I completely agree with you. Turning off the R600 optimizing Shader Backend would also work, but the performance drop would be unpleasant.
Marek On Wed, Feb 11, 2015 at 4:11 PM, Roland Scheidegger <srol...@vmware.com> wrote: > I don't think this is a good idea. This pollutes the gallium interface > (albeit in some rather minor way, but still) to just cover up a driver > bug. It does not do anything to actually fix the root cause of the bug > (presumably it would still just lock up if the loop would actually have > 256 iterations and hence still not get unrolled, and it's a hint only so > even with less iterations you could still get such loops with other > state trackers). > Unless such a hint would be useful in general for drivers to set some > limit for loop unrolling. > > Roland > > > Am 11.02.2015 um 15:23 schrieb Marek Olšák: >> From: Marek Olšák <marek.ol...@amd.com> >> >> This is the same as the Mesa core setting. >> >> This avoids a serious r600g bug. >> Bugzilla:_https://bugs.freedesktop.org/show_bug.cgi?id=86720 >> >> Cc: 10.5 10.4 10.3 <mesa-sta...@lists.freedesktop.org> >> --- >> src/gallium/auxiliary/gallivm/lp_bld_limits.h | 2 ++ >> src/gallium/auxiliary/tgsi/tgsi_exec.h | 2 ++ >> src/gallium/docs/source/screen.rst | 4 ++++ >> src/gallium/drivers/freedreno/freedreno_screen.c | 2 ++ >> src/gallium/drivers/i915/i915_screen.c | 2 ++ >> src/gallium/drivers/ilo/ilo_screen.c | 2 ++ >> src/gallium/drivers/nouveau/nv30/nv30_screen.c | 4 ++++ >> src/gallium/drivers/nouveau/nv50/nv50_screen.c | 2 ++ >> src/gallium/drivers/nouveau/nvc0/nvc0_screen.c | 2 ++ >> src/gallium/drivers/r300/r300_screen.c | 4 ++++ >> src/gallium/drivers/r600/r600_pipe.c | 6 ++++++ >> src/gallium/drivers/radeonsi/si_pipe.c | 2 ++ >> src/gallium/drivers/svga/svga_screen.c | 4 ++++ >> src/gallium/drivers/vc4/vc4_screen.c | 2 ++ >> src/gallium/include/pipe/p_defines.h | 3 ++- >> src/mesa/state_tracker/st_extensions.c | 3 +++ >> 16 files changed, 45 insertions(+), 1 deletion(-) >> >> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_limits.h >> b/src/gallium/auxiliary/gallivm/lp_bld_limits.h >> index 8c66f9d..7856006 100644 >> --- a/src/gallium/auxiliary/gallivm/lp_bld_limits.h >> +++ b/src/gallium/auxiliary/gallivm/lp_bld_limits.h >> @@ -128,6 +128,8 @@ gallivm_get_shader_param(enum pipe_shader_cap param) >> return 1; >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> } >> /* if we get here, we missed a shader cap above (and should have seen >> * a compiler warning.) >> diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.h >> b/src/gallium/auxiliary/tgsi/tgsi_exec.h >> index cc5a916..56c8930 100644 >> --- a/src/gallium/auxiliary/tgsi/tgsi_exec.h >> +++ b/src/gallium/auxiliary/tgsi/tgsi_exec.h >> @@ -457,6 +457,8 @@ tgsi_exec_get_shader_param(enum pipe_shader_cap param) >> return 1; >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> } >> /* if we get here, we missed a shader cap above (and should have seen >> * a compiler warning.) >> diff --git a/src/gallium/docs/source/screen.rst >> b/src/gallium/docs/source/screen.rst >> index 5d80908..aa519d2 100644 >> --- a/src/gallium/docs/source/screen.rst >> +++ b/src/gallium/docs/source/screen.rst >> @@ -326,6 +326,10 @@ to be 0. >> sampler views. Must not be lower than >> PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS. >> * ``PIPE_SHADER_CAP_DOUBLES``: Whether double precision floating-point >> operations are supported. >> +* ``PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS``: This is the maximum number of >> + iterations that loops are allowed to have to be unrolled. It is only >> + a hint to state trackers. Whether any loops will be unrolled is not >> + guaranteed. >> >> >> .. _pipe_compute_cap: >> diff --git a/src/gallium/drivers/freedreno/freedreno_screen.c >> b/src/gallium/drivers/freedreno/freedreno_screen.c >> index 1ce96d3..90fd6f8 100644 >> --- a/src/gallium/drivers/freedreno/freedreno_screen.c >> +++ b/src/gallium/drivers/freedreno/freedreno_screen.c >> @@ -398,6 +398,8 @@ fd_screen_get_shader_param(struct pipe_screen *pscreen, >> unsigned