diff --git a/120529.patch b/120529.patch
new file mode 100644
index 0000000..9e53295
--- /dev/null
+++ b/120529.patch
@@ -0,0 +1,62 @@
+From 8eb48b4f4c6e3d48f2600159a75184ec4d74b249 Mon Sep 17 00:00:00 2001
+From: Nikita Popov <npopov@redhat.com>
+Date: Wed, 31 Jan 2024 15:08:08 +0100
+Subject: [PATCH] Update data layouts in custom target tests for LLVM 18
+
+Fixes https://github.com/rust-lang/rust/issues/120492.
+---
+ tests/run-make/rust-lld-custom-target/custom-target.json        | 2 +-
+ tests/run-make/rustdoc-target-spec-json-path/target.json        | 2 +-
+ tests/run-make/target-specs/my-awesome-platform.json            | 2 +-
+ .../target-specs/my-x86_64-unknown-linux-gnu-platform.json      | 2 +-
+ 4 files changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/tests/run-make/rust-lld-custom-target/custom-target.json b/tests/run-make/rust-lld-custom-target/custom-target.json
+index 7828a99f235c1..e2c64cbdb43c2 100644
+--- a/tests/run-make/rust-lld-custom-target/custom-target.json
++++ b/tests/run-make/rust-lld-custom-target/custom-target.json
+@@ -2,7 +2,7 @@
+   "arch": "x86_64",
+   "cpu": "x86-64",
+   "crt-static-respected": true,
+-  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
++  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
+   "dynamic-linking": true,
+   "env": "gnu",
+   "has-rpath": true,
+diff --git a/tests/run-make/rustdoc-target-spec-json-path/target.json b/tests/run-make/rustdoc-target-spec-json-path/target.json
+index 34357182c205e..c478f1196fae0 100644
+--- a/tests/run-make/rustdoc-target-spec-json-path/target.json
++++ b/tests/run-make/rustdoc-target-spec-json-path/target.json
+@@ -2,7 +2,7 @@
+   "arch": "x86_64",
+   "cpu": "x86-64",
+   "crt-static-respected": true,
+-  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
++  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
+   "dynamic-linking": true,
+   "env": "gnu",
+   "executables": true,
+diff --git a/tests/run-make/target-specs/my-awesome-platform.json b/tests/run-make/target-specs/my-awesome-platform.json
+index 00de3de05f07a..1673ef7bd54d1 100644
+--- a/tests/run-make/target-specs/my-awesome-platform.json
++++ b/tests/run-make/target-specs/my-awesome-platform.json
+@@ -1,5 +1,5 @@
+ {
+-    "data-layout": "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-f64:32:64-f80:32-n8:16:32-S128",
++    "data-layout": "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-i128:128-f64:32:64-f80:32-n8:16:32-S128",
+     "linker-flavor": "gcc",
+     "llvm-target": "i686-unknown-linux-gnu",
+     "target-endian": "little",
+diff --git a/tests/run-make/target-specs/my-x86_64-unknown-linux-gnu-platform.json b/tests/run-make/target-specs/my-x86_64-unknown-linux-gnu-platform.json
+index 6d5e964ed4fee..0cafce15a9fef 100644
+--- a/tests/run-make/target-specs/my-x86_64-unknown-linux-gnu-platform.json
++++ b/tests/run-make/target-specs/my-x86_64-unknown-linux-gnu-platform.json
+@@ -1,6 +1,6 @@
+ {
+     "pre-link-args": {"gcc": ["-m64"]},
+-    "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128",
++    "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
+     "linker-flavor": "gcc",
+     "llvm-target": "x86_64-unknown-linux-gnu",
+     "target-endian": "little",
diff --git a/121088.patch b/121088.patch
new file mode 100644
index 0000000..b70b52a
--- /dev/null
+++ b/121088.patch
@@ -0,0 +1,55 @@
+From 369fff6c0640fe89be9b915adaa83e66a022e00d Mon Sep 17 00:00:00 2001
+From: Nikita Popov <npopov@redhat.com>
+Date: Wed, 14 Feb 2024 16:26:20 +0100
+Subject: [PATCH] Implicitly enable evex512 if avx512 is enabled
+
+LLVM 18 requires the evex512 feature to allow use of zmm registers.
+LLVM automatically sets it when using a generic CPU, but not when
+`-C target-cpu` is specified. This will result either in backend
+legalization crashes, or code unexpectedly using ymm instead of
+zmm registers.
+
+For now, make sure that `avx512*` features imply `evex512`. Long
+term we'll probably have to deal with the AVX10 mess somehow.
+---
+ compiler/rustc_codegen_llvm/src/llvm_util.rs    |  4 ++++
+ tests/ui/asm/x86_64/evex512-implicit-feature.rs | 15 +++++++++++++++
+ 2 files changed, 19 insertions(+)
+ create mode 100644 tests/ui/asm/x86_64/evex512-implicit-feature.rs
+
+diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
+index e48479c8da279..54e8ed85e3250 100644
+--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
++++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
+@@ -266,6 +266,10 @@ pub fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> LLVMFeature<'a> {
+         ("riscv32" | "riscv64", "fast-unaligned-access") if get_version().0 <= 17 => {
+             LLVMFeature::new("unaligned-scalar-mem")
+         }
++        // For LLVM 18, enable the evex512 target feature if a avx512 target feature is enabled.
++        ("x86", s) if get_version().0 >= 18 && s.starts_with("avx512") => {
++            LLVMFeature::with_dependency(s, TargetFeatureFoldStrength::EnableOnly("evex512"))
++        }
+         (_, s) => LLVMFeature::new(s),
+     }
+ }
+diff --git a/tests/ui/asm/x86_64/evex512-implicit-feature.rs b/tests/ui/asm/x86_64/evex512-implicit-feature.rs
+new file mode 100644
+index 0000000000000..a15060857eccb
+--- /dev/null
++++ b/tests/ui/asm/x86_64/evex512-implicit-feature.rs
+@@ -0,0 +1,15 @@
++// build-pass
++// only-x86_64
++// compile-flags: --crate-type=lib -C target-cpu=skylake
++
++#![feature(avx512_target_feature)]
++#![feature(stdarch_x86_avx512)]
++
++use std::arch::x86_64::*;
++
++#[target_feature(enable = "avx512f")]
++#[no_mangle]
++pub unsafe fn test(res: *mut f64, p: *const f64) {
++    let arg = _mm512_load_pd(p);
++    _mm512_store_pd(res, _mm512_fmaddsub_pd(arg, arg, arg));
++}
diff --git a/rust.spec b/rust.spec
index 3cddd3a..776d5ef 100644
--- a/rust.spec
+++ b/rust.spec
@@ -137,6 +137,10 @@ Patch5:         0002-set-an-external-library-path-for-wasm32-wasi.patch
 # We don't want to use the bundled library in libsqlite3-sys
 Patch6:         rustc-1.77.0-unbundle-sqlite.patch
 
+# Backports of fixes for LLVM 18 compatibility
+Patch7:         120529.patch
+Patch8:         121088.patch
+
 ### RHEL-specific patches below ###
 
 # Simple rpm macros for rust-toolset (as opposed to full rust-packaging)
@@ -591,6 +595,9 @@ rm -rf %{wasi_libc_dir}/dlmalloc/
 %endif
 %patch -P6 -p1
 
+%patch -P7 -p1
+%patch -P8 -p1
+
 %if %with disabled_libssh2
 %patch -P100 -p1
 %endif