OK_DEFER_POP;
return target;
}
- else if (suggest_reg && GET_CODE (target) == MEM
+ else if (suggest_reg && GET_CODE (target) == MEM && ! MEM_VOLATILE_P (target)
&& GET_MODE (target) != BLKmode)
/* If target is in memory and caller wants value in a register instead,
arrange that. Pass TARGET as target for expand_expr so that,
if EXP is another assignment, SUGGEST_REG will be nonzero for it.
- We know expand_expr will not use the target in that case. */
+ We know expand_expr will not use the target in that case.
+ Don't do this if TARGET is volatile because we are supposed
+ to write it and then read it. */
{
temp = expand_expr (exp, cse_not_expected ? NULL_RTX : target,
GET_MODE (target), 0);
So copy the value through a temporary and use that temp
as the result. */
{
+ /* ??? There may be a bug here in the case of a target
+ that is volatile, but I' too sleepy today to write anything
+ to handle it. */
if (GET_MODE (target) != BLKmode && GET_MODE (target) != VOIDmode)
{
/* Expand EXP into a new pseudo. */
{
temp = expand_expr (exp, target, GET_MODE (target), 0);
/* DO return TARGET if it's a specified hardware register.
- expand_return relies on this. */
+ expand_return relies on this.
+ DO return TARGET if it's a volatile mem ref; ANSI requires this. */
if (!(target && GET_CODE (target) == REG
&& REGNO (target) < FIRST_PSEUDO_REGISTER)
- && CONSTANT_P (temp))
+ && CONSTANT_P (temp)
+ && !(GET_CODE (target) == MEM && MEM_VOLATILE_P (target)))
dont_return_target = 1;
}