pan/csf: add cs_builder unit test infrastructure

For now, just comparing the raw contents of the output buffer. Possibly
in the future we could hook this up to the disassembly from decode_csf.c
to make it a easier to edit.

Signed-off-by: Olivia Lee <olivia.lee@collabora.com>
Tested-by: Mary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: Ryan Mckeever <ryan.mckeever@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34974>

src/panfrost/genxml/meson.build

@@ -45,3 +45,19 @@ libpanfrost_decode = static_library(
   build_by_default : false,
   link_with: [libpanfrost_decode_per_arch],
 )
+
+if with_tests
+  test('cs_builder_tests',
+    executable(
+      'cs_builder_tests',
+      ['test/cs_builder.cpp'],
+      # Nothing arch-specific is tested currently, only compile v10.
+      cpp_args : [cpp_msvc_compat_args, no_override_init_args, '-DPAN_ARCH=10'],
+      gnu_symbol_visibility : 'hidden',
+      include_directories: [inc_include, inc_src, inc_panfrost],
+      dependencies: [idep_gtest, idep_pan_packers, idep_mesautil],
+    ),
+    suite: ['panfrost'],
+    protocol: 'gtest',
+  )
+endif

src/panfrost/genxml/test/cs_builder.cpp

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2025 Collabora Ltd
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "cs_builder.h"
+
+#include <gtest/gtest.h>
+#include "mesa-gtest-extras.h"
+
+#define MAX_OUTPUT_SIZE 512
+
+class CsBuilderTest : public ::testing::Test {
+public:
+   CsBuilderTest();
+   ~CsBuilderTest();
+
+   struct cs_builder b;
+   uint64_t *output;
+};
+
+CsBuilderTest::CsBuilderTest()
+{
+   output = new uint64_t[MAX_OUTPUT_SIZE];
+   struct cs_builder_conf conf = {
+      .nr_registers = 96,
+      .nr_kernel_registers = 4,
+   };
+   struct cs_buffer buffer = {
+      .cpu = output,
+      .gpu = 0x0,
+      .capacity = MAX_OUTPUT_SIZE,
+   };
+   cs_builder_init(&b, &conf, buffer);
+}
+
+CsBuilderTest::~CsBuilderTest()
+{
+   delete output;
+}
+
+TEST_F(CsBuilderTest, basic)
+{
+   cs_move32_to(&b, cs_reg32(&b, 42), 0xdeadbeef);
+   cs_finish(&b);
+
+   uint64_t expected[] = {
+      0x022a0000deadbeef, /* MOVE32 r42, #0xdeadbeef */
+   };
+
+   EXPECT_EQ(b.root_chunk.size, ARRAY_SIZE(expected));
+   EXPECT_U64_ARRAY_EQUAL(output, expected, ARRAY_SIZE(expected));
+}