[Mesa-dev] [PATCH] gallium: add PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS

Marek Olšák maraeo at gmail.com
Wed Feb 11 06:23:44 PST 2015 

From: Marek Olšák <marek.olsak at 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-stable at 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;
    }
-- 
2.1.0

More information about the mesa-dev mailing list