[Beignet] [PATCH] GBE: Optimize extraLiveOut register info.
Yang, Rong R
rong.r.yang at intel.com
Sun Jun 12 07:34:44 UTC 2016
Pushed, thanks.
From: Beignet [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of Zhigang Gong
Sent: Monday, June 6, 2016 11:19
To: Song, Ruiling <ruiling.song at intel.com>
Cc: beignet at lists.freedesktop.org
Subject: Re: [Beignet] [PATCH] GBE: Optimize extraLiveOut register info.
This patch LGTM, thx.
On Thu, Jun 2, 2016 at 10:21 AM, Ruiling Song <ruiling.song at intel.com<mailto:ruiling.song at intel.com>> wrote:
extraLiveout anlysis is used to detect registers defined in loop and
used out-of the loop. Previous logic may also include registers defined
BEFORE loop and live-through loop as extraLiveout, which is not accurate.
As the extraLiveout registers will be forced as non-uniform, which may
waste some register space. Excluding registers that are defined before loop
while used out-of loop will make such registers get correct uniform/non-uniform
information. This would benefit some gemm cl kernel.
also fix a small issue: do intersection when the exit-block has more
than one predecessors.
Signed-off-by: Ruiling Song <ruiling.song at intel.com<mailto:ruiling.song at intel.com>>
---
backend/src/ir/function.cpp | 4 ++--
backend/src/ir/function.hpp | 7 ++++---
backend/src/ir/liveness.cpp | 25 +++++++++++++++++++++---
backend/src/llvm/llvm_gen_backend.cpp | 36 ++++++-----------------------------
4 files changed, 34 insertions(+), 38 deletions(-)
diff --git a/backend/src/ir/function.cpp b/backend/src/ir/function.cpp
index 3b7891b..4112f06 100644
--- a/backend/src/ir/function.cpp
+++ b/backend/src/ir/function.cpp
@@ -62,8 +62,8 @@ namespace ir {
return unit.getPointerFamily();
}
- void Function::addLoop(const vector<LabelIndex> &bbs, const vector<std::pair<LabelIndex, LabelIndex>> &exits) {
- loops.push_back(GBE_NEW(Loop, bbs, exits));
+ void Function::addLoop(LabelIndex preheader, const vector<LabelIndex> &bbs, const vector<std::pair<LabelIndex, LabelIndex>> &exits) {
+ loops.push_back(GBE_NEW(Loop, preheader, bbs, exits));
}
void Function::checkEmptyLabels(void) {
diff --git a/backend/src/ir/function.hpp b/backend/src/ir/function.hpp
index 5785bee..6a90767 100644
--- a/backend/src/ir/function.hpp
+++ b/backend/src/ir/function.hpp
@@ -273,8 +273,9 @@ namespace ir {
struct Loop : public NonCopyable
{
public:
- Loop(const vector<LabelIndex> &in, const vector<std::pair<LabelIndex, LabelIndex>> &exit) :
- bbs(in), exits(exit) {}
+ Loop(LabelIndex pre, const vector<LabelIndex> &in, const vector<std::pair<LabelIndex, LabelIndex>> &exit) :
+ preheader(pre), bbs(in), exits(exit) {}
+ LabelIndex preheader;
vector<LabelIndex> bbs;
vector<std::pair<LabelIndex, LabelIndex>> exits;
GBE_STRUCT(Loop);
@@ -522,7 +523,7 @@ namespace ir {
/*! Push stack size. */
INLINE void pushStackSize(uint32_t step) { this->stackSize += step; }
/*! add the loop info for later liveness analysis */
- void addLoop(const vector<LabelIndex> &bbs, const vector<std::pair<LabelIndex, LabelIndex>> &exits);
+ void addLoop(LabelIndex preheader, const vector<LabelIndex> &bbs, const vector<std::pair<LabelIndex, LabelIndex>> &exits);
INLINE const vector<Loop * > &getLoops() { return loops; }
vector<BasicBlock *> &getBlocks() { return blocks; }
/*! Get surface starting address register from bti */
diff --git a/backend/src/ir/liveness.cpp b/backend/src/ir/liveness.cpp
index d48f067..4a89a73 100644
--- a/backend/src/ir/liveness.cpp
+++ b/backend/src/ir/liveness.cpp
@@ -217,19 +217,38 @@ namespace ir {
if(loops.size() == 0) return;
for (auto l : loops) {
+ const BasicBlock &preheader = fn.getBlock(l->preheader);
+ BlockInfo *preheaderInfo = liveness[&preheader];
for (auto x : l->exits) {
const BasicBlock &a = fn.getBlock(x.first);
const BasicBlock &b = fn.getBlock(x.second);
BlockInfo * exiting = liveness[&a];
BlockInfo * exit = liveness[&b];
std::vector<Register> toExtend;
+ std::vector<Register> toExtendCand;
- if(b.getPredecessorSet().size() > 1) {
+ if(b.getPredecessorSet().size() <= 1) {
+ // the exits only have one predecessor
for (auto p : exit->upwardUsed)
- toExtend.push_back(p);
+ toExtendCand.push_back(p);
} else {
- std::set_intersection(exiting->liveOut.begin(), exiting->liveOut.end(), exit->upwardUsed.begin(), exit->upwardUsed.end(), std::back_inserter(toExtend));
+ // the exits have more than one predecessors
+ std::set_intersection(exiting->liveOut.begin(),
+ exiting->liveOut.end(),
+ exit->upwardUsed.begin(),
+ exit->upwardUsed.end(),
+ std::back_inserter(toExtendCand));
}
+ // toExtendCand may contain some virtual register defined before loop,
+ // which need to be excluded. Because what we need is registers defined
+ // in the loop. Such kind of registers must be in live-out of the loop's
+ // preheader. So we do the subtraction here.
