VFMSUB132PS/VFMSUB213PS/VFMSUB231PS—Fused Multiply-Subtract of Packed Single-Precision Floating-Point Values

Instruction Operand Encoding

Description

Performs a set of SIMD multiply-subtract computation on packed single-precision floating-point values using three source operands and writes the multiply-subtract results in the destination operand. The destination operand is also the first source operand. The second operand must be a SIMD register. The third source operand can be a SIMD register or a memory location.

VFMSUB132PS: Multiplies the four, eight or sixteen packed single-precision floating-point values from the first source operand to the four, eight or sixteen packed single-precision floating-point values in the third source operand. From the infinite precision intermediate result, subtracts the four, eight or sixteen packed single-precision floating-point values in the second source operand, performs rounding and stores the resulting four, eight or sixteen packed single-precision floating-point values to the destination operand (first source operand).

VFMSUB213PS: Multiplies the four, eight or sixteen packed single-precision floating-point values from the second source operand to the four, eight or sixteen packed single-precision floating-point values in the first source operand. From the infinite precision intermediate result, subtracts the four, eight or sixteen packed single-precision floating-point values in the third source operand, performs rounding and stores the resulting four, eight or sixteen packed single-precision floating-point values to the destination operand (first source operand).

VFMSUB231PS: Multiplies the four, eight or sixteen packed single-precision floating-point values from the second source to the four, eight or sixteen packed single-precision floating-point values in the third source operand. From the infinite precision intermediate result, subtracts the four, eight or sixteen packed single-precision floating-point values in the first source operand, performs rounding and stores the resulting four, eight or sixteen packed single-precision floating-point values to the destination operand (first source operand).

EVEX encoded versions: The destination operand (also first source operand) and the second source operand are ZMM/YMM/XMM register. The third source operand is a ZMM/YMM/XMM register, a 512/256/128-bit memory loca-tion or a 512/256/128-bit vector broadcasted from a 32-bit memory location. The destination operand is condition-ally updated with write mask k1.

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.

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.

Operation

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

VFMSUB132PS DEST, SRC2, SRC3 (VEX encoded version)

IF (VEX.128) THEN

MAXNUM (cid:197)2

ELSEIF (VEX.256)

MAXNUM (cid:197) 4

FI

For i = 0 to MAXNUM-1 {

n (cid:197) 32*i;

DEST[n+31:n] (cid:197) RoundFPControl_MXCSR(DEST[n+31:n]*SRC3[n+31:n] - SRC2[n+31:n])

}

IF (VEX.128) THEN

DEST[MAX_VL-1:128] (cid:197) 0

ELSEIF (VEX.256)

DEST[MAX_VL-1:256] (cid:197) 0

FI

VFMSUB213PS DEST, SRC2, SRC3 (VEX encoded version)

IF (VEX.128) THEN

MAXNUM (cid:197)2

ELSEIF (VEX.256)

MAXNUM (cid:197) 4

FI

For i = 0 to MAXNUM-1 {

n (cid:197) 32*i;

DEST[n+31:n] (cid:197) RoundFPControl_MXCSR(SRC2[n+31:n]*DEST[n+31:n] - SRC3[n+31:n])

}

IF (VEX.128) THEN

DEST[MAX_VL-1:128] (cid:197) 0

ELSEIF (VEX.256)

DEST[MAX_VL-1:256] (cid:197) 0

FI

VFMSUB231PS DEST, SRC2, SRC3 (VEX encoded version)

IF (VEX.128) THEN

MAXNUM (cid:197)2

ELSEIF (VEX.256)

MAXNUM (cid:197) 4

FI

For i = 0 to MAXNUM-1 {

n (cid:197) 32*i;

DEST[n+31:n] (cid:197) RoundFPControl_MXCSR(SRC2[n+31:n]*SRC3[n+31:n] - DEST[n+31:n])

}

IF (VEX.128) THEN

DEST[MAX_VL-1:128] (cid:197) 0

ELSEIF (VEX.256)

