/*
* mono_local_cprop:
*
* A combined local copy and constant propagation pass.
*/
void
mono_local_cprop (MonoCompile *cfg)
{
MonoBasicBlock *bb;
MonoInst **defs;
gint32 *def_index;
int max;
restart:
max = cfg->next_vreg;
defs = mono_mempool_alloc (cfg->mempool, sizeof (MonoInst*) * (cfg->next_vreg + 1));
def_index = mono_mempool_alloc (cfg->mempool, sizeof (guint32) * (cfg->next_vreg + 1));
for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
MonoInst *ins;
int ins_index;
int last_call_index;
/* Manually init the defs entries used by the bblock */
MONO_BB_FOR_EACH_INS (bb, ins) {
int sregs [MONO_MAX_SRC_REGS];
int num_sregs, i;
if ((ins->dreg != -1) && (ins->dreg < max)) {
defs [ins->dreg] = NULL;
#if SIZEOF_REGISTER == 4
defs [ins->dreg + 1] = NULL;
#endif
}
num_sregs = mono_inst_get_src_registers (ins, sregs);
for (i = 0; i < num_sregs; ++i) {
int sreg = sregs [i];
if (sreg < max) {
defs [sreg] = NULL;
#if SIZEOF_REGISTER == 4
defs [sreg + 1] = NULL;
#endif
}
}
}
ins_index = 0;
last_call_index = -1;
MONO_BB_FOR_EACH_INS (bb, ins) {
const char *spec = INS_INFO (ins->opcode);
int regtype, srcindex, sreg;
int num_sregs;
int sregs [MONO_MAX_SRC_REGS];
if (ins->opcode == OP_NOP) {
MONO_DELETE_INS (bb, ins);
continue;
}
g_assert (ins->opcode > MONO_CEE_LAST);
/* FIXME: Optimize this */
if (ins->opcode == OP_LDADDR) {
MonoInst *var = ins->inst_p0;
defs [var->dreg] = NULL;
/*
if (!MONO_TYPE_ISSTRUCT (var->inst_vtype))
break;
*/
}
if (MONO_IS_STORE_MEMBASE (ins)) {
sreg = ins->dreg;
regtype = 'i';
if ((regtype == 'i') && (sreg != -1) && defs [sreg]) {
MonoInst *def = defs [sreg];
if ((def->opcode == OP_MOVE) && (!defs [def->sreg1] || (def_index [def->sreg1] < def_index [sreg])) && !vreg_is_volatile (cfg, def->sreg1)) {
int vreg = def->sreg1;
if (cfg->verbose_level > 2) printf ("CCOPY: R%d -> R%d\n", sreg, vreg);
ins->dreg = vreg;
}
}
}
num_sregs = mono_inst_get_src_registers (ins, sregs);
for (srcindex = 0; srcindex < num_sregs; ++srcindex) {
MonoInst *def;
int nregs;
nregs = mono_inst_get_src_registers (ins, sregs);
regtype = spec [MONO_INST_SRC1 + srcindex];
sreg = sregs [srcindex];
if ((regtype == ' ') || (sreg == -1) || (!defs [sreg]))
continue;
def = defs [sreg];
/* Copy propagation */
/*
* The first check makes sure the source of the copy did not change since
* the copy was made.
* The second check avoids volatile variables.
* The third check avoids copy propagating local vregs through a call,
* since the lvreg will be spilled
* The fourth check avoids copy propagating a vreg in cases where
* it would be eliminated anyway by reverse copy propagation later,
* because propagating it would create another use for it, thus making
* it impossible to use reverse copy propagation.
*/
/* Enabling this for floats trips up the fp stack */
/*
* Enabling this for floats on amd64 seems to cause a failure in
* basic-math.cs, most likely because it gets rid of some r8->r4
* conversions.
