Bug: Rust build does not use simsimd (`index.hardware_acceleration()` reports `serial`) about usearch

[ashvardanian]

Hi @jrcavani! That is definitely a bug.
The warning isn't telling us much, especially as it redefines the macro with the same value. Can you also report the lscpu outputs, to make sure your CPU supports all the right features?

[jrcavani]

The macro that got overwritten was originally specified to be SIMSIMD_DYNAMIC_DISPATCH=1

    if cfg!(feature = "simsimd") {
        build
            .define("USEARCH_USE_SIMSIMD", "1")
            .define("SIMSIMD_DYNAMIC_DISPATCH", "1")
            .define("SIMSIMD_NATIVE_F16", "0");
    } else {

But it was redefined to be 1

warning: [email protected]:    52 | #define SIMSIMD_DYNAMIC_DISPATCH 0

Again, I haven't looked closely enough to know which one was an env var, and which one was a compile time constant, and how they interact between build.rs and C++ code.

Here is the lscpu output:

--> lscpu
Architecture:            x86_64
  CPU op-mode(s):        32-bit, 64-bit
  Address sizes:         46 bits physical, 48 bits virtual
  Byte Order:            Little Endian
CPU(s):                  64
  On-line CPU(s) list:   0-63
Vendor ID:               GenuineIntel
  Model name:            Intel(R) Xeon(R) Platinum 8375C CPU @ 2.90GHz
    CPU family:          6
    Model:               106
    Thread(s) per core:  2
    Core(s) per socket:  32
    Socket(s):           1
    Stepping:            6
    BogoMIPS:            5799.96
    Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology nonst
                         op_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq monitor ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnow
                         prefetch invpcid_single ssbd ibrs ibpb stibp ibrs_enhanced fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid avx512f avx512dq rdseed adx smap avx512ifma clflushopt clwb avx512cd sha_ni
                         avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves wbnoinvd ida arat avx512vbmi pku ospke avx512_vbmi2 gfni vaes vpclmulqdq avx512_vnni avx512_bitalg tme avx512_vpopcntdq rdpid md_clear flus
                         h_l1d arch_capabilities
Virtualization features:
  Hypervisor vendor:     KVM
  Virtualization type:   full
Caches (sum of all):
  L1d:                   1.5 MiB (32 instances)
  L1i:                   1 MiB (32 instances)
  L2:                    40 MiB (32 instances)
  L3:                    54 MiB (1 instance)
NUMA:
  NUMA node(s):          1
  NUMA node0 CPU(s):     0-63
Vulnerabilities:
  Itlb multihit:         Not affected
  L1tf:                  Not affected
  Mds:                   Not affected
  Meltdown:              Not affected
  Mmio stale data:       Mitigation; Clear CPU buffers; SMT Host state unknown
  Retbleed:              Not affected
  Spec store bypass:     Mitigation; Speculative Store Bypass disabled via prctl
  Spectre v1:            Mitigation; usercopy/swapgs barriers and __user pointer sanitization
  Spectre v2:            Mitigation; Enhanced IBRS, IBPB conditional, RSB filling, PBRSB-eIBRS SW sequence
  Srbds:                 Not affected
  Tsx async abort:       Not affected