VANDPD

VANDPD is the bitwise AND of two vectors, read as 64-bit elements. The bits are the same as those of VANDPS, whose page covers what the instruction is for (absolute values, copied signs, selecting with a compare result) and why its EVEX forms need AVX512DQ; nothing is rounded and no MXCSR flag can change. The element size matters only where the EVEX form looks at elements: a write mask selects doubles, and a broadcast from memory repeats one 64-bit value.

Which of the two compilers emit#

GCC 14 and Clang 23 at -O2 with -march=x86-64-v3 choose differently for the same code on doubles:

• fabs(b[i]) is VANDPD with a broadcast 7FFFFFFFFFFFFFFFh in GCC and VANDPS with the same constant in Clang;
• copysign(b[i], c[i]) is VANDNPD, VANDPD and VORPD in GCC and their PS forms in Clang;
• b[i] < c[i] ? b[i] : 0.0 is VCMPPD and VANDPD in both, the compare’s all-ones elements keeping b and its zeros clearing it.

Clang picks the PS form where only bits are moved and keeps the PD form next to a compare on doubles. With -march=x86-64-v4, the same select needs no AND: both compilers compare into a mask register and copy b with a zeroing VMOVAPD, and copysign becomes a single VPTERNLOGQ.

Masks recorded on Zen 5#

The masked cases show that elements, not bits, are selected: vandpd zmm0{k5}, zmm31, zmm16, with k5 selecting elements 0 and 5 to 7, wrote the AND there and left elements 1 to 4 as zmm0 held them, and vandpd zmm1{k7}, zmm2, qword bcst [mem] with an all-ones double broadcast passed zmm2’s elements through where k7 selected them.

AMD’s Zen 5 guide lists VANDPD as it lists VANDPS, with a latency of 1 cycle on all four vector pipes.

Forms

Latency and throughput

Data flow

Where the elements of the sources go, element 0 on the right; results that depend on a control value are drawn for an example. How to read.

Operation

What the forms do, in pseudocode that our tests run against results recorded on real processors. How to read.

for i in range(VL // 64):
    if k1[i]:  # 1 without a write mask
        zmm1.q[i] = zmm2.q[i] & src3.q[i]
    elif zeroing:
        zmm1.q[i] = 0
    # else: zmm1.q[i] keeps its value
# m64bcst: src3.q[i] is the m64 for every i
# zmm1 is zeroed from bit VL up

Operands

Flags

None: XED records no flag that the forms test or change.

Exceptions

The exception class is XED's name for the set of exception conditions that a form follows. How to read.

VEX forms

avx-type-4

EVEX forms

AVX512-E4

Attributes

What else XED records about the forms. How to read.

EVEX forms

write masking

EVEX memory forms

embedded broadcast (tuple Full); memory fault suppression

Intrinsics

The C intrinsics of Clang 23.1.2 that compile to VANDPD, each with the form it compiles to and the Clang options it needs. The forms come from compiling every intrinsic and decoding the result with Intel XED; all intrinsics A–Z explains the method.

CPUID and processors

Each form belongs to an XED ISA set. A form can be used when the processor reports every CPUID bit of one of its ISA set's alternatives.

More AVX instructions

• VADDPD
• VADDPS
• VADDSD
• VADDSS
• VADDSUBPD
• VADDSUBPS
• VANDNPD
• VANDNPS
• VANDPS
• VBLENDPD
• VBLENDPS
• VBLENDVPD
• VBLENDVPS
• VBROADCASTF128
• VBROADCASTSD
• VBROADCASTSS
• VCMPPD
• VCMPPS
• VCMPSD
• VCMPSS
• VCOMISD
• VCOMISS
• VCVTDQ2PD
• VCVTDQ2PS
• VCVTPD2DQ
• VCVTPD2PS
• VCVTPS2DQ
• VCVTPS2PD
• VCVTSD2SI
• VCVTSD2SS
• VCVTSI2SD
• VCVTSI2SS
• VCVTSS2SD
• VCVTSS2SI
• VCVTTPD2DQ
• VCVTTPS2DQ
• VCVTTSD2SI
• VCVTTSS2SI
• VDIVPD
• VDIVPS

All 253 AVX instructions

More AVX10.1 instructions

• KXNORQ
• KXNORW
• KXORB
• KXORD
• KXORQ
• KXORW
• VADDPD
• VADDPH
• VADDPS
• VADDSD
• VADDSH
• VADDSS
• VAESDEC
• VAESDECLAST
• VAESENC
• VAESENCLAST
• VALIGND
• VALIGNQ
• VANDNPD
• VANDNPS
• VANDPS
• VBLENDMPD
• VBLENDMPS
• VBROADCASTF32X2
• VBROADCASTF32X4
• VBROADCASTF32X8
• VBROADCASTF64X2
• VBROADCASTF64X4
• VBROADCASTI32X2
• VBROADCASTI32X4
• VBROADCASTI32X8
• VBROADCASTI64X2
• VBROADCASTI64X4
• VBROADCASTSD
• VBROADCASTSS
• VCMPPD
• VCMPPH
• VCMPPS
• VCMPSD
• VCMPSH

All 686 AVX10.1 instructions