| Opcode/Instruction | Op/En | 64/32-bit Mode | CPUID Feature Flag | Description |
|---|---|---|---|---|
|
F2 0F 5A /r CVTSD2SS xmm1, xmm2/m64 |
RM | V/V | SSE2 | Convert one double-precision floating-point value in xmm2/m64 to one single-precision floating-point value in xmm1. |
|
VEX.NDS.LIG.F2.0F.WIG 5A /r VCVTSD2SS xmm1,xmm2, xmm3/m64 |
RVM | V/V | AVX | Convert one double-precision floating-point value in xmm3/m64 to one single-precision floating-point value and merge with high bits in xmm2. |
| Op/En | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
| RM | ModRM:reg (w) | ModRM:r/m (r) | NA | NA |
| RVM | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | NA |
Converts a double-precision floating-point value in the source operand (second operand) to a single-precision floating-point value in the destination operand (first operand).
The source operand can be an XMM register or a 64-bit memory location. The destination operand is an XMM register. When the source operand is an XMM register, the double-precision floating-point value is contained in the low quadword of the register. The result is stored in the low doubleword of the destination operand, and the upper 3 doublewords are left unchanged. When the conversion is inexact, the value returned is rounded according to the rounding control bits in the MXCSR register.
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 destination and first source operand are the same. Bits (VLMAX-1:32) of the corresponding YMM destination register remain unchanged.
VEX.128 encoded version: Bits (127:64) of the XMM register destination are copied from corresponding bits in the first source operand. Bits (VLMAX-1:128) of the destination YMM register are zeroed.
CVTSD2SS (128-bit Legacy SSE version)
DEST[31:0] ← Convert_Double_Precision_To_Single_Precision_Floating_Point(SRC[63:0]); (* DEST[VLMAX-1:32] Unmodified *)
VCVTSD2SS (VEX.128 encoded version)
DEST[31:0] ← Convert_Double_Precision_To_Single_Precision_Floating_Point(SRC2[63:0]); DEST[127:32] ← SRC1[127:32] DEST[VLMAX-1:128] ← 0
CVTSD2SS:
__m128 _mm_cvtsd_ss(__m128 a, __m128d b)
Overflow, Underflow, Invalid, Precision, Denormal.
See Exceptions Type 3.