Warn at start when using AVX build of Bun without AVX support (#6242)

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

3 files changed, 41 insertions, 12 deletions

diff --git a/src/bun.js/bindings/c-bindings.cpp b/src/bun.js/bindings/c-bindings.cpp
index ff4c8c4e7..f53ff52cc 100644
--- a/src/bun.js/bindings/c-bindings.cpp
+++ b/src/bun.js/bindings/c-bindings.cpp
@@ -1,4 +1,5 @@
 // when we don't want to use @cInclude, we can just stick wrapper functions here
+#include "root.h"
 #include <sys/resource.h>
 #include <cstdint>
 #include <unistd.h>
@@ -6,6 +7,32 @@
 #include <sys/stat.h>
 #include <sys/signal.h>
 
+#if CPU(X86_64)
+#include <cstring>
+#include <cpuid.h>
+
+extern "C" void bun_warn_avx_missing(const char* url)
+{
+    __builtin_cpu_init();
+    if (__builtin_cpu_supports("avx")) {
+        return;
+    }
+
+    static constexpr const char* str = "warn: CPU lacks AVX support, strange crashes may occur. Reinstall Bun or use *-baseline build:\n  ";
+    const size_t len = strlen(str);
+
+    char buf[512];
+    strcpy(buf, str);
+    strcpy(buf + len, url);
+    strcpy(buf + len + strlen(url), "\n\0");
+    write(STDERR_FILENO, buf, strlen(buf));
+}
+#else
+extern "C" void bun_warn_avx_missing(char* url)
+{
+}
+#endif
+
 extern "C" int32_t get_process_priority(uint32_t pid)
 {
     return getpriority(PRIO_PROCESS, pid);
@@ -48,4 +75,4 @@ extern "C" ssize_t bun_sysconf__SC_CLK_TCK()
 #else
     return 0;
 #endif
-}
\ No newline at end of file
+}
diff --git a/src/cli/upgrade_command.zig b/src/cli/upgrade_command.zig
index 60ae953d3..d865d990d 100644
--- a/src/cli/upgrade_command.zig
+++ b/src/cli/upgrade_command.zig
@@ -83,7 +83,9 @@ pub const Version = struct {
     pub const triplet = platform_label ++ "-" ++ arch_label;
     const suffix = if (Environment.baseline) "-baseline" else "";
     pub const folder_name = "bun-" ++ triplet ++ suffix;
+    pub const baseline_folder_name = "bun-" ++ triplet ++ "-baseline";
     pub const zip_filename = folder_name ++ ".zip";
+    pub const baseline_zip_filename = baseline_folder_name ++ ".zip";
 
     pub const profile_folder_name = "bun-" ++ triplet ++ suffix ++ "-profile";
     pub const profile_zip_filename = profile_folder_name ++ ".zip";
@@ -95,6 +97,11 @@ pub const Version = struct {
         zip_filename,
     });
 
+    pub const Bun__githubBaselineURL: [:0]const u8 = std.fmt.comptimePrint("https://github.com/oven-sh/bun/release/bun-v{s}/{s}", .{
+        Global.package_json_version,
+        baseline_zip_filename,
+    });
+
     pub fn isCurrent(this: Version) bool {
         return strings.eqlComptime(this.tag, current_version);
     }
diff --git a/src/main.zig b/src/main.zig
index 52cf33d53..ee8b0fb47 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -10,6 +10,7 @@ pub fn panic(msg: []const u8, error_return_trace: ?*std.builtin.StackTrace, addr
 }
 
 const CrashReporter = @import("./crash_reporter.zig");
+extern fn bun_warn_avx_missing(url: [*:0]const u8) void;
 
 pub fn main() void {
     const bun = @import("root").bun;
@@ -24,25 +25,19 @@ pub fn main() void {
 
     bun.start_time = std.time.nanoTimestamp();
 
-    // The memory allocator makes a massive difference.
-    // std.heap.raw_c_allocator and default_allocator perform similarly.
-    // std.heap.GeneralPurposeAllocator makes this about 3x _slower_ than esbuild.
-    // var root_alloc = @import("root").bun.ArenaAllocator.init(std.heap.raw_c_allocator);
-    // var root_alloc_ = &root_alloc.allocator;
-
     var stdout = std.io.getStdOut();
-    // var stdout = std.io.bufferedWriter(stdout_file.writer());
     var stderr = std.io.getStdErr();
     var output_source = Output.Source.init(stdout, stderr);
 
     Output.Source.set(&output_source);
     defer Output.flush();
+    if (comptime Environment.isX64) {
+        if (comptime Environment.enableSIMD) {
+            bun_warn_avx_missing(@import("./cli/upgrade_command.zig").Version.Bun__githubBaselineURL.ptr);
+        }
+    }
 
     bun.CLI.Cli.start(bun.default_allocator, stdout, stderr, MainPanicHandler);
 }
 
-test "panic" {
-    panic("woah", null);
-}
-
 pub const build_options = @import("build_options");