# VSUBSH — Subtract Scalar FP16 Value

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 5C /r VSUBSH xmm1{k1}{z}, xmm2, xmm3/m16 {er} | A | V/V | AVX512-FP16 | Subtract the low FP16 value in xmm3/m16 from xmm2 and store the result in xmm1 subject to writemask k1. Bits 127:16 from 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 subtracts the low FP16 value from the second source operand from the corresponding value in the first source operand, storing 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 ¶

#### VSUBSH (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-1:128] := 0

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

    VSUBSH __m128h _mm_mask_sub_round_sh (__m128h src, __mmask8 k, __m128h a, __m128h b, int rounding);

    VSUBSH __m128h _mm_maskz_sub_round_sh (__mmask8 k, __m128h a, __m128h b, int rounding);

    VSUBSH __m128h _mm_sub_round_sh (__m128h a, __m128h b, int rounding);

    VSUBSH __m128h _mm_mask_sub_sh (__m128h src, __mmask8 k, __m128h a, __m128h b);

    VSUBSH __m128h _mm_maskz_sub_sh (__mmask8 k, __m128h a, __m128h b);

    VSUBSH __m128h _mm_sub_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.”