From ef5fb6fa46e71eb0e152c493d60858a4d73ef07b Mon Sep 17 00:00:00 2001
From: Michael Vines <mvines@gmail.com>
Date: Fri, 7 Feb 2020 16:01:45 -0700
Subject: [PATCH] Check for AVX512 at runtime to avoid invalid opcode trap
 (#8166)

automerge
---
 core/build.rs         |  8 ++++++++
 core/src/validator.rs | 10 ++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 core/build.rs

diff --git a/core/build.rs b/core/build.rs
new file mode 100644
index 000000000..a2fbf3bef
--- /dev/null
+++ b/core/build.rs
@@ -0,0 +1,8 @@
+fn main() {
+    // Until https://github.com/rust-lang/rust/issues/44839 is resolved
+    // `#[target_feature(enable = "avx512f")]` is not available.
+    // Use an env flag instead:
+    if is_x86_feature_detected!("avx512f") {
+        println!("cargo:rustc-env=TARGET_FEATURE_AVX512F=1");
+    }
+}
diff --git a/core/src/validator.rs b/core/src/validator.rs
index ed79c5fe2..a504b7469 100644
--- a/core/src/validator.rs
+++ b/core/src/validator.rs
@@ -646,6 +646,16 @@ fn report_target_features() {
             process::exit(1);
         }
     }
+
+    // TARGET_FEATURE_AVX512F is defined by build.rs
+    if option_env!("TARGET_FEATURE_AVX512F").is_some() {
+        if is_x86_feature_detected!("avx512f") {
+            info!("AVX512 detected");
+        } else {
+            error!("Your machine does not have AVX512 support, please rebuild from source on your machine");
+            process::exit(1);
+        }
+    }
 }
 
 // Get the activated stake percentage (based on the provided bank) that is visible in gossip