panfrost: Inline panfrost_get_default_swizzle

This commit replaces panfrost_get_default_swizzle with an inlined
implementation where the returned values can be determined at compile
time.

According to perf, this previously used about 2% CPU for Openarena.

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3824>

src/gallium/drivers/panfrost/pan_assemble.c

@@ -27,6 +27,7 @@
 #include <string.h>
 #include "pan_bo.h"
 #include "pan_context.h"
+#include "pan_format.h"
 #include "pan_util.h"
 
 #include "compiler/nir/nir.h"

src/gallium/drivers/panfrost/pan_context.h

@@ -297,9 +297,6 @@ panfrost_emit_for_draw(struct panfrost_context *ctx, bool with_vertex_data);
 struct panfrost_transfer
 panfrost_vertex_tiler_job(struct panfrost_context *ctx, bool is_tiler);
 
-unsigned
-panfrost_get_default_swizzle(unsigned components);
-
 void
 panfrost_flush(
         struct pipe_context *pipe,

src/gallium/drivers/panfrost/pan_format.c

@@ -72,20 +72,6 @@ panfrost_translate_swizzle_4(const unsigned char swizzle[4])
         return out;
 }
 
-unsigned
-panfrost_get_default_swizzle(unsigned components)
-{
-        unsigned char default_swizzles[4][4] = {
-                {PIPE_SWIZZLE_X, PIPE_SWIZZLE_0, PIPE_SWIZZLE_0, PIPE_SWIZZLE_1},
-                {PIPE_SWIZZLE_X, PIPE_SWIZZLE_Y, PIPE_SWIZZLE_0, PIPE_SWIZZLE_1},
-                {PIPE_SWIZZLE_X, PIPE_SWIZZLE_Y, PIPE_SWIZZLE_Z, PIPE_SWIZZLE_1},
-                {PIPE_SWIZZLE_X, PIPE_SWIZZLE_Y, PIPE_SWIZZLE_Z, PIPE_SWIZZLE_W},
-        };
-
-        assert(components >= 1 && components <= 4);
-        return panfrost_translate_swizzle_4(default_swizzles[components - 1]);
-}
-
 static unsigned
 panfrost_translate_channel_width(unsigned size)
 {

src/gallium/drivers/panfrost/pan_format.h

@@ -31,9 +31,6 @@
 unsigned
 panfrost_translate_swizzle_4(const unsigned char swizzle[4]);
 
-unsigned
-panfrost_get_default_swizzle(unsigned components);
-
 enum mali_format
 panfrost_find_format(const struct util_format_description *desc);
 
@@ -43,6 +40,27 @@ panfrost_invert_swizzle(const unsigned char *in, unsigned char *out);
 bool
 panfrost_is_z24s8_variant(enum pipe_format fmt);
 
+static inline unsigned
+panfrost_get_default_swizzle(unsigned components)
+{
+        switch (components) {
+        case 1:
+                return (MALI_CHANNEL_RED << 0) | (MALI_CHANNEL_ZERO << 3) |
+                        (MALI_CHANNEL_ZERO << 6) | (MALI_CHANNEL_ONE << 9);
+        case 2:
+                return (MALI_CHANNEL_RED << 0) | (MALI_CHANNEL_GREEN << 3) |
+                        (MALI_CHANNEL_ZERO << 6) | (MALI_CHANNEL_ONE << 9);
+        case 3:
+                return (MALI_CHANNEL_RED << 0) | (MALI_CHANNEL_GREEN << 3) |
+                        (MALI_CHANNEL_BLUE << 6) | (MALI_CHANNEL_ONE << 9);
+        case 4:
+                return (MALI_CHANNEL_RED << 0) | (MALI_CHANNEL_GREEN << 3) |
+                        (MALI_CHANNEL_BLUE << 6) | (MALI_CHANNEL_ALPHA << 9);
+        default:
+                unreachable("Invalid number of components");
+        }
+}
+
 #endif
 
 

src/gallium/drivers/panfrost/pan_varyings.c

@@ -25,6 +25,7 @@
 
 #include "pan_bo.h"
 #include "pan_context.h"
+#include "pan_format.h"
 #include "util/u_prim.h"
 
 static mali_ptr