asahi: Use PIPE_FORMATs for driver-compiler ABI

This avoids exposing the ISA-internal agx_format to the driver, instead hiding
it behind a real PIPE_FORMAT. This lets us use real pipe formats in formatted
intrinsics in NIR, which is convenient; it will allow us to simplify the
compiler/driver ABI; and it lets us use common format helpers (e.g.
util_format_get_blocksize) for the internal formats in driver lowering.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19871>

src/asahi/compiler/agx_internal_formats.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2022 Alyssa Rosenzweig
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef AGX_INTERNAL_FORMATS_H
+#define AGX_INTERNAL_FORMATS_H
+
+#include "util/format/u_formats.h"
+
+/* Define aliases for the subset formats that are accessible in the ISA. These
+ * subsets disregard component mapping and number of components. This
+ * constitutes ABI with the compiler.
+ */
+enum agx_internal_formats {
+   AGX_INTERNAL_FORMAT_I8 = PIPE_FORMAT_R8_UINT,
+   AGX_INTERNAL_FORMAT_I16 = PIPE_FORMAT_R16_UINT,
+   AGX_INTERNAL_FORMAT_I32 = PIPE_FORMAT_R32_UINT,
+   AGX_INTERNAL_FORMAT_F16 = PIPE_FORMAT_R16_FLOAT,
+   AGX_INTERNAL_FORMAT_U8NORM = PIPE_FORMAT_R8_UNORM,
+   AGX_INTERNAL_FORMAT_S8NORM = PIPE_FORMAT_R8_SNORM,
+   AGX_INTERNAL_FORMAT_U16NORM = PIPE_FORMAT_R16_UNORM,
+   AGX_INTERNAL_FORMAT_S16NORM = PIPE_FORMAT_R16_SNORM,
+   AGX_INTERNAL_FORMAT_RGB10A2 = PIPE_FORMAT_R10G10B10A2_UNORM,
+   AGX_INTERNAL_FORMAT_SRGBA8 = PIPE_FORMAT_R8G8B8A8_SRGB,
+   AGX_INTERNAL_FORMAT_RG11B10F = PIPE_FORMAT_R11G11B10_FLOAT,
+   AGX_INTERNAL_FORMAT_RGB9E5 = PIPE_FORMAT_R9G9B9E5_FLOAT
+};
+
+#endif

src/asahi/lib/agx_formats.c

@@ -23,17 +23,18 @@
 
 #include "agx_pack.h"
 #include "agx_formats.h"
+#include "agx_internal_formats.h"
 
 #define T true
 #define F false
-#define AGX_FORMAT__ 0
+#define AGX_INTERNAL_FORMAT__ PIPE_FORMAT_NONE
 
 #define AGX_FMT(pipe, channels_, type_, is_renderable, internal_fmt) \
    [PIPE_FORMAT_ ## pipe] = { \
       .channels = AGX_CHANNELS_ ## channels_, \
       .type = AGX_TEXTURE_TYPE_ ## type_, \
       .renderable = is_renderable, \
-      .internal = AGX_FORMAT_ ## internal_fmt,\
+      .internal = (enum pipe_format) AGX_INTERNAL_FORMAT_ ## internal_fmt,\
    }
 
 const struct agx_pixel_format_entry agx_pixel_format[PIPE_FORMAT_COUNT] = {

src/asahi/lib/agx_formats.h

@@ -32,7 +32,7 @@ struct agx_pixel_format_entry {
    uint8_t channels;
    uint8_t type;
    bool renderable : 1;
-   enum agx_format internal : 4;
+   enum pipe_format internal;
 };
 
 extern const struct agx_pixel_format_entry agx_pixel_format[PIPE_FORMAT_COUNT];

src/gallium/drivers/asahi/agx_pipe.c

@@ -746,8 +746,7 @@ agx_flush_batch(struct agx_context *ctx, struct agx_batch *batch)
          agx_pool_upload(&batch->pool, clear_colour, sizeof(clear_colour)));
 
    if (batch->key.cbufs[0]) {
-      enum pipe_format fmt = batch->key.cbufs[0]->format;
-      enum agx_format internal = agx_pixel_format[fmt].internal;
+      enum agx_format internal = AGX_FORMAT_U8NORM /* other formats broken */;
       uint32_t shader = dev->reload.format[internal];
 
       pipeline_reload = agx_build_reload_pipeline(batch, shader,

src/gallium/drivers/asahi/agx_state.c

@@ -1240,7 +1240,7 @@ agx_update_fs(struct agx_batch *batch)
       if (surf) {
          enum pipe_format fmt = surf->format;
          key.rt_formats[i] = fmt;
-         key.base.fs.tib_formats[i] = agx_pixel_format[fmt].internal;
+         key.base.fs.tib_formats[i] = AGX_FORMAT_U8NORM /* other formats broken */;
       } else {
          key.rt_formats[i] = PIPE_FORMAT_NONE;
       }