[Mesa-dev] [PATCH 2/2] radeonsi: add RADEON_REPLACE_SHADERS debug option
Nicolai Hähnle
nhaehnle at gmail.com
Thu Dec 17 14:01:54 PST 2015
From: Nicolai Hähnle <nicolai.haehnle at amd.com>
This option allows replacing a single shader by a pre-compiled ELF object
as generated by LLVM's llc, for example. This can be useful for debugging a
deterministically occuring error in shaders (and has in fact helped find
the causes of https://bugs.freedesktop.org/show_bug.cgi?id=93264).
---
src/gallium/drivers/radeon/r600_pipe_common.h | 1 +
src/gallium/drivers/radeonsi/si_debug.c | 94 +++++++++++++++++++++++++++
src/gallium/drivers/radeonsi/si_pipe.c | 3 +
src/gallium/drivers/radeonsi/si_pipe.h | 1 +
src/gallium/drivers/radeonsi/si_shader.c | 18 +++--
5 files changed, 112 insertions(+), 5 deletions(-)
diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
index c3933b1d..556c7cc 100644
--- a/src/gallium/drivers/radeon/r600_pipe_common.h
+++ b/src/gallium/drivers/radeon/r600_pipe_common.h
@@ -87,6 +87,7 @@
#define DBG_NO_DCC (1llu << 43)
#define DBG_NO_DCC_CLEAR (1llu << 44)
#define DBG_NO_RB_PLUS (1llu << 45)
+#define DBG_REPLACE_SHADERS (1llu << 46)
#define R600_MAP_BUFFER_ALIGNMENT 64
diff --git a/src/gallium/drivers/radeonsi/si_debug.c b/src/gallium/drivers/radeonsi/si_debug.c
index c45f8c0..f50d98c 100644
--- a/src/gallium/drivers/radeonsi/si_debug.c
+++ b/src/gallium/drivers/radeonsi/si_debug.c
@@ -28,7 +28,9 @@
#include "si_shader.h"
#include "sid.h"
#include "sid_tables.h"
+#include "radeon/radeon_elf_util.h"
#include "ddebug/dd_util.h"
+#include "util/u_memory.h"
static void si_dump_shader(struct si_shader_ctx_state *state, const char *name,
@@ -42,6 +44,98 @@ static void si_dump_shader(struct si_shader_ctx_state *state, const char *name,
fprintf(f, "%s\n\n", state->current->binary.disasm_string);
}
+/**
+ * Shader compiles can be overridden with arbitrary ELF objects by setting
+ * the environment variable RADEON_REPLACE_SHADERS=num1:filename1[;num2:filename2]
+ */
+bool si_replace_shader(unsigned num, struct radeon_shader_binary *binary)
+{
+ const char *p = debug_get_option("RADEON_REPLACE_SHADERS", NULL);
+ const char *semicolon;
+ char *copy = NULL;
+ FILE *f;
+ long filesize, nread;
+ char *buf = NULL;
+ bool replaced = false;
+
+ if (!p)
+ return false;
+
+ while (*p) {
+ unsigned long i;
+ char *endp;
+ i = strtoul(p, &endp, 0);
+
+ p = endp;
+ if (*p != ':') {
+ fprintf(stderr, "RADEON_REPLACE_SHADERS formatted badly.\n");
+ exit(1);
+ }
+ ++p;
+
+ if (i == num)
+ break;
+
+ p = strchr(p, ';');
+ if (!p)
+ return false;
+ ++p;
+ }
+ if (!*p)
+ return false;
+
+ semicolon = strchr(p, ';');
+ if (semicolon) {
+ p = copy = strndup(p, semicolon - p);
+ if (!copy) {
+ fprintf(stderr, "out of memory\n");
+ return false;
+ }
+ }
+
+ fprintf(stderr, "radeonsi: replace shader %u by %s\n", num, p);
+
+ f = fopen(p, "r");
+ if (!f) {
+ perror("radeonsi: failed to open file");
+ goto out_free;
+ }
+
+ if (fseek(f, 0, SEEK_END) != 0)
+ goto file_error;
+
+ filesize = ftell(f);
+ if (filesize < 0)
+ goto file_error;
+
+ if (fseek(f, 0, SEEK_SET) != 0)
+ goto file_error;
+
+ buf = MALLOC(filesize);
+ if (!buf) {
+ fprintf(stderr, "out of memory\n");
+ goto out_close;
+ }
+
+ nread = fread(buf, 1, filesize, f);
+ if (nread != filesize)
+ goto file_error;
+
+ radeon_elf_read(buf, filesize, binary);
+ replaced = true;
+
+out_close:
+ fclose(f);
+out_free:
+ FREE(buf);
+ free(copy);
+ return replaced;
+
+file_error:
+ perror("radeonsi: reading shader");
+ goto out_close;
+}
+
/* Parsed IBs are difficult to read without colors. Use "less -R file" to
* read them, or use "aha -b -f file" to convert them to html.
*/
diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c
index ac13407..6a1911f 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.c
+++ b/src/gallium/drivers/radeonsi/si_pipe.c
@@ -639,6 +639,9 @@ struct pipe_screen *radeonsi_screen_create(struct radeon_winsys *ws)
if (debug_get_bool_option("RADEON_DUMP_SHADERS", FALSE))
sscreen->b.debug_flags |= DBG_FS | DBG_VS | DBG_GS | DBG_PS | DBG_CS;
+ if (debug_get_option("RADEON_REPLACE_SHADERS", NULL))
+ sscreen->b.debug_flags |= DBG_REPLACE_SHADERS;
+
/* Create the auxiliary context. This must be done last. */
sscreen->b.aux_context = sscreen->b.b.context_create(&sscreen->b.b, NULL, 0);
diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index 65c7e19..f83cb02 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -329,6 +329,7 @@ void si_init_cp_dma_functions(struct si_context *sctx);
/* si_debug.c */
void si_init_debug_functions(struct si_context *sctx);
void si_check_vm_faults(struct si_context *sctx);
+bool si_replace_shader(unsigned num, struct radeon_shader_binary *binary);
/* si_dma.c */
void si_dma_copy(struct pipe_context *ctx,
diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 511ed88..3b19713 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -3884,13 +3884,21 @@ int si_compile_llvm(struct si_screen *sscreen, struct si_shader *shader,
bool dump_asm = r600_can_dump_shader(&sscreen->b,
shader->selector ? shader->selector->tokens : NULL);
bool dump_ir = dump_asm && !(sscreen->b.debug_flags & DBG_NO_IR);
+ bool replaced = false;
+ unsigned count = p_atomic_inc_return(&sscreen->b.num_compilations);
- p_atomic_inc(&sscreen->b.num_compilations);
+ if (dump_ir || dump_asm)
+ fprintf(stderr, "radeonsi: Compiling shader %d\n", count);
- r = radeon_llvm_compile(mod, &shader->binary,
- r600_get_llvm_processor_name(sscreen->b.family), dump_ir, dump_asm, tm);
- if (r)
- return r;
+ if (sscreen->b.debug_flags & DBG_REPLACE_SHADERS)
+ replaced = si_replace_shader(count, &shader->binary);
+
+ if (!replaced) {
+ r = radeon_llvm_compile(mod, &shader->binary,
+ r600_get_llvm_processor_name(sscreen->b.family), dump_ir, dump_asm, tm);
+ if (r)
+ return r;
+ }
r = si_shader_binary_read(sscreen, shader);
--
2.5.0
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