From ac32902a87147f78d63c931aa8a23dee762660e7 Mon Sep 17 00:00:00 2001
From: Karthik Kumar Viswanathan <195178+guilt@users.noreply.github.com>
Date: Sun, 14 Jan 2024 00:41:44 -0800
Subject: [PATCH] llama : support WinXP build with MinGW 8.1.0 (#3419)

---
 CMakeLists.txt | 8 ++++++--
 llama.cpp      | 4 ++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 668669c6d..2741568ed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.13)  # for add_link_options
+cmake_minimum_required(VERSION 3.14)  # for add_link_options and implicit target directories.
 project("llama.cpp" C CXX)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
@@ -76,6 +76,10 @@ if (NOT MSVC)
     option(LLAMA_F16C                        "llama: enable F16C"                               ${INS_ENB})
 endif()
 
+if (WIN32)
+    option(LLAMA_WIN_VER                     "llama: Windows Version"                           0x602)
+endif()
+
 # 3rd party libs
 option(LLAMA_ACCELERATE                      "llama: enable Accelerate framework"               ON)
 option(LLAMA_BLAS                            "llama: use BLAS"                                  OFF)
@@ -686,7 +690,7 @@ endif()
 
 if (MINGW)
     # Target Windows 8 for PrefetchVirtualMemory
-    add_compile_definitions(_WIN32_WINNT=0x602)
+    add_compile_definitions(_WIN32_WINNT=${LLAMA_WIN_VER})
 endif()
 
 #
diff --git a/llama.cpp b/llama.cpp
index 107b05114..51e9bdaed 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -987,6 +987,7 @@ struct llama_mmap {
         }
 
         if (prefetch > 0) {
+#if _WIN32_WINNT >= 0x602
             // PrefetchVirtualMemory is only present on Windows 8 and above, so we dynamically load it
             BOOL (WINAPI *pPrefetchVirtualMemory) (HANDLE, ULONG_PTR, PWIN32_MEMORY_RANGE_ENTRY, ULONG);
             HMODULE hKernel32 = GetModuleHandleW(L"kernel32.dll");
@@ -1004,6 +1005,9 @@ struct llama_mmap {
                             llama_format_win_err(GetLastError()).c_str());
                 }
             }
+#else
+            throw std::runtime_error("PrefetchVirtualMemory unavailable");
+#endif
         }
     }