VFMADDSUB132PS/VFMADDSUB213PS/VFMADDSUB231PS — Fused Multiply-Alternating Add/Subtract of Packed Single-Precision Floating-Point Values

Instruction Operand Encoding

Description

VFMADDSUB132PS: Multiplies the four or eight packed single-precision floating-point values from the first source operand to the four or eight packed single-precision floating-point values in the third source operand. From the infi-nite precision intermediate result, adds the odd single-precision floating-point elements and subtracts the even single-precision floating-point values in the second source operand, performs rounding and stores the resulting four or eight packed single-precision floating-point values to the destination operand (first source operand).

VFMADDSUB213PS: Multiplies the four or eight packed single-precision floating-point values from the second source operand to the four or eight packed single-precision floating-point values in the first source operand. From the infinite precision intermediate result, adds the odd single-precision floating-point elements and subtracts the even single-precision floating-point values in the third source operand, performs rounding and stores the resulting four or eight packed single-precision floating-point values to the destination operand (first source operand).

VFMADDSUB231PS: Multiplies the four or eight packed single-precision floating-point values from the second source operand to the four or eight packed single-precision floating-point values in the third source operand. From the infinite precision intermediate result, adds the odd single-precision floating-point elements and subtracts the even single-precision floating-point values in the first source operand, performs rounding and stores the resulting four or eight packed single-precision floating-point values to the destination operand (first source operand).

VEX.128 encoded version: The destination operand (also first source operand) is a XMM register and encoded in reg_field. The second source operand is a XMM register and encoded in VEX.vvvv. The third source operand is a XMM register or a 128-bit memory location and encoded in rm_field. The upper 128 bits of the YMM destination register are zeroed.

VEX.256 encoded version: The destination operand (also first source operand) is a YMM register and encoded in reg_field. The second source operand is a YMM register and encoded in VEX.vvvv. The third source operand is a YMM register or a 256-bit memory location and encoded in rm_field.

Compiler tools may optionally support a complementary mnemonic for each instruction mnemonic listed in the opcode/instruction column of the summary table. The behavior of the complementary mnemonic in situations involving NANs are governed by the definition of the instruction mnemonic defined in the opcode/instruction column. See also Section 14.5.1, “FMA Instruction Operand Order and Arithmetic Behavior” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 1.

Operation

In the operations below, "+", "-", and "*" symbols represent addition, subtraction, and multiplication operations with infinite precision inputs and outputs (no rounding).

VFMADDSUB132PS DEST, SRC2, SRC3

IF (VEX.128) THEN
    MAXVL =2
ELSEIF (VEX.256)
    MAXVL = 4
FI
For i = 0 to MAXVL -1{
    n = 64*i;
    DEST[n+31:n] ← RoundFPControl_MXCSR(DEST[n+31:n]*SRC3[n+31:n] - SRC2[n+31:n])
    DEST[n+63:n+32] ← RoundFPControl_MXCSR(DEST[n+63:n+32]*SRC3[n+63:n+32] + SRC2[n+63:n+32])
}
IF (VEX.128) THEN
    DEST[VLMAX-1:128] ← 0
FI

VFMADDSUB213PS DEST, SRC2, SRC3

IF (VEX.128) THEN
    MAXVL =2
ELSEIF (VEX.256)
    MAXVL = 4
FI
For i = 0 to MAXVL -1{
    n = 64*i;
    DEST[n+31:n] ← RoundFPControl_MXCSR(SRC2[n+31:n]*DEST[n+31:n] - SRC3[n+31:n])
    DEST[n+63:n+32] ← RoundFPControl_MXCSR(SRC2[n+63:n+32]*DEST[n+63:n+32] + SRC3[n+63:n+32])
}
IF (VEX.128) THEN
    DEST[VLMAX-1:128] ← 0
FI

VFMADDSUB231PS DEST, SRC2, SRC3

IF (VEX.128) THEN
    MAXVL =2
ELSEIF (VEX.256)
    MAXVL = 4
FI
For i = 0 to MAXVL -1{
    n = 64*i;
    DEST[n+31:n] ← RoundFPControl_MXCSR(SRC2[n+31:n]*SRC3[n+31:n] - DEST[n+31:n])
    DEST[n+63:n+32] ← RoundFPControl_MXCSR(SRC2[n+63:n+32]*SRC3[n+63:n+32] + DEST[n+63:n+32])
}
IF (VEX.128) THEN
    DEST[VLMAX-1:128] ← 0
FI

Intel C/C++ Compiler Intrinsic Equivalent

VFMADDSUB132PS: __m128 _mm_fmaddsub_ps (__m128 a, __m128 b, __m128 c);

VFMADDSUB213PS: __m128 _mm_fmaddsub_ps (__m128 a, __m128 b, __m128 c);

VFMADDSUB231PS: __m128 _mm_fmaddsub_ps (__m128 a, __m128 b, __m128 c);

VFMADDSUB132PS: __m256 _mm256_fmaddsub_ps (__m256 a, __m256 b, __m256 c);

VFMADDSUB213PS: __m256 _mm256_fmaddsub_ps (__m256 a, __m256 b, __m256 c);

VFMADDSUB231PS: __m256 _mm256_fmaddsub_ps (__m256 a, __m256 b, __m256 c);

SIMD Floating-Point Exceptions

Overflow, Underflow, Invalid, Precision, Denormal

Other Exceptions

See Exceptions Type 2