vtn: Add a debug flag to dump SPIR-V assembly

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30875>

meson.build

@@ -1916,14 +1916,21 @@ if with_clover_spirv or with_clc
     '>= @0@.@1@'.format(chosen_llvm_version_major, chosen_llvm_version_minor),
     '< @0@.@1@'.format(chosen_llvm_version_major, chosen_llvm_version_minor + 1) ]
 
-  dep_spirv_tools = dependency('SPIRV-Tools', required : true, version : '>= 2018.0')
   # LLVMSPIRVLib is available at https://github.com/KhronosGroup/SPIRV-LLVM-Translator
   dep_llvmspirvlib = dependency('LLVMSPIRVLib', required : true, version : _llvmspirvlib_version)
 else
-  dep_spirv_tools = null_dep
   dep_llvmspirvlib = null_dep
 endif
 
+dep_spirv_tools = dependency(
+  'SPIRV-Tools',
+  required : with_clover_spirv or with_clc,
+  version : '>= 2018.0'
+)
+if dep_spirv_tools.found()
+  pre_args += '-DHAVE_SPIRV_TOOLS'
+endif
+
 dep_clang = null_dep
 if with_clc
   llvm_libdir = dep_llvm.get_variable(cmake : 'LLVM_LIBRARY_DIR', configtool: 'libdir')

src/compiler/spirv/meson.build

@@ -36,6 +36,7 @@ files_libvtn = files(
   'vtn_amd.c',
   'vtn_cfg.c',
   'vtn_cmat.c',
+  'vtn_debug.c',
   'vtn_glsl450.c',
   'vtn_opencl.c',
   'vtn_private.h',
@@ -54,12 +55,12 @@ libvtn = static_library(
   include_directories : [inc_include, inc_src, inc_mapi, inc_mesa],
   c_args : [c_msvc_compat_args, no_override_init_args],
   gnu_symbol_visibility : 'hidden',
-  dependencies : [idep_nir, dep_valgrind],
+  dependencies : [dep_spirv_tools, idep_nir, dep_valgrind],
   build_by_default : false,
 )
 
 idep_vtn = declare_dependency(
-  dependencies : [idep_nir, idep_mesautil],
+  dependencies : [dep_spirv_tools, idep_nir, idep_mesautil],
   link_with : libvtn,
 )
 

src/compiler/spirv/nir_spirv.h

@@ -166,6 +166,8 @@ bool
 spirv_library_to_nir_builder(FILE *fp, const uint32_t *words, size_t word_count,
                              const struct spirv_to_nir_options *options);
 
+void spirv_print_asm(FILE *fp, const uint32_t *words, size_t word_count);
+
 #ifdef __cplusplus
 }
 #endif

src/compiler/spirv/spirv_to_nir.c

@@ -206,6 +206,8 @@ static const struct debug_named_value mesa_spirv_debug_control[] = {
      "Print information of the SPIR-V structured control flow parsing" },
    { "values", MESA_SPIRV_DEBUG_VALUES,
      "Print information of the SPIR-V values" },
+   { "asm", MESA_SPIRV_DEBUG_ASM, "Print the SPIR-V assembly" },
+   { "color", MESA_SPIRV_DEBUG_COLOR, "Debug in color, if available" },
    DEBUG_NAMED_VALUE_END,
 };
 
@@ -6847,6 +6849,9 @@ spirv_to_nir(const uint32_t *words, size_t word_count,
 {
    mesa_spirv_debug_init();
 
+   if (MESA_SPIRV_DEBUG(ASM))
+      spirv_print_asm(stderr, words, word_count);
+
    const uint32_t *word_end = words + word_count;
 
    struct vtn_builder *b = vtn_create_builder(words, word_count,

src/compiler/spirv/vtn_debug.c

@@ -0,0 +1,65 @@
+/*
+ * Copyright © 2024 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Faith Ekstrand (faith@gfxstrand.net)
+ *
+ */
+
+#include "vtn_private.h"
+
+#ifdef HAVE_SPIRV_TOOLS
+#include <spirv-tools/libspirv.h>
+#endif /* HAVE_SPIRV_TOOLS */
+
+void
+spirv_print_asm(FILE *fp, const uint32_t *words, size_t word_count)
+{
+#ifdef HAVE_SPIRV_TOOLS
+   spv_context ctx = spvContextCreate(SPV_ENV_UNIVERSAL_1_6);
+
+   spv_binary_to_text_options_t options =
+      SPV_BINARY_TO_TEXT_OPTION_INDENT |
+      SPV_BINARY_TO_TEXT_OPTION_FRIENDLY_NAMES;
+
+   if (MESA_SPIRV_DEBUG(COLOR))
+      options |= SPV_BINARY_TO_TEXT_OPTION_COLOR;
+
+   spv_text text = NULL;
+   spv_diagnostic diagnostic = NULL;
+   spv_result_t res = spvBinaryToText(ctx, words, word_count, options,
+                                      &text, &diagnostic);
+   if (res == SPV_SUCCESS) {
+      fprintf(fp, "SPIR-V assembly:\n");
+      fwrite(text->str, 1, text->length, fp);
+   } else {
+      fprintf(fp, "Failed to disassemble SPIR-V:\n");
+      spvDiagnosticPrint(diagnostic);
+      spvDiagnosticDestroy(diagnostic);
+   }
+
+   spvTextDestroy(text);
+#else
+   fprintf(fp, "Cannot dump SPIR-V assembly. "
+               "You need to build against SPIR-V tools.\n");
+#endif /* HAVE_SPIRV_TOOLS */
+}

src/compiler/spirv/vtn_private.h

@@ -40,6 +40,8 @@ extern uint32_t mesa_spirv_debug;
 
 #define MESA_SPIRV_DEBUG_STRUCTURED     (1u << 0)
 #define MESA_SPIRV_DEBUG_VALUES         (1u << 1)
+#define MESA_SPIRV_DEBUG_ASM            (1u << 2)
+#define MESA_SPIRV_DEBUG_COLOR          (1u << 3)
 
 struct vtn_builder;
 struct vtn_decoration;