From c1826849eabe7ff5d5c8e749129cbec36131abaa Mon Sep 17 00:00:00 2001
From: clubby789 <jamie@hill-daniel.co.uk>
Date: Thu, 21 Mar 2024 22:38:22 +0000
Subject: [PATCH] Don't emit load metadata in debug mode

---
 compiler/rustc_codegen_llvm/src/builder.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 63e59ea13fc35..3555c7d8b3446 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -20,6 +20,7 @@ use rustc_middle::ty::layout::{
     FnAbiError, FnAbiOfHelpers, FnAbiRequest, LayoutError, LayoutOfHelpers, TyAndLayout,
 };
 use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_session::config::OptLevel;
 use rustc_span::Span;
 use rustc_symbol_mangling::typeid::{kcfi_typeid_for_fnabi, typeid_for_fnabi, TypeIdOptions};
 use rustc_target::abi::{self, call::FnAbi, Align, Size, WrappingRange};
@@ -547,6 +548,11 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             layout: TyAndLayout<'tcx>,
             offset: Size,
         ) {
+            if bx.cx.sess().opts.optimize == OptLevel::No {
+                // Don't emit metadata we're not going to use
+                return;
+            }
+
             if !scalar.is_uninit_valid() {
                 bx.noundef_metadata(load);
             }
@@ -663,6 +669,11 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
             return;
         }
 
+        if self.cx.sess().opts.optimize == OptLevel::No {
+            // Don't emit metadata we're not going to use
+            return;
+        }
+
         unsafe {
             let llty = self.cx.val_ty(load);
             let v = [