st/mesa: For vertex shaders, don't emit saturate when SM 3.0 is unsupported

There is a bug in the current lowering pass implementation where we lower saturate
to clamp only for vertex shaders on drivers supporting SM 3.0. The correct behavior
is to actually lower to clamp only when we don't support saturate which happens
on drivers that don't support SM 3.0

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>

diff --git a/src/mesa/state_tracker/st_context.c b/src/mesa/state_tracker/st_context.c
index 17235132eeab177def0b530bcc766a706029309e..9da0c776d9613bd0651c222873217c9efc6848ff 100644 (file)
--- a/src/mesa/state_tracker/st_context.c
+++ b/src/mesa/state_tracker/st_context.c
@@ -271,6 +271,8 @@ st_create_context_priv( struct gl_context *ctx, struct pipe_context *pipe,
     */
    st->ctx->Point.MaxSize = MAX2(ctx->Const.MaxPointSize,
                                  ctx->Const.MaxPointSizeAA);
+   /* For vertex shaders, make sure not to emit saturate when SM 3.0 is not supported */
+   ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].EmitNoSat = !st->has_shader_model3;
 
    _mesa_compute_version(ctx);
 

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index fd51595b749d3929e7f87b299254a9a45de969b5..80dd1028a523f602c51cbb3242f067442bff58f5 100644 (file)
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -5419,9 +5419,6 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
       if (!pscreen->get_param(pscreen, PIPE_CAP_TEXTURE_GATHER_OFFSETS))
          lower_offset_arrays(ir);
       do_mat_op_to_vec(ir);
-      /* Emit saturates in the vertex shader only if SM 3.0 is supported. */
-      bool vs_sm3 = (_mesa_shader_stage_to_program(prog->_LinkedShaders[i]->Stage) ==
-                         GL_VERTEX_PROGRAM_ARB) && st_context(ctx)->has_shader_model3;
       lower_instructions(ir,
                          MOD_TO_FRACT |
                          DIV_TO_MUL_RCP |
@@ -5432,7 +5429,7 @@ st_link_shader(struct gl_context *ctx, struct gl_shader_program *prog)
                          BORROW_TO_ARITH |
                          (options->EmitNoPow ? POW_TO_EXP2 : 0) |
                          (!ctx->Const.NativeIntegers ? INT_DIV_TO_MUL_RCP : 0) |
-                         (vs_sm3 ? SAT_TO_CLAMP : 0));
+                         (options->EmitNoSat ? SAT_TO_CLAMP : 0));
 
       lower_ubo_reference(prog->_LinkedShaders[i], ir);
       do_vec_index_to_cond_assign(ir);