| Opcode/Instruction | Op/En | 64/32-bit Mode | CPUID Feature Flag | Description |
| F3 0F 59 /r MULSS xmm1, xmm2/m32 | RM | V/V | SSE | Multiply the low single-precision floating-point value in xmm2/mem by the low singleprecision floating-point value in xmm1. |
| VEX.NDS.LIG.F3.0F.WIG 59 /r VMULSS xmm1,xmm2, xmm3/m32 | RVM | V/V | AVX | Multiply the low single-precision floating-point value in xmm3/mem by the low singleprecision floating-point value in xmm2. |
| Op/En | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
| RM | ModRM:reg (r, w) | ModRM:r/m (r) | NA | NA |
| RVM | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | NA |
Multiplies the low single-precision floating-point value from the source operand (second operand) by 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 Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 1, for an illustration of a scalar single-precision floating-point operation.
In 64-bit mode, use of the REX.R prefix permits this instruction to access additional registers (XMM8-XMM15). 128-bit Legacy SSE version: The first source operand and the destination operand are the same. Bits (VLMAX1:32) of the corresponding YMM destination register remain unchanged. VEX.128 encoded version: Bits (VLMAX-1:128) of the destination YMM register are zeroed.
MULSS (128-bit Legacy SSE version) DEST[31:0] ← DEST[31:0] * SRC[31:0] DEST[VLMAX-1:32] (Unmodified) VMULSS (VEX.128 encoded version) DEST[31:0] ← SRC1[31:0] * SRC2[31:0] DEST[127:32] ← SRC1[127:32] DEST[VLMAX-1:128] ← 0
| MULSS: | __m128 _mm_mul_ss(__m128 a, __m128 b) |
Overflow, Underflow, Invalid, Precision, Denormal.
See Exceptions Type 3