feat: collect cpu flags in system info

Author: GuillaumeLagrange

src/system/info.rs

@@ -30,6 +30,7 @@ pub struct SystemInfo {
     pub cpu_vendor_id: String,
     pub cpu_cores: usize,
     pub total_memory_gb: u64,
+    pub cpu_flags: Vec<String>,
 }
 
 #[cfg(test)]
@@ -46,10 +47,96 @@ impl SystemInfo {
             cpu_vendor_id: "GenuineIntel".to_string(),
             cpu_cores: 2,
             total_memory_gb: 8,
+            cpu_flags: vec![
+                "sse2".to_string(),
+                "avx".to_string(),
+                "avx2".to_string(),
+                "erms".to_string(),
+            ],
         }
     }
 }
 
+#[cfg(target_os = "linux")]
+fn get_glibc_relevant_cpu_flags() -> Vec<String> {
+    use procfs::Current;
+
+    /// CPU flags that influence glibc's ifunc dispatch (memcpy, strlen, strcmp, etc.)
+    ///
+    /// x86_64: selected from glibc's ifunc resolver logic:
+    /// - sysdeps/x86_64/multiarch/ifunc-impl-list.c
+    /// - sysdeps/x86/include/cpu-features.h
+    ///
+    /// aarch64: selected from glibc's ifunc resolver logic:
+    /// - sysdeps/aarch64/multiarch/ifunc-impl-list.c
+    /// - sysdeps/unix/sysv/linux/aarch64/cpu-features.h
+    ///
+    /// Source sources: https://sourceware.org/git/?p=glibc.git
+    #[rustfmt::skip]
+    const RELEVANT_X86_64_FLAGS: &[&str] = &[
+        // SIMD
+        "sse2", "ssse3", "sse4_1", "sse4_2",
+        // AVX
+        "avx", "avx2",
+        // AVX-512
+        "avx512f", "avx512bw", "avx512vl",
+        // REP string optimizations
+        "erms", "fsrm",
+        // Other flags used in glibc dispatch decisions
+        "rtm", "bmi1", "bmi2", "popcnt", "fma", "movbe",
+    ];
+
+    #[rustfmt::skip]
+    const RELEVANT_AARCH64_FLAGS: &[&str] = &[
+        // SVE-optimized memcpy/memmove/memset
+        "sve",
+        // Memory Copy/Set instructions (ARMv9, takes priority over SVE)
+        "mops",
+        // Memory Tagging Extension (affects memchr/strlen variant selection)
+        "mte",
+        // Enables MIDR_EL1 reads for CPU-specific variants (A64FX, Oryon1, etc.)
+        "cpuid",
+    ];
+
+    let cpuinfo = match procfs::CpuInfo::current() {
+        Ok(cpuinfo) => cpuinfo,
+        Err(e) => {
+            warn!("Failed to read /proc/cpuinfo: {e}");
+            return Vec::new();
+        }
+    };
+
+    // /proc/cpuinfo uses "flags" on x86_64 and "Features" on aarch64
+    let (relevant_flags, field_name) = if cfg!(target_arch = "x86_64") {
+        (RELEVANT_X86_64_FLAGS, "flags")
+    } else if cfg!(target_arch = "aarch64") {
+        (RELEVANT_AARCH64_FLAGS, "Features")
+    } else {
+        return Vec::new();
+    };
+
+    let all_flags: Vec<&str> = match cpuinfo.get_field(0, field_name) {
+        Some(value) => value.split_whitespace().collect(),
+        None => {
+            warn!("No CPU flags found in /proc/cpuinfo (field: {field_name})");
+            return Vec::new();
+        }
+    };
+
+    let mut flags: Vec<String> = all_flags
+        .into_iter()
+        .filter(|flag| relevant_flags.contains(flag))
+        .map(|flag| flag.to_string())
+        .collect();
+    flags.sort();
+    flags
+}
+
+#[cfg(not(target_os = "linux"))]
+fn get_glibc_relevant_cpu_flags() -> Vec<String> {
+    Vec::new()
+}
+
 impl SystemInfo {
     pub fn new() -> Result<Self> {
         let os = System::distribution_id();
@@ -85,6 +172,8 @@ impl SystemInfo {
         let cpu_name = cpu.name().to_string();
         let cpu_vendor_id = cpu.vendor_id().to_string();
 
+        let cpu_flags = get_glibc_relevant_cpu_flags();
+
         Ok(SystemInfo {
             os,
             os_version,
@@ -96,6 +185,7 @@ impl SystemInfo {
             cpu_vendor_id,
             cpu_cores,
             total_memory_gb,
+            cpu_flags,
         })
     }
 }

src/upload/snapshots/codspeed_runner__upload__upload_metadata__tests__get_local_metadata_hash-2.snap

@@ -22,7 +22,13 @@ expression: upload_metadata
     "cpuName": "cpu0",
     "cpuVendorId": "GenuineIntel",
     "cpuCores": 6,
-    "totalMemoryGb": 16
+    "totalMemoryGb": 16,
+    "cpuFlags": [
+      "sse2",
+      "avx",
+      "avx2",
+      "erms"
+    ]
   },
   "runEnvironment": "LOCAL",
   "runPart": {

src/upload/snapshots/codspeed_runner__upload__upload_metadata__tests__get_metadata_hash-2.snap

@@ -24,7 +24,13 @@ expression: upload_metadata
     "cpuName": "cpu0",
     "cpuVendorId": "GenuineIntel",
     "cpuCores": 2,
-    "totalMemoryGb": 8
+    "totalMemoryGb": 8,
+    "cpuFlags": [
+      "sse2",
+      "avx",
+      "avx2",
+      "erms"
+    ]
   },
   "runEnvironment": "GITHUB_ACTIONS",
   "runPart": {

src/upload/upload_metadata.rs

@@ -77,7 +77,7 @@ mod tests {
             hash,
             // Caution: when changing this value, we need to ensure that
             // the related backend snapshot remains the same
-            @"b2c6175fa81d4c4c5eb215e2e77667891f33abca9f8614b45899e3ee070bdca6"
+            @"bcf7fd0b0fcaf597a832478517599e13a0513587c98538cc9f8f8b4dc288e8d4"
         );
         assert_json_snapshot!(upload_metadata);
     }
@@ -106,6 +106,12 @@ mod tests {
                     cpu_vendor_id: "GenuineIntel".to_string(),
                     cpu_cores: 6,
                     total_memory_gb: 16,
+                    cpu_flags: vec![
+                        "sse2".to_string(),
+                        "avx".to_string(),
+                        "avx2".to_string(),
+                        "erms".to_string(),
+                    ],
                 },
             },
             run_environment: RunEnvironment::Local,
@@ -139,7 +145,7 @@ mod tests {
             hash,
             // Caution: when changing this value, we need to ensure that
             // the related backend snapshot remains the same
-            @"47b6317da2747edae177d8a99143efc6f7516beb3222b9d45331ba48d4e1c369"
+            @"00e1df4c32a46e25479c30d5792e46d71f5cfcafb24dda7a5c81c609363aa1f4"
         );
         assert_json_snapshot!(upload_metadata);
     }