[Mesa-dev] [PATCH v2] mesa/st: provide native integers implementation of ir_unop_any

Ilia Mirkin imirkin at alum.mit.edu
Tue May 13 10:10:58 PDT 2014


On Thu, May 8, 2014 at 7:52 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> Previously, ir_unop_any was implemented via a dot-product call, which
> uses floating point multiplication and addition. The multiplication was
> completely pointless, and the addition can just as well be done with an
> or. Since we know that the inputs are booleans, they must already be in
> canonical 0/~0 format, and the final SNE can also be avoided.
>
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>
> v1 -> v2:
>  - set swizzle mask on accum
>  - set swizzle mask on op
>
> Roland, Marek, the changes are relatively small compared to v1, but would be
> nice to have another look if you don't mind.

ping... you guys already looked at the v1, so the v2 should be a quick
review hopefully :)

>
> Amazingly, only one test failed without those -- glsl-fs-any. All the other
> any_*'s don't need this logic because they start out with a FSNE/etc which
> takes care of the op's swizzles.
>
> This is what the glsl-fs-any shader looks like:
>
> uniform vec2 args;
>
> void main()
> {
>         bvec2 argsb = bvec2(args);
>
>         bvec2 v_true = bvec2(argsb.xx);
>         bvec2 v_some = bvec2(argsb.xy);
>         bvec2 v_none = bvec2(argsb.yy);
>         bool true1 = any(v_true);
>         bool true2 = any(v_some);
>         bool false1 = any(v_none);
>         gl_FragColor = vec4(float(true1), float(true2), float(false1), 0.0);
> }
>
> FRAG
> PROPERTY FS_COLOR0_WRITES_ALL_CBUFS 1
> DCL OUT[0], COLOR
> DCL CONST[0]
> DCL TEMP[0..2], LOCAL
> IMM[0] FLT32 {    0.0000,     1.0000,     0.0000,     0.0000}
>   0: FSNE TEMP[0].xy, CONST[0].xyyy, IMM[0].xxxx
>   1: MOV TEMP[1].w, IMM[0].xxxx
>   2: OR TEMP[2].x, TEMP[0].xxxx, TEMP[0].xxxx
>   3: AND TEMP[1].x, TEMP[2].xxxx, IMM[0].yyyy
>   4: OR TEMP[2].x, TEMP[0].xxxx, TEMP[0].yyyy
>   5: AND TEMP[2].x, TEMP[2].xxxx, IMM[0].yyyy
>   6: MOV TEMP[1].y, TEMP[2].xxxx
>   7: OR TEMP[0].x, TEMP[0].yyyy, TEMP[0].yyyy
>   8: AND TEMP[0].x, TEMP[0].xxxx, IMM[0].yyyy
>   9: MOV TEMP[1].z, TEMP[0].xxxx
>  10: MOV OUT[0], TEMP[1]
>  11: END
>
> Any half-decent optimizing backend should have no trouble removing the "or a,
> a" types of things too, whereas that might have been trickier with a DP2 +
> FSNE.
>
>  src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 100 ++++++++++++++++++++++-------
>  1 file changed, 76 insertions(+), 24 deletions(-)
>
> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> index bdee1f4..1a37ba9 100644
> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> @@ -1671,30 +1671,82 @@ glsl_to_tgsi_visitor::visit(ir_expression *ir)
>     case ir_unop_any: {
>        assert(ir->operands[0]->type->is_vector());
>
> -      /* After the dot-product, the value will be an integer on the
> -       * range [0,4].  Zero stays zero, and positive values become 1.0.
> -       */
> -      glsl_to_tgsi_instruction *const dp =
> -         emit_dp(ir, result_dst, op[0], op[0],
> -                 ir->operands[0]->type->vector_elements);
> -      if (this->prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
> -          result_dst.type == GLSL_TYPE_FLOAT) {
> -             /* The clamping to [0,1] can be done for free in the fragment
> -              * shader with a saturate.
> -              */
> -             dp->saturate = true;
> -      } else if (result_dst.type == GLSL_TYPE_FLOAT) {
> -             /* Negating the result of the dot-product gives values on the range
> -              * [-4, 0].  Zero stays zero, and negative values become 1.0.  This
> -              * is achieved using SLT.
> -              */
> -             st_src_reg slt_src = result_src;
> -             slt_src.negate = ~slt_src.negate;
> -             emit(ir, TGSI_OPCODE_SLT, result_dst, slt_src, st_src_reg_for_float(0.0));
> -      }
> -      else {
