From 1ed61918a93f0fdef1f66d72faccf25b61d75cff Mon Sep 17 00:00:00 2001
From: Diogo Correia <me@diogotc.com>
Date: Mon, 6 Jul 2026 16:58:41 +0100
Subject: [PATCH] postgresqlPackages.vectorchord: disable avx512vnni support

Due to a bug in LLVM 21, build fails on x86_64 with:
`rustc-LLVM ERROR: Cannot select: intrinsic %llvm.x86.avx512.vpdpbusd.512`.
This has been fixed in Rust's build of LLVM and LLVM 22 [1]
but this is not reflected in nixpkgs' packaging of rustc.
For this reason, we temporarily disable avx512vnni support until this is fixed in nixpkgs.
This might cause a performance penalty, but should not affect correctness.

See https://github.com/NixOS/nixpkgs/pull/537113#issuecomment-4846239887

[1]: https://github.com/rust-lang/llvm-project/commit/94e2c19f86a699d7a19ff0f4130b696699189c8d
---
 .../vectorchord/0001-disable-avx512vnni.patch | 29 +++++++++++++++++++
 .../postgresql/ext/vectorchord/package.nix    | 13 +++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 pkgs/servers/sql/postgresql/ext/vectorchord/0001-disable-avx512vnni.patch

diff --git a/pkgs/servers/sql/postgresql/ext/vectorchord/0001-disable-avx512vnni.patch b/pkgs/servers/sql/postgresql/ext/vectorchord/0001-disable-avx512vnni.patch
new file mode 100644
index 000000000000..093663c162dd
--- /dev/null
+++ b/pkgs/servers/sql/postgresql/ext/vectorchord/0001-disable-avx512vnni.patch
@@ -0,0 +1,29 @@
+diff --git a/crates/simd/src/byte.rs b/crates/simd/src/byte.rs
+index 0c7c4be..87737d4 100644
+--- a/crates/simd/src/byte.rs
++++ b/crates/simd/src/byte.rs
+@@ -389,7 +389,7 @@ mod reduce_sum_of_xy {
+         }
+     }
+ 
+-    #[crate::multiversion(@"v4:avx512vnni", @"v4", @"v3", @"v2", @"a2:dotprod", @"a2", "z17", "z16", "z15", "z14", "z13", "p9", "p8", "p7", "r1")]
++    #[crate::multiversion(@"v4", @"v3", @"v2", @"a2:dotprod", @"a2", "z17", "z16", "z15", "z14", "z13", "p9", "p8", "p7", "r1")]
+     pub fn reduce_sum_of_xy(s: &[u8], t: &[u8]) -> u32 {
+         assert_eq!(s.len(), t.len());
+         let n = s.len();
+diff --git a/crates/simd/src/halfbyte.rs b/crates/simd/src/halfbyte.rs
+index e1aa016..f7dc3dc 100644
+--- a/crates/simd/src/halfbyte.rs
++++ b/crates/simd/src/halfbyte.rs
+@@ -411,7 +411,7 @@ mod reduce_sum_of_xy {
+         }
+     }
+ 
+-    #[crate::multiversion(@"v4:avx512vnni", @"v4", @"v3", @"v2", @"a2:dotprod", @"a2", "z17", "z16", "z15", "z14", "z13", "p9", "p8", "p7", "r1")]
++    #[crate::multiversion(@"v4", @"v3", @"v2", @"a2:dotprod", @"a2", "z17", "z16", "z15", "z14", "z13", "p9", "p8", "p7", "r1")]
+     pub fn reduce_sum_of_xy(s: &[u8], t: &[u8]) -> u32 {
+         assert_eq!(s.len(), t.len());
+         let n = s.len();
+-- 
+2.54.0
+
diff --git a/pkgs/servers/sql/postgresql/ext/vectorchord/package.nix b/pkgs/servers/sql/postgresql/ext/vectorchord/package.nix
index 1dd1d6283a81..7d40097abf6a 100644
--- a/pkgs/servers/sql/postgresql/ext/vectorchord/package.nix
+++ b/pkgs/servers/sql/postgresql/ext/vectorchord/package.nix
@@ -6,6 +6,8 @@
   nix-update-script,
   postgresql,
   postgresqlTestExtension,
+  rustc,
+  stdenv,
 }:
 buildPgrxExtension (finalAttrs: {
   inherit postgresql;
@@ -23,6 +25,17 @@ buildPgrxExtension (finalAttrs: {
 
   cargoHash = "sha256-IXOCzKJArNOcb/2TcJbLz1XdCquUpyF/cLHYU5vmlko=";
 
+  patches = lib.optional (lib.versionOlder rustc.llvm.version "22.0.0" && stdenv.isx86_64) [
+    # Due to a bug in LLVM 21, build fails on x86_64 with:
+    # `rustc-LLVM ERROR: Cannot select: intrinsic %llvm.x86.avx512.vpdpbusd.512`.
+    # This has been fixed in Rust's build of LLVM and LLVM 22 with https://github.com/rust-lang/llvm-project/commit/94e2c19f86a699d7a19ff0f4130b696699189c8d,
+    # but this is not reflected in nixpkgs' packaging of rustc.
+    # For this reason, we temporarily disable avx512vnni support until this is fixed in nixpkgs.
+    # This might cause a performance penalty, but should not affect correctness.
+    # See https://github.com/NixOS/nixpkgs/pull/537113#issuecomment-4846239887
+    ./0001-disable-avx512vnni.patch
+  ];
+
   # Include upgrade scripts in the final package
   # https://github.com/supervc-stack/VectorChord/blob/0.5.0/crates/make/src/main.rs#L366
   postInstall = ''