x86 Instruction Set Reference

SUBSS - Subtract Scalar Single-Precision Floating-Point Values

Opcode Mnemonic Description
F3 0F 5C /r SUBSS xmm1, xmm2/m32 Subtract the lower single-precision floating-point values in xmm2/m32 from xmm1.
Description

Subtracts the low single-precision floating-point value in the source operand (second operand) from the low single-precision floating-point value in the destination operand (first operand), and stores the single-precision floating-point result in the destination operand. The source operand can be an XMM register or a 32-bit memory location. The destination operand is an XMM register. The three high-order doublewords of the destination operand remain unchanged. See Figure 10-6 in the IA-32 Intel Architecture Software Developer's Manual, Volume 1 for an illustration of a scalar single-precision floating-point operation.
Operation 
Destination[0..31] = Destination[0..31] - Source[0..31];
//Destination[96..127] remains unchanged
Instruction Latency Throughput Execution Unit
CPUID0F3n/0F2n/069n0F3n/0F2n/069n0F2n
SUBSS xmm, xmm5/4/32/2/1FP_ADD