Refactor windows generate for more modular usage

llm/generate/gen_windows.ps1

@@ -26,14 +26,20 @@ function amdGPUs {
     $GPU_LIST -join ';'
 }
 
+$script:cmakeTargets = @("ollama_llama_server")
+
 function init_vars {
+    if (!$script:SRC_DIR) {
         $script:SRC_DIR = $(resolve-path "..\..\")
+    }
+    if (!$script:llamacppDir) {
         $script:llamacppDir = "../llama.cpp"
+    }
     $script:cmakeDefs = @(
         "-DBUILD_SHARED_LIBS=on",
         "-DLLAMA_NATIVE=off"
         )
-    $script:cmakeTargets = @("ollama_llama_server")
+    $script:commonCpuDefs = @("-DCMAKE_POSITION_INDEPENDENT_CODE=on")
     $script:ARCH = "amd64" # arm not yet supported.
     $script:DIST_BASE = "${script:SRC_DIR}\dist\windows-${script:ARCH}\ollama_runners"
     if ($env:CGO_CFLAGS -contains "-g") {
@@ -166,18 +172,14 @@ function cleanup {
     }
 }
 
-init_vars
-git_module_setup
-apply_patches
 
 # -DLLAMA_AVX -- 2011 Intel Sandy Bridge & AMD Bulldozer
 # -DLLAMA_AVX2 -- 2013 Intel Haswell & 2015 AMD Excavator / 2017 AMD Zen
 # -DLLAMA_FMA (FMA3) -- 2013 Intel Haswell & 2012 AMD Piledriver
 
-$script:commonCpuDefs = @("-DCMAKE_POSITION_INDEPENDENT_CODE=on")
 
+function build_static() {
     if ($null -eq ${env:OLLAMA_SKIP_CPU_GENERATE}) {
-
         # GCC build for direct linking into the Go binary
         init_vars
         # cmake will silently fallback to msvc compilers if mingw isn't in the path, so detect and fail fast
@@ -201,7 +203,13 @@ $script:cmakeDefs = @(
         $script:buildDir="../build/windows/${script:ARCH}_static"
         write-host "Building static library"
         build
+    } else {
+        write-host "Skipping CPU generation step as requested"
+    }
+}
 
+function build_cpu() {
+    if ($null -eq ${env:OLLAMA_SKIP_CPU_GENERATE}) {
         # remaining llama.cpp builds use MSVC 
         init_vars
         $script:cmakeDefs = $script:commonCpuDefs + @("-A", "x64", "-DLLAMA_AVX=off", "-DLLAMA_AVX2=off", "-DLLAMA_AVX512=off", "-DLLAMA_FMA=off", "-DLLAMA_F16C=off") + $script:cmakeDefs
@@ -211,7 +219,13 @@ build
         build
         sign
         install
+    } else {
+        write-host "Skipping CPU generation step as requested"
+    }
+}
 
+function build_cpu_avx() {
+    if ($null -eq ${env:OLLAMA_SKIP_CPU_GENERATE}) {
         init_vars
         $script:cmakeDefs = $script:commonCpuDefs + @("-A", "x64", "-DLLAMA_AVX=on", "-DLLAMA_AVX2=off", "-DLLAMA_AVX512=off", "-DLLAMA_FMA=off", "-DLLAMA_F16C=off") + $script:cmakeDefs
         $script:buildDir="../build/windows/${script:ARCH}/cpu_avx"
@@ -220,7 +234,13 @@ build
         build
         sign
         install
+    } else {
+        write-host "Skipping CPU generation step as requested"
+    }
+}
 
+function build_cpu_avx2() {
+    if ($null -eq ${env:OLLAMA_SKIP_CPU_GENERATE}) {
         init_vars
         $script:cmakeDefs = $script:commonCpuDefs + @("-A", "x64", "-DLLAMA_AVX=on", "-DLLAMA_AVX2=on", "-DLLAMA_AVX512=off", "-DLLAMA_FMA=on", "-DLLAMA_F16C=on") + $script:cmakeDefs
         $script:buildDir="../build/windows/${script:ARCH}/cpu_avx2"
@@ -232,7 +252,9 @@ build
     } else {
         write-host "Skipping CPU generation step as requested"
     }
+}
 
+function build_cuda() {
     if ($null -ne $script:CUDA_LIB_DIR) {
         # Then build cuda as a dynamically loaded library
         $nvcc = "$script:CUDA_LIB_DIR\nvcc.exe"
@@ -258,7 +280,9 @@ if ($null -ne $script:CUDA_LIB_DIR) {
         cp "${script:CUDA_LIB_DIR}\cublas64_*.dll" "${script:SRC_DIR}\dist\windows-${script:ARCH}\"
         cp "${script:CUDA_LIB_DIR}\cublasLt64_*.dll" "${script:SRC_DIR}\dist\windows-${script:ARCH}\"
     }
+}
 
+function build_rocm() {
     if ($null -ne $env:HIP_PATH) {
         $script:ROCM_VERSION=(get-item $env:HIP_PATH).Basename
         if ($null -ne $script:ROCM_VERSION) {
@@ -309,7 +333,23 @@ if ($null -ne $env:HIP_PATH) {
         # amdhip64.dll dependency comes from the driver and must be installed on the host to use AMD GPUs
         cp "${env:HIP_PATH}\bin\rocblas\library\*" "${script:SRC_DIR}\dist\windows-${script:ARCH}\rocm\rocblas\library\"
     }
+}
 
+init_vars
+if ($($args.count) -eq 0) {
+    git_module_setup
+    apply_patches
+    build_static
+    build_cpu_avx
+    build_cpu_avx2
+    build_cuda
+    build_rocm
 
     cleanup
     write-host "`ngo generate completed.  LLM runners: $(get-childitem -path $script:DIST_BASE)"
+} else {
+    for ( $i = 0; $i -lt $args.count; $i++ ) {
+        write-host "performing $($args[$i])"
+        & $($args[$i])
+    } 
+}