+ std::set_difference(toExtendCand.begin(),
+ toExtendCand.end(),
+ preheaderInfo->liveOut.begin(),
+ preheaderInfo->liveOut.end(),
+ std::back_inserter(toExtend));
+
if (toExtend.size() == 0) continue;
for(auto r : toExtend)
extentRegs.insert(r);
diff --git a/backend/src/llvm/llvm_gen_backend.cpp b/backend/src/llvm/llvm_gen_backend.cpp
index acad1b2..0b44f24 100644
--- a/backend/src/llvm/llvm_gen_backend.cpp
+++ b/backend/src/llvm/llvm_gen_backend.cpp
@@ -2737,35 +2737,6 @@ namespace gbe
std::vector<std::pair<Loop*, int>> lp;
findAllLoops(LI, lp);
-#if GBE_DEBUG
- // check two loops' interference
- for(unsigned int i = 0; i < lp.size(); i++) {
- SmallVector<Loop::Edge, 8> exitBBs;
- lp[i].first->getExitEdges(exitBBs);
-
- const std::vector<BasicBlock*> &inBBs = lp[i].first->getBlocks();
- std::vector<ir::LabelIndex> bbs1;
- for(auto x : inBBs) {
- bbs1.push_back(labelMap[x]);
- }
- std::sort(bbs1.begin(), bbs1.end());
- for(unsigned int j = i+1; j < lp.size(); j++) {
- if(! lp[i].first->contains(lp[j].first)) {
- const std::vector<BasicBlock*> &inBBs2 = lp[j].first->getBlocks();
- std::vector<ir::LabelIndex> bbs2;
- std::vector<ir::LabelIndex> bbs3;
-
- for(auto x : inBBs2) {
- bbs2.push_back(labelMap[x]);
- }
-
- std::sort(bbs2.begin(), bbs2.end());
- std::set_intersection(bbs1.begin(), bbs1.end(), bbs2.begin(), bbs2.end(), std::back_inserter(bbs3));
- GBE_ASSERT(bbs3.size() < 1);
- }
- }
- }
-#endif
for (auto loop : lp) {
loopBBs.clear();
@@ -2776,6 +2747,11 @@ namespace gbe
GBE_ASSERT(labelMap.find(b) != labelMap.end());
loopBBs.push_back(labelMap[b]);
}
+ BasicBlock *preheader = loop.first->getLoopPreheader();
+ ir::LabelIndex preheaderBB(0);
+ if (preheader) {
+ preheaderBB = labelMap[preheader];
+ }
SmallVector<Loop::Edge, 8> exitBBs;
loop.first->getExitEdges(exitBBs);
@@ -2784,7 +2760,7 @@ namespace gbe
GBE_ASSERT(labelMap.find(b.second) != labelMap.end());
loopExits.push_back(std::make_pair(labelMap[b.first], labelMap[b.second]));
}
- fn.addLoop(loopBBs, loopExits);
+ fn.addLoop(preheaderBB, loopBBs, loopExits);
}
}
--
2.4.1
_______________________________________________
Beignet mailing list
Beignet at lists.freedesktop.org<mailto:Beignet at lists.freedesktop.org>
https://lists.freedesktop.org/mailman/listinfo/beignet
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/beignet/attachments/20160612/793caecf/attachment-0001.html>
More information about the Beignet
mailing list