diff --git a/.github/workflows/emcc.yml b/.github/workflows/emcc.yml
deleted file mode 100644
index b883cfa0a..000000000
--- a/.github/workflows/emcc.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-name: Emscripten Build
-
-on: [push, pull_request]
-
-jobs:
-  emcc:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: mymindstorm/setup-emsdk@v14
-      - uses: actions/checkout@v4
-        with:
-         submodules: true
-      - name: Build
-        run: |
-          make config-emcc
-          make YOSYS_VER=latest
-      - uses: actions/upload-artifact@v4
-        with:
-          name: yosysjs
-          path: yosysjs-latest.zip
diff --git a/.github/workflows/extra-builds.yml b/.github/workflows/extra-builds.yml
new file mode 100644
index 000000000..260394a3f
--- /dev/null
+++ b/.github/workflows/extra-builds.yml
@@ -0,0 +1,83 @@
+name: Test extra build flows
+
+on: [push, pull_request]
+
+jobs:
+  pre_job:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@v5
+        with:
+          paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
+          # cancel previous builds if a new commit is pushed
+          cancel_others: 'true'
+          # only run on push *or* pull_request, not both
+          concurrent_skipping: 'same_content_newer'
+
+  vs-prep:
+    name: Prepare Visual Studio build
+    runs-on: ubuntu-latest
+    needs: [pre_job]
+    if: needs.pre_job.outputs.should_skip != 'true'
+    steps:
+      - uses: actions/checkout@v4
+        with:
+         submodules: true
+      - name: Build
+        run: make vcxsrc YOSYS_VER=latest
+      - uses: actions/upload-artifact@v4
+        with:
+          name: vcxsrc
+          path: yosys-win32-vcxsrc-latest.zip
+  
+  vs-build:
+    name: Visual Studio build
+    runs-on: windows-2019
+    needs: [vs-prep, pre_job]
+    if: needs.pre_job.outputs.should_skip != 'true'
+    steps:  
+      - uses: actions/download-artifact@v4
+        with:
+          name: vcxsrc
+          path: .
+      - name: unzip
+        run: unzip yosys-win32-vcxsrc-latest.zip
+      - name: setup-msbuild
+        uses: microsoft/setup-msbuild@v2
+      - name: MSBuild
+        working-directory: yosys-win32-vcxsrc-latest
+        run: msbuild YosysVS.sln /p:PlatformToolset=v142 /p:Configuration=Release /p:WindowsTargetPlatformVersion=10.0.17763.0
+
+  wasi-build:
+    name: WASI build
+    needs: pre_job
+    if: needs.pre_job.outputs.should_skip != 'true'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+         submodules: true
+      - name: Build
+        run: |
+          WASI_SDK=wasi-sdk-19.0
+          WASI_SDK_URL=https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-19/wasi-sdk-19.0-linux.tar.gz
+          if ! [ -d ${WASI_SDK} ]; then curl -L ${WASI_SDK_URL} | tar xzf -; fi
+
+          mkdir -p build
+          cat > build/Makefile.conf <<END
+          export PATH := $(pwd)/${WASI_SDK}/bin:${PATH}
+          WASI_SYSROOT := $(pwd)/${WASI_SDK}/share/wasi-sysroot
+
+          CONFIG := wasi
+          PREFIX := /
+
+          ENABLE_TCL := 0
+          ENABLE_READLINE := 0
+          ENABLE_PLUGINS := 0
+          ENABLE_ZLIB := 0
+          END
+
+          make -C build -f ../Makefile CXX=clang -j$(nproc)
diff --git a/.github/workflows/test-docs.yml b/.github/workflows/test-docs.yml
index f6bcd33eb..7b3906c52 100644
--- a/.github/workflows/test-docs.yml
+++ b/.github/workflows/test-docs.yml
@@ -6,7 +6,22 @@ on:
     - main
 
 jobs:
+  pre_job:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@v5
+        with:
+          # cancel previous builds if a new commit is pushed
+          cancel_others: 'true'
+          # only run on push *or* pull_request, not both
+          concurrent_skipping: 'same_content_newer'
+
   test-docs:
+    needs: pre_job
+    if: needs.pre_job.outputs.should_skip != 'true'
     runs-on: ubuntu-latest
     steps:
       - name: Install Dependencies
@@ -28,7 +43,7 @@ jobs:
           echo "procs=$(nproc)" >> $GITHUB_ENV
 
