On Alpha and Integrity server systems, modifies IEEE floating- point state and, optionally, returns the previous value. The service provides the mechanism to set the specified state bits, to clear the specified state bits, and to swap one set of state bits for another. Format SYS$IEEE_SET_FP_CONTROL [clrmsk] ,[setmsk] ,[prvmsk] C Prototype int sys$ieee_set_fp_control (struct _ieee *clrmsk, struct _ieee *setmsk, struct _ieee *prvmsk);
1 – Arguments
clrmsk OpenVMS usage:mask_quadword type: quadword (unsigned) access: read only mechanism: by reference Address of a quadword bit mask to be cleared in the IEEE floating-point control register. The $IEEEDEF macro defines symbols for the floating-point control register. The following table shows the symbols, their corresponding masks, and their meaning: Table SYS-21 Format of the IEEE Floating-Point Control Register (Alpha and Integrity servers) Symbol Mask Meaning IEEE$M_TRAP_ENABLE_ 2 Enable invalid operation exception INV IEEE$M_TRAP_ENABLE_ 4 Enable divide by 0 exception DZE IEEE$M_TRAP_ENABLE_ 8 Enable overflow exception OVF IEEE$M_TRAP_ENABLE_ 10 Enable underflow exception UNF IEEE$M_TRAP_ENABLE_ 20 Enable inexact exception INE IEEE$M_TRAP_ENABLE_ 40 Enable denormal operand exception DNOE IEEE$M_MAP_DNZ 2000 Denormal operands are mapped to 0.0 IEEE$M_MAP_UMZ 4000 Underflow results are mapped to 0.0 IEEE$M_INHERIT 8000 Inherit FP state on thread create IEEE$M_STATUS_INV 20000 Invalid operation IEEE$M_STATUS_DZE 40000 Divide by 0 IEEE$M_STATUS_OVF 80000 Overflow IEEE$M_STATUS_UNF 100000 Underflow IEEE$M_STATUS_INE 200000 Inexact IEEE$M_STATUS_DNO 400000 Denormal operand setmsk OpenVMS usage:mask_quadword type: quadword (unsigned) access: read only mechanism: by reference Address of a quadword bit mask to be set in the IEEE floating- point control register. See the clrmsk argument for the format of the IEEE floating-point control register. prvmsk OpenVMS usage:mask_quadword type: quadword (unsigned) access: write only mechanism: by reference Address of a quadword to receive the previous value of the IEEE floating-point control register.