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

/* -*- c++ -*- */
/*
 * Copyright © 2010-2015 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef BRW_IR_FS_H
#define BRW_IR_FS_H

#include "brw_shader.h"

class fs_inst;

class fs_reg : public backend_reg {
public:
   DECLARE_RALLOC_CXX_OPERATORS(fs_reg)

   void init();

   fs_reg();
   explicit fs_reg(float f);
   explicit fs_reg(int32_t i);
   explicit fs_reg(uint32_t u);
   explicit fs_reg(uint8_t vf[4]);
   explicit fs_reg(uint8_t vf0, uint8_t vf1, uint8_t vf2, uint8_t vf3);
   fs_reg(struct brw_reg reg);
   fs_reg(enum register_file file, int nr);
   fs_reg(enum register_file file, int nr, enum brw_reg_type type);

   bool equals(const fs_reg &r) const;
   bool is_contiguous() const;

   /**
    * Return the size in bytes of a single logical component of the
    * register assuming the given execution width.
    */
   unsigned component_size(unsigned width) const;

   /** Smear a channel of the reg to all channels. */
   fs_reg &set_smear(unsigned subreg);

   /**
    * Offset in bytes from the start of the register.  Values up to a
    * backend_reg::reg_offset unit are valid.
    */
   int subreg_offset;

   fs_reg *reladdr;

   /** Register region horizontal stride */
   uint8_t stride;
};

static inline fs_reg
negate(fs_reg reg)
{
   assert(reg.file != IMM);
   reg.negate = !reg.negate;
   return reg;
}

static inline fs_reg
retype(fs_reg reg, enum brw_reg_type type)
{
   reg.type = type;
   return reg;
}

static inline fs_reg
byte_offset(fs_reg reg, unsigned delta)
{
   switch (reg.file) {
   case BAD_FILE:
      break;
   case VGRF:
   case ATTR:
      reg.reg_offset += delta / 32;
      break;
   case MRF:
      reg.nr += delta / 32;
      break;
   case IMM:
   case HW_REG:
   case UNIFORM:
      assert(delta == 0);
   }
   reg.subreg_offset += delta % 32;
   return reg;
}

static inline fs_reg
horiz_offset(fs_reg reg, unsigned delta)
{
   switch (reg.file) {
   case BAD_FILE:
   case UNIFORM:
   case IMM:
      /* These only have a single component that is implicitly splatted.  A
       * horizontal offset should be a harmless no-op.
       */
      break;
   case VGRF:
   case MRF:
   case ATTR:
      return byte_offset(reg, delta * reg.stride * type_sz(reg.type));
   case HW_REG:
      assert(delta == 0);
   }
   return reg;
}

static inline fs_reg
component(fs_reg reg, unsigned idx)
{
   assert(reg.subreg_offset == 0);
   reg.subreg_offset = idx * type_sz(reg.type);
   reg.stride = 0;
   return reg;
}

static inline bool
is_uniform(const fs_reg &reg)
{
   return (reg.stride == 0 || reg.is_null()) &&
          (!reg.reladdr || is_uniform(*reg.reladdr));
}

/**
 * Get either of the 8-component halves of a 16-component register.
 *
 * Note: this also works if \c reg represents a SIMD16 pair of registers.
 */
static inline fs_reg
half(fs_reg reg, unsigned idx)
{
   assert(idx < 2);

   switch (reg.file) {
   case BAD_FILE:
   case UNIFORM:
   case IMM:
      return reg;

   case VGRF:
   case MRF:
      return horiz_offset(reg, 8 * idx);

   case ATTR:
   case HW_REG:
      unreachable("Cannot take half of this register type");
   }
   return reg;
}

static const fs_reg reg_undef;

class fs_inst : public backend_instruction {
   fs_inst &operator=(const fs_inst &);

   void init(enum opcode opcode, uint8_t exec_width, const fs_reg &dst,
             const fs_reg *src, unsigned sources);

public:
   DECLARE_RALLOC_CXX_OPERATORS(fs_inst)

   fs_inst();
   fs_inst(enum opcode opcode, uint8_t exec_size);
   fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst);
   fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
           const fs_reg &src0);
   fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
           const fs_reg &src0, const fs_reg &src1);
   fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
           const fs_reg &src0, const fs_reg &src1, const fs_reg &src2);
   fs_inst(enum opcode opcode, uint8_t exec_size, const fs_reg &dst,
           const fs_reg src[], unsigned sources);
   fs_inst(const fs_inst &that);
   ~fs_inst();

   void resize_sources(uint8_t num_sources);

   bool equals(fs_inst *inst) const;
   bool overwrites_reg(const fs_reg &reg) const;
   bool is_send_from_grf() const;
   bool is_partial_write() const;
   bool is_copy_payload(const brw::simple_allocator &grf_alloc) const;
   unsigned components_read(unsigned i) const;
   int regs_read(int arg) const;
   bool can_do_source_mods(const struct brw_device_info *devinfo);
   bool can_change_types() const;
   bool has_side_effects() const;

   bool reads_flag() const;
   bool writes_flag() const;

   fs_reg dst;
   fs_reg *src;

   uint8_t sources; /**< Number of fs_reg sources. */

   /**
    * Execution size of the instruction.  This is used by the generator to
    * generate the correct binary for the given fs_inst.  Current valid
    * values are 1, 8, 16.
    */
   uint8_t exec_size;

   bool eot:1;
   bool force_sechalf:1;
   bool pi_noperspective:1;   /**< Pixel interpolator noperspective flag */
};

/**
 * Set second-half quarter control on \p inst.
 */
static inline fs_inst *
set_sechalf(fs_inst *inst)
{
   inst->force_sechalf = true;
   return inst;
}

/**
 * Make the execution of \p inst dependent on the evaluation of a possibly
 * inverted predicate.
 */
static inline fs_inst *
set_predicate_inv(enum brw_predicate pred, bool inverse,
                  fs_inst *inst)
{
   inst->predicate = pred;
   inst->predicate_inverse = inverse;
   return inst;
}

/**
 * Make the execution of \p inst dependent on the evaluation of a predicate.
 */
static inline fs_inst *
set_predicate(enum brw_predicate pred, fs_inst *inst)
{
   return set_predicate_inv(pred, false, inst);
}

/**
 * Write the result of evaluating the condition given by \p mod to a flag
 * register.
 */
static inline fs_inst *
set_condmod(enum brw_conditional_mod mod, fs_inst *inst)
{
   inst->conditional_mod = mod;
   return inst;
}

/**
 * Clamp the result of \p inst to the saturation range of its destination
 * datatype.
 */
static inline fs_inst *
set_saturate(bool saturate, fs_inst *inst)
{
   inst->saturate = saturate;
   return inst;
}

#endif