       - name: Checkout Yosys
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
          submodules: true
       - name: Build yosys
diff --git a/.github/workflows/test-linux.yml b/.github/workflows/test-linux.yml
index a75873d89..911b3b66e 100644
--- a/.github/workflows/test-linux.yml
+++ b/.github/workflows/test-linux.yml
@@ -3,7 +3,23 @@ name: Build and run tests (Linux)
 on: [push, pull_request]
 
 jobs:
+  pre_job:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@v5
+        with:
+          paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
+          # cancel previous builds if a new commit is pushed
+          cancel_others: 'true'
+          # only run on push *or* pull_request, not both
+          concurrent_skipping: 'same_content_newer'
+
   test-linux:
+    needs: pre_job
+    if: needs.pre_job.outputs.should_skip != 'true'
     runs-on: ${{ matrix.os.id }}
     strategy:
       matrix:
diff --git a/.github/workflows/test-macos.yml b/.github/workflows/test-macos.yml
index 37b66df9b..cbba8adbd 100644
--- a/.github/workflows/test-macos.yml
+++ b/.github/workflows/test-macos.yml
@@ -3,7 +3,23 @@ name: Build and run tests (macOS)
 on: [push, pull_request]
 
 jobs:
+  pre_job:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@v5
+        with:
+          paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
+          # cancel previous builds if a new commit is pushed
+          cancel_others: 'true'
+          # only run on push *or* pull_request, not both
+          concurrent_skipping: 'same_content_newer'
+
   test-macos:
+    needs: pre_job
+    if: needs.pre_job.outputs.should_skip != 'true'
     runs-on: ${{ matrix.os.id }}
     strategy:
       matrix:
diff --git a/.github/workflows/test-verific.yml b/.github/workflows/test-verific.yml
index ef7fa3829..54d9487ac 100644
--- a/.github/workflows/test-verific.yml
+++ b/.github/workflows/test-verific.yml
@@ -3,7 +3,25 @@ name: Build and run tests with Verific (Linux)
 on: [push, pull_request]
 
 jobs:
+  pre_job:
+    runs-on: ubuntu-latest
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@v5
+        with:
+          paths_ignore: '["**/README.md"]'
+          # don't cancel previous builds
+          cancel_others: 'true'
+          # only run on push *or* pull_request, not both
+          concurrent_skipping: 'same_content_newer'
+          # we have special actions when running on main, so this should be off
+          skip_after_successful_duplicate: 'false'
+
   test-verific:
+    needs: pre_job
+    if: needs.pre_job.outputs.should_skip != 'true'
     runs-on: [self-hosted, linux, x64]
     steps:
       - name: Checkout Yosys
diff --git a/.github/workflows/vs.yml b/.github/workflows/vs.yml
deleted file mode 100644
index 0647cff1a..000000000
--- a/.github/workflows/vs.yml
+++ /dev/null
@@ -1,33 +0,0 @@
-name: Visual Studio Build
-
-on: [push, pull_request]
-
-jobs:
-  yosys-vcxsrc:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-        with:
-         submodules: true
-      - name: Build
-        run: make vcxsrc YOSYS_VER=latest
-      - uses: actions/upload-artifact@v4
-        with:
-          name: vcxsrc
-          path: yosys-win32-vcxsrc-latest.zip
-
-  build:
-    runs-on: windows-2019
-    needs: yosys-vcxsrc
-    steps:
-      - uses: actions/download-artifact@v4
-        with:
-          name: vcxsrc
-          path: .
-      - name: unzip
-        run: unzip yosys-win32-vcxsrc-latest.zip
-      - name: setup-msbuild
-        uses: microsoft/setup-msbuild@v1
-      - name: MSBuild
-        working-directory: yosys-win32-vcxsrc-latest
-        run: msbuild YosysVS.sln /p:PlatformToolset=v142 /p:Configuration=Release /p:WindowsTargetPlatformVersion=10.0.17763.0
diff --git a/.github/workflows/wasi.yml b/.github/workflows/wasi.yml
deleted file mode 100644
index d65a96227..000000000
--- a/.github/workflows/wasi.yml
+++ /dev/null
@@ -1,32 +0,0 @@
-name: WASI Build
-
-on: [push, pull_request]
-
-jobs:
-  wasi:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-        with:
-         submodules: true
-      - name: Build
-        run: |
-          WASI_SDK=wasi-sdk-19.0
-          WASI_SDK_URL=https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-19/wasi-sdk-19.0-linux.tar.gz
-          if ! [ -d ${WASI_SDK} ]; then curl -L ${WASI_SDK_URL} | tar xzf -; fi
-
-          mkdir -p build
-          cat > build/Makefile.conf <<END
-          export PATH := $(pwd)/${WASI_SDK}/bin:${PATH}
-          WASI_SYSROOT := $(pwd)/${WASI_SDK}/share/wasi-sysroot
-
-          CONFIG := wasi
-          PREFIX := /
-
-          ENABLE_TCL := 0
-          ENABLE_READLINE := 0
-          ENABLE_PLUGINS := 0
-          ENABLE_ZLIB := 0
-          END
-
-          make -C build -f ../Makefile CXX=clang -j$(nproc)