Re-apply 56835 along with header file changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56848 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index bc66321..4ed456b 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -819,6 +819,7 @@
/// val# of the specified interval is re-materializable.
bool LiveIntervals::isReMaterializable(const LiveInterval &li,
const VNInfo *ValNo, MachineInstr *MI,
+ SmallVectorImpl<LiveInterval*> &SpillIs,
bool &isLoad) {
if (DisableReMat)
return false;
@@ -855,8 +856,8 @@
// If the instruction accesses memory and the memory could be non-constant,
// assume the instruction is not rematerializable.
- for (std::list<MachineMemOperand>::const_iterator I = MI->memoperands_begin(),
- E = MI->memoperands_end(); I != E; ++I) {
+ for (std::list<MachineMemOperand>::const_iterator
+ I = MI->memoperands_begin(), E = MI->memoperands_end(); I != E; ++I){
const MachineMemOperand &MMO = *I;
if (MMO.isVolatile() || MMO.isStore())
return false;
@@ -924,13 +925,21 @@
if (!isValNoAvailableAt(ImpLi, MI, UseIdx))
return false;
}
+
+ // If a register operand of the re-materialized instruction is going to
+ // be spilled next, then it's not legal to re-materialize this instruction.
+ for (unsigned i = 0, e = SpillIs.size(); i != e; ++i)
+ if (ImpUse == SpillIs[i]->reg)
+ return false;
}
return true;
}
/// isReMaterializable - Returns true if every definition of MI of every
/// val# of the specified interval is re-materializable.
-bool LiveIntervals::isReMaterializable(const LiveInterval &li, bool &isLoad) {
+bool LiveIntervals::isReMaterializable(const LiveInterval &li,
+ SmallVectorImpl<LiveInterval*> &SpillIs,
+ bool &isLoad) {
isLoad = false;
for (LiveInterval::const_vni_iterator i = li.vni_begin(), e = li.vni_end();
i != e; ++i) {
@@ -944,7 +953,7 @@
MachineInstr *ReMatDefMI = getInstructionFromIndex(DefIdx);
bool DefIsLoad = false;
if (!ReMatDefMI ||
- !isReMaterializable(li, VNI, ReMatDefMI, DefIsLoad))
+ !isReMaterializable(li, VNI, ReMatDefMI, SpillIs, DefIsLoad))
return false;
isLoad |= DefIsLoad;
}
@@ -1728,6 +1737,7 @@
std::vector<LiveInterval*> LiveIntervals::
addIntervalsForSpills(const LiveInterval &li,
+ SmallVectorImpl<LiveInterval*> &SpillIs,
const MachineLoopInfo *loopInfo, VirtRegMap &vrm,
float &SSWeight) {
@@ -1831,7 +1841,7 @@
MachineInstr *ReMatDefMI = (DefIdx == ~0u)
? 0 : getInstructionFromIndex(DefIdx);
bool dummy;
- if (ReMatDefMI && isReMaterializable(li, VNI, ReMatDefMI, dummy)) {
+ if (ReMatDefMI && isReMaterializable(li, VNI, ReMatDefMI, SpillIs, dummy)) {
// Remember how to remat the def of this val#.
ReMatOrigDefs[VN] = ReMatDefMI;
// Original def may be modified so we have to make a copy here.
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index d834031..7291e12 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -879,8 +879,9 @@
if (cur->weight != HUGE_VALF && cur->weight <= minWeight) {
DOUT << "\t\t\tspilling(c): " << *cur << '\n';
float SSWeight;
+ SmallVector<LiveInterval*, 8> spillIs;
std::vector<LiveInterval*> added =
- li_->addIntervalsForSpills(*cur, loopInfo, *vrm_, SSWeight);
+ li_->addIntervalsForSpills(*cur, spillIs, loopInfo, *vrm_, SSWeight);
addStackInterval(cur, ls_, li_, SSWeight, *vrm_);
if (added.empty())
return; // Early exit if all spills were folded.
@@ -931,7 +932,7 @@
earliestStart = std::min(earliestStart, sli->beginNumber());
float SSWeight;
std::vector<LiveInterval*> newIs =
- li_->addIntervalsForSpills(*sli, loopInfo, *vrm_, SSWeight);
+ li_->addIntervalsForSpills(*sli, spillIs, loopInfo, *vrm_, SSWeight);
addStackInterval(sli, ls_, li_, SSWeight, *vrm_);
std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
spilled.insert(sli->reg);
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index bdc37b1..86065f0 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -2361,7 +2361,8 @@
LI.weight = HUGE_VALF;
else {
bool isLoad = false;
- if (li_->isReMaterializable(LI, isLoad)) {
+ SmallVector<LiveInterval*, 4> SpillIs;
+ if (li_->isReMaterializable(LI, SpillIs, isLoad)) {
// If all of the definitions of the interval are re-materializable,
// it is a preferred candidate for spilling. If non of the defs are
// loads, then it's potentially very cheap to re-materialize.