*/
if (MONO_IS_MOVE (def) &&
(!defs [def->sreg1] || (def_index [def->sreg1] < def_index [sreg])) &&
!vreg_is_volatile (cfg, def->sreg1) &&
/* This avoids propagating local vregs across calls */
((get_vreg_to_inst (cfg, def->sreg1) || !defs [def->sreg1] || (def_index [def->sreg1] >= last_call_index) || (def->opcode == OP_VMOVE))) &&
!(defs [def->sreg1] && mono_inst_next (defs [def->sreg1], FILTER_IL_SEQ_POINT) == def) &&
(!MONO_ARCH_USE_FPSTACK || (def->opcode != OP_FMOVE)) &&
(def->opcode != OP_FMOVE)) {
int vreg = def->sreg1;
if (cfg->verbose_level > 2) printf ("CCOPY/2: R%d -> R%d\n", sreg, vreg);
sregs [srcindex] = vreg;
mono_inst_set_src_registers (ins, sregs);
/* Allow further iterations */
srcindex = -1;
continue;
}
/* Constant propagation */
/* FIXME: Make is_inst_imm a macro */
/* FIXME: Make is_inst_imm take an opcode argument */
/* is_inst_imm is only needed for binops */
if ((((def->opcode == OP_ICONST) || ((sizeof (gpointer) == 8) && (def->opcode == OP_I8CONST))) &&
(((srcindex == 0) && (ins->sreg2 == -1)) || mono_arch_is_inst_imm (def->inst_c0))) ||
(!MONO_ARCH_USE_FPSTACK && (def->opcode == OP_R8CONST))) {
guint32 opcode2;
/* srcindex == 1 -> binop, ins->sreg2 == -1 -> unop */
if ((srcindex == 1) && (ins->sreg1 != -1) && defs [ins->sreg1] && (defs [ins->sreg1]->opcode == OP_ICONST) && defs [ins->sreg2]) {
/* Both arguments are constants, perform cfold */
mono_constant_fold_ins (cfg, ins, defs [ins->sreg1], defs [ins->sreg2], TRUE);
} else if ((srcindex == 0) && (ins->sreg2 != -1) && defs [ins->sreg2]) {
/* Arg 1 is constant, swap arguments if possible */
int opcode = ins->opcode;
mono_constant_fold_ins (cfg, ins, defs [ins->sreg1], defs [ins->sreg2], TRUE);
if (ins->opcode != opcode) {
/* Allow further iterations */
srcindex = -1;
continue;
}
} else if ((srcindex == 0) && (ins->sreg2 == -1)) {
/* Constant unop, perform cfold */
mono_constant_fold_ins (cfg, ins, defs [ins->sreg1], NULL, TRUE);
}
opcode2 = mono_op_to_op_imm (ins->opcode);
if ((opcode2 != -1) && mono_arch_is_inst_imm (def->inst_c0) && ((srcindex == 1) || (ins->sreg2 == -1))) {
ins->opcode = opcode2;
if ((def->opcode == OP_I8CONST) && (sizeof (gpointer) == 4)) {
ins->inst_ls_word = def->inst_ls_word;
ins->inst_ms_word = def->inst_ms_word;
} else {
ins->inst_imm = def->inst_c0;
}
sregs [srcindex] = -1;
mono_inst_set_src_registers (ins, sregs);
if ((opcode2 == OP_VOIDCALL) || (opcode2 == OP_CALL) || (opcode2 == OP_LCALL) || (opcode2 == OP_FCALL))
((MonoCallInst*)ins)->fptr = (gpointer)ins->inst_imm;
/* Allow further iterations */
srcindex = -1;
continue;
}
else {
/* Special cases */
#if defined(TARGET_X86) || defined(TARGET_AMD64)
if ((ins->opcode == OP_X86_LEA) && (srcindex == 1)) {
#if SIZEOF_REGISTER == 8
/* FIXME: Use OP_PADD_IMM when the new JIT is done */
ins->opcode = OP_LADD_IMM;
#else
ins->opcode = OP_ADD_IMM;
#endif
ins->inst_imm += def->inst_c0 << ins->backend.shift_amount;
ins->sreg2 = -1;
}
#endif
opcode2 = mono_load_membase_to_load_mem (ins->opcode);
if ((srcindex == 0) && (opcode2 != -1) && mono_arch_is_inst_imm (def->inst_c0)) {
ins->opcode = opcode2;
ins->inst_imm = def->inst_c0 + ins->inst_offset;
ins->sreg1 = -1;
}
}
}
else if (((def->opcode == OP_ADD_IMM) || (def->opcode == OP_LADD_IMM)) && (MONO_IS_LOAD_MEMBASE (ins) || MONO_ARCH_IS_OP_MEMBASE (ins->opcode))) {
/* ADD_IMM is created by spill_global_vars */
/*
* We have to guarantee that def->sreg1 haven't changed since def->dreg
* was defined. cfg->frame_reg is assumed to remain constant.
