pan/bi: Add "word equivalence" relation for index

Takes offset *but not swizzle* into account, so the scheduler can
predict whether indices will end up mapped to the same scalar register.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8723>

src/panfrost/bifrost/compiler.h

@@ -232,6 +232,16 @@ bi_is_equiv(bi_index left, bi_index right)
                 (left.value == right.value);
 }
 
+/* A stronger equivalence relation that requires the indices access the
+ * same offset, useful for RA/scheduling to see what registers will
+ * correspond to */
+
+static inline bool
+bi_is_word_equiv(bi_index left, bi_index right)
+{
+        return bi_is_equiv(left, right) && left.offset == right.offset;
+}
+
 #define BI_MAX_DESTS 2
 #define BI_MAX_SRCS 4