i965/fs: add a NIR frontend

This is similar to the GLSL IR frontend, except consuming NIR. This lets
us test NIR as part of an actual compiler.

v2: Jason Ekstrand <jason.ekstrand@intel.com>:
   Make brw_fs_nir build again
   Only use NIR of INTEL_USE_NIR is set
   whitespace fixes

src/mesa/drivers/dri/i965/Makefile.sources

@@ -48,6 +48,7 @@ i965_FILES = \
 	brw_fs.h \
 	brw_fs_live_variables.cpp \
 	brw_fs_live_variables.h \
+	brw_fs_nir.cpp \
 	brw_fs_peephole_predicated_break.cpp \
 	brw_fs_reg_allocate.cpp \
 	brw_fs_register_coalesce.cpp \

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

@@ -3743,10 +3743,14 @@ fs_visitor::run_fs()
        * functions called "main").
        */
       if (shader) {
-         foreach_in_list(ir_instruction, ir, shader->base.ir) {
-            base_ir = ir;
-            this->result = reg_undef;
-            ir->accept(this);
+         if (getenv("INTEL_USE_NIR") != NULL) {
+            emit_nir_code();
+         } else {
+            foreach_in_list(ir_instruction, ir, shader->base.ir) {
+               base_ir = ir;
+               this->result = reg_undef;
+               ir->accept(this);
+            }
          }
       } else {
          emit_fragment_program_code();

src/mesa/drivers/dri/i965/brw_fs.h

@@ -49,6 +49,7 @@ extern "C" {
 }
 #include "glsl/glsl_types.h"
 #include "glsl/ir.h"
+#include "glsl/nir/nir.h"
 #include "program/sampler.h"
 
 #define MAX_SAMPLER_MESSAGE_SIZE 11
@@ -563,6 +564,45 @@ public:
                     const struct prog_instruction *fpi,
                     fs_reg dst, fs_reg src0, fs_reg src1, fs_reg one);
 
+   void emit_nir_code();
+   void nir_setup_inputs(nir_shader *shader);
+   void nir_setup_outputs(nir_shader *shader);
+   void nir_setup_uniforms(nir_shader *shader);
+   void nir_setup_registers(exec_list *regs);
+   void nir_emit_interpolation(nir_variable *var, fs_reg *reg);
+   void nir_setup_uniform(nir_variable *var);
+   void nir_setup_builtin_uniform(nir_variable *var);
+   void nir_emit_impl(nir_function_impl *impl);
+   void nir_emit_cf_list(exec_list *list);
+   void nir_emit_if(nir_if *if_stmt);
+   void nir_emit_loop(nir_loop *loop);
+   void nir_emit_block(nir_block *block);
+   void nir_emit_instr(nir_instr *instr);
+   void nir_emit_alu(nir_alu_instr *instr);
+   void nir_emit_intrinsic(nir_intrinsic_instr *instr);
+   void nir_emit_texture(nir_tex_instr *instr);
+   void nir_emit_load_const(nir_load_const_instr *instr);
+   void nir_emit_jump(nir_jump_instr *instr);
+   fs_reg get_nir_src(nir_src src);
+   fs_reg get_nir_alu_src(nir_alu_instr *instr, unsigned src);
+   fs_reg get_nir_dest(nir_dest dest);
+   void emit_percomp(fs_inst *inst, unsigned wr_mask);
+   void emit_percomp(enum opcode op, fs_reg dest, fs_reg src0,
+                     unsigned wr_mask, bool saturate = false,
+                     enum brw_predicate predicate = BRW_PREDICATE_NONE,
+                     enum brw_conditional_mod mod = BRW_CONDITIONAL_NONE);
+   void emit_percomp(enum opcode op, fs_reg dest, fs_reg src0, fs_reg src1,
+                     unsigned wr_mask, bool saturate = false,
+                     enum brw_predicate predicate = BRW_PREDICATE_NONE,
+                     enum brw_conditional_mod mod = BRW_CONDITIONAL_NONE);
+   void emit_math_percomp(enum opcode op, fs_reg dest, fs_reg src0,
+                          unsigned wr_mask, bool saturate = false);
+   void emit_math_percomp(enum opcode op, fs_reg dest, fs_reg src0,
+                          fs_reg src1, unsigned wr_mask,
+                          bool saturate = false);
+   void emit_reduction(enum opcode op, fs_reg dest, fs_reg src,
+                       unsigned num_components);
+
    int setup_color_payload(fs_reg *dst, fs_reg color, unsigned components);
    void emit_alpha_test();
    fs_inst *emit_single_fb_write(fs_reg color1, fs_reg color2,
@@ -655,6 +695,11 @@ public:
    fs_reg *fp_temp_regs;
    fs_reg *fp_input_regs;
 
+   struct hash_table *nir_reg_ht;
+   fs_reg nir_inputs;
+   fs_reg nir_outputs;
+   fs_reg nir_uniforms;
+
    /** @{ debug annotation info */
    const char *current_annotation;
    const void *base_ir;

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

@@ -3820,6 +3820,8 @@ fs_visitor::init()
    this->variable_ht = hash_table_ctor(0,
                                        hash_table_pointer_hash,
                                        hash_table_pointer_compare);
+   this->nir_reg_ht = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
+                                              _mesa_key_pointer_equal);
 
    memset(&this->payload, 0, sizeof(this->payload));
    memset(this->outputs, 0, sizeof(this->outputs));
@@ -3855,4 +3857,5 @@ fs_visitor::init()
 fs_visitor::~fs_visitor()
 {
    hash_table_dtor(this->variable_ht);
+   _mesa_hash_table_destroy(this->nir_reg_ht, NULL);
 }