigned Shift;
unsigned Count;
/* Get next entry */
CodeEntry* E = CS_GetEntry (S, I);
/* Check for the sequence */
if (E->OPC == OP65_JSR &&
(Shift = GetShift (E->Arg)) != SHIFT_NONE &&
SHIFT_TYPE (Shift) == SHIFT_TYPE_ASR &&
(Count = SHIFT_COUNT (Shift)) > 0 &&
Count * 100 <= S->CodeSizeFactor &&
!RegXUsed (S, I+1)) {
CodeEntry* X;
unsigned J = I+1;
/* Generate the replacement sequence */
while (Count--) {
/* cmp #$80 */
X = NewCodeEntry (OP65_CMP, AM65_IMM, "$80", 0, E->LI);
CS_InsertEntry (S, X, J++);
/* ror a */
X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, E->LI);
CS_InsertEntry (S, X, J++);
}
/* Delete the call to asrax */
CS_DelEntry (S, I);
/* Remember, we had changes */
++Changes;
}
/* Next entry */
++I;
}
/* Return the number of changes made */
return Changes;
}
int do_alignment(unsigned long addr, int error_code, struct pt_regs *regs)
{
union offset_union offset;
unsigned long instr, instrptr;
int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs *regs);
unsigned int type;
instrptr = instruction_pointer(regs);
instr = *(unsigned long *)instrptr;
if (user_mode(regs))
goto user;
ai_sys += 1;
fixup:
regs->ARM_pc += 4;
switch (CODING_BITS(instr)) {
case 0x00000000: /* ldrh or strh */
if (LDSTH_I_BIT(instr))
offset.un = (instr & 0xf00) >> 4 | (instr & 15);
else
offset.un = regs->uregs[RM_BITS(instr)];
handler = do_alignment_ldrhstrh;
break;
case 0x04000000: /* ldr or str immediate */
offset.un = OFFSET_BITS(instr);
handler = do_alignment_ldrstr;
break;
case 0x06000000: /* ldr or str register */
offset.un = regs->uregs[RM_BITS(instr)];
if (IS_SHIFT(instr)) {
unsigned int shiftval = SHIFT_BITS(instr);
switch(SHIFT_TYPE(instr)) {
case SHIFT_LSL:
offset.un <<= shiftval;
break;
case SHIFT_LSR:
offset.un >>= shiftval;
break;
case SHIFT_ASR:
offset.sn >>= shiftval;
break;
case SHIFT_RORRRX:
if (shiftval == 0) {
offset.un >>= 1;
if (regs->ARM_cpsr & PSR_C_BIT)
offset.un |= 1 << 31;
} else
offset.un = offset.un >> shiftval |
offset.un << (32 - shiftval);
break;
}
static int
do_alignment(unsigned long addr, unsigned int error_code, struct pt_regs *regs)
{
union offset_union offset;
unsigned long instr, instrptr;
int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs *regs);
unsigned int type;
if (user_mode(regs))
ai_user += 1;
else
ai_sys += 1;
instrptr = instruction_pointer(regs);
if (instrptr >= SVC_SPACE)
instr = *(unsigned long *)instrptr;
else
{
__asm__ __volatile__(
"ldw.u %0, [%1]\n"
:"=&r"(instr)
:"r"(instrptr));
}
regs->UCreg_pc += 4;
switch (CODING_BITS(instr)) {
case 0x40000120: /* ldrh or strh */
if (LDSTH_I_BIT(instr))
offset.un = (instr & 0x3e00) >> 4 | (instr & 31);
else
offset.un = regs->uregs[RM_BITS(instr)];
handler = do_alignment_ldrhstrh;
break;
case 0x60000000: /* ldr or str immediate */
case 0x60000100: /* ldr or str immediate */
case 0x60000020: /* ldr or str immediate */
case 0x60000120: /* ldr or str immediate */
offset.un = OFFSET_BITS(instr);
handler = do_alignment_ldrstr;
break;
case 0x40000000: /* ldr or str register */
offset.un = regs->uregs[RM_BITS(instr)];
{
unsigned int shiftval = SHIFT_BITS(instr);
switch(SHIFT_TYPE(instr)) {
case SHIFT_LSL:
offset.un <<= shiftval;
break;
case SHIFT_LSR:
offset.un >>= shiftval;
break;
case SHIFT_ASR:
offset.sn >>= shiftval;
break;
case SHIFT_RORRRX:
if (shiftval == 0) {
offset.un >>= 1;
if (regs->UCreg_csr & PSR_C_BIT)
offset.un |= 1 << 31;
} else
offset.un = offset.un >> shiftval |
offset.un << (32 - shiftval);
break;
}
