diff --git a/library/stdarch/.github/workflows/main.yml b/library/stdarch/.github/workflows/main.yml
index 9f165231a456..d6ea2ea2cdf1 100644
--- a/library/stdarch/.github/workflows/main.yml
+++ b/library/stdarch/.github/workflows/main.yml
@@ -146,7 +146,7 @@ jobs:
         - target: aarch64-unknown-linux-gnu
           os: ubuntu-latest
         - target: x86_64-apple-darwin
-          os: macos-11
+          os: macos-13
         - target: x86_64-pc-windows-msvc
           os: windows-latest
         - target: i686-pc-windows-msvc
@@ -175,21 +175,11 @@ jobs:
     - uses: actions/checkout@v4
       with:
         submodules: recursive
-    - name: Install Rust (rustup)
+    - name: Install Rust
       run: |
         rustup update nightly --no-self-update
         rustup default nightly
-      if: matrix.os != 'macos-latest'
-    - name: Install Rust (macos)
-      run: |
-        curl https://sh.rustup.rs | sh -s -- -y --default-toolchain nightly
-        echo "$HOME/.cargo/bin" >> $GITHUB_PATH
-        rustup update nightly --no-self-update
-        rustup default nightly
-      if: matrix.os == 'macos-latest'
-    - run: |
-        rustup default nightly
-        rustup target add ${{ matrix.target }}
+    - run: rustup target add ${{ matrix.target }}
       if: "!endsWith(matrix.target, 'emulated')"
     - name: Setup (aarch64-apple-darwin)
       run: |
diff --git a/library/stdarch/ci/docker/aarch64-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/aarch64-unknown-linux-gnu/Dockerfile
index 8f4aba45c35f..7f09ca053afc 100644
--- a/library/stdarch/ci/docker/aarch64-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/aarch64-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:22.04
+FROM ubuntu:24.04
 RUN apt-get update && apt-get install -y --no-install-recommends \
   gcc \
   g++ \
diff --git a/library/stdarch/ci/docker/arm-unknown-linux-gnueabihf/Dockerfile b/library/stdarch/ci/docker/arm-unknown-linux-gnueabihf/Dockerfile
index 757b79e7ecc1..2e5a18b546a7 100644
--- a/library/stdarch/ci/docker/arm-unknown-linux-gnueabihf/Dockerfile
+++ b/library/stdarch/ci/docker/arm-unknown-linux-gnueabihf/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 RUN apt-get update && apt-get install -y --no-install-recommends \
   gcc \
   ca-certificates \
diff --git a/library/stdarch/ci/docker/i586-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/i586-unknown-linux-gnu/Dockerfile
index 0e4d1c6eb466..a865305707be 100644
--- a/library/stdarch/ci/docker/i586-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/i586-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:20.04
+FROM ubuntu:24.04
 RUN apt-get update && apt-get install -y --no-install-recommends \
   gcc-multilib \
   libc6-dev \
diff --git a/library/stdarch/ci/docker/i686-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/i686-unknown-linux-gnu/Dockerfile
index 0e4d1c6eb466..a865305707be 100644
--- a/library/stdarch/ci/docker/i686-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/i686-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:20.04
+FROM ubuntu:24.04
 RUN apt-get update && apt-get install -y --no-install-recommends \
   gcc-multilib \
   libc6-dev \
diff --git a/library/stdarch/ci/docker/mips-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/mips-unknown-linux-gnu/Dockerfile
index 3bd471e87d4d..db0bc86348e4 100644
--- a/library/stdarch/ci/docker/mips-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/mips-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         gcc libc6-dev qemu-user ca-certificates \
diff --git a/library/stdarch/ci/docker/mips64-unknown-linux-gnuabi64/Dockerfile b/library/stdarch/ci/docker/mips64-unknown-linux-gnuabi64/Dockerfile
index f26f1f38eb22..4fa2671ba585 100644
--- a/library/stdarch/ci/docker/mips64-unknown-linux-gnuabi64/Dockerfile
+++ b/library/stdarch/ci/docker/mips64-unknown-linux-gnuabi64/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         gcc libc6-dev qemu-user ca-certificates \
diff --git a/library/stdarch/ci/docker/mips64el-unknown-linux-gnuabi64/Dockerfile b/library/stdarch/ci/docker/mips64el-unknown-linux-gnuabi64/Dockerfile
index 7d9f0bd99250..f35d7ed2b694 100644
--- a/library/stdarch/ci/docker/mips64el-unknown-linux-gnuabi64/Dockerfile
+++ b/library/stdarch/ci/docker/mips64el-unknown-linux-gnuabi64/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         gcc libc6-dev qemu-user ca-certificates \
diff --git a/library/stdarch/ci/docker/mipsel-unknown-linux-musl/Dockerfile b/library/stdarch/ci/docker/mipsel-unknown-linux-musl/Dockerfile
index 5d19d7c93d0a..e5540f28f8a3 100644
--- a/library/stdarch/ci/docker/mipsel-unknown-linux-musl/Dockerfile
+++ b/library/stdarch/ci/docker/mipsel-unknown-linux-musl/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
diff --git a/library/stdarch/ci/docker/nvptx64-nvidia-cuda/Dockerfile b/library/stdarch/ci/docker/nvptx64-nvidia-cuda/Dockerfile
index 864d72e628e9..574fca6903f6 100644
--- a/library/stdarch/ci/docker/nvptx64-nvidia-cuda/Dockerfile
+++ b/library/stdarch/ci/docker/nvptx64-nvidia-cuda/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 RUN apt-get update && apt-get install -y --no-install-recommends \
   gcc \
   libc6-dev \
diff --git a/library/stdarch/ci/docker/powerpc-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/powerpc-unknown-linux-gnu/Dockerfile
index 877468e5d427..05eb09389389 100644
--- a/library/stdarch/ci/docker/powerpc-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/powerpc-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         gcc libc6-dev qemu-user ca-certificates \
diff --git a/library/stdarch/ci/docker/powerpc64-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/powerpc64-unknown-linux-gnu/Dockerfile
index c030e6818a8e..a9de944b0c3e 100644
--- a/library/stdarch/ci/docker/powerpc64-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/powerpc64-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         gcc libc6-dev qemu-user ca-certificates \
diff --git a/library/stdarch/ci/docker/powerpc64le-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/powerpc64le-unknown-linux-gnu/Dockerfile
index df611b47caed..66e7fd3b77e5 100644
--- a/library/stdarch/ci/docker/powerpc64le-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/powerpc64le-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         gcc libc6-dev qemu-user ca-certificates \
diff --git a/library/stdarch/ci/docker/riscv64gc-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/riscv64gc-unknown-linux-gnu/Dockerfile
index af26b26822cb..eb22bd11a58a 100644
--- a/library/stdarch/ci/docker/riscv64gc-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/riscv64gc-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:23.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         gcc libc6-dev qemu-user ca-certificates \
diff --git a/library/stdarch/ci/docker/s390x-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/s390x-unknown-linux-gnu/Dockerfile
index 65796923451e..e40adbb4a888 100644
--- a/library/stdarch/ci/docker/s390x-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/s390x-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:24.04
 
