i965/nir/vec4: Implement various rounding functions

Adds NIR ALU operations:
   * nir_op_ftrunc
   * nir_op_fceil
   * nir_op_ffloor
   * nir_op_ffrac
   * nir_op_fround_even

Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>

diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
index 7576bbd455bdf6a88f24526516562b47c4dd79fe..ab6335a85461f45f4bbe6dd72bfe00833b9933c6 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
@@ -812,6 +812,41 @@ vec4_visitor::nir_emit_alu(nir_alu_instr *instr)
       break;
    }
 
+   case nir_op_ftrunc:
+      inst = emit(RNDZ(dst, op[0]));
+      inst->saturate = instr->dest.saturate;
+      break;
+
+   case nir_op_fceil: {
+      src_reg tmp = src_reg(this, glsl_type::float_type);
+      tmp.swizzle =
+         brw_swizzle_for_size(instr->src[0].src.is_ssa ?
+                              instr->src[0].src.ssa->num_components :
+                              instr->src[0].src.reg.reg->num_components);
+
+      op[0].negate = !op[0].negate;
+      emit(RNDD(dst_reg(tmp), op[0]));
+      tmp.negate = true;
+      inst = emit(MOV(dst, tmp));
+      inst->saturate = instr->dest.saturate;
+      break;
+   }
+
+   case nir_op_ffloor:
+      inst = emit(RNDD(dst, op[0]));
+      inst->saturate = instr->dest.saturate;
+      break;
+
+   case nir_op_ffract:
+      inst = emit(FRC(dst, op[0]));
+      inst->saturate = instr->dest.saturate;
+      break;
+
+   case nir_op_fround_even:
+      inst = emit(RNDE(dst, op[0]));
+      inst->saturate = instr->dest.saturate;
+      break;
+
    default:
       unreachable("Unimplemented ALU operation");
    }