From ac8088e2b20450d44bc74962244c6f5daf83712e Mon Sep 17 00:00:00 2001
From: syurkevi <stefan@arrayfire.com>
Date: Wed, 21 Feb 2018 18:34:31 -0500
Subject: [PATCH 1/2] fixes batch matmul for opencl::cpu backend

---
 src/backend/opencl/cpu/cpu_blas.cpp | 77 +++++++++++++++++++----------
 1 file changed, 51 insertions(+), 26 deletions(-)

diff --git a/src/backend/opencl/cpu/cpu_blas.cpp b/src/backend/opencl/cpu/cpu_blas.cpp
index 9511523c1b..1d22f47124 100644
--- a/src/backend/opencl/cpu/cpu_blas.cpp
+++ b/src/backend/opencl/cpu/cpu_blas.cpp
@@ -158,40 +158,65 @@ Array<T> matmul(const Array<T> &lhs, const Array<T> &rhs,
     int M = lDims[aRowDim];
     int N = rDims[bColDim];
     int K = lDims[aColDim];
+    dim_t d2 = std::max(lDims[2], rDims[2]);
+    dim_t d3 = std::max(lDims[3], rDims[3]);
+    dim4 oDims = af::dim4(M, N, d2, d3);
 
     //FIXME: Leaks on errors.
-    Array<T> out = createValueArray<T>(af::dim4(M, N, 1, 1), scalar<T>(0));
+    Array<T> out = createValueArray<T>(oDims, scalar<T>(0));
     auto alpha = getScale<T, 1>();
     auto beta  = getScale<T, 0>();
 
     dim4 lStrides = lhs.strides();
     dim4 rStrides = rhs.strides();
-    using BT  =       typename blas_base<T>::type;
+    dim4 oStrides = out.strides();
 
-    // get host pointers from mapped memory
-    auto lPtr = lhs.getMappedPtr();
-    auto rPtr = rhs.getMappedPtr();
-    auto oPtr = out.getMappedPtr();
-
-    if(rDims[bColDim] == 1) {
-        N = lDims[aColDim];
-        gemv_func<T>()(
-            CblasColMajor, lOpts,
-            lDims[0], lDims[1],
-            alpha,
-            (BT*)lPtr.get(), lStrides[1],
-            (BT*)rPtr.get(), rStrides[0],
-            beta,
-            (BT*)oPtr.get(), 1);
-    } else {
-        gemm_func<T>()(
-            CblasColMajor, lOpts, rOpts,
-            M, N, K,
-            alpha,
-            (BT*)lPtr.get(), lStrides[1],
-            (BT*)rPtr.get(), rStrides[1],
-            beta,
-            (BT*)oPtr.get(), out.dims()[0]);
+    using BT  =       typename blas_base<T>::type;
+    using CBT = const typename blas_base<T>::type;
+
+    int batchSize = oDims[2] * oDims[3];
+
+    bool is_l_d2_batched = (oDims[2] == lDims[2]);
+    bool is_l_d3_batched = (oDims[3] == lDims[3]);
+    bool is_r_d2_batched = (oDims[2] == rDims[2]);
+    bool is_r_d3_batched = (oDims[3] == rDims[3]);
+
+    for(int n = 0; n < batchSize; ++n) {
+        int w = n / rDims[2];
+        int z = n - w * rDims[2];
+
+        int loff = z * (is_l_d2_batched * lStrides[2]) + w * (is_l_d3_batched * lStrides[3]);
+        int roff = z * (is_r_d2_batched * rStrides[2]) + w * (is_r_d3_batched * rStrides[3]);
+
+        // get host pointers from mapped memory
+        auto lPtr = lhs.getMappedPtr();
+        auto rPtr = rhs.getMappedPtr();
+        auto oPtr = out.getMappedPtr();
+
+        CBT *lptr = (CBT*)(lPtr.get() + loff);
+        CBT *rptr = (CBT*)(rPtr.get() + roff);
+        BT  *optr = (BT*)(oPtr.get() + z * oStrides[2] + w * oStrides[3]);
+
+        if(rDims[bColDim] == 1) {
+            N = lDims[aColDim];
+            gemv_func<T>()(
+                CblasColMajor, lOpts,
+                lDims[0], lDims[1],
+                alpha,
+                lptr, lStrides[1],
+                rptr, rStrides[0],
+                beta,
+                optr, 1);
+        } else {
+            gemm_func<T>()(
+                CblasColMajor, lOpts, rOpts,
+                M, N, K,
+                alpha,
+                lptr, lStrides[1],
+                rptr, rStrides[1],
+                beta,
+                optr, out.dims()[0]);
+        }
     }
 
     return out;

From 2c73c66ed546f6415493f26c8ca601b4b5d49283 Mon Sep 17 00:00:00 2001
From: syurkevi <stefan@arrayfire.com>
Date: Thu, 22 Feb 2018 12:18:48 -0500
Subject: [PATCH 2/2] fixes issue 1882 for opencl::cpu backend

---
 src/backend/opencl/cpu/cpu_blas.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/backend/opencl/cpu/cpu_blas.cpp b/src/backend/opencl/cpu/cpu_blas.cpp
index 1d22f47124..38679cc8c4 100644
--- a/src/backend/opencl/cpu/cpu_blas.cpp
+++ b/src/backend/opencl/cpu/cpu_blas.cpp
@@ -198,13 +198,14 @@ Array<T> matmul(const Array<T> &lhs, const Array<T> &rhs,
         BT  *optr = (BT*)(oPtr.get() + z * oStrides[2] + w * oStrides[3]);
 
         if(rDims[bColDim] == 1) {
+            dim_t incr = (rOpts == CblasNoTrans) ? rStrides[0] : rStrides[1];
             N = lDims[aColDim];
             gemv_func<T>()(
                 CblasColMajor, lOpts,
                 lDims[0], lDims[1],
                 alpha,
                 lptr, lStrides[1],
-                rptr, rStrides[0],
+                rptr, incr,
                 beta,
                 optr, 1);
         } else {