diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-18/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-18/Dockerfile
index 487da58015222..42df58517caf4 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-18/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-18/Dockerfile
@@ -59,5 +59,10 @@ COPY host-x86_64/dist-x86_64-linux/build-gccjit.sh /scripts/
 
 RUN /scripts/build-gccjit.sh /scripts
 
-COPY scripts/x86_64-gnu-llvm.sh /tmp/script.sh
-ENV SCRIPT /tmp/script.sh
+ARG SCRIPT_ARG
+COPY scripts/add_dummy_commit.sh /tmp/add_dummy_commit.sh
+COPY scripts/x86_64-gnu-llvm.sh /tmp/x86_64-gnu-llvm.sh
+COPY scripts/x86_64-gnu-llvm1.sh /tmp/x86_64-gnu-llvm1.sh
+COPY scripts/x86_64-gnu-llvm2.sh /tmp/x86_64-gnu-llvm2.sh
+COPY scripts/x86_64-gnu-llvm3.sh /tmp/x86_64-gnu-llvm3.sh
+ENV SCRIPT /tmp/${SCRIPT_ARG}
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-19/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-19/Dockerfile
index 4991908fe7734..f2aadbe87cfec 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-19/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-19/Dockerfile
@@ -59,5 +59,10 @@ COPY host-x86_64/dist-x86_64-linux/build-gccjit.sh /scripts/
 
 RUN /scripts/build-gccjit.sh /scripts
 
-COPY scripts/x86_64-gnu-llvm.sh /tmp/script.sh
-ENV SCRIPT /tmp/script.sh
+ARG SCRIPT_ARG
+COPY scripts/add_dummy_commit.sh /tmp/add_dummy_commit.sh
+COPY scripts/x86_64-gnu-llvm.sh /tmp/x86_64-gnu-llvm.sh
+COPY scripts/x86_64-gnu-llvm1.sh /tmp/x86_64-gnu-llvm1.sh
+COPY scripts/x86_64-gnu-llvm2.sh /tmp/x86_64-gnu-llvm2.sh
+COPY scripts/x86_64-gnu-llvm3.sh /tmp/x86_64-gnu-llvm3.sh
+ENV SCRIPT /tmp/${SCRIPT_ARG}
diff --git a/src/ci/docker/scripts/add_dummy_commit.sh b/src/ci/docker/scripts/add_dummy_commit.sh
new file mode 100755
index 0000000000000..029e4ae141f8f
--- /dev/null
+++ b/src/ci/docker/scripts/add_dummy_commit.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+set -ex
+
+if [ "$READ_ONLY_SRC" = "0" ]; then
+    # `core::builder::tests::ci_rustc_if_unchanged_logic` bootstrap test ensures that
+    # "download-rustc=if-unchanged" logic don't use CI rustc while there are changes on
+    # compiler and/or library. Here we are adding a dummy commit on compiler and running
+    # that test to make sure we never download CI rustc with a change on the compiler tree.
+    echo "" >> ../compiler/rustc/src/main.rs
+    git config --global user.email "dummy@dummy.com"
+    git config --global user.name "dummy"
+    git add ../compiler/rustc/src/main.rs
+    git commit -m "test commit for rust.download-rustc=if-unchanged logic"
+    DISABLE_CI_RUSTC_IF_INCOMPATIBLE=0 ../x.py test bootstrap \
+        -- core::builder::tests::ci_rustc_if_unchanged_logic
+    # Revert the dummy commit
+    git reset --hard HEAD~1
+fi
diff --git a/src/ci/docker/scripts/x86_64-gnu-llvm.sh b/src/ci/docker/scripts/x86_64-gnu-llvm.sh
index dea38b6fd2a4a..e7dcc1ddff449 100755
--- a/src/ci/docker/scripts/x86_64-gnu-llvm.sh
+++ b/src/ci/docker/scripts/x86_64-gnu-llvm.sh
@@ -2,42 +2,7 @@
 