*/
if ((def->sreg1 == cfg->frame_reg) || ((def->next == ins) && (def->dreg != def->sreg1))) {
ins->inst_basereg = def->sreg1;
ins->inst_offset += def->inst_imm;
}
} else if ((ins->opcode == OP_ISUB_IMM) && (def->opcode == OP_IADD_IMM) && (def->next == ins) && (def->dreg != def->sreg1)) {
ins->sreg1 = def->sreg1;
ins->inst_imm -= def->inst_imm;
} else if ((ins->opcode == OP_IADD_IMM) && (def->opcode == OP_ISUB_IMM) && (def->next == ins) && (def->dreg != def->sreg1)) {
ins->sreg1 = def->sreg1;
ins->inst_imm -= def->inst_imm;
} else if (ins->opcode == OP_STOREI1_MEMBASE_REG &&
(def->opcode == OP_ICONV_TO_U1 || def->opcode == OP_ICONV_TO_I1 || def->opcode == OP_SEXT_I4 || (SIZEOF_REGISTER == 8 && def->opcode == OP_LCONV_TO_U1)) &&
(!defs [def->sreg1] || (def_index [def->sreg1] < def_index [sreg]))) {
/* Avoid needless sign extension */
ins->sreg1 = def->sreg1;
} else if (ins->opcode == OP_STOREI2_MEMBASE_REG &&
(def->opcode == OP_ICONV_TO_U2 || def->opcode == OP_ICONV_TO_I2 || def->opcode == OP_SEXT_I4 || (SIZEOF_REGISTER == 8 && def->opcode == OP_LCONV_TO_I2)) &&
(!defs [def->sreg1] || (def_index [def->sreg1] < def_index [sreg]))) {
/* Avoid needless sign extension */
ins->sreg1 = def->sreg1;
}
}
/* Do strength reduction here */
/* FIXME: Add long/float */
switch (ins->opcode) {
case OP_MOVE:
case OP_XMOVE:
if (ins->dreg == ins->sreg1) {
MONO_DELETE_INS (bb, ins);
spec = INS_INFO (ins->opcode);
}
break;
case OP_ADD_IMM:
case OP_IADD_IMM:
case OP_SUB_IMM:
case OP_ISUB_IMM:
#if SIZEOF_REGISTER == 8
case OP_LADD_IMM:
case OP_LSUB_IMM:
#endif
if (ins->inst_imm == 0) {
ins->opcode = OP_MOVE;
spec = INS_INFO (ins->opcode);
}
break;
case OP_MUL_IMM:
case OP_IMUL_IMM:
#if SIZEOF_REGISTER == 8
case OP_LMUL_IMM:
#endif
if (ins->inst_imm == 0) {
ins->opcode = (ins->opcode == OP_LMUL_IMM) ? OP_I8CONST : OP_ICONST;
ins->inst_c0 = 0;
ins->sreg1 = -1;
} else if (ins->inst_imm == 1) {
ins->opcode = OP_MOVE;
} else if ((ins->opcode == OP_IMUL_IMM) && (ins->inst_imm == -1)) {
ins->opcode = OP_INEG;
} else if ((ins->opcode == OP_LMUL_IMM) && (ins->inst_imm == -1)) {
ins->opcode = OP_LNEG;
} else {
int power2 = mono_is_power_of_two (ins->inst_imm);
if (power2 >= 0) {
ins->opcode = (ins->opcode == OP_MUL_IMM) ? OP_SHL_IMM : ((ins->opcode == OP_LMUL_IMM) ? OP_LSHL_IMM : OP_ISHL_IMM);
ins->inst_imm = power2;
}
}
spec = INS_INFO (ins->opcode);
break;
case OP_IREM_UN_IMM:
case OP_IDIV_UN_IMM: {
int c = ins->inst_imm;
int power2 = mono_is_power_of_two (c);
if (power2 >= 0) {
if (ins->opcode == OP_IREM_UN_IMM) {
ins->opcode = OP_IAND_IMM;
ins->sreg2 = -1;
ins->inst_imm = (1 << power2) - 1;
} else if (ins->opcode == OP_IDIV_UN_IMM) {
ins->opcode = OP_ISHR_UN_IMM;
ins->sreg2 = -1;
ins->inst_imm = power2;
}
}
spec = INS_INFO (ins->opcode);
break;
}
case OP_IDIV_IMM: {
int c = ins->inst_imm;
int power2 = mono_is_power_of_two (c);
MonoInst *tmp1, *tmp2, *tmp3, *tmp4;
/* FIXME: Move this elsewhere cause its hard to implement it here */
if (power2 == 1) {
int r1 = mono_alloc_ireg (cfg);
NEW_BIALU_IMM (cfg, tmp1, OP_ISHR_UN_IMM, r1, ins->sreg1, 31);
mono_bblock_insert_after_ins (bb, ins, tmp1);
NEW_BIALU (cfg, tmp2, OP_IADD, r1, r1, ins->sreg1);