shader, >> return 16; >> case PIPE_SHADER_CAP_PREFERRED_IR: >> return PIPE_SHADER_IR_TGSI; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> } >> debug_printf("unknown shader param %d\n", param); >> return 0; >> diff --git a/src/gallium/drivers/i915/i915_screen.c >> b/src/gallium/drivers/i915/i915_screen.c >> index 2dcb507..d2199a2 100644 >> --- a/src/gallium/drivers/i915/i915_screen.c >> +++ b/src/gallium/drivers/i915/i915_screen.c >> @@ -155,6 +155,8 @@ i915_get_shader_param(struct pipe_screen *screen, >> unsigned shader, enum pipe_sha >> case PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS: >> case PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS: >> return I915_TEX_UNITS; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> default: >> debug_printf("%s: Unknown cap %u.\n", __FUNCTION__, cap); >> return 0; >> diff --git a/src/gallium/drivers/ilo/ilo_screen.c >> b/src/gallium/drivers/ilo/ilo_screen.c >> index 04c1283..6e9e723 100644 >> --- a/src/gallium/drivers/ilo/ilo_screen.c >> +++ b/src/gallium/drivers/ilo/ilo_screen.c >> @@ -154,6 +154,8 @@ ilo_get_shader_param(struct pipe_screen *screen, >> unsigned shader, >> return PIPE_SHADER_IR_TGSI; >> case PIPE_SHADER_CAP_TGSI_SQRT_SUPPORTED: >> return 1; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> >> default: >> return 0; >> diff --git a/src/gallium/drivers/nouveau/nv30/nv30_screen.c >> b/src/gallium/drivers/nouveau/nv30/nv30_screen.c >> index 83cae7a..9c183f2 100644 >> --- a/src/gallium/drivers/nouveau/nv30/nv30_screen.c >> +++ b/src/gallium/drivers/nouveau/nv30/nv30_screen.c >> @@ -247,6 +247,8 @@ nv30_screen_get_shader_param(struct pipe_screen >> *pscreen, unsigned shader, >> case PIPE_SHADER_CAP_SUBROUTINES: >> case PIPE_SHADER_CAP_INTEGERS: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> default: >> debug_printf("unknown vertex shader param %d\n", param); >> return 0; >> @@ -283,6 +285,8 @@ nv30_screen_get_shader_param(struct pipe_screen >> *pscreen, unsigned shader, >> case PIPE_SHADER_CAP_INDIRECT_CONST_ADDR: >> case PIPE_SHADER_CAP_SUBROUTINES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> default: >> debug_printf("unknown fragment shader param %d\n", param); >> return 0; >> diff --git a/src/gallium/drivers/nouveau/nv50/nv50_screen.c >> b/src/gallium/drivers/nouveau/nv50/nv50_screen.c >> index 222fa65..b79c237 100644 >> --- a/src/gallium/drivers/nouveau/nv50/nv50_screen.c >> +++ b/src/gallium/drivers/nouveau/nv50/nv50_screen.c >> @@ -285,6 +285,8 @@ nv50_screen_get_shader_param(struct pipe_screen >> *pscreen, unsigned shader, >> /* The chip could handle more sampler views than samplers */ >> case PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS: >> return MIN2(32, PIPE_MAX_SAMPLERS); >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> default: >> NOUVEAU_ERR("unknown PIPE_SHADER_CAP %d\n", param); >> return 0; >> diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c >> b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c >> index 63fbad7..4e53ca4 100644 >> --- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c >> +++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c >> @@ -293,6 +293,8 @@ nvc0_screen_get_shader_param(struct pipe_screen >> *pscreen, unsigned shader, >> return 16; /* would be 32 in linked (OpenGL-style) mode */ >> case PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS: >> return 16; /* XXX not sure if more are really safe */ >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> default: >> NOUVEAU_ERR("unknown PIPE_SHADER_CAP %d\n", param); >> return 0; >> diff --git a/src/gallium/drivers/r300/r300_screen.c >> b/src/gallium/drivers/r300/r300_screen.c >> index 7794fc2..e6b826d 100644 >> --- a/src/gallium/drivers/r300/r300_screen.c >> +++ b/src/gallium/drivers/r300/r300_screen.c >> @@ -285,6 +285,8 @@ static int r300_get_shader_param(struct pipe_screen >> *pscreen, unsigned shader, e >> case PIPE_SHADER_CAP_INTEGERS: >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> case PIPE_SHADER_CAP_PREFERRED_IR: >> return PIPE_SHADER_IR_TGSI; >> } >> @@ -337,6 +339,8 @@ static int r300_get_shader_param(struct pipe_screen >> *pscreen, unsigned shader, e >> case PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS: >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> case PIPE_SHADER_CAP_PREFERRED_IR: >> return PIPE_SHADER_IR_TGSI; >> } >> diff --git a/src/gallium/drivers/r600/r600_pipe.c >> b/src/gallium/drivers/r600/r600_pipe.c >> index 60bed0e..e10b224 100644 >> --- a/src/gallium/drivers/r600/r600_pipe.c >> +++ b/src/gallium/drivers/r600/r600_pipe.c >> @@ -486,6 +486,12 @@ static int r600_get_shader_param(struct pipe_screen* >> pscreen, unsigned shader, e >> } >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + /* due to a bug in the shader compiler, some loops hang >> + * if they are not unrolled, see: >> + * https://bugs.freedesktop.org/show_bug.cgi?id=86720 >> + */ >> + return 255; >> } >> return 0; >> } >> diff --git a/src/gallium/drivers/radeonsi/si_pipe.c >> b/src/gallium/drivers/radeonsi/si_pipe.c >> index 26182c2..d88ad14 100644 >> --- a/src/gallium/drivers/radeonsi/si_pipe.c >> +++ b/src/gallium/drivers/radeonsi/si_pipe.c >> @@ -421,6 +421,8 @@ static int si_get_shader_param(struct pipe_screen* >> pscreen, unsigned shader, enu >> return PIPE_SHADER_IR_TGSI; >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> } >> return 0; >> } >> diff --git a/src/gallium/drivers/svga/svga_screen.c >> b/src/gallium/drivers/svga/svga_screen.c >> index e3db4a8..0156001 100644 >> --- a/src/gallium/drivers/svga/svga_screen.c >> +++ b/src/gallium/drivers/svga/svga_screen.c >> @@ -373,6 +373,8 @@ static int svga_get_shader_param(struct pipe_screen >> *screen, unsigned shader, en >> return PIPE_SHADER_IR_TGSI; >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> } >> /* If we get here, we failed to handle a cap above */ >> debug_printf("Unexpected fragment shader query %u\n", param); >> @@ -427,6 +429,8 @@ static int svga_get_shader_param(struct pipe_screen >> *screen, unsigned shader, en >> return PIPE_SHADER_IR_TGSI; >> case PIPE_SHADER_CAP_DOUBLES: >> return 0; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> } >> /* If we get here, we failed to handle a cap above */ >> debug_printf("Unexpected vertex shader query %u\n", param); >> diff --git a/src/gallium/drivers/vc4/vc4_screen.c >> b/src/gallium/drivers/vc4/vc4_screen.c >> index db88eaa..29637fb 100644 >> --- a/src/gallium/drivers/vc4/vc4_screen.c >> +++ b/src/gallium/drivers/vc4/vc4_screen.c >> @@ -322,6 +322,8 @@ vc4_screen_get_shader_param(struct pipe_screen *pscreen, >> unsigned shader, >> return VC4_MAX_TEXTURE_SAMPLERS; >> case PIPE_SHADER_CAP_PREFERRED_IR: >> return PIPE_SHADER_IR_TGSI; >> + case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS: >> + return 32; >> default: >> fprintf(stderr, "unknown shader param %d\n", param); >> return 0; >> diff --git a/src/gallium/include/pipe/p_defines.h >> b/src/gallium/include/pipe/p_defines.h >> index 7ce25af..192af63 100644 >> --- a/src/gallium/include/pipe/p_defines.h >> +++ b/src/gallium/include/pipe/p_defines.h >> @@ -634,7 +634,8 @@ enum pipe_shader_cap >> PIPE_SHADER_CAP_PREFERRED_IR, >> PIPE_SHADER_CAP_TGSI_SQRT_SUPPORTED, >> PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS, >> - PIPE_SHADER_CAP_DOUBLES >> + PIPE_SHADER_CAP_DOUBLES, >> + PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS >> }; >> >> /** >> diff --git a/src/mesa/state_tracker/st_extensions.c >> b/src/mesa/state_tracker/st_extensions.c >> index 2b5cde2..240308a 100644 >> --- a/src/mesa/state_tracker/st_extensions.c >> +++ b/src/mesa/state_tracker/st_extensions.c >> @@ -241,6 +241,9 @@ void st_init_limits(struct pipe_screen *screen, >> >> if (options->EmitNoLoops) >> options->MaxUnrollIterations = >> MIN2(screen->get_shader_param(screen, sh, PIPE_SHADER_CAP_MAX_INSTRUCTIONS), >> 65536); >> + else >> + options->MaxUnrollIterations = screen->get_shader_param(screen, sh, >> + >> PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS); >> >> options->LowerClipDistance = true; >> } >> > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
