Sprinkle "unlikely()" branch hints in all places where the memory view C code raises exceptions.

Cython/Utility/MemoryView_C.c

@@ -181,13 +181,13 @@ __pyx_check_strides(Py_buffer *buf, int dim, int ndim, int spec)
     if (buf->strides) {
         if (spec & __Pyx_MEMVIEW_CONTIG) {
             if (spec & (__Pyx_MEMVIEW_PTR|__Pyx_MEMVIEW_FULL)) {
-                if (buf->strides[dim] != sizeof(void *)) {
+                if (unlikely(buf->strides[dim] != sizeof(void *))) {
                     PyErr_Format(PyExc_ValueError,
                                  "Buffer is not indirectly contiguous "
                                  "in dimension %d.", dim);
                     goto fail;
                 }
-            } else if (buf->strides[dim] != buf->itemsize) {
+            } else if (unlikely(buf->strides[dim] != buf->itemsize)) {
                 PyErr_SetString(PyExc_ValueError,
                                 "Buffer and memoryview are not contiguous "
                                 "in the same dimension.");
@@ -199,7 +199,7 @@ __pyx_check_strides(Py_buffer *buf, int dim, int ndim, int spec)
             Py_ssize_t stride = buf->strides[dim];
             if (stride < 0)
                 stride = -stride;
-            if (stride < buf->itemsize) {
+            if (unlikely(stride < buf->itemsize)) {
                 PyErr_SetString(PyExc_ValueError,
                                 "Buffer and memoryview are not contiguous "
                                 "in the same dimension.");
@@ -207,17 +207,17 @@ __pyx_check_strides(Py_buffer *buf, int dim, int ndim, int spec)
             }
         }
     } else {
-        if (spec & __Pyx_MEMVIEW_CONTIG && dim != ndim - 1) {
+        if (unlikely(spec & __Pyx_MEMVIEW_CONTIG && dim != ndim - 1)) {
             PyErr_Format(PyExc_ValueError,
                          "C-contiguous buffer is not contiguous in "
                          "dimension %d", dim);
             goto fail;
-        } else if (spec & (__Pyx_MEMVIEW_PTR)) {
+        } else if (unlikely(spec & (__Pyx_MEMVIEW_PTR))) {
             PyErr_Format(PyExc_ValueError,
                          "C-contiguous buffer is not indirect in "
                          "dimension %d", dim);
             goto fail;
-        } else if (buf->suboffsets) {
+        } else if (unlikely(buf->suboffsets)) {
             PyErr_SetString(PyExc_ValueError,
                             "Buffer exposes suboffsets but no strides");
             goto fail;
@@ -235,7 +235,7 @@ __pyx_check_suboffsets(Py_buffer *buf, int dim, CYTHON_UNUSED int ndim, int spec
     // Todo: without PyBUF_INDIRECT we may not have suboffset information, i.e., the
     //       ptr may not be set to NULL but may be uninitialized?
     if (spec & __Pyx_MEMVIEW_DIRECT) {
-        if (buf->suboffsets && buf->suboffsets[dim] >= 0) {
+        if (unlikely(buf->suboffsets && buf->suboffsets[dim] >= 0)) {
             PyErr_Format(PyExc_ValueError,
                          "Buffer not compatible with direct access "
                          "in dimension %d.", dim);
@@ -244,7 +244,7 @@ __pyx_check_suboffsets(Py_buffer *buf, int dim, CYTHON_UNUSED int ndim, int spec
     }
 
     if (spec & __Pyx_MEMVIEW_PTR) {
-        if (!buf->suboffsets || (buf->suboffsets[dim] < 0)) {
+        if (unlikely(!buf->suboffsets || (buf->suboffsets[dim] < 0))) {
             PyErr_Format(PyExc_ValueError,
                          "Buffer is not indirectly accessible "
                          "in dimension %d.", dim);
@@ -265,9 +265,7 @@ __pyx_verify_contig(Py_buffer *buf, int ndim, int c_or_f_flag)
     if (c_or_f_flag & __Pyx_IS_F_CONTIG) {
         Py_ssize_t stride = 1;
         for (i = 0; i < ndim; i++) {
-            if (stride * buf->itemsize != buf->strides[i] &&
-                    buf->shape[i] > 1)
-            {
+            if (unlikely(stride * buf->itemsize != buf->strides[i]  &&  buf->shape[i] > 1)) {
                 PyErr_SetString(PyExc_ValueError,
                     "Buffer not fortran contiguous.");
                 goto fail;
@@ -277,8 +275,7 @@ __pyx_verify_contig(Py_buffer *buf, int ndim, int c_or_f_flag)
     } else if (c_or_f_flag & __Pyx_IS_C_CONTIG) {
         Py_ssize_t stride = 1;
         for (i = ndim - 1; i >- 1; i--) {
-            if (stride * buf->itemsize != buf->strides[i] &&
-                    buf->shape[i] > 1) {
+            if (unlikely(stride * buf->itemsize != buf->strides[i]  &&  buf->shape[i] > 1)) {
                 PyErr_SetString(PyExc_ValueError,
                     "Buffer not C contiguous.");
                 goto fail;
@@ -325,7 +322,7 @@ static int __Pyx_ValidateAndInit_memviewslice(
     }
 