mono_bblock_insert_after_ins (bb, tmp1, tmp2);
NEW_BIALU_IMM (cfg, tmp3, OP_ISHR_IMM, ins->dreg, r1, 1);
mono_bblock_insert_after_ins (bb, tmp2, tmp3);
NULLIFY_INS (ins);
// We allocated a new vreg, so need to restart
goto restart;
} else if (power2 > 0) {
int r1 = mono_alloc_ireg (cfg);
NEW_BIALU_IMM (cfg, tmp1, OP_ISHR_IMM, r1, ins->sreg1, 31);
mono_bblock_insert_after_ins (bb, ins, tmp1);
NEW_BIALU_IMM (cfg, tmp2, OP_ISHR_UN_IMM, r1, r1, (32 - power2));
mono_bblock_insert_after_ins (bb, tmp1, tmp2);
NEW_BIALU (cfg, tmp3, OP_IADD, r1, r1, ins->sreg1);
mono_bblock_insert_after_ins (bb, tmp2, tmp3);
NEW_BIALU_IMM (cfg, tmp4, OP_ISHR_IMM, ins->dreg, r1, power2);
mono_bblock_insert_after_ins (bb, tmp3, tmp4);
NULLIFY_INS (ins);
// We allocated a new vreg, so need to restart
goto restart;
}
break;
}
}
if (spec [MONO_INST_DEST] != ' ') {
MonoInst *def = defs [ins->dreg];
if (def && (def->opcode == OP_ADD_IMM) && (def->sreg1 == cfg->frame_reg) && (MONO_IS_STORE_MEMBASE (ins))) {
/* ADD_IMM is created by spill_global_vars */
/* cfg->frame_reg is assumed to remain constant */
ins->inst_destbasereg = def->sreg1;
ins->inst_offset += def->inst_imm;
}
}
if ((spec [MONO_INST_DEST] != ' ') && !MONO_IS_STORE_MEMBASE (ins) && !vreg_is_volatile (cfg, ins->dreg)) {
defs [ins->dreg] = ins;
def_index [ins->dreg] = ins_index;
}
if (MONO_IS_CALL (ins))
last_call_index = ins_index;
ins_index ++;
}
}
/**
* mono_perform_abc_removal:
* @cfg: Control Flow Graph
*
* Performs the ABC removal from a cfg in SSA form.
* It does the following:
* - Prepare the evaluation area
* - Allocate memory for the relation graph in the evaluation area
* (of course, only for variable definitions) and summarize there all
* variable definitions
* - Allocate memory for the evaluation contexts in the evaluation area
* - Recursively process all the BBs in the dominator tree (it is enough
* to invoke the processing on the entry BB)
*
* cfg: the method code
*/
void
mono_perform_abc_removal (MonoCompile *cfg)
{
MonoVariableRelationsEvaluationArea area;
MonoBasicBlock *bb;
int i;
verbose_level = cfg->verbose_level;
if (TRACE_ABC_REMOVAL) {
printf ("\nRemoving array bound checks in %s\n", mono_method_full_name (cfg->method, TRUE));
}
area.cfg = cfg;
area.relations = (MonoSummarizedValueRelation *)
mono_mempool_alloc (cfg->mempool, sizeof (MonoSummarizedValueRelation) * (cfg->next_vreg) * 2);
area.contexts = (MonoRelationsEvaluationContext *)
mono_mempool_alloc (cfg->mempool, sizeof (MonoRelationsEvaluationContext) * (cfg->next_vreg));
area.variable_value_kind = (MonoIntegerValueKind *)
mono_mempool_alloc (cfg->mempool, sizeof (MonoIntegerValueKind) * (cfg->next_vreg));
for (i = 0; i < cfg->next_vreg; i++) {
area.variable_value_kind [i] = MONO_UNKNOWN_INTEGER_VALUE;
area.relations [i].relation = MONO_EQ_RELATION;
area.relations [i].relation_is_static_definition = TRUE;
MAKE_VALUE_ANY (area.relations [i].related_value);
area.relations [i].next = NULL;
}
for (bb = cfg->bb_entry; bb; bb = bb->next_bb) {
MonoInst *ins;
if (TRACE_ABC_REMOVAL)
printf ("\nABCREM BLOCK %d:\n", bb->block_num);
for (ins = bb->code; ins; ins = ins->next) {
