intel/compiler: Add variable to dump binaries of all compiled shaders

This can be useful for testing i965_disasm and i965_asm by comparing
bin -> asm -> bin results.

Signed-off-by: Sviatoslav Peleshko <sviatoslav.peleshko@globallogic.com>
Reviewed-by: Sagar Ghuge <sagar.ghuge@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25657>

docs/envvars.rst

@@ -753,6 +753,19 @@ Intel driver environment variables
    overrode shader with sha1 <SHA-1>" in stderr replacing the original
    assembly.
 
+.. envvar:: INTEL_SHADER_BIN_DUMP_PATH
+
+   if set, determines the directory to which the compiled shaders will be
+   dumped. They will be dumped as ``sha1_of_assembly.bin``, where the sha1
+   values will be the same as can be found in the :envvar:`INTEL_DEBUG`
+   output, and can be used for :envvar:`INTEL_SHADER_ASM_READ_PATH` input.
+
+   .. note::
+      Unlike the text form of shader dumping, :envvar:`INTEL_DEBUG`
+      does not affect on the list of shaders to dump. All generated shaders
+      are always dumped if :envvar:`INTEL_SHADER_BIN_DUMP_PATH` variable is
+      set.
+
 .. envvar:: INTEL_SIMD_DEBUG
 
    a comma-separated list of named flags, which control simd dispatch widths:

src/intel/compiler/brw_eu.c

@@ -38,6 +38,7 @@
 #include "brw_gfx_ver_enum.h"
 #include "dev/intel_debug.h"
 
+#include "util/u_debug.h"
 #include "util/ralloc.h"
 
 /* Returns a conditional modifier that negates the condition. */
@@ -371,6 +372,50 @@ brw_get_shader_relocs(struct brw_codegen *p, unsigned *num_relocs)
    return p->relocs;
 }
 
+DEBUG_GET_ONCE_OPTION(shader_bin_dump_path, "INTEL_SHADER_BIN_DUMP_PATH", NULL);
+
+bool brw_should_dump_shader_bin(void)
+{
+   return debug_get_option_shader_bin_dump_path() != NULL;
+}
+
+void brw_dump_shader_bin(void *assembly, int start_offset, int end_offset,
+                         const char *identifier)
+{
+   char *name = ralloc_asprintf(NULL, "%s/%s.bin",
+                                debug_get_option_shader_bin_dump_path(),
+                                identifier);
+
+   int fd = open(name, O_CREAT | O_WRONLY, 0777);
+   ralloc_free(name);
+
+   if (fd < 0)
+      return;
+
+   struct stat sb;
+   if (fstat(fd, &sb) != 0 || (!S_ISREG(sb.st_mode))) {
+      close(fd);
+      return;
+   }
+
+   size_t to_write = end_offset - start_offset;
+   void *write_ptr = assembly + start_offset;
+
+   while (to_write) {
+      ssize_t ret = write(fd, write_ptr, to_write);
+
+      if (ret <= 0) {
+         close(fd);
+         return;
+      }
+
+      to_write -= ret;
+      write_ptr += ret;
+   }
+
+   close(fd);
+}
+
 bool brw_try_override_assembly(struct brw_codegen *p, int start_offset,
                                const char *identifier)
 {

src/intel/compiler/brw_eu.h

@@ -197,6 +197,10 @@ const struct brw_shader_reloc *brw_get_shader_relocs(struct brw_codegen *p,
                                                      unsigned *num_relocs);
 const unsigned *brw_get_program( struct brw_codegen *p, unsigned *sz );
 
+bool brw_should_dump_shader_bin(void);
+void brw_dump_shader_bin(void *assembly, int start_offset, int end_offset,
+                         const char *identifier);
+
 bool brw_try_override_assembly(struct brw_codegen *p, int start_offset,
                                const char *identifier);
 

src/intel/compiler/brw_fs_generator.cpp

@@ -2400,14 +2400,21 @@ fs_generator::generate_code(const cfg_t *cfg, int dispatch_width,
    brw_compact_instructions(p, start_offset, disasm_info);
    int after_size = p->next_insn_offset - start_offset;
 
-   if (unlikely(debug_flag)) {
-      unsigned char sha1[21];
-      char sha1buf[41];
+   bool dump_shader_bin = brw_should_dump_shader_bin();
+   unsigned char sha1[21];
+   char sha1buf[41];
 
+   if (unlikely(debug_flag || dump_shader_bin)) {
       _mesa_sha1_compute(p->store + start_offset / sizeof(brw_inst),
                          after_size, sha1);
       _mesa_sha1_format(sha1buf, sha1);
+   }
 
+   if (unlikely(dump_shader_bin))
+      brw_dump_shader_bin(p->store, start_offset, p->next_insn_offset,
+                          sha1buf);
+
+   if (unlikely(debug_flag)) {
       fprintf(stderr, "Native code for %s (src_hash 0x%08x) (sha1 %s)\n"
               "SIMD%d shader: %d instructions. %d loops. %u cycles. "
               "%d:%d spills:fills, %u sends, "

src/intel/compiler/brw_vec4_generator.cpp

@@ -2231,13 +2231,19 @@ generate_code(struct brw_codegen *p,
    brw_compact_instructions(p, 0, disasm_info);
    int after_size = p->next_insn_offset;
 
-   if (unlikely(debug_enabled)) {
-      unsigned char sha1[21];
-      char sha1buf[41];
+   bool dump_shader_bin = brw_should_dump_shader_bin();
+   unsigned char sha1[21];
+   char sha1buf[41];
 
+   if (unlikely(debug_enabled || dump_shader_bin)) {
       _mesa_sha1_compute(p->store, p->next_insn_offset, sha1);
       _mesa_sha1_format(sha1buf, sha1);
+   }
 
+   if (unlikely(dump_shader_bin))
+      brw_dump_shader_bin(p->store, 0, p->next_insn_offset, sha1buf);
+
+   if (unlikely(debug_enabled)) {
       fprintf(stderr, "Native code for %s %s shader %s (src_hash 0x%08x) (sha1 %s):\n",
             nir->info.label ? nir->info.label : "unnamed",
             _mesa_shader_stage_to_string(nir->info.stage), nir->info.name,