Enable unity builds

Author: daleroberts

.github/workflows/build.yml

@@ -42,7 +42,7 @@ jobs:
 
       - name: Build with CMake
         run: |
-          cmake dynadjust -DBUILD_TESTING=OFF
+          cmake dynadjust -DBUILD_TESTING=OFF -DUSE_UNITY_BUILD=ON
           make -j2
           ls -la bin/
           
@@ -92,7 +92,7 @@ jobs:
       - name: Build with CMake
         run: |
           source /opt/intel/oneapi/setvars.sh
-          cmake dynadjust -DUSE_MKL=ON -DBUILD_TESTING=OFF
+          cmake dynadjust -DUSE_MKL=ON -DBUILD_TESTING=OFF -DUSE_UNITY_BUILD=ON
           make -j2
           ls -la bin/
 
@@ -143,7 +143,7 @@ jobs:
 
       - name: Build with CMake
         run: |
-          cmake -DBUILD_STATIC=ON -DCMAKE_BUILD_TYPE=Release -DBUILD_TESTING=OFF dynadjust
+          cmake -DBUILD_STATIC=ON -DCMAKE_BUILD_TYPE=Release -DBUILD_TESTING=OFF -DUSE_UNITY_BUILD=ON dynadjust
           make -j2
           ls -la bin/
 
@@ -179,7 +179,7 @@ jobs:
 
       - name: Build with CMake
         run: |
-          cmake dynadjust -DBUILD_TESTING=OFF
+          cmake dynadjust -DBUILD_TESTING=OFF -DUSE_UNITY_BUILD=ON
           make -j2 VERBOSE=1
           ls -la bin/
 
@@ -204,7 +204,7 @@ jobs:
 
       - name: Build with CMake
         run: |
-          cmake -DBUILD_STATIC=ON -DBUILD_TESTING=OFF -DCMAKE_BUILD_TYPE=Release dynadjust
+          cmake -DBUILD_STATIC=ON -DBUILD_TESTING=OFF -DCMAKE_BUILD_TYPE=Release -DUSE_UNITY_BUILD=ON dynadjust
           make -j2 VERBOSE=1
           ls -la bin/
 

dynadjust/CMakeLists.txt

@@ -9,10 +9,18 @@ option(ILP64 "Use ILP64 interface (64-bit matrix indexing) for BLAS and LAPACK"
 
 # Build optimization options
 option(USE_PRECOMPILED_HEADERS "Use precompiled headers to speed up compilation" ON)
+option(USE_UNITY_BUILD "Use unity builds to speed up compilation" OFF)
 
 # Enable precompiled headers
 set(CMAKE_DISABLE_PRECOMPILE_HEADERS OFF)
 
+# Enable unity builds if requested
+if(USE_UNITY_BUILD)
+    set(CMAKE_UNITY_BUILD ON)
+    set(CMAKE_UNITY_BUILD_BATCH_SIZE 16)
+    message(STATUS "Unity builds enabled (batch size: ${CMAKE_UNITY_BUILD_BATCH_SIZE})")
+endif()
+
 # Fix Boost 1.70+ issue with CMake 3.14+
 if(POLICY CMP0167)
     cmake_policy(SET CMP0167 NEW)