DEST[MAX_VL-1:256] (cid:197) 0

FI

VFMSUB132PS DEST, SRC2, SRC3 (EVEX encoded version, when src3 operand is a register)

(KL, VL) = (4, 128), (8, 256), (16, 512)

IF (VL = 512) AND (EVEX.b = 1)

THEN

SET_RM(EVEX.RC);

ELSE

SET_RM(MXCSR.RM);

FI;

FOR j (cid:197) 0 TO KL-1

i (cid:197) j * 32

IF k1[j] OR *no writemask*

THEN DEST[i+31:i] (cid:197)

RoundFPControl(DEST[i+31:i]*SRC3[i+31:i] - SRC2[i+31:i])

ELSE

IF *merging-masking*

; merging-masking

THEN *DEST[i+31:i] remains unchanged*

ELSE

; zeroing-masking

DEST[i+31:i] (cid:197) 0

FI

FI;

ENDFOR

DEST[MAX_VL-1:VL] (cid:197) 0

VFMSUB132PS DEST, SRC2, SRC3 (EVEX encoded version, when src3 operand is a memory source)

(KL, VL) = (4, 128), (8, 256), (16, 512)

FOR j (cid:197) 0 TO KL-1

i (cid:197) j * 32

IF k1[j] OR *no writemask*

THEN

IF (EVEX.b = 1)

THEN

DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(DEST[i+31:i]*SRC3[31:0] - SRC2[i+31:i])

ELSE

DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(DEST[i+31:i]*SRC3[i+31:i] - SRC2[i+31:i])

FI;

ELSE

IF *merging-masking*

; merging-masking

THEN *DEST[i+31:i] remains unchanged*

ELSE

; zeroing-masking

DEST[i+31:i] (cid:197) 0

FI

FI;

ENDFOR

DEST[MAX_VL-1:VL] (cid:197) 0

VFMSUB213PS DEST, SRC2, SRC3 (EVEX encoded version, when src3 operand is a register)

(KL, VL) = (4, 128), (8, 256), (16, 512)

IF (VL = 512) AND (EVEX.b = 1)

THEN

SET_RM(EVEX.RC);

ELSE

SET_RM(MXCSR.RM);

FI;

FOR j (cid:197) 0 TO KL-1

i (cid:197) j * 32

IF k1[j] OR *no writemask*

THEN DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(SRC2[i+31:i]*DEST[i+31:i] - SRC3[i+31:i])

ELSE

IF *merging-masking*

; merging-masking

THEN *DEST[i+31:i] remains unchanged*

ELSE

; zeroing-masking

DEST[i+31:i] (cid:197) 0

FI

FI;

ENDFOR

DEST[MAX_VL-1:VL] (cid:197) 0

VFMSUB213PS DEST, SRC2, SRC3 (EVEX encoded version, when src3 operand is a memory source)

(KL, VL) = (4, 128), (8, 256), (16, 512)

FOR j (cid:197) 0 TO KL-1

i (cid:197) j * 32

IF k1[j] OR *no writemask*

THEN

IF (EVEX.b = 1)

THEN

DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(SRC2[i+31:i]*DEST[i+31:i] - SRC3[31:0])

ELSE

DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(SRC2[i+31:i]*DEST[i+31:i] - SRC3[i+31:i])

FI;

ELSE

IF *merging-masking*

; merging-masking

THEN *DEST[i+31:i] remains unchanged*

ELSE

; zeroing-masking

DEST[i+31:i] (cid:197) 0

FI

FI;

ENDFOR

DEST[MAX_VL-1:VL] (cid:197) 0

VFMSUB231PS DEST, SRC2, SRC3 (EVEX encoded version, when src3 operand is a register)

(KL, VL) = (4, 128), (8, 256), (16, 512)

IF (VL = 512) AND (EVEX.b = 1)

THEN

SET_RM(EVEX.RC);

ELSE

SET_RM(MXCSR.RM);

