VCMPSH — Compare 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.F3.0F3A.W0 C2 /r /ib VCMPSH k1{k2}, xmm2, xmm3/m16 {sae}, imm8 A V/V AVX512-FP16 Compare low FP16 values in xmm3/m16 and xmm2 using bits 4:0 of imm8 as a comparison predicate subject to writemask k2, and store the result in mask register k1.

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) imm8 (r)

Description

This instruction compares the FP16 values from the lowest element of the source operands and stores the result in the destination mask operand. The comparison predicate operand (immediate byte bits 4:0) specifies the type of comparison performed on the pair of packed FP16 values. The low destination bit is updated according to the writemask. Bits MAXKL-1:1 of the destination operand are zeroed.

Operation

CASE (imm8 & 0x1F) OF
0: CMP_OPERATOR := EQ_OQ;
1: CMP_OPERATOR := LT_OS;
2: CMP_OPERATOR := LE_OS;
3: CMP_OPERATOR := UNORD_Q;
4: CMP_OPERATOR := NEQ_UQ;
5: CMP_OPERATOR := NLT_US;
6: CMP_OPERATOR := NLE_US;
7: CMP_OPERATOR := ORD_Q;
8: CMP_OPERATOR := EQ_UQ;
9: CMP_OPERATOR := NGE_US;
10: CMP_OPERATOR := NGT_US;
11: CMP_OPERATOR := FALSE_OQ;
12: CMP_OPERATOR := NEQ_OQ;
13: CMP_OPERATOR := GE_OS;
14: CMP_OPERATOR := GT_OS;
15: CMP_OPERATOR := TRUE_UQ;
16: CMP_OPERATOR := EQ_OS;
17: CMP_OPERATOR := LT_OQ;
18: CMP_OPERATOR := LE_OQ;
19: CMP_OPERATOR := UNORD_S;
20: CMP_OPERATOR := NEQ_US;
21: CMP_OPERATOR := NLT_UQ;
22: CMP_OPERATOR := NLE_UQ;
23: CMP_OPERATOR := ORD_S;
24: CMP_OPERATOR := EQ_US;
25: CMP_OPERATOR := NGE_UQ;
26: CMP_OPERATOR := NGT_UQ;
27: CMP_OPERATOR := FALSE_OS;
28: CMP_OPERATOR := NEQ_OS;
29: CMP_OPERATOR := GE_OQ;
30: CMP_OPERATOR := GT_OQ;
31: CMP_OPERATOR := TRUE_US;
ESAC

VCMPSH (EVEX Encoded Versions)

IF k2[0] OR *no writemask*:
    DEST.bit[0] := SRC1.fp16[0] CMP_OPERATOR SRC2.fp16[0]
ELSE
    DEST.bit[0] := 0
DEST[MAXKL-1:1] := 0

Intel C/C++ Compiler Intrinsic Equivalent

VCMPSH __mmask8 _mm_cmp_round_sh_mask (__m128h a, __m128h b, const int imm8, const int sae);
VCMPSH __mmask8 _mm_mask_cmp_round_sh_mask (__mmask8 k1, __m128h a, __m128h b, const int imm8, const int sae);
VCMPSH __mmask8 _mm_cmp_sh_mask (__m128h a, __m128h b, const int imm8);
VCMPSH __mmask8 _mm_mask_cmp_sh_mask (__mmask8 k1, __m128h a, __m128h b, const int imm8);

SIMD Floating-Point Exceptions

Invalid, Denormal.

Other Exceptions

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