allow people to manually override gfx12 fa

Author: LostRuins

CMakeLists.txt

@@ -62,6 +62,10 @@ add_compile_definitions(GGML_USE_CPU)
 add_compile_definitions(GGML_USE_CPU_REPACK)
 add_compile_definitions(NOMINMAX)
 
+if (GGML_HIP_FORCE_ROCWMMA_FATTN_GFX12)
+    add_compile_definitions(GGML_HIP_ROCWMMA_FATTN_GFX12)
+endif()
+
 if (MSVC)
     add_compile_options("$<$<COMPILE_LANGUAGE:C>:/utf-8>")
     add_compile_options("$<$<COMPILE_LANGUAGE:CXX>:/utf-8>")

Makefile

@@ -260,6 +260,11 @@ endif
 	HCC         := $(ROCM_PATH)/llvm/bin/clang
 	HCXX        := $(ROCM_PATH)/llvm/bin/clang++
 endif
+ifdef GGML_HIP_FORCE_ROCWMMA_FATTN_GFX12
+	HIPFLAGS   += -GGML_HIP_ROCWMMA_FATTN_GFX12
+	CFLAGS     += -GGML_HIP_ROCWMMA_FATTN_GFX12
+	CXXFLAGS   += -GGML_HIP_ROCWMMA_FATTN_GFX12
+endif
 ifdef LLAMA_NO_WMMA
 	HIPFLAGS   += -DGGML_HIP_NO_ROCWMMA_FATTN
 else