src/intel/common/gen_disasm.c

/*
 * Copyright © 2014 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.
 */

#include <stdlib.h>

#include "compiler/brw_inst.h"
#include "compiler/brw_eu.h"

#include "gen_disasm.h"

struct gen_disasm {
    struct gen_device_info devinfo;
};

static bool
is_send(uint32_t opcode)
{
   return (opcode == BRW_OPCODE_SEND  ||
           opcode == BRW_OPCODE_SENDC ||
           opcode == BRW_OPCODE_SENDS ||
           opcode == BRW_OPCODE_SENDSC );
}

static int
gen_disasm_find_end(struct gen_disasm *disasm,
                    const void *assembly, int start)
{
   struct gen_device_info *devinfo = &disasm->devinfo;
   int offset = start;

   /* This loop exits when send-with-EOT or when opcode is 0 */
   while (true) {
      const brw_inst *insn = assembly + offset;

      if (brw_inst_cmpt_control(devinfo, insn)) {
         offset += 8;
      } else {
         offset += 16;
      }

      /* Simplistic, but efficient way to terminate disasm */
      uint32_t opcode = brw_inst_opcode(devinfo, insn);
      if (opcode == 0 || (is_send(opcode) && brw_inst_eot(devinfo, insn))) {
         break;
      }
   }

   return offset;
}

void
gen_disasm_disassemble(struct gen_disasm *disasm, const void *assembly,
                       int start, FILE *out)
{
   struct gen_device_info *devinfo = &disasm->devinfo;
   int end = gen_disasm_find_end(disasm, assembly, start);

   /* Make a dummy disasm structure that brw_validate_instructions
    * can work from.
    */
   struct disasm_info *disasm_info = disasm_initialize(devinfo, NULL);
   disasm_new_inst_group(disasm_info, start);
   disasm_new_inst_group(disasm_info, end);

   brw_validate_instructions(devinfo, assembly, start, end, disasm_info);

   void *mem_ctx = ralloc_context(NULL);
   const struct brw_label *root_label =
      brw_label_assembly(devinfo, assembly, start, end, mem_ctx);

   foreach_list_typed(struct inst_group, group, link,
                      &disasm_info->group_list) {
      struct exec_node *next_node = exec_node_get_next(&group->link);
      if (exec_node_is_tail_sentinel(next_node))
         break;

      struct inst_group *next =
         exec_node_data(struct inst_group, next_node, link);

      int start_offset = group->offset;
      int end_offset = next->offset;

      brw_disassemble(devinfo, assembly, start_offset, end_offset,
                      root_label, out);

      if (group->error) {
         fputs(group->error, out);
      }
   }

   ralloc_free(mem_ctx);
   ralloc_free(disasm_info);
}

struct gen_disasm *
gen_disasm_create(const struct gen_device_info *devinfo)
{
   struct gen_disasm *gd;

   gd = malloc(sizeof *gd);
   if (gd == NULL)
      return NULL;

   gd->devinfo = *devinfo;

   return gd;
}

void
gen_disasm_destroy(struct gen_disasm *disasm)
{
   free(disasm);
}