x86 Instruction Set Reference

MOVSS - Move Scalar Single-Precision Floating-Point Values

Opcode Mnemonic Description
F3 0F 10 /r MOVSS xmm1, xmm2/m32 Move scalar single-precision floating-point value from xmm2/m32 to xmm1 register.
F3 0F 11 /r MOVSS xmm2/m32, xmm1 Move scalar single-precision floating-point value from xmm1 register to xmm2/m32.
Description

Moves a scalar single-precision floating-point value from the source operand (second operand) to the destination operand (first operand). The source and destination operands can be XMM registers or 32-bit memory locations. This instruction can be used to move a single-precision floating-point value to and from the low doubleword of an XMM register and a 32-bit memory location, or to move a single-precision floating-point value between the low doublewords of two XMM registers. The instruction cannot be used to transfer data between memory locations.

When the source and destination operands are XMM registers, the three high-order doublewords of the destination operand remain unchanged. When the source operand is a memory location and destination operand is an XMM registers, the three high-order doublewords of the destination operand are cleared to all 0s.

Operation
//MOVSS instruction when source and destination operands are XMM registers:
if(IsXMM(Source) && IsXMM(Destination)) Destination[0..31] = Source[0..31];
//Destination[32..127] remains unchanged
//MOVSS instruction when source operand is XMM register and destination operand is memory location:
else if(IsXMM(Source) && IsMemory(Destination)) Destination = Source[0..31];
//MOVSS instruction when source operand is memory location and destination operand is XMM register:
else {
	Destination[0..31] = Source;
	Destination[32..127] = 0;
}
SIMD Floating-Point Exceptions
None.
Protected Mode Exceptions
#GP(0)For an illegal memory operand effective address in the CS, DS, ES, FS or GS segments.
#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.
#NMIf TS in CR0 is set.
#UDIf EM in CR0 is set. If OSFXSR in CR4 is 0. If CPUID feature flag SSE is 0.
Real-Address Mode Exceptions
#GP(0)If any part of the operand lies outside the effective address space from 0 to FFFFH.
#GP(0)If any part of the operand lies outside the effective address space from 0 to FFFFH.
#NMIf TS in CR0 is set.
Virtual-8086 Mode Exceptions
Same exceptions as in Real Address Mode
#PF(fault-code)For a page fault.
#PF(fault-code)For a page fault.
Instruction Latency Throughput Execution Unit
CPUID0F3n/0F2n0F3n/0F2n0F2n
MOVSS xmm, xmm4/42/2MMX_SHFT