 RUN apt-get update && apt-get install -y --no-install-recommends \
         curl ca-certificates \
diff --git a/library/stdarch/ci/docker/wasm32-wasip1/Dockerfile b/library/stdarch/ci/docker/wasm32-wasip1/Dockerfile
index f92539b302e7..109c41c01dc4 100644
--- a/library/stdarch/ci/docker/wasm32-wasip1/Dockerfile
+++ b/library/stdarch/ci/docker/wasm32-wasip1/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:20.04
+FROM ubuntu:24.04
 
 ENV DEBIAN_FRONTEND=noninteractive
 RUN apt-get update -y && apt-get install -y --no-install-recommends \
diff --git a/library/stdarch/ci/docker/x86_64-unknown-linux-gnu/Dockerfile b/library/stdarch/ci/docker/x86_64-unknown-linux-gnu/Dockerfile
index dc4c4e59897d..8d478d6d8d03 100644
--- a/library/stdarch/ci/docker/x86_64-unknown-linux-gnu/Dockerfile
+++ b/library/stdarch/ci/docker/x86_64-unknown-linux-gnu/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:20.04
+FROM ubuntu:24.04
 RUN apt-get update && apt-get install -y --no-install-recommends \
   gcc \
   libc6-dev \
diff --git a/library/stdarch/crates/core_arch/src/x86/avx2.rs b/library/stdarch/crates/core_arch/src/x86/avx2.rs
index 9a0ed0a4bc59..0343416a9213 100644
--- a/library/stdarch/crates/core_arch/src/x86/avx2.rs
+++ b/library/stdarch/crates/core_arch/src/x86/avx2.rs
@@ -5200,9 +5200,6 @@ unsafe fn test_mm256_srlv_epi64() {
     }
 
     #[simd_test(enable = "avx2")]
-    // Miri cannot support this until it is clear how it fits in the Rust memory model
-    // (non-temporal store)
-    #[cfg_attr(miri, ignore)]
     unsafe fn test_mm256_stream_load_si256() {
         let a = _mm256_set_epi64x(5, 6, 7, 8);
         let r = _mm256_stream_load_si256(core::ptr::addr_of!(a) as *const _);
diff --git a/library/stdarch/crates/core_arch/src/x86/sse41.rs b/library/stdarch/crates/core_arch/src/x86/sse41.rs
index 81478de04119..c8b260bec8e2 100644
--- a/library/stdarch/crates/core_arch/src/x86/sse41.rs
+++ b/library/stdarch/crates/core_arch/src/x86/sse41.rs
@@ -1958,9 +1958,6 @@ unsafe fn test_mm_test_mix_ones_zeros() {
     }
 
     #[simd_test(enable = "sse4.1")]
-    // Miri cannot support this until it is clear how it fits in the Rust memory model
-    // (non-temporal store)
-    #[cfg_attr(miri, ignore)]
     unsafe fn test_mm_stream_load_si128() {
         let a = _mm_set_epi64x(5, 6);
         let r = _mm_stream_load_si128(core::ptr::addr_of!(a) as *const _);