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Source code

VFNMSUB132SS, VFNMSUB213SS, VFNMSUB231SS

Fused Negative Multiply-Subtract of

stableVMJITAOTinstruction

Encodings

OpcodeInstructionOp/En64-bitCompat/LegacyDescription
VEX.LIG.66.0F38.W0 9F /rVFNMSUB132SS xmm1, xmm2, xmm3/m32AValidValidMultiply scalar single precision floating-point value from xmm1 and xmm3/m32, negate the multiplication result and subtract xmm2 and put result in xmm1.
VEX.LIG.66.0F38.W0 AF /rVFNMSUB213SS xmm1, xmm2, xmm3/m32AValidValidMultiply scalar single precision floating-point value from xmm1 and xmm2, negate the multiplication result and subtract xmm3/m32 and put result in xmm1.
VEX.LIG.66.0F38.W0 BF /rVFNMSUB231SS xmm1, xmm2, xmm3/m32AValidValidMultiply scalar single precision floating-point value from xmm2 and xmm3/m32, negate the multiplication result and subtract xmm1 and put result in xmm1.
EVEX.LLIG.66.0F38.W0 9F /rVFNMSUB132SS xmm1 {k1}{z}, xmm2, xmm3/m32{er}BValidValidMultiply scalar single-precision floating-point value from OR AVX10.1 xmm1 and xmm3/m32, negate the multiplication result and subtract xmm2 and put result in xmm1.
EVEX.LLIG.66.0F38.W0 AF /rVFNMSUB213SS xmm1 {k1}{z}, xmm2, xmm3/m32{er}BValidValidMultiply scalar single-precision floating-point value from OR AVX10.1 xmm1 and xmm2, negate the multiplication result and subtract xmm3/m32 and put result in xmm1.
EVEX.LLIG.66.0F38.W0 BF /rVFNMSUB231SS xmm1 {k1}{z}, xmm2, xmm3/m32{er}BValidValidMultiply scalar single-precision floating-point value from OR AVX10.1 xmm2 and xmm3/m32, negate the multiplication result and subtract xmm1 and put result in xmm1.

Operand encoding

Each mode is a value of the Op/En column above. It says which field of the encoded instruction carries each operand, in the order they are written, and whether the instruction reads it, writes it or both.

A

  1. modrm.reg lectura y escrituraModRM byte, reg field (bits 5-3)
  2. vex.vvvv lecturaVEX prefix, vvvv field (inverted)
  3. modrm.rm lecturaModRM byte, r/m field (bits 2-0); with the SIB byte and the displacement when the mod field asks for them

B

  1. modrm.reg lectura y escrituraModRM byte, reg field (bits 5-3)
  2. evex.vvvv lecturaEVEX prefix, vvvv field (inverted)
  3. modrm.rm lecturaModRM byte, r/m field (bits 2-0); with the SIB byte and the displacement when the mod field asks for them

Tupla: Tuple1 Scalar

Measured cost

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Description

VFNMSUB132SS: Multiplies the low packed single precision floating-point value from the first source operand to the low packed single precision floating-point value in the third source operand. From negated infinite precision intermediate result, the low single precision floating-point value in the second source operand, performs rounding and stores the resulting packed single precision floating-point value to the destination operand (first source operand).

VFNMSUB213SS: Multiplies the low packed single precision floating-point value from the second source operand to the low packed single precision floating-point value in the first source operand. From negated infinite precision intermediate result, the low single precision floating-point value in the third source operand, performs rounding and stores the resulting packed single precision floating-point value to the destination operand (first source operand).

VFNMSUB231SS: Multiplies the low packed single precision floating-point value from the second source to the low packed single precision floating-point value in the third source operand. From negated infinite precision intermediate result, the low single precision floating-point value in the first source operand, performs rounding and stores the resulting packed single precision floating-point value to the destination operand (first source operand).

VEX.128 and EVEX encoded version: The destination operand (also first source operand) is encoded in reg_field. The second source operand is encoded in VEX.vvvv/EVEX.vvvv. The third source operand is encoded in rm_field. Bits 127:32 of the destination are unchanged. Bits MAXVL-1:128 of the destination register are zeroed.

EVEX encoded version: The low doubleword element of the destination is updated according to the writemask.

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.

