image/svg+xml ROUNDSD — Round Scalar Double Precision Floating-Point Values Instruction Operand Encoding Description Round the DP FP value in the lower qword of the source operand (second operand) using the rounding mode spec- ified in the immediate operand (third operand) and place the result in the destination operand (first operand). The rounding process rounds a double-precision floating-point input to an integer value and returns the integer result as a double precision floating-point value in the lowest position. The upper double precision floating-point value in the destination is retained. The immediate operand specifies control fields for the rounding operation, three bit fields are defined and shown in Figure4-24. Bit 3 of the immediate byte controls processor behavior for a precision exception, bit 2 selects the source of rounding mode control. Bits 1:0 specify a non-sticky rounding-mode value (Table 4-23 lists the encoded values for rounding-mode field). The Precision Floating-Point Exception is signaled according to the immediate operand. If any source operand is an SNaN then it will be converted to a QNaN. If DAZ is set to ‘1 then denormals will be converted to zero before rounding. 128-bit Legacy SSE version: The first source operand and the destination operand are the same. Bits (MAXVL- 1:64) of the corresponding YMM destination register remain unchanged. VEX.128 encoded version: Bits (MAXVL-1:128) of the destination YMM register are zeroed. Operation IF (imm[2] = ‘1) THEN // rounding mode is determined by MXCSR.RC DEST[63:0] := ConvertDPFPToInteger_M(SRC[63:0]); ELSE// rounding mode is determined by IMM8.RC DEST[63:0] := ConvertDPFPToInteger_Imm(SRC[63:0]); FI; DEST[127:63] remains unchanged ; ROUNDSD (128-bit Legacy SSE version) DEST[63:0] := RoundToInteger(SRC[63:0], ROUND_CONTROL) DEST[MAXVL-1:64] (Unmodified) Opcode*/ Instruction Op/ En 64/32 bit Mode Support CPUID Feature Flag Description 66 0F 3A 0B /r ib ROUNDSD xmm1, xmm2/m64, imm8 RMIV/VSSE4_1Round the low packed double precision floating-point value in xmm2/m64 and place the result in xmm1. The rounding mode is determined by imm8 . VEX.LIG.66.0F3A.WIG 0B /r ib VROUNDSD xmm1, xmm2, xmm3/m64, imm8 RVMIV/VAVXRound the low packed double precision floating-point value in xmm3/m64 and place the result in xmm1 . The rounding mode is determined by imm8 . Upper packed double precision floating-point value (bits[127:64]) from xmm2 is copied to xmm1 [127:64]. Op/EnOperand 1Operand 2Operand 3Operand 4 RMIModRM:reg (w)ModRM:r/m (r)imm8NA RVMIModRM:reg (w)VEX.vvvv (r)ModRM:r/m (r)imm8 image/svg+xml VROUNDSD (VEX.128 encoded version) DEST[63:0] := RoundToInteger(SRC2[63:0], ROUND_CONTROL) DEST[127:64] := SRC1[127:64] DEST[MAXVL-1:128] := 0 Intel C/C++ Compiler Intrinsic Equivalent ROUNDSD:__m128d mm_round_sd(__m128d dst, __m128d s1, int iRoundMode); __m128d mm_floor_sd(__m128d dst, __m128d s1); __m128d mm_ceil_sd(__m128d dst, __m128d s1); SIMD Floating-Point Exceptions Invalid (signaled only if SRC = SNaN) Precision (signaled only if imm[3] = ‘0; if imm[3] = ‘1, then the Precision Mask in the MXSCSR is ignored and preci- sion exception is not signaled.) Note that Denormal is not signaled by ROUNDSD. Other Exceptions See Table2-20, “Type 3 Class Exception Conditions”. This UNOFFICIAL reference was generated from the official Intel® 64 and IA-32 Architectures Software Developer’s Manual by a dumb script. There is no guarantee that some parts aren't mangled or broken and is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .