Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1847

RCPSS: Scalar Single-FP Reciprocal
Opcode
F3,0F,53,/r RCPSS xmm1, xmm2/m32
Operation: xmm1[31-0]
xmm1[63-32]
xmm1[95-64]
xmm1[127-96] = xmm1[127-96];
RCPSS returns an approximation of the reciprocal of the lower SP FP number from
Description:
xmm2/m32; the upper 3 fields are passed through from xmm1. The relative error for
this approximation is Error, which satisfies:
|Error| <= 1.5x2
None.
Numeric Exceptions:
Protected Mode Exceptions:
#GP(0) for an illegal memory operand effective address in the CS, DS, ES, FS or GS
segments; #SS(0) for an illegal address in the SS segment; #PF (fault-code) for a page
fault; #UD if CR0.EM = 1; #AC for unaligned memory reference if the current privilege
level is 3; #NM if TS bit in CR0 is set.
Real Address Mode Exceptions:
Interrupt 13 if any part of the operand would lie outside of the effective address space
from 0 to 0FFFFH; #UD if CR0.EM = 1; #NM if TS bit in CR0 is set.
Virtual 8086 Mode Exceptions:
Same exceptions as in Real Address Mode; #AC for unaligned memory reference if the
current privilege level is 3; #PF (fault-code) for a page fault.
Additional Itanium System Environment Exceptions
Itanium Reg Faults
Itanium Mem Faults VHPT Data Fault, Data TLB Fault, Alternate Data TLB Fault, Data
RCPSS is not affected by the rounding control in MXCSR. Denormal inputs are treated
Comments:
as zeros (of the same sign) and tiny results are always flushed to zero, with the sign of
the operand.
Results are guaranteed not to be tiny, and therefore not flushed to zero, for input
values x which satisfy
|x| <= 1.11111111110100000000000
Volume 4: IA-32 SSE Instruction Reference
Instruction
= approx (1.0/(xmm2/m32[31-0]));
= xmm1[63-32];
= xmm1[95-64];
-12
Disabled FP Register Fault if PSR.dfl is 1, NaT Register
Consumption Fault
Page Not Present Fault, Data NaT Page Consumption Abort, Data
Key Miss Fault, Data Key Permission Fault, Data Access Rights
Fault, Data Access Bit Fault
Description
Return an approximation of the reciprocal of the lower SP FP
number in XMM2/Mem.
125
×2
B
4:545