Operation

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

VFNMSUB132SS DEST, SRC2, SRC3 (EVEX encoded version)

IF (EVEX.b = 1) and SRC3 *is a register*

     THEN

     SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(EVEX.RC);

     ELSE

     SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(MXCSR.RC);

FI;

IF k1[0] or *no writemask*

     THEN DEST[31:0] := RoundFPControl(-(DEST[31:0]*SRC3[31:0]) - SRC2[31:0])

     ELSE

     IF *merging-masking*                 ; merging-masking

           THEN *DEST[31:0] remains unchanged*

           ELSE                           ; zeroing-masking

           THEN DEST[31:0] := 0

     FI;

FI;

DEST[127:32] := DEST[127:32]

DEST[MAXVL-1:128] := 0

VFNMSUB213SS DEST, SRC2, SRC3 (EVEX encoded version)

IF (EVEX.b = 1) and SRC3 *is a register*

     THEN

     SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(EVEX.RC);

     ELSE

     SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(MXCSR.RC);

FI;

IF k1[0] or *no writemask*

     THEN DEST[31:0] := RoundFPControl(-(SRC2[31:0]*DEST[31:0]) - SRC3[31:0])

     ELSE

     IF *merging-masking*                 ; merging-masking

           THEN *DEST[31:0] remains unchanged*

           ELSE                           ; zeroing-masking

           THEN DEST[31:0] := 0

     FI;

FI;

DEST[127:32] := DEST[127:32]

DEST[MAXVL-1:128] := 0


VFNMSUB231SS DEST, SRC2, SRC3 (EVEX encoded version)

IF (EVEX.b = 1) and SRC3 *is a register*

     THEN

     SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(EVEX.RC);

     ELSE

     SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(MXCSR.RC);

FI;

IF k1[0] or *no writemask*

     THEN DEST[31:0] := RoundFPControl(-(SRC2[31:0]*SRC3[63:0]) - DEST[31:0])

     ELSE

     IF *merging-masking*                 ; merging-masking

           THEN *DEST[31:0] remains unchanged*

           ELSE                           ; zeroing-masking

           THEN DEST[31:0] := 0

     FI;

FI;

DEST[127:32] := DEST[127:32]

DEST[MAXVL-1:128] := 0

VFNMSUB132SS DEST, SRC2, SRC3 (VEX encoded version)
DEST[31:0] := RoundFPControl_MXCSR(- (DEST[31:0]*SRC3[31:0]) - SRC2[31:0])
DEST[127:32] := DEST[127:32]
DEST[MAXVL-1:128] := 0

VFNMSUB213SS DEST, SRC2, SRC3 (VEX encoded version)
DEST[31:0] := RoundFPControl_MXCSR(- (SRC2[31:0]*DEST[31:0]) - SRC3[31:0])
DEST[127:32] := DEST[127:32]
DEST[MAXVL-1:128] := 0

VFNMSUB231SS DEST, SRC2, SRC3 (VEX encoded version)
DEST[31:0] := RoundFPControl_MXCSR(- (SRC2[31:0]*SRC3[31:0]) - DEST[31:0])
DEST[127:32] := DEST[127:32]
DEST[MAXVL-1:128] := 0

Intel C/C++ compiler intrinsics

VFNMSUBxxxSS __m128 _mm_fnmsub_round_ss(__m128 a, __m128 b, __m128 c, int r);
VFNMSUBxxxSS __m128 _mm_mask_fnmsub_ss(__m128 a, __mmask8 k, __m128 b, __m128 c);
VFNMSUBxxxSS __m128 _mm_maskz_fnmsub_ss(__mmask8 k, __m128 a, __m128 b, __m128 c);
VFNMSUBxxxSS __m128 _mm_mask3_fnmsub_ss(__m128 a, __m128 b, __m128 c, __mmask8 k);
VFNMSUBxxxSS __m128 _mm_mask_fnmsub_round_ss(__m128 a, __mmask8 k, __m128 b, __m128 c, int r);
VFNMSUBxxxSS __m128 _mm_maskz_fnmsub_round_ss(__mmask8 k, __m128 a, __m128 b, __m128 c, int r);
VFNMSUBxxxSS __m128 _mm_mask3_fnmsub_round_ss(__m128 a, __m128 b, __m128 c, __mmask8 k, int r);
VFNMSUBxxxSS __m128 _mm_fnmsub_ss (__m128 a, __m128 b, __m128 c);

SIMD Floating-Point Exceptions

Overflow, Underflow, Invalid, Precision, Denormal.

Other Exceptions

VEX-encoded instructions, see Table 2-20, "Type 3 Class Exception Conditions." EVEX-encoded instructions, see Table 2-49, "Type E3 Class Exception Conditions."

Sources