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Commit 47b3dc1b authored by Matthias Braun's avatar Matthias Braun
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ia32: cleanup condjmp emitter, sort non-fallthrough cases by execfreq

parent 560b86b5
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ir/be/ia32/ia32_emitter.c
View file @ 47b3dc1b
......@@ -791,11 +791,9 @@ static void ia32_emit_exc_label(const ir_node *node)
be_emit_irprintf("%lu", get_ia32_exc_label_id(node));
}
static int can_be_fallthrough(const ir_node *node)
static bool fallthrough_possible(const ir_node *block, const ir_node *target)
{
ir_node *target_block = get_cfop_target_block(node);
ir_node *block = get_nodes_block(node);
return get_prev_block_sched(target_block) == block;
return get_prev_block_sched(target) == block;
}
/**
......@@ -803,19 +801,15 @@ static int can_be_fallthrough(const ir_node *node)
*/
static void emit_ia32_Jcc(const ir_node *node)
{
int need_parity_label = 0;
x86_condition_code_t cc = get_ia32_condcode(node);
cc = determine_final_cc(node, 0, cc);
/* get both Projs */
ir_node const *proj_true = be_get_Proj_for_pn(node, pn_ia32_Jcc_true);
assert(proj_true && "Jcc without true Proj");
ir_node const *target_true = get_cfop_target_block(proj_true);
ir_node const *proj_false = be_get_Proj_for_pn(node, pn_ia32_Jcc_false);
assert(proj_false && "Jcc without false Proj");
if (can_be_fallthrough(proj_true)) {
ir_node const *block = get_nodes_block(node);
if (fallthrough_possible(block, target_true)) {
/* exchange both proj's so the second one can be omitted */
const ir_node *t = proj_true;
......@@ -823,7 +817,23 @@ static void emit_ia32_Jcc(const ir_node *node)
proj_false = t;
cc = x86_negate_condition_code(cc);
}
const ir_node *target_false = get_cfop_target_block(proj_false);
bool fallthrough = fallthrough_possible(block, target_false);
/* if we can't have a fallthrough anyway, put the more likely case first */
if (!fallthrough) {
/* We would need execfreq for the concrete edge, but don't have it
* available here, so we use the block execfreq :-( */
double freq_true = get_block_execfreq(target_true);
double freq_false = get_block_execfreq(target_false);
if (freq_false > freq_true) {
const ir_node *t = proj_true;
proj_true = proj_false;
proj_false = t;
cc = x86_negate_condition_code(cc);
}
}
bool need_parity_label = false;
if (cc & x86_cc_float_parity_cases) {
/* Some floating point comparisons require a test of the parity flag,
* which indicates that the result is unordered */
......@@ -832,8 +842,8 @@ static void emit_ia32_Jcc(const ir_node *node)
} else {
/* we need a local label if the false proj is a fallthrough
* as the falseblock might have no label emitted then */
if (can_be_fallthrough(proj_false)) {
need_parity_label = 1;
if (fallthrough) {
need_parity_label = true;
ia32_emitf(proj_false, "jp 1f");
} else {
ia32_emitf(proj_false, "jp %L");
......@@ -847,7 +857,7 @@ static void emit_ia32_Jcc(const ir_node *node)
}
/* the second Proj might be a fallthrough */
if (can_be_fallthrough(proj_false)) {
if (fallthrough) {
if (be_options.verbose_asm)
ia32_emitf(proj_false, "/* fallthrough to %L */");
} else {
......@@ -942,7 +952,9 @@ static void emit_ia32_SwitchJmp(const ir_node *node)
static void emit_ia32_Jmp(const ir_node *node)
{
/* we have a block schedule */
if (can_be_fallthrough(node)) {
ir_node *block = get_nodes_block(node);
ir_node *target = get_cfop_target_block(node);
if (fallthrough_possible(block, target)) {
if (be_options.verbose_asm)
