i965/vec4_nir: Do boolean source modifier resolves on BDW+

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.

Reviewed-by: Matt Turner <mattst88@gmail.com>

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(const src_reg& src);
 
    vec4_instruction *emit_math(enum opcode opcode, const dst_reg &dst, const src_reg &src0,
                                const src_reg &src1 = src_reg());

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;
 

src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp

@@ -312,6 +312,19 @@ vec4_visitor::fix_3src_operand(src_reg src)
    return src_reg(expanded);
 }
 
+src_reg
+vec4_visitor::resolve_source_modifiers(const 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);
+}
+
 src_reg
 vec4_visitor::fix_math_operand(src_reg src)
 {