Try with cblas fix

Author: pedrovgs

Sources/Matft/library/cblas.swift

@@ -854,7 +854,10 @@ internal func copy_mfarray<T: MfStorable>(_ mfarray: MfArray, dsttmpMfarray: MfA
         mfarray.withUnsafeMutableStartPointer(datatype: T.self){
             [unowned mfarray] (srcptr) in
             for cblasPrams in OptOffsetParamsSequence(shape: dsttmpMfarray.shape, bigger_strides: dsttmpMfarray.strides, smaller_strides: mfarray.strides){
-                wrap_cblas_copy(cblasPrams.blocksize, srcptr + cblasPrams.s_offset, cblasPrams.s_stride, dstptr + cblasPrams.b_offset, cblasPrams.b_stride, cblas_func)
+                // Match Accelerate behavior: adjust pointer for negative strides
+                let srcptr = cblasPrams.s_stride >= 0 ? srcptr + cblasPrams.s_offset : srcptr + (cblasPrams.blocksize - 1) * cblasPrams.s_stride + cblasPrams.s_offset
+                let dstptr = cblasPrams.b_stride >= 0 ? dstptr + cblasPrams.b_offset : dstptr + (cblasPrams.blocksize - 1) * cblasPrams.b_stride + cblasPrams.b_offset
+                wrap_cblas_copy(cblasPrams.blocksize, srcptr, cblasPrams.s_stride, dstptr, cblasPrams.b_stride, cblas_func)
             }
         }
     }
@@ -873,7 +876,10 @@ internal func copy_by_cblas<T: MfStorable>(_ src_mfarray: MfArray, _ dst_mfarray
         src_mfarray.withUnsafeMutableStartPointer(datatype: T.self){
             srcptr in
             for cblasPrams in OptOffsetParamsSequence(shape: shape, bigger_strides: bigger_strides, smaller_strides: smaller_strides){
-                wrap_cblas_copy(cblasPrams.blocksize, srcptr + cblasPrams.s_offset, cblasPrams.s_stride, dstptr + cblasPrams.b_offset, cblasPrams.b_stride, cblas_func)
+                // Match Accelerate behavior: adjust pointer for negative strides
+                let srcptr = cblasPrams.s_stride >= 0 ? srcptr + cblasPrams.s_offset : srcptr + (cblasPrams.blocksize - 1) * cblasPrams.s_stride + cblasPrams.s_offset
+                let dstptr = cblasPrams.b_stride >= 0 ? dstptr + cblasPrams.b_offset : dstptr + (cblasPrams.blocksize - 1) * cblasPrams.b_stride + cblasPrams.b_offset
+                wrap_cblas_copy(cblasPrams.blocksize, srcptr, cblasPrams.s_stride, dstptr, cblasPrams.b_stride, cblas_func)
             }
         }
     }