> -         /* Use SNE 0 if integers are being used as boolean values. */
> -         emit(ir, TGSI_OPCODE_SNE, result_dst, result_src, st_src_reg_for_int(0));
> +      if (native_integers) {
> +         int dst_swizzle = 0, op0_swizzle, i;
> +         st_src_reg accum = op[0];
> +
> +         op0_swizzle = op[0].swizzle;
> +         accum.swizzle = MAKE_SWIZZLE4(GET_SWZ(op0_swizzle, 0),
> +                                       GET_SWZ(op0_swizzle, 0),
> +                                       GET_SWZ(op0_swizzle, 0),
> +                                       GET_SWZ(op0_swizzle, 0));
> +         for (i = 0; i < 4; i++) {
> +            if (result_dst.writemask & (1 << i)) {
> +               dst_swizzle = MAKE_SWIZZLE4(i, i, i, i);
> +               break;
> +            }
> +         }
> +         assert(i != 4);
> +         assert(ir->operands[0]->type->is_boolean());
> +
> +         /* OR all the components together, since they should be either 0 or ~0
> +          */
> +         switch (ir->operands[0]->type->vector_elements) {
> +         case 4:
> +            op[0].swizzle = MAKE_SWIZZLE4(GET_SWZ(op0_swizzle, 3),
> +                                          GET_SWZ(op0_swizzle, 3),
> +                                          GET_SWZ(op0_swizzle, 3),
> +                                          GET_SWZ(op0_swizzle, 3));
> +            emit(ir, TGSI_OPCODE_OR, result_dst, accum, op[0]);
> +            accum = st_src_reg(result_dst);
> +            accum.swizzle = dst_swizzle;
> +            /* fallthrough */
> +         case 3:
> +            op[0].swizzle = MAKE_SWIZZLE4(GET_SWZ(op0_swizzle, 2),
> +                                          GET_SWZ(op0_swizzle, 2),
> +                                          GET_SWZ(op0_swizzle, 2),
> +                                          GET_SWZ(op0_swizzle, 2));
> +            emit(ir, TGSI_OPCODE_OR, result_dst, accum, op[0]);
> +            accum = st_src_reg(result_dst);
> +            accum.swizzle = dst_swizzle;
> +            /* fallthrough */
> +         case 2:
> +            op[0].swizzle = MAKE_SWIZZLE4(GET_SWZ(op0_swizzle, 1),
> +                                          GET_SWZ(op0_swizzle, 1),
> +                                          GET_SWZ(op0_swizzle, 1),
> +                                          GET_SWZ(op0_swizzle, 1));
> +            emit(ir, TGSI_OPCODE_OR, result_dst, accum, op[0]);
> +            break;
> +         default:
> +            assert(!"Unexpected vector size");
> +            break;
> +         }
> +      } else {
> +         /* After the dot-product, the value will be an integer on the
> +          * range [0,4].  Zero stays zero, and positive values become 1.0.
> +          */
> +         glsl_to_tgsi_instruction *const dp =
> +            emit_dp(ir, result_dst, op[0], op[0],
> +                    ir->operands[0]->type->vector_elements);
> +         if (this->prog->Target == GL_FRAGMENT_PROGRAM_ARB &&
> +             result_dst.type == GLSL_TYPE_FLOAT) {
> +            /* The clamping to [0,1] can be done for free in the fragment
> +             * shader with a saturate.
> +             */
> +            dp->saturate = true;
> +         } else if (result_dst.type == GLSL_TYPE_FLOAT) {
> +            /* Negating the result of the dot-product gives values on the range
> +             * [-4, 0].  Zero stays zero, and negative values become 1.0.  This
> +             * is achieved using SLT.
> +             */
> +            st_src_reg slt_src = result_src;
> +            slt_src.negate = ~slt_src.negate;
> +            emit(ir, TGSI_OPCODE_SLT, result_dst, slt_src, st_src_reg_for_float(0.0));
> +         }
> +         else {
> +            /* Use SNE 0 if integers are being used as boolean values. */
> +            emit(ir, TGSI_OPCODE_SNE, result_dst, result_src, st_src_reg_for_int(0));
> +         }
>        }
>        break;
>     }
> --
> 1.8.3.2
>


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