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8129920: Vectorized loop unrolling

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Optimize loop opts for vectorizible loops.

Reviewed-by: kvn, roland
This commit is contained in:
Vladimir Kozlov 2015-07-10 11:59:09 -07:00
parent 963c3852a3
commit b5284a93ce
6 changed files with 83 additions and 27 deletions
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33
hotspot/src/share/vm/opto/superword.cpp
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@ -100,6 +100,10 @@ void SuperWord::transform_loop(IdealLoopTree* lpt, bool do_optimization) {
return;
}
// We only re-enter slp when we vector mapped a queried loop and we want to
// continue unrolling, in this case, slp is not subsequently done.
if (cl->do_unroll_only()) return;
// Check for pre-loop ending with CountedLoopEnd(Bool(Cmp(x,Opaque1(limit))))
CountedLoopEndNode* pre_end = get_pre_loop_end(cl);
if (pre_end == NULL) return;
@ -121,12 +125,13 @@ void SuperWord::transform_loop(IdealLoopTree* lpt, bool do_optimization) {
}
//------------------------------early unrolling analysis------------------------------
void SuperWord::unrolling_analysis(CountedLoopNode *cl, int &local_loop_unroll_factor) {
void SuperWord::unrolling_analysis(int &local_loop_unroll_factor) {
bool is_slp = true;
ResourceMark rm;
size_t ignored_size = lpt()->_body.size();
int *ignored_loop_nodes = NEW_RESOURCE_ARRAY(int, ignored_size);
Node_Stack nstack((int)ignored_size);
CountedLoopNode *cl = lpt()->_head->as_CountedLoop();
Node *cl_exit = cl->loopexit();
// First clear the entries
@ -249,13 +254,9 @@ void SuperWord::unrolling_analysis(CountedLoopNode *cl, int &local_loop_unroll_f
// If a max vector exists which is not larger than _local_loop_unroll_factor
// stop looking, we already have the max vector to map to.
if (cur_max_vector <= local_loop_unroll_factor) {
if (cur_max_vector < local_loop_unroll_factor) {
is_slp = false;
#ifndef PRODUCT
if (TraceSuperWordLoopUnrollAnalysis) {
tty->print_cr("slp analysis fails: unroll limit equals max vector\n");
}
#endif
NOT_PRODUCT(if (TraceSuperWordLoopUnrollAnalysis) tty->print_cr("slp analysis fails: unroll limit greater than max vector\n"));
break;
}
@ -268,8 +269,9 @@ void SuperWord::unrolling_analysis(CountedLoopNode *cl, int &local_loop_unroll_f
}
if (is_slp) {
local_loop_unroll_factor = max_vector;
cl->mark_passed_slp();
}
cl->mark_passed_slp();
cl->mark_was_slp();
cl->set_slp_max_unroll(local_loop_unroll_factor);
}
}
@ -1758,7 +1760,9 @@ void SuperWord::output() {
}
Compile* C = _phase->C;
CountedLoopNode *cl = lpt()->_head->as_CountedLoop();
uint max_vlen_in_bytes = 0;
uint max_vlen = 0;
for (int i = 0; i < _block.length(); i++) {
Node* n = _block.at(i);
Node_List* p = my_pack(n);
@ -1841,6 +1845,7 @@ void SuperWord::output() {
_igvn._worklist.push(vn);
if (vlen_in_bytes > max_vlen_in_bytes) {
max_vlen = vlen;
max_vlen_in_bytes = vlen_in_bytes;
}
#ifdef ASSERT
@ -1852,6 +1857,18 @@ void SuperWord::output() {
}
}
C->set_max_vector_size(max_vlen_in_bytes);
if (SuperWordLoopUnrollAnalysis) {
if (cl->has_passed_slp()) {
uint slp_max_unroll_factor = cl->slp_max_unroll();
if (slp_max_unroll_factor == max_vlen) {
NOT_PRODUCT(if (TraceSuperWordLoopUnrollAnalysis) tty->print_cr("vector loop(unroll=%d, len=%d)\n", max_vlen, max_vlen_in_bytes*BitsPerByte));
// For atomic unrolled loops which are vector mapped, instigate more unrolling.
cl->set_notpassed_slp();
C->set_major_progress();
cl->mark_do_unroll_only();
}
}
}
}
//------------------------------vector_opd---------------------------