FI;

FOR j (cid:197) 0 TO KL-1

i (cid:197) j * 32

IF k1[j] OR *no writemask*

THEN DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(SRC2[i+31:i]*SRC3[i+31:i] - DEST[i+31:i])

ELSE

IF *merging-masking*

; merging-masking

THEN *DEST[i+31:i] remains unchanged*

ELSE

; zeroing-masking

DEST[i+31:i] (cid:197) 0

FI

FI;

ENDFOR

DEST[MAX_VL-1:VL] (cid:197) 0

VFMSUB231PS DEST, SRC2, SRC3 (EVEX encoded version, when src3 operand is a memory source)

(KL, VL) = (4, 128), (8, 256), (16, 512)

FOR j (cid:197) 0 TO KL-1

i (cid:197) j * 32

IF k1[j] OR *no writemask*

THEN

IF (EVEX.b = 1)

THEN

DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(SRC2[i+31:i]*SRC3[31:0] - DEST[i+31:i])

ELSE

DEST[i+31:i] (cid:197)

RoundFPControl_MXCSR(SRC2[i+31:i]*SRC3[i+31:i] - DEST[i+31:i])

FI;

ELSE

IF *merging-masking*

; merging-masking

THEN *DEST[i+31:i] remains unchanged*

ELSE

; zeroing-masking

DEST[i+31:i] (cid:197) 0

FI

FI;

ENDFOR

DEST[MAX_VL-1:VL] (cid:197) 0

Intel C/C++ Compiler Intrinsic Equivalent

VFMSUBxxxPS __m512 _mm512_fmsub_ps(__m512 a, __m512 b, __m512 c);

VFMSUBxxxPS __m512 _mm512_fmsub_round_ps(__m512 a, __m512 b, __m512 c, int r);

VFMSUBxxxPS __m512 _mm512_mask_fmsub_ps(__m512 a, __mmask16 k, __m512 b, __m512 c);

VFMSUBxxxPS __m512 _mm512_maskz_fmsub_ps(__mmask16 k, __m512 a, __m512 b, __m512 c);

VFMSUBxxxPS __m512 _mm512_mask3_fmsub_ps(__m512 a, __m512 b, __m512 c, __mmask16 k);

VFMSUBxxxPS __m512 _mm512_mask_fmsub_round_ps(__m512 a, __mmask16 k, __m512 b, __m512 c, int r);

VFMSUBxxxPS __m512 _mm512_maskz_fmsub_round_ps(__mmask16 k, __m512 a, __m512 b, __m512 c, int r);

VFMSUBxxxPS __m512 _mm512_mask3_fmsub_round_ps(__m512 a, __m512 b, __m512 c, __mmask16 k, int r);

VFMSUBxxxPS __m256 _mm256_mask_fmsub_ps(__m256 a, __mmask8 k, __m256 b, __m256 c);

VFMSUBxxxPS __m256 _mm256_maskz_fmsub_ps(__mmask8 k, __m256 a, __m256 b, __m256 c);

VFMSUBxxxPS __m256 _mm256_mask3_fmsub_ps(__m256 a, __m256 b, __m256 c, __mmask8 k);

VFMSUBxxxPS __m128 _mm_mask_fmsub_ps(__m128 a, __mmask8 k, __m128 b, __m128 c);

VFMSUBxxxPS __m128 _mm_maskz_fmsub_ps(__mmask8 k, __m128 a, __m128 b, __m128 c);

VFMSUBxxxPS __m128 _mm_mask3_fmsub_ps(__m128 a, __m128 b, __m128 c, __mmask8 k);

VFMSUBxxxPS __m128 _mm_fmsub_ps (__m128 a, __m128 b, __m128 c);

VFMSUBxxxPS __m256 _mm256_fmsub_ps (__m256 a, __m256 b, __m256 c);

SIMD Floating-Point Exceptions

Overflow, Underflow, Invalid, Precision, Denormal

Other Exceptions