Volume 4: IA-32 SSE Instruction Reference
4:545
RCPSS: Scalar Single-FP Reciprocal
Operation:
xmm1[31-0] = approx (1.0/(xmm2/m32[31-0]));
xmm1[63-32] = xmm1[63-32];
xmm1[95-64] = xmm1[95-64];
xmm1[127-96] = xmm1[127-96];
Description:
RCPSS returns an approximation of the reciprocal of the lower SP FP number from
xmm2/m32; the upper 3 fields are passed through from xmm1. The relative error for
this approximation is Error, which satisfies:
|Error| <= 1.5x2
-12
Numeric Exceptions:
None.
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 Disabled FP Register Fault if PSR.dfl is 1, NaT Register
Consumption Fault
Itanium Mem Faults VHPT Data Fault, Data TLB Fault, Alternate Data TLB Fault, Data
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
Comments:
RCPSS is not affected by the rounding control in MXCSR. Denormal inputs are treated
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
B
×2
125
Opcode
Instruction
Description
F3,0F,53,/r RCPSS xmm1, xmm2/m32
Return an approximation of the reciprocal of the lower SP FP
number in XMM2/Mem.
Summary of Contents for ITANIUM ARCHITECTURE
Page 1: ......
Page 7: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 199: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Page 352: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Page 589: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Page 590: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Page 591: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Page 603: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...
Page 604: ......