Add OpenBLAS support

Supported via CMake - just add:

cmake .. -DWHISPER_SUPPORT_OPENBLAS=ON

On Ubuntu, you have to install the library like this:

apt install libopenblas-dev

Unfortunately, I don't observe any benefit compared to the
original AVX2 + FP16 implementation. Maybe I'm missing something

CMakeLists.txt

@@ -41,8 +41,13 @@ option(WHISPER_BUILD_EXAMPLES          "whisper: build examples" ${WHISPER_STAND
 
 option(WHISPER_SUPPORT_SDL2            "whisper: support for libSDL2" OFF)
 
+if (APPLE)
+    option(WHISPER_NO_ACCELERATE       "whisper: disable Accelerate framework" OFF)
+else()
+    option(WHISPER_SUPPORT_OPENBLAS    "whisper: support for OpenBLAS" OFF)
+endif()
+
 option(WHISPER_PERF                    "whisper: enable perf timings"          OFF)
-option(WHISPER_NO_ACCELERATE           "whisper: disable Accelerate framework" OFF)
 
 # sanitizers
 
@@ -86,6 +91,18 @@ if (APPLE AND NOT WHISPER_NO_ACCELERATE)
     endif()
 endif()
 
+if (WHISPER_SUPPORT_OPENBLAS)
+    find_library(OPENBLAS_LIB openblas)
+    if (OPENBLAS_LIB)
+        message(STATUS "OpenBLAS found")
+
+        set(WHISPER_EXTRA_LIBS  ${WHISPER_EXTRA_LIBS}  ${OPENBLAS_LIB})
+        set(WHISPER_EXTRA_FLAGS ${WHISPER_EXTRA_FLAGS} -DGGML_USE_OPENBLAS)
+    else()
+        message(WARNING "OpenBLAS not found")
+    endif()
+endif()
+
 # compiler flags
 
 if (NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)

ggml.c

@@ -76,6 +76,8 @@ typedef void* thread_ret_t;
 
 #ifdef GGML_USE_ACCELERATE
 #include <Accelerate/Accelerate.h>
+#elif GGML_USE_OPENBLAS
+#include <cblas.h>
 #endif
 
 // floating point type used to accumulate sums
@@ -4055,46 +4057,44 @@ void ggml_compute_forward_mul_mat_f32(
     // nb00 <  nb01 - src0 is transposed
     //   compute by src0 columns
 
-//#ifdef GGML_USE_ACCELERATE
+#if defined(GGML_USE_ACCELERATE) || defined(GGML_USE_OPENBLAS)
-//    if (ggml_compute_forward_mul_mat_use_blas(src0, src1, dst)) {
+    if (ggml_compute_forward_mul_mat_use_blas(src0, src1, dst)) {
-//        GGML_ASSERT(ggml_is_contiguous(src0));
+        GGML_ASSERT(ggml_is_contiguous(src0));
-//        GGML_ASSERT(nb10 == sizeof(float));
+        GGML_ASSERT(nb10 == sizeof(float));
-//
+
-//        if (params->ith != 0) return;
+        if (params->ith != 0) return;
-//
+
-//        if (params->type == GGML_TASK_INIT) {
+        if (params->type == GGML_TASK_INIT) {
-//            return;
+            return;
-//        }
+        }
-//
+
-//        if (params->type == GGML_TASK_FINALIZE) {
+        if (params->type == GGML_TASK_FINALIZE) {
-//            return;
+            return;
-//        }
+        }
-//
+
-//        float * const wdata = params->wdata;
+        for (int i03 = 0; i03 < ne03; i03++) {
-//
+            for (int i02 = 0; i02 < ne02; i02++) {
-//        for (int i03 = 0; i03 < ne03; i03++) {
+                const float * x = (float *) (src0->data);
-//            for (int i02 = 0; i02 < ne02; i02++) {
+                const float * y = (float *) ((char *) src1->data + i02*nb12 + i03*nb13);
-//                const float * x = (float *) (src0->data);
+
-//                const float * y = (float *) ((char *) src1->data + i02*nb12 + i03*nb13);
+                float * d = (float *) ((char *) dst->data + i02*nb2 + i03*nb3);
-//
+
-//                float * d = (float *) ((char *) dst->data + i02*nb2 + i03*nb3);
+                // zT = y * xT
-//
+                {
-//                // zT = y * xT
+                    cblas_sgemm(CblasRowMajor, CblasNoTrans, CblasTrans,
-//                {
+                            ne11, ne01, ne10,
-//                    cblas_sgemm(CblasRowMajor, CblasNoTrans, CblasTrans,
+                            1.0f,    y, ne10,
-//                            ne11, ne01, ne10,
+                                     x, ne10,
-//                            1.0f,    y, ne10,
+                            0.0f,    d, ne01);
-//                                     x, ne10,
+                }
-//                            0.0f,    d, ne01);
+            }
-//                }
+        }
-//            }
+
-//        }
+        //printf("CBLAS F32 = %f ms, %d x %d x %d x %d\n", (ggml_perf_time_us() - t0)/1000.0, ne0, ne1, ne2, ne3);
-//
+
-//        //printf("CBLAS F32 = %f ms, %d x %d x %d x %d\n", (ggml_perf_time_us() - t0)/1000.0, ne0, ne1, ne2, ne3);
+        return;
-//
+    }
-//        return;
+#endif
-//    }
-//#endif
 
     if (params->type == GGML_TASK_INIT) {
         if (nb01 >= nb00) {
@@ -4301,7 +4301,7 @@ void ggml_compute_forward_mul_mat_f16_f32(
     // nb00 <  nb01 - src0 is transposed
     //   compute by src0 columns
 
-#ifdef GGML_USE_ACCELERATE
+#if defined(GGML_USE_ACCELERATE) || defined(GGML_USE_OPENBLAS)
     if (ggml_compute_forward_mul_mat_use_blas(src0, src1, dst)) {
         GGML_ASSERT(nb10 == sizeof(float));
 
@@ -6857,7 +6857,7 @@ void ggml_graph_compute(struct ggml_context * ctx, struct ggml_cgraph * cgraph)
                         } else {
                             if (node->src0->type == GGML_TYPE_F16 &&
                                 node->src1->type == GGML_TYPE_F32) {
-#ifdef GGML_USE_ACCELERATE
+#if defined(GGML_USE_ACCELERATE) || defined(GGML_USE_OPENBLAS)
                                 if (ggml_compute_forward_mul_mat_use_blas(node->src0, node->src1, node)) {
                                     cur = sizeof(float)*(node->src0->ne[0]*node->src0->ne[1]);
                                 } else {
@@ -8074,7 +8074,7 @@ int ggml_cpu_has_wasm_simd(void) {
 }
 
 int ggml_cpu_has_blas(void) {
-#if defined(GGML_USE_BLAS) || defined(GGML_USE_ACCELERATE)
+#if defined(GGML_USE_ACCELERATE) || defined(GGML_USE_OPENBLAS)
     return 1;
 #else
     return 0;