diff --git a/libswscale/ops_backend.c b/libswscale/ops_backend.c
index 248a591fd2..a503139016 100644
--- a/libswscale/ops_backend.c
+++ b/libswscale/ops_backend.c
@@ -53,18 +53,20 @@ static void process(const SwsOpExec *exec, const void *priv,
 {
     const SwsOpChain *chain = priv;
     const SwsOpImpl *impl = chain->impl;
-    SwsOpIter iter;
+    u32block_t x, y, z, w; /* allocate enough space for any intermediate */
 
-    for (iter.y = y_start; iter.y < y_end; iter.y++) {
+    SwsOpIter iterdata;
+    SwsOpIter *iter = &iterdata; /* for CONTINUE() macro to work */
+
+    for (iter->y = y_start; iter->y < y_end; iter->y++) {
         for (int i = 0; i < 4; i++) {
-            iter.in[i]  = exec->in[i]  + (iter.y - y_start) * exec->in_stride[i];
-            iter.out[i] = exec->out[i] + (iter.y - y_start) * exec->out_stride[i];
+            iter->in[i]  = exec->in[i]  + (iter->y - y_start) * exec->in_stride[i];
+            iter->out[i] = exec->out[i] + (iter->y - y_start) * exec->out_stride[i];
         }
 
         for (int block = bx_start; block < bx_end; block++) {
-            iter.x = block * SWS_BLOCK_SIZE;
-            ((void (*)(SwsOpIter *, const SwsOpImpl *)) impl->cont)
-                (&iter, &impl[1]);
+            iter->x = block * SWS_BLOCK_SIZE;
+            CONTINUE(u32block_t, x, y, z, w);
         }
     }
 }
diff --git a/libswscale/ops_backend.h b/libswscale/ops_backend.h
index 4a1794af8a..b1616f6b02 100644
--- a/libswscale/ops_backend.h
+++ b/libswscale/ops_backend.h
@@ -78,13 +78,9 @@ typedef struct SwsOpIter {
                                           __VA_ARGS__)
 
 #define DECL_READ(NAME, ...)                                                    \
-    static av_always_inline void fn(NAME)(SwsOpIter *restrict iter,             \
-                                          const SwsOpImpl *restrict impl,       \
-                                          const pixel_t *restrict in0,          \
-                                          const pixel_t *restrict in1,          \
-                                          const pixel_t *restrict in2,          \
-                                          const pixel_t *restrict in3,          \
-                                          __VA_ARGS__)
+    DECL_FUNC(NAME, const pixel_t *restrict in0, const pixel_t *restrict in1,   \
+                    const pixel_t *restrict in2, const pixel_t *restrict in3,   \
+                    __VA_ARGS__)
 
 #define DECL_WRITE(NAME, ...)                                                   \
     DECL_FUNC(NAME, pixel_t *restrict out0, pixel_t *restrict out1,             \
@@ -96,10 +92,9 @@ typedef struct SwsOpIter {
     fn(FUNC)(iter, impl, x, y, z, w, __VA_ARGS__)
 
 #define CALL_READ(FUNC, ...)                                                    \
-    fn(FUNC)(iter, impl, (const pixel_t *) iter->in[0],                         \
-                         (const pixel_t *) iter->in[1],                         \
-                         (const pixel_t *) iter->in[2],                         \
-                         (const pixel_t *) iter->in[3], __VA_ARGS__)
+    CALL(FUNC, (const pixel_t *) iter->in[0], (const pixel_t *) iter->in[1],    \
+               (const pixel_t *) iter->in[2], (const pixel_t *) iter->in[3],    \
+               __VA_ARGS__)
 
 #define CALL_WRITE(FUNC, ...)                                                   \
     CALL(FUNC, (pixel_t *) iter->out[0], (pixel_t *) iter->out[1],              \
@@ -112,10 +107,6 @@ typedef struct SwsOpIter {
                                   block_t x, block_t y,                         \
                                   block_t z, block_t w)
 
-#define DECL_IMPL_READ(NAME)                                                    \
-    static SWS_FUNC void fn(NAME)(SwsOpIter *restrict iter,                     \
-                                  const SwsOpImpl *restrict impl)
-
 /* Helper macro to call into the next continuation with a given type */
 #define CONTINUE(TYPE, ...)                                                     \
     ((void (*)(SwsOpIter *, const SwsOpImpl *,                                  \
diff --git a/libswscale/ops_tmpl_int.c b/libswscale/ops_tmpl_int.c
index 84596e2763..d9870faf34 100644
--- a/libswscale/ops_tmpl_int.c
+++ b/libswscale/ops_tmpl_int.c
@@ -58,8 +58,6 @@
 
 DECL_READ(read_planar, const int elems)
 {
-    block_t x, y, z, w;
-
     SWS_LOOP
     for (int i = 0; i < SWS_BLOCK_SIZE; i++) {
         x[i] = in0[i];
@@ -76,8 +74,6 @@ DECL_READ(read_planar, const int elems)
 
 DECL_READ(read_packed, const int elems)
 {
-    block_t x, y, z, w;
-
     SWS_LOOP
     for (int i = 0; i < SWS_BLOCK_SIZE; i++) {
         x[i] = in0[elems * i + 0];
@@ -121,7 +117,7 @@ DECL_WRITE(write_packed, const int elems)
 }
 
 #define WRAP_READ(FUNC, ELEMS, FRAC, PACKED)                                    \
-DECL_IMPL_READ(FUNC##ELEMS)                                                     \
+DECL_IMPL(FUNC##ELEMS)                                                          \
 {                                                                               \
     CALL_READ(FUNC, ELEMS);                                                     \
     for (int i = 0; i < (PACKED ? 1 : ELEMS); i++)                              \
@@ -173,8 +169,6 @@ WRAP_WRITE(write_packed, 4, 0, true)
 #if BIT_DEPTH == 8
 DECL_READ(read_nibbles, const int elems)
 {
-    block_t x, y, z, w;
-
     SWS_LOOP
     for (int i = 0; i < SWS_BLOCK_SIZE; i += 2) {
         const pixel_t val = ((const pixel_t *) in0)[i >> 1];
@@ -187,8 +181,6 @@ DECL_READ(read_nibbles, const int elems)
 
 DECL_READ(read_bits, const int elems)
 {
-    block_t x, y, z, w;
-
     SWS_LOOP
     for (int i = 0; i < SWS_BLOCK_SIZE; i += 8) {
         const pixel_t val = ((const pixel_t *) in0)[i >> 3];