const char *spec = INS_INFO (ins->opcode);
if (spec [MONO_INST_DEST] == ' ' || MONO_IS_STORE_MEMBASE (ins))
continue;
if (spec [MONO_INST_DEST] == 'i') {
MonoIntegerValueKind effective_value_kind;
MonoRelationsEvaluationRange range;
MonoSummarizedValueRelation *type_relation;
MonoInst *var;
if (TRACE_ABC_REMOVAL)
mono_print_ins (ins);
var = get_vreg_to_inst (cfg, ins->dreg);
if (var)
area.variable_value_kind [ins->dreg] = type_to_value_kind (var->inst_vtype);
effective_value_kind = get_relation_from_ins (&area, ins, &area.relations [ins->dreg], area.variable_value_kind [ins->dreg]);
MONO_MAKE_RELATIONS_EVALUATION_RANGE_WEAK (range);
apply_value_kind_to_range (&range, area.variable_value_kind [ins->dreg]);
apply_value_kind_to_range (&range, effective_value_kind);
if (range.upper < INT_MAX) {
type_relation = (MonoSummarizedValueRelation *) mono_mempool_alloc (cfg->mempool, sizeof (MonoSummarizedValueRelation));
type_relation->relation = MONO_LE_RELATION;
type_relation->related_value.type = MONO_CONSTANT_SUMMARIZED_VALUE;
type_relation->related_value.value.constant.value = range.upper;
type_relation->relation_is_static_definition = TRUE;
type_relation->next = area.relations [ins->dreg].next;
area.relations [ins->dreg].next = type_relation;
if (TRACE_ABC_REMOVAL) {
printf ("[var%d <= %d]", ins->dreg, range.upper);
}
}
if (range.lower > INT_MIN) {
type_relation = (MonoSummarizedValueRelation *) mono_mempool_alloc (cfg->mempool, sizeof (MonoSummarizedValueRelation));
type_relation->relation = MONO_GE_RELATION;
type_relation->related_value.type = MONO_CONSTANT_SUMMARIZED_VALUE;
type_relation->related_value.value.constant.value = range.lower;
type_relation->relation_is_static_definition = TRUE;
type_relation->next = area.relations [ins->dreg].next;
area.relations [ins->dreg].next = type_relation;
if (TRACE_ABC_REMOVAL) {
printf ("[var%d >= %d]", ins->dreg, range.lower);
}
}
if (TRACE_ABC_REMOVAL) {
printf ("Summarized variable %d: ", ins->dreg);
print_summarized_value (&(area.relations [ins->dreg].related_value));
printf ("\n");
}
}
}
}
/* Add symmetric relations */
for (i = 0; i < cfg->next_vreg; i++) {
if (area.relations [i].related_value.type == MONO_VARIABLE_SUMMARIZED_VALUE) {
int related_index = cfg->next_vreg + i;
int related_variable = area.relations [i].related_value.value.variable.variable;
area.relations [related_index].relation = MONO_EQ_RELATION;
area.relations [related_index].relation_is_static_definition = TRUE;
area.relations [related_index].related_value.type = MONO_VARIABLE_SUMMARIZED_VALUE;
area.relations [related_index].related_value.value.variable.variable = i;
area.relations [related_index].related_value.value.variable.delta = - area.relations [i].related_value.value.variable.delta;
area.relations [related_index].next = area.relations [related_variable].next;
area.relations [related_variable].next = &(area.relations [related_index]);
if (TRACE_ABC_REMOVAL) {
printf ("Added symmetric summarized value for variable variable %d (to %d): ", i, related_variable);
print_summarized_value (&(area.relations [related_index].related_value));
printf ("\n");
}
}
}
process_block (cfg, cfg->bblocks [0], &area);
}
