[Mesa-dev] [PATCH 4/5] i965/vec4_nir: Do boolean source modifier resolves on BDW+

[Matt Turner]

On Mon, Aug 3, 2015 at 5:22 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
> On BDW+, the negation source modifier on NOT, AND, OR, and XOR, is actually
> a boolean negate and not an integer negate.  However, NIR's soruce
> modifiers are the integer version.  We have to resolve it with a MOV prior
> to emitting the actual instruction.  This is basically the same thing we do
> in the FS backend.
> ---
>  src/mesa/drivers/dri/i965/brw_vec4.h           |  1 +
>  src/mesa/drivers/dri/i965/brw_vec4_nir.cpp     | 15 +++++++++++++++
>  src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 13 +++++++++++++
>  3 files changed, 29 insertions(+)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
> index 985886d..ff143be 100644
> --- a/src/mesa/drivers/dri/i965/brw_vec4.h
> +++ b/src/mesa/drivers/dri/i965/brw_vec4.h
> @@ -320,6 +320,7 @@ public:
>                     dst_reg dst, src_reg src0, src_reg src1);
>
>     src_reg fix_3src_operand(src_reg src);
> +   src_reg resolve_source_modifiers(src_reg src);
>
>     vec4_instruction *emit_math(enum opcode opcode, const dst_reg &dst, const src_reg &src0,
>                                 const src_reg &src1 = src_reg());
> diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
> index 27f23d0..1b7fb5e 100644
> --- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
> @@ -1020,18 +1020,33 @@ vec4_visitor::nir_emit_alu(nir_alu_instr *instr)
>     }
>
>     case nir_op_inot:
> +      if (devinfo->gen >= 8) {
> +         op[0] = resolve_source_modifiers(op[0]);
> +      }
>        emit(NOT(dst, op[0]));
>        break;
>
>     case nir_op_ixor:
> +      if (devinfo->gen >= 8) {
> +         op[0] = resolve_source_modifiers(op[0]);
> +         op[1] = resolve_source_modifiers(op[1]);
> +      }
>        emit(XOR(dst, op[0], op[1]));
>        break;
>
>     case nir_op_ior:
> +      if (devinfo->gen >= 8) {
> +         op[0] = resolve_source_modifiers(op[0]);
> +         op[1] = resolve_source_modifiers(op[1]);
> +      }
>        emit(OR(dst, op[0], op[1]));
>        break;
>
>     case nir_op_iand:
> +      if (devinfo->gen >= 8) {
> +         op[0] = resolve_source_modifiers(op[0]);
> +         op[1] = resolve_source_modifiers(op[1]);
> +      }
>        emit(AND(dst, op[0], op[1]));
>        break;
>
> diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
> index c5c0d2c..639f829 100644
> --- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
> @@ -313,6 +313,19 @@ vec4_visitor::fix_3src_operand(src_reg src)
>  }
>
>  src_reg
> +vec4_visitor::resolve_source_modifiers(src_reg src)
> +{
> +   if (!src.abs && !src.negate)
> +      return src;
> +
> +   dst_reg resolved = dst_reg(this, glsl_type::ivec4_type);
> +   resolved.type = src.type;
> +   emit(MOV(resolved, src));
> +
> +   return src_reg(resolved);
> +}

The FS passes a pointer to an fs_reg and then updates that. Let's do
that here to be consistent.