Mesa (master): i965/fs: Implement ARB_shader_ballot operations

[Matt Turner]

Module: Mesa
Branch: master
Commit: 782ef3045162493c9bccd0fd996c93f9f4533948
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=782ef3045162493c9bccd0fd996c93f9f4533948

Author: Matt Turner <mattst88 at gmail.com>
Date:   Thu Jun 22 16:46:39 2017 -0700

i965/fs: Implement ARB_shader_ballot operations

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/intel/compiler/brw_compiler.c |  1 +
 src/intel/compiler/brw_fs_nir.cpp | 46 +++++++++++++++++++++++++++++++++++++++
 src/intel/compiler/brw_nir.c      |  1 +
 3 files changed, 48 insertions(+)

diff --git a/src/intel/compiler/brw_compiler.c b/src/intel/compiler/brw_compiler.c
index 397c8cccf9..39a8237ff0 100644
--- a/src/intel/compiler/brw_compiler.c
+++ b/src/intel/compiler/brw_compiler.c
@@ -57,6 +57,7 @@ static const struct nir_shader_compiler_options scalar_nir_options = {
    .lower_unpack_snorm_4x8 = true,
    .lower_unpack_unorm_2x16 = true,
    .lower_unpack_unorm_4x8 = true,
+   .lower_subgroup_masks = true,
    .max_unroll_iterations = 32,
 };
 
diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
index 491f5184e3..74f90dabea 100644
--- a/src/intel/compiler/brw_fs_nir.cpp
+++ b/src/intel/compiler/brw_fs_nir.cpp
@@ -4103,6 +4103,10 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
       break;
    }
 
+   case nir_intrinsic_load_subgroup_size:
+      bld.MOV(retype(dest, BRW_REGISTER_TYPE_D), brw_imm_d(dispatch_width));
+      break;
+
    case nir_intrinsic_load_subgroup_invocation: {
       fs_reg tmp = bld.vgrf(BRW_REGISTER_TYPE_UW);
       dest = retype(dest, BRW_REGISTER_TYPE_UD);
@@ -4118,6 +4122,13 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
       break;
    }
 
+   case nir_intrinsic_load_subgroup_eq_mask:
+   case nir_intrinsic_load_subgroup_ge_mask:
+   case nir_intrinsic_load_subgroup_gt_mask:
+   case nir_intrinsic_load_subgroup_le_mask:
+   case nir_intrinsic_load_subgroup_lt_mask:
+      unreachable("not reached");
+
    case nir_intrinsic_vote_any: {
       const fs_builder ubld = bld.exec_all();
 
@@ -4168,6 +4179,41 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
                     bld.SEL(dest, dest, brw_imm_d(0)));
       break;
    }
+
+   case nir_intrinsic_ballot: {
+      const fs_reg value = retype(get_nir_src(instr->src[0]),
+                                  BRW_REGISTER_TYPE_UD);
+      const struct brw_reg flag = retype(brw_flag_reg(0, 0),
+                                         BRW_REGISTER_TYPE_UD);
+
+      bld.exec_all().MOV(flag, brw_imm_ud(0u));
+      bld.CMP(bld.null_reg_ud(), value, brw_imm_ud(0u), BRW_CONDITIONAL_NZ);
+
+      dest.type = BRW_REGISTER_TYPE_UQ;
+      bld.MOV(dest, flag);
+      break;
+   }
+
+   case nir_intrinsic_read_invocation: {
+      const fs_reg value = get_nir_src(instr->src[0]);
+      const fs_reg invocation = get_nir_src(instr->src[1]);
+      fs_reg tmp = bld.vgrf(value.type);
+
+      bld.exec_all().emit(SHADER_OPCODE_BROADCAST, tmp, value,
+                          component(invocation, 0));
+
+      bld.MOV(retype(dest, BRW_REGISTER_TYPE_D),
+              fs_reg(component(tmp, 0)));
+      break;
+   }
+
+   case nir_intrinsic_read_first_invocation: {
+      const fs_reg value = get_nir_src(instr->src[0]);
+      bld.MOV(retype(dest, BRW_REGISTER_TYPE_D),
+              bld.emit_uniformize(value));
+      break;
+   }
+
    default:
       unreachable("unknown intrinsic");
    }
diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index cede77fbc8..ce21c01669 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -620,6 +620,7 @@ brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir)
 
    OPT(nir_lower_tex, &tex_options);
    OPT(nir_normalize_cubemap_coords);
+   OPT(nir_lower_read_invocation_to_scalar);
 
    OPT(nir_lower_global_vars_to_local);