---
src/compiler/nir/nir.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++
src/compiler/nir/nir.h | 2 ++
2 files changed, 65 insertions(+)
diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c
index cd78475..468065a 100644
--- a/src/compiler/nir/nir.c
+++ b/src/compiler/nir/nir.c
@@ -716,6 +716,69 @@ nir_cf_node_get_function(nir_cf_node *node)
return nir_cf_node_as_function(node);
}
+/* Reduces a cursor by trying to convert everything to after and trying to
+ * go up to block granularity when possible.
+ */
+static nir_cursor
+reduce_cursor(nir_cursor cursor)
+{
+ switch (cursor.option) {
+ case nir_cursor_before_block:
+ if (exec_list_is_empty(&cursor.block->instr_list)) {
+ /* Empty block. After is as good as before. */
+ cursor.option = nir_cursor_after_block;
+ } else {
+ /* Try to switch to after the previous block if there is one.
+ * (This isn't likely, but it can happen.)
+ */
+ nir_cf_node *prev_node = nir_cf_node_prev(&cursor.block->cf_node);
+ if (prev_node && prev_node->type == nir_cf_node_block) {
+ cursor.block = nir_cf_node_as_block(prev_node);
+ cursor.option = nir_cursor_after_block;
+ }
+ }
+ return cursor;
+
+ case nir_cursor_after_block:
+ return cursor;
+
+ case nir_cursor_before_instr: {
+ nir_instr *prev_instr = nir_instr_prev(cursor.instr);
+ if (prev_instr) {
+ /* Before this instruction is after the previous */
+ cursor.instr = prev_instr;
+ cursor.option = nir_cursor_after_instr;
+ } else {
+ /* No previous instruction. Switch to before block */
+ cursor.block = cursor.instr->block;
+ cursor.option = nir_cursor_before_block;
+ }
+ return reduce_cursor(cursor);
+ }
+
+ case nir_cursor_after_instr:
+ if (nir_instr_next(cursor.instr) == NULL) {
+ /* This is the last instruction, switch to after block */
+ cursor.option = nir_cursor_after_block;
+ cursor.block = cursor.instr->block;
+ }
+ return cursor;
+
+ default:
+ unreachable("Inavlid cursor option");
+ }
+}
+
+bool
+nir_cursors_equal(nir_cursor a, nir_cursor b)
+{
+ /* Reduced cursors should be unique */
+ a = reduce_cursor(a);
+ b = reduce_cursor(b);
+
+ return a.block == b.block && a.option == b.option;
+}
+
static bool
add_use_cb(nir_src *src, void *state)
{
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 4c6c22f..c856b83 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -1803,6 +1803,8 @@ typedef struct {
};
} nir_cursor;
+bool nir_cursors_equal(nir_cursor a, nir_cursor b);
+
static inline nir_cursor
nir_before_block(nir_block *block)
{
--
2.5.0.400.gff86faf
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