# VMULSH — Multiply Scalar FP16 Values

Instruction En bit Mode Flag Support Instruction En bit Mode Flag Support 64/32 CPUID Feature Instruction En bit Mode Flag CPUID Feature Instruction En bit Mode Flag Op/ 64/32 CPUID Feature Instruction En bit Mode Flag 64/32 CPUID Feature Instruction En bit Mode Flag CPUID Feature Instruction En bit Mode Flag Op/ 64/32 CPUID Feature |  | Support |  | Description
--- | --- | --- | --- | ---
EVEX.LLIG.F3.MAP5.W0 59 /r VMULSH xmm1{k1}{z}, xmm2, xmm3/m16 {er} | A | V/V | AVX512-FP16 | Multiply the low FP16 value in xmm3/m16 by low FP16 value in xmm2, and store the result in xmm1 subject to writemask k1. Bits 127:16 of xmm2 are copied to xmm1[127:16].

## Instruction Operand Encoding ¶

Op/En | Tuple | Operand 1 | Operand 2 | Operand 3 | Operand 4
--- | --- | --- | --- | --- | ---
A | Scalar | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | N/A

### Description ¶

This instruction multiplies the low FP16 value from the source operands and stores the FP16 result in the destination operand. Bits 127:16 of the destination operand are copied from the corresponding bits of the first source operand. Bits MAXVL-1:128 of the destination operand are zeroed. The low FP16 element of the destination is updated according to the writemask.

### Operation ¶

#### VMULSH (EVEX encoded versions) ¶

    IF EVEX.b = 1 and SRC2 is a register:
        SET_RM(EVEX.RC)
    ELSE
        SET_RM(MXCSR.RC)
    IF k1[0] OR *no writemask*:
        DEST.fp16[0] := SRC1.fp16[0] * SRC2.fp16[0]
    ELSE IF *zeroing*:
        DEST.fp16[0] := 0
    // else dest.fp16[0] remains unchanged
    DEST[127:16] := SRC1[127:16]
    DEST[MAXVL-1:VL] := 0

### Intel C/C++ Compiler Intrinsic Equivalent ¶

    VMULSH __m128h _mm_mask_mul_round_sh (__m128h src, __mmask8 k, __m128h a, __m128h b, int rounding);

    VMULSH __m128h _mm_maskz_mul_round_sh (__mmask8 k, __m128h a, __m128h b, int rounding);

    VMULSH __m128h _mm_mul_round_sh (__m128h a, __m128h b, int rounding);

    VMULSH __m128h _mm_mask_mul_sh (__m128h src, __mmask8 k, __m128h a, __m128h b);

    VMULSH __m128h _mm_maskz_mul_sh (__mmask8 k, __m128h a, __m128h b);

    VMULSH __m128h _mm_mul_sh (__m128h a, __m128h b);

### SIMD Floating-Point Exceptions ¶

Invalid, Underflow, Overflow, Precision, Denormal

### Other Exceptions ¶

EVEX-encoded instructions, see Table 2-47, “Type E3 Class Exception Conditions.”