ia32_emitf(node, "/* fallthrough to %L */");
} else {
......@@ -1555,13 +1567,11 @@ static void ia32_emit_block_header(ir_node *block)
} else {
/* if the predecessor block has no fall-through,
we can always align the label. */
int i;
int has_fallthrough = 0;
for (i = get_Block_n_cfgpreds(block) - 1; i >= 0; --i) {
ir_node *cfg_pred = get_Block_cfgpred(block, i);
if (can_be_fallthrough(cfg_pred)) {
has_fallthrough = 1;
bool has_fallthrough = false;
for (int i = get_Block_n_cfgpreds(block); i-- > 0; ) {
ir_node *pred_block = get_Block_cfgpred_block(block, i);
if (fallthrough_possible(pred_block, block)) {
has_fallthrough = true;
break;
}
}
......@@ -2855,7 +2865,9 @@ static void bemit_jmp(const ir_node *dest_block)
static void bemit_jump(const ir_node *node)
{
if (can_be_fallthrough(node))
ir_node *block = get_nodes_block(node);
ir_node *target = get_cfop_target_block(node);
if (fallthrough_possible(block, target))
return;
bemit_jmp(get_cfop_target_block(node));
......@@ -2879,19 +2891,14 @@ static void bemit_jp(bool odd, const ir_node *dest_block)
static void bemit_ia32_jcc(const ir_node *node)
{
x86_condition_code_t cc = get_ia32_condcode(node);
const ir_node *dest_true;
const ir_node *dest_false;
cc = determine_final_cc(node, 0, cc);
/* get both Projs */
ir_node const *proj_true = be_get_Proj_for_pn(node, pn_ia32_Jcc_true);
assert(proj_true && "Jcc without true Proj");
ir_node const *proj_false = be_get_Proj_for_pn(node, pn_ia32_Jcc_false);
assert(proj_false && "Jcc without false Proj");
if (can_be_fallthrough(proj_true)) {
ir_node const *block = get_nodes_block(node);
ir_node const *target_true = get_cfop_target_block(proj_true);
if (fallthrough_possible(block, target_true)) {
/* exchange both proj's so the second one can be omitted */
const ir_node *t = proj_true;
......@@ -2900,32 +2907,48 @@ static void bemit_ia32_jcc(const ir_node *node)
cc = x86_negate_condition_code(cc);
}
dest_true = get_cfop_target_block(proj_true);
dest_false = get_cfop_target_block(proj_false);
ir_node const *target_false = get_cfop_target_block(proj_false);
bool const fallthrough = fallthrough_possible(block, target_false);
/* if we can't have a fallthrough anyway, put the more likely case first */
if (!fallthrough) {
/* We would need execfreq for the concrete edge, but don't have it
* available here, so we use the block execfreq :-( */
double freq_true = get_block_execfreq(target_true);
double freq_false = get_block_execfreq(target_false);
if (freq_false > freq_true) {
const ir_node *t = proj_true;
proj_true = proj_false;
proj_false = t;
cc = x86_negate_condition_code(cc);
}
}
target_true = get_cfop_target_block(proj_true);
target_false = get_cfop_target_block(proj_false);
if (cc & x86_cc_float_parity_cases) {
/* Some floating point comparisons require a test of the parity flag,
* which indicates that the result is unordered */
if (cc & x86_cc_negated) {
bemit_jp(false, dest_true);
bemit_jp(false, target_true);
} else {
/* we need a local label if the false proj is a fallthrough
* as the falseblock might have no label emitted then */
if (can_be_fallthrough(proj_false)) {
if (fallthrough) {
bemit8(0x7A);
bemit8(0x06); // jp + 6
} else {
bemit_jp(false, dest_false);
bemit_jp(false, target_false);
}
}
}
bemit_jcc(cc, dest_true);
bemit_jcc(cc, target_true);
/* the second Proj might be a fallthrough */
if (can_be_fallthrough(proj_false)) {
if (fallthrough) {
/* it's a fallthrough */
} else {
bemit_jmp(dest_false);
bemit_jmp(target_false);
}
}
......
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