 set -ex
 
-if [ "$READ_ONLY_SRC" = "0" ]; then
-    # `core::builder::tests::ci_rustc_if_unchanged_logic` bootstrap test ensures that
-    # "download-rustc=if-unchanged" logic don't use CI rustc while there are changes on
-    # compiler and/or library. Here we are adding a dummy commit on compiler and running
-    # that test to make sure we never download CI rustc with a change on the compiler tree.
-    echo "" >> ../compiler/rustc/src/main.rs
-    git config --global user.email "dummy@dummy.com"
-    git config --global user.name "dummy"
-    git add ../compiler/rustc/src/main.rs
-    git commit -m "test commit for rust.download-rustc=if-unchanged logic"
-    DISABLE_CI_RUSTC_IF_INCOMPATIBLE=0 ../x.py test bootstrap \
-        -- core::builder::tests::ci_rustc_if_unchanged_logic
-    # Revert the dummy commit
-    git reset --hard HEAD~1
-fi
-
-# Only run the stage 1 tests on merges, not on PR CI jobs.
-if [[ -z "${PR_CI_JOB}" ]]; then
-    ../x.py --stage 1 test --skip src/tools/tidy
-
-    # Run the `mir-opt` tests again but this time for a 32-bit target.
-    # This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
-    # both 32-bit and 64-bit outputs updated by the PR author, before
-    # the PR is approved and tested for merging.
-    # It will also detect tests lacking `// EMIT_MIR_FOR_EACH_BIT_WIDTH`,
-    # despite having different output on 32-bit vs 64-bit targets.
-    ../x.py --stage 1 test tests/mir-opt --host='' --target=i686-unknown-linux-gnu
-
-    # Run `ui-fulldeps` in `--stage=1`, which actually uses the stage0
-    # compiler, and is sensitive to the addition of new flags.
-    ../x.py --stage 1 test tests/ui-fulldeps
-
-    # Rebuild the stdlib with the size optimizations enabled and run tests again.
-    RUSTFLAGS_NOT_BOOTSTRAP="--cfg feature=\"optimize_for_size\"" ../x.py --stage 1 test \
-        library/std library/alloc library/core
-fi
+/tmp/add_dummy_commit.sh
 
 # NOTE: intentionally uses all of `x.py`, `x`, and `x.ps1` to make sure they all work on Linux.
 ../x.py --stage 2 test --skip src/tools/tidy
diff --git a/src/ci/docker/scripts/x86_64-gnu-llvm1.sh b/src/ci/docker/scripts/x86_64-gnu-llvm1.sh
new file mode 100755
index 0000000000000..56ef39aae1556
--- /dev/null
+++ b/src/ci/docker/scripts/x86_64-gnu-llvm1.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -ex
+
+/tmp/add_dummy_commit.sh
+
+../x.py --stage 2 test \
+  --skip tests \
+  --skip coverage-map \
+  --skip coverage-run \
+  --skip library \
+  --skip tidyselftest
diff --git a/src/ci/docker/scripts/x86_64-gnu-llvm2.sh b/src/ci/docker/scripts/x86_64-gnu-llvm2.sh
new file mode 100755
index 0000000000000..c9f6b98f01f4f
--- /dev/null
+++ b/src/ci/docker/scripts/x86_64-gnu-llvm2.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+set -ex
+
+/tmp/add_dummy_commit.sh
+
+##### Test stage 2 #####
+
+../x.py --stage 2 test \
+  --skip compiler \
+  --skip src
+
+# Run the `mir-opt` tests again but this time for a 32-bit target.
+# This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
+# both 32-bit and 64-bit outputs updated by the PR author, before
+# the PR is approved and tested for merging.
+# It will also detect tests lacking `// EMIT_MIR_FOR_EACH_BIT_WIDTH`,
+# despite having different output on 32-bit vs 64-bit targets.
+../x --stage 2 test tests/mir-opt --host='' --target=i686-unknown-linux-gnu
+
+# Run the UI test suite again, but in `--pass=check` mode
+#
+# This is intended to make sure that both `--pass=check` continues to
+# work.
+../x.ps1 --stage 2 test tests/ui --pass=check --host='' --target=i686-unknown-linux-gnu
diff --git a/src/ci/docker/scripts/x86_64-gnu-llvm3.sh b/src/ci/docker/scripts/x86_64-gnu-llvm3.sh
new file mode 100755
index 0000000000000..d1bf2dab1e2d7
--- /dev/null
+++ b/src/ci/docker/scripts/x86_64-gnu-llvm3.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+set -ex
+
+/tmp/add_dummy_commit.sh
+
+##### Test stage 1 #####
+
+../x.py --stage 1 test --skip src/tools/tidy
+
+# Run the `mir-opt` tests again but this time for a 32-bit target.
+# This enforces that tests using `// EMIT_MIR_FOR_EACH_BIT_WIDTH` have
+# both 32-bit and 64-bit outputs updated by the PR author, before
+# the PR is approved and tested for merging.
+# It will also detect tests lacking `// EMIT_MIR_FOR_EACH_BIT_WIDTH`,
+# despite having different output on 32-bit vs 64-bit targets.
+../x.py --stage 1 test tests/mir-opt --host='' --target=i686-unknown-linux-gnu
+
+# Run `ui-fulldeps` in `--stage=1`, which actually uses the stage0
+# compiler, and is sensitive to the addition of new flags.
+../x.py --stage 1 test tests/ui-fulldeps
+
+# Rebuild the stdlib with the size optimizations enabled and run tests again.
+RUSTFLAGS_NOT_BOOTSTRAP="--cfg feature=\"optimize_for_size\"" ../x.py --stage 1 test \
+    library/std library/alloc library/core
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 959a9580e6003..5732a428f67d7 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -117,6 +117,7 @@ pr:
       ENABLE_GCC_CODEGEN: "1"
       # We are adding (temporarily) a dummy commit on the compiler
       READ_ONLY_SRC: "0"
+      DOCKER_SCRIPT: x86_64-gnu-llvm.sh
     <<: *job-linux-16c
   - image: x86_64-gnu-tools
     <<: *job-linux-16c
@@ -312,16 +313,58 @@ auto:
   - image: x86_64-gnu-distcheck
     <<: *job-linux-8c
 
