Allocate some registers.
Input:
pretregs Pointer to mask of registers to make selection from.
tym Mask of type we will store in registers.
Output:
*pretregs Mask of allocated registers.
*preg Register number of first allocated register.
msavereg,mfuncreg retregs bits are cleared.
regcon.cse.mval,regcon.cse.mops updated
Allocate some registers. Input: pretregs Pointer to mask of registers to make selection from. tym Mask of type we will store in registers. Output: *pretregs Mask of allocated registers. *preg Register number of first allocated register. msavereg,mfuncreg retregs bits are cleared. regcon.cse.mval,regcon.cse.mops updated