fix compile warnings

Author: JohannesGaessler

ggml-cuda/fattn.cu

@@ -16,18 +16,18 @@ static __device__ __forceinline__ half2 warp_reduce_sum(half2 a) {
 #endif // !(defined(GGML_USE_HIPBLAS) && defined(__HIP_PLATFORM_AMD__)) && __CUDA_ARCH__ >= CC_PASCAL
 }
 
-static __device__ __forceinline__ half2 warp_reduce_max(half2 x) {
-#if !(defined(GGML_USE_HIPBLAS) && defined(__HIP_PLATFORM_AMD__)) && __CUDA_ARCH__ >= CC_PASCAL && CUDART_VERSION >= CUDART_HMAX
-#pragma unroll
-    for (int mask = 16; mask > 0; mask >>= 1) {
-        x = __hmax2(x, __shfl_xor_sync(0xffffffff, x, mask, 32));
-    }
-    return x;
-#else
-    GGML_UNUSED(x);
-    NO_DEVICE_CODE;
-#endif // !(defined(GGML_USE_HIPBLAS) && defined(__HIP_PLATFORM_AMD__)) && __CUDA_ARCH__ >= CC_PASCAL && CUDART_VERSION >= CUDART_HMAX
-}
+// static __device__ __forceinline__ half2 warp_reduce_max(half2 x) {
+// #if !(defined(GGML_USE_HIPBLAS) && defined(__HIP_PLATFORM_AMD__)) && __CUDA_ARCH__ >= CC_PASCAL && CUDART_VERSION >= CUDART_HMAX
+// #pragma unroll
+//     for (int mask = 16; mask > 0; mask >>= 1) {
+//         x = __hmax2(x, __shfl_xor_sync(0xffffffff, x, mask, 32));
+//     }
+//     return x;
+// #else
+//     GGML_UNUSED(x);
+//     NO_DEVICE_CODE;
+// #endif // !(defined(GGML_USE_HIPBLAS) && defined(__HIP_PLATFORM_AMD__)) && __CUDA_ARCH__ >= CC_PASCAL && CUDART_VERSION >= CUDART_HMAX
+// }
 
 #define FATTN_KQ_STRIDE 256
 
@@ -472,21 +472,20 @@ static __global__ void flash_attn_ext_f16(
                 dst[D*gridDim.y*(ncols*blockIdx.x + j) + D*blockIdx.y + i] = __half2float(VKQ[j*D_padded + i]) / KQ_rowsum_j;
             }
         }
-        return;
-    }
-
+    } else {
 #pragma unroll
-    for (int i0 = 0; i0 < D; i0 += nwarps*WARP_SIZE) {
-        const int i = i0 + threadIdx.y*WARP_SIZE + threadIdx.x;
-        if (i0 + nwarps*WARP_SIZE > D && i >= D) {
-            return;
+        for (int i0 = 0; i0 < D; i0 += nwarps*WARP_SIZE) {
+            const int i = i0 + threadIdx.y*WARP_SIZE + threadIdx.x;
+            if (i0 + nwarps*WARP_SIZE > D && i >= D) {
+                return;
+            }
+            dst[D*gridDim.y*blockIdx.x + D*blockIdx.y + i] = VKQ[i];
         }
-        dst[D*gridDim.y*blockIdx.x + D*blockIdx.y + i] = VKQ[i];
-    }
 
-    if (threadIdx.y == 0 && threadIdx.x == 0) {
-        dst_meta[blockIdx.y*parallel_blocks + blockIdx.x] = make_half2(
-            __low2half(KQ_max[0]), __low2half(KQ_rowsum[0]) + __high2half(KQ_rowsum[0]));
+        if (threadIdx.y == 0 && threadIdx.x == 0) {
+            dst_meta[blockIdx.y*parallel_blocks + blockIdx.x] = make_half2(
+                __low2half(KQ_max[0]), __low2half(KQ_rowsum[0]) + __high2half(KQ_rowsum[0]));
+        }
     }
 }
 
@@ -781,7 +780,6 @@ void ggml_cuda_flash_attn_ext(ggml_backend_cuda_context & ctx, ggml_tensor * dst
     } else  {
         cols_per_block = 8;
     }
-    const int frag_m = cols_per_block == 8 ? 32 : 16;
     constexpr int nwarps = 4;
     const dim3 blocks_num((Q->ne[1] + cols_per_block - 1) / cols_per_block, Q->ne[2], Q->ne[3]);
     const dim3 block_dim(WARP_SIZE, nwarps, 1);