无法设置rustflags target-cpu = cargo.toml（simd-json）

Question

我正在尝试编译Rust Simd-Json软件包。它抱怨盒子不兼容SIMD：

    |
221 | fn please_compile_with_a_simd_compatible_cpu_setting_read_the_simdjsonrs_readme() -> ! {}
    |    ----------------------------------------------------------------------------      ^ expected `!`, found `()`
    |    |
    |    implicitly returns `()` as its body has no tail or `return` expression

但是，该框是x86所需的：

$ uname -a
Linux ip-172-31-68-220 5.15.0-1011-aws #14-Ubuntu SMP Wed Jun 1 20:54:22 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

和cargo.toml包含所需的编译器标志：

[build]
rustflags = ["-C", "target-cpu=native"]

[target.wasm32-unknown-unknown]
rustflags = ["-C", "target-feature=+simd128"]

[target.wasm32-wasi]
rustflags = ["-C", "target-feature=+simd128"]

为什么SIMD-JSON不快乐？

完整/proc/cpuinfo以下输出。

processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 85
model name  : Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
stepping    : 7
microcode   : 0x500320a
cpu MHz     : 2500.006
cache size  : 36608 KB
physical id : 0
siblings    : 4
core id     : 0
cpu cores   : 2
apicid      : 0
initial apicid  : 0
fpu     : yes
fpu_exception   : yes
cpuid level : 13
wp      : yes
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 rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single pti fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves ida arat pku ospke
bugs        : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips    : 5000.01
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

processor   : 1
vendor_id   : GenuineIntel
cpu family  : 6
model       : 85
model name  : Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
stepping    : 7
microcode   : 0x500320a
cpu MHz     : 2500.006
cache size  : 36608 KB
physical id : 0
siblings    : 4
core id     : 1
cpu cores   : 2
apicid      : 2
initial apicid  : 2
fpu     : yes
fpu_exception   : yes
cpuid level : 13
wp      : yes
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 rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single pti fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves ida arat pku ospke
bugs        : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips    : 5000.01
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

processor   : 2
vendor_id   : GenuineIntel
cpu family  : 6
model       : 85
model name  : Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
stepping    : 7
microcode   : 0x500320a
cpu MHz     : 2500.006
cache size  : 36608 KB
physical id : 0
siblings    : 4
core id     : 0
cpu cores   : 2
apicid      : 1
initial apicid  : 1
fpu     : yes
fpu_exception   : yes
cpuid level : 13
wp      : yes
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 rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single pti fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves ida arat pku ospke
bugs        : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips    : 5000.01
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

processor   : 3
vendor_id   : GenuineIntel
cpu family  : 6
model       : 85
model name  : Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
stepping    : 7
microcode   : 0x500320a
cpu MHz     : 2500.006
cache size  : 36608 KB
physical id : 0
siblings    : 4
core id     : 1
cpu cores   : 2
apicid      : 3
initial apicid  : 3
fpu     : yes
fpu_exception   : yes
cpuid level : 13
wp      : yes
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 rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single pti fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves ida arat pku ospke
bugs        : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips    : 5000.01
clflush size    : 64
cache_alignment : 64
address sizes   : 46 bits physical, 48 bits virtual
power management:

Answer 1

该功能的实现定义如下：

#[cfg(all(
    not(feature = "allow-non-simd"),
    not(any(
        target_feature = "sse4.2",
        target_feature = "avx2",
        target_feature = "neon",
        target_feature = "simd128"
    ))
))]
fn please_compile_with_a_simd_compatible_cpu_setting_read_the_simdjsonrs_readme() -> ! {}

这意味着Rust编译器认为您的CPU没有sse 4.2或avx2或neon或SIMD128。

您的/proc/cpuinfo似乎具有avx2，因此赠品的赠品是奇怪的事情。

问题是RustFlags在您的cargo.toml，需要将其添加到您的 .cargo/config.toml 文件。该配置文件主要用于用于货物和Rustc的全局设置，但是您可以将一个本地化为项目根部的存储库。 myproject/.cargo/config.toml）

（例如 /config“ rel =“ noreferrer”> simd-json 的示例，您可以看到这就是他们所做的。