freedreno/ir3: add helper to determine point-coord inputs

This will simplify a bit the logic for setting up vinterp/vprepl in the
driver backend, and also avoid it being a flag-day when we switch the
texcoord pipe cap.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5595>
diff --git a/src/freedreno/ir3/ir3_shader.h b/src/freedreno/ir3/ir3_shader.h
index 5ccbd8c..3e7ee89 100644
--- a/src/freedreno/ir3/ir3_shader.h
+++ b/src/freedreno/ir3/ir3_shader.h
@@ -769,8 +769,6 @@
 static inline void
 ir3_link_add(struct ir3_shader_linkage *l, uint8_t regid_, uint8_t compmask, uint8_t loc)
 {
-
-
 	for (int j = 0; j < util_last_bit(compmask); j++) {
 		uint8_t comploc = loc + j;
 		l->varmask[comploc / 32] |= 1 << (comploc % 32);
diff --git a/src/gallium/drivers/freedreno/ir3/ir3_gallium.h b/src/gallium/drivers/freedreno/ir3/ir3_gallium.h
index 0f10338..e0a8d20 100644
--- a/src/gallium/drivers/freedreno/ir3/ir3_gallium.h
+++ b/src/gallium/drivers/freedreno/ir3/ir3_gallium.h
@@ -49,4 +49,22 @@
 
 void ir3_prog_init(struct pipe_context *pctx);
 
+/**
+ * A helper to determine if a fs input 'i' is point/sprite coord, given
+ * the specified sprite_coord_enable mask
+ */
+static inline bool
+ir3_point_sprite(const struct ir3_shader_variant *fs, int i,
+		uint32_t sprite_coord_enable, bool *coord_mode)
+{
+	gl_varying_slot slot = fs->inputs[i].slot;
+	(void)coord_mode; /* this will be used later */
+	/* since we don't enable PIPE_CAP_TGSI_TEXCOORD: */
+	if (slot >= VARYING_SLOT_VAR0) {
+		unsigned texmask = 1 << (slot - VARYING_SLOT_VAR0);
+		return !!(sprite_coord_enable & texmask);
+	}
+	return false;
+}
+
 #endif /* IR3_GALLIUM_H_ */