     buf = &memview->view;
-    if (buf->ndim != ndim) {
+    if (unlikely(buf->ndim != ndim)) {
         PyErr_Format(PyExc_ValueError,
                 "Buffer has wrong number of dimensions (expected %d, got %d)",
                 ndim, buf->ndim);
@@ -334,10 +331,10 @@ static int __Pyx_ValidateAndInit_memviewslice(
 
     if (new_memview) {
         __Pyx_BufFmt_Init(&ctx, stack, dtype);
-        if (!__Pyx_BufFmt_CheckString(&ctx, buf->format)) goto fail;
+        if (unlikely(!__Pyx_BufFmt_CheckString(&ctx, buf->format))) goto fail;
     }
 
-    if ((unsigned) buf->itemsize != dtype->size) {
+    if (unlikely((unsigned) buf->itemsize != dtype->size)) {
         PyErr_Format(PyExc_ValueError,
                      "Item size of buffer (%" CYTHON_FORMAT_SSIZE_T "u byte%s) "
                      "does not match size of '%s' (%" CYTHON_FORMAT_SSIZE_T "u byte%s)",
@@ -352,14 +349,14 @@ static int __Pyx_ValidateAndInit_memviewslice(
     /* Check axes */
     for (i = 0; i < ndim; i++) {
         spec = axes_specs[i];
-        if (!__pyx_check_strides(buf, i, ndim, spec))
+        if (unlikely(!__pyx_check_strides(buf, i, ndim, spec)))
             goto fail;
-        if (!__pyx_check_suboffsets(buf, i, ndim, spec))
+        if (unlikely(!__pyx_check_suboffsets(buf, i, ndim, spec)))
             goto fail;
     }
 
     /* Check contiguity */
-    if (buf->strides && !__pyx_verify_contig(buf, ndim, c_or_f_flag))
+    if (unlikely(buf->strides && !__pyx_verify_contig(buf, ndim, c_or_f_flag)))
         goto fail;
 
     /* Initialize */
@@ -394,7 +391,7 @@ __Pyx_init_memviewslice(struct __pyx_memoryview_obj *memview,
     Py_buffer *buf = &memview->view;
     __Pyx_RefNannySetupContext("init_memviewslice", 0);
 
-    if (memviewslice->memview || memviewslice->data) {
+    if (unlikely(memviewslice->memview || memviewslice->data)) {
         PyErr_SetString(PyExc_ValueError,
             "memviewslice is already initialized!");
         goto fail;
@@ -491,7 +488,7 @@ __Pyx_INC_MEMVIEW({{memviewslice_name}} *memslice, int have_gil, int lineno)
     if (!memview || (PyObject *) memview == Py_None)
         return; /* allow uninitialized memoryview assignment */
 
-    if (__pyx_get_slice_count(memview) < 0)
+    if (unlikely(__pyx_get_slice_count(memview) < 0))
         __pyx_fatalerror("Acquisition count is %d (line %d)",
                          __pyx_get_slice_count(memview), lineno);
 
@@ -570,7 +567,7 @@ __pyx_memoryview_copy_new_contig(const __Pyx_memviewslice *from_mvs,
     __Pyx_RefNannySetupContext("__pyx_memoryview_copy_new_contig", 0);
 
     for (i = 0; i < ndim; i++) {
-        if (from_mvs->suboffsets[i] >= 0) {
+        if (unlikely(from_mvs->suboffsets[i] >= 0)) {
             PyErr_Format(PyExc_ValueError, "Cannot copy memoryview slice with "
                                            "indirect dimensions (axis %d)", i);
             goto fail;
@@ -860,7 +857,7 @@ if (unlikely(__pyx_memoryview_slice_memviewslice(
     {{endif}}
 
     {{if boundscheck}}
-        if (!__Pyx_is_valid_index(__pyx_tmp_idx, __pyx_tmp_shape)) {
+        if (unlikely(!__Pyx_is_valid_index(__pyx_tmp_idx, __pyx_tmp_shape))) {
             {{if not have_gil}}
                 #ifdef WITH_THREAD
                 PyGILState_STATE __pyx_gilstate_save = PyGILState_Ensure();