pike.git/ src/ code/ amd64.c

Branch: Tag:

2014-08-14

2014-08-14 13:36:53 by Per Hedbor <ph@opera.com>

Added F_ASSIGN_PRIVATE_TYPED_GLOBAL[_AND_POP].

This completes the suite of private global opcodes.

3058:    ins_f_byte(F_MARK);    ins_f_byte_with_2_args(F_EXTERNAL, b, c);    return; +  +  case F_ASSIGN_PRIVATE_TYPED_GLOBAL_AND_POP: +  case F_ASSIGN_PRIVATE_TYPED_GLOBAL: +  { +  LABELS(); +  amd64_load_sp_reg(); +  +  ins_debug_instr_prologue(a-F_OFFSET, b, 0); +  +  amd64_get_storage( P_REG_RBX, b ); +  +  /* do not assign anything if this object is destructed. */ +  +  /* we really only need to redo this check after we have called +  some other function. It is sort of hard to know when that +  happens while generating the code, however. Simply assigning +  the global could in theory actually destruct this object (old +  value includes something with a destroy that calls destruct on +  this object...) +  +  Note that nothing crash if we do the assign. We "just" leak the +  variable when the storage is eventually free:d. +  +  The generated code does look sort of silly, however. +  */ +  mov_mem_reg( fp_reg, OFFSETOF(pike_frame,current_object), ARG1_REG ); +  mov_mem_reg( ARG1_REG, OFFSETOF(object,prog), P_REG_RAX ); +  test_reg(P_REG_RAX); +  jnz(&label_A); +  +  /* will not return. */ +  amd64_call_c_function(object_low_set_index); +  +  LABEL_A; +  /* 1: check type of argument */ +  mov_mem8_reg( sp_reg, -sizeof(struct svalue )+OFFSETOF(svalue,tu.t.type), P_REG_RAX); +  cmp_reg32_imm( P_REG_RAX, c ); +  je( &label_B ); +  +  /* not the same type. Fall back to use C-function (for code size mainly).. */ +  mov_reg_reg( P_REG_RBX, ARG1_REG ); +  mov_imm_reg( c, ARG2_REG ); +  add_reg_imm_reg( sp_reg, -sizeof(struct svalue), ARG3_REG ); +  amd64_call_c_function(assign_to_short_svalue); +  /* pop stack if needed. */ +  if( a == F_ASSIGN_PRIVATE_GLOBAL_AND_POP ) +  { +  amd64_add_sp(-1); +  /* this will either have assigned 0 or thrown an error. +  * if we assigned 0, it was because the argument evaluated as false. +  * However, that means that we might possibly have to free it here.. +  * +  * We do not even know that is has at least two references. +  */ +  amd64_free_svalue( sp_reg, 0 ); +  } +  +  jmp( &label_E ); /* pop or not. */ +  +  LABEL_B; +  /* at this point: o->storage + off in RBX. */ +  if( c >= MIN_REF_TYPE ) +  { +  mov_mem_reg( P_REG_RBX, 0, P_REG_RAX ); +  test_reg(P_REG_RAX); /* old value == NULL? */ +  jz(&label_C); +  +  /* deref. */ +  add_mem32_imm( P_REG_RAX, OFFSETOF(pike_string,refs), -1); +  jnz(&label_C); +  +  mov_reg_reg( P_REG_RBX, ARG1_REG ); +  mov_imm_reg( c, ARG2_REG ); +  amd64_call_c_function(really_free_short_svalue_ptr); +  } +  LABEL_C; /* old value is gone. Assign new value */ +  mov_mem_reg( sp_reg, -8, P_REG_RAX ); +  mov_reg_mem( P_REG_RAX, P_REG_RBX, 0 ); +  +  if( a == F_ASSIGN_PRIVATE_GLOBAL_AND_POP ) +  amd64_add_sp( -1 ); +  else if( c >= MIN_REF_TYPE ) +  add_mem_imm( P_REG_RAX, OFFSETOF(pike_string,refs), 1 ); +  LABEL_E; +  } +  return;    case F_PRIVATE_TYPED_GLOBAL:    /* b -> off, c -> type */    ins_debug_instr_prologue(a-F_OFFSET, b, c);