-  - image: x86_64-gnu-llvm-19
+  # The x86_64-gnu-llvm-19 job is split into multiple jobs to run tests in parallel.
+  # x86_64-gnu-llvm-19-1 skips tests that run in x86_64-gnu-llvm-19-{2,3}.
+  - image: x86_64-gnu-llvm-19-1
     env:
       RUST_BACKTRACE: 1
-    <<: *job-linux-8c
+      IMAGE: x86_64-gnu-llvm-19
+      DOCKER_SCRIPT: x86_64-gnu-llvm1.sh
+    <<: *job-linux-4c
 
-  - image: x86_64-gnu-llvm-18
+  # Skip tests that run in x86_64-gnu-llvm-19-{1,3}
+  - image: x86_64-gnu-llvm-19-2
+    env:
+      RUST_BACKTRACE: 1
+      IMAGE: x86_64-gnu-llvm-19
+      DOCKER_SCRIPT: x86_64-gnu-llvm2.sh
+    <<: *job-linux-4c
+
+  # Skip tests that run in x86_64-gnu-llvm-19-{1,2}
+  - image: x86_64-gnu-llvm-19-3
+    env:
+      RUST_BACKTRACE: 1
+      IMAGE: x86_64-gnu-llvm-19
+      DOCKER_SCRIPT: x86_64-gnu-llvm3.sh
+    <<: *job-linux-4c
+
+  # The x86_64-gnu-llvm-18 job is split into multiple jobs to run tests in parallel.
+  # x86_64-gnu-llvm-18-1 skips tests that run in x86_64-gnu-llvm-18-{2,3}.
+  - image: x86_64-gnu-llvm-18-1
     env:
       RUST_BACKTRACE: 1
       READ_ONLY_SRC: "0"
-    <<: *job-linux-8c
+      IMAGE: x86_64-gnu-llvm-18
+      DOCKER_SCRIPT: x86_64-gnu-llvm1.sh
+    <<: *job-linux-4c
+
+  # Skip tests that run in x86_64-gnu-llvm-18-{1,3}
+  - image: x86_64-gnu-llvm-18-2
+    env:
+      RUST_BACKTRACE: 1
+      READ_ONLY_SRC: "0"
+      IMAGE: x86_64-gnu-llvm-18
+      DOCKER_SCRIPT: x86_64-gnu-llvm2.sh
+    <<: *job-linux-4c
+
+  # Skip tests that run in x86_64-gnu-llvm-18-{1,2}
+  - image: x86_64-gnu-llvm-18-3
+    env:
+      RUST_BACKTRACE: 1
+      READ_ONLY_SRC: "0"
+      IMAGE: x86_64-gnu-llvm-18
+      DOCKER_SCRIPT: x86_64-gnu-llvm3.sh
+    <<: *job-linux-4c
 
   - image: x86_64-gnu-nopt
     <<: *job-linux-4c