[llvm] r280987 - [RDF] Further improve handling of multiple phis reached from shadows
Krzysztof Parzyszek via llvm-commits
llvm-commits at lists.llvm.org
Thu Sep 8 13:48:43 PDT 2016
Author: kparzysz
Date: Thu Sep 8 15:48:42 2016
New Revision: 280987
URL: http://llvm.org/viewvc/llvm-project?rev=280987&view=rev
Log:
[RDF] Further improve handling of multiple phis reached from shadows
Added:
llvm/trunk/test/CodeGen/Hexagon/rdf-multiple-phis-up.ll
Modified:
llvm/trunk/lib/Target/Hexagon/RDFLiveness.cpp
Modified: llvm/trunk/lib/Target/Hexagon/RDFLiveness.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/RDFLiveness.cpp?rev=280987&r1=280986&r2=280987&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/RDFLiveness.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/RDFLiveness.cpp Thu Sep 8 15:48:42 2016
@@ -109,9 +109,8 @@ NodeList Liveness::getAllReachingDefs(Re
continue;
// Stop at the covering/overwriting def of the initial register reference.
RegisterRef RR = TA.Addr->getRegRef();
- if (RAI.covers(RR, RefRR))
- if (!DFG.IsPreservingDef(TA))
- continue;
+ if (!DFG.IsPreservingDef(TA) && RAI.covers(RR, RefRR))
+ continue;
// Get the next level of reaching defs. This will include multiple
// reaching defs for shadows.
for (auto S : DFG.getRelatedRefs(TA.Addr->getOwner(DFG), TA))
@@ -336,13 +335,6 @@ void Liveness::computePhiInfo() {
std::map<NodeId,std::map<NodeId,RegisterSet>> PhiUp;
std::vector<NodeId> PhiUQ; // Work list of phis for upward propagation.
- auto isEntryPhi = [this] (NodeId P) -> bool {
- auto PA = DFG.addr<PhiNode*>(P);
- NodeAddr<BlockNode*> BA = PA.Addr->getOwner(DFG);
- MachineBasicBlock *BB = BA.Addr->getCode();
- return BB == &BB->getParent()->front();
- };
-
// Go over all phis.
for (NodeAddr<PhiNode*> PhiA : Phis) {
// Go over all defs and collect the reached uses that are non-phi uses
@@ -440,38 +432,31 @@ void Liveness::computePhiInfo() {
// the set of registers defined between this phi (PhiA) and the owner phi
// of the reaching def.
NodeSet SeenUses;
+
for (auto I : PhiRefs) {
if (!DFG.IsRef<NodeAttrs::Use>(I) || SeenUses.count(I.Id))
continue;
NodeAddr<UseNode*> UA = I;
- std::map<NodeId,RegisterSet> &PUM = PhiUp[UA.Id];
- RegisterSet DefRRs;
- NodeId RP = 0; // Phi node reached upwards.
+
+ // Given a phi use UA, traverse all related phi uses (including UA).
+ // The related phi uses may reach different phi nodes or may reach the
+ // same phi node. If multiple uses reach the same phi P, the intervening
+ // defs must be accumulated for all such uses. To group all such uses
+ // into one set, map their node ids to the first use id that reaches P.
+ std::map<NodeId,NodeId> FirstUse; // Phi reached up -> first phi use.
for (NodeAddr<UseNode*> VA : DFG.getRelatedRefs(PhiA, UA)) {
SeenUses.insert(VA.Id);
+ RegisterSet DefRRs;
for (NodeAddr<DefNode*> DA : getAllReachingDefs(VA)) {
if (DA.Addr->getFlags() & NodeAttrs::PhiRef) {
- // For all related phi uses, if they are reached by a phi def,
- // all the reaching defs must belong to the same phi node.
- // The only exception to that are the function entry phis, but
- // are not playing any role in the subsequent propagation.
- NodeId P = DA.Addr->getOwner(DFG).Id;
- if (RP == 0)
- RP = P;
- assert(P == RP || (isEntryPhi(P) && isEntryPhi(RP)));
- } else
- DefRRs.insert(DA.Addr->getRegRef());
+ NodeId RP = DA.Addr->getOwner(DFG).Id;
+ NodeId FU = FirstUse.insert({RP,VA.Id}).first->second;
+ PhiUp[FU][RP].insert(DefRRs.begin(), DefRRs.end());
+ }
+ DefRRs.insert(DA.Addr->getRegRef());
}
}
- // Do not add reaching information for entry phis. The data collection
- // above was done under the assumption that registers on all phis
- // contain all actual data-flow (i.e. a phi for R0 will not convey
- // data-flow information for D0). This is not true for entry phis.
- // They are not participating in the propagation anyway, so that is
- // not a problem.
- if (RP && !isEntryPhi(RP))
- PUM[RP] = DefRRs;
}
}
Added: llvm/trunk/test/CodeGen/Hexagon/rdf-multiple-phis-up.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Hexagon/rdf-multiple-phis-up.ll?rev=280987&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Hexagon/rdf-multiple-phis-up.ll (added)
+++ llvm/trunk/test/CodeGen/Hexagon/rdf-multiple-phis-up.ll Thu Sep 8 15:48:42 2016
@@ -0,0 +1,40 @@
+; RUN: llc -march=hexagon < %s | FileCheck %s
+; REQUIRES: asserts
+
+; Check that we do not crash.
+; CHECK: call foo
+
+target triple = "hexagon"
+
+%struct.0 = type { i8*, i8*, [2 x i8*], i32, i32, i8*, i32, i32, i32, i32, i32, [2 x i32], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
+
+define i32 @fred(i8* %p0) local_unnamed_addr #0 {
+entry:
+ %0 = bitcast i8* %p0 to %struct.0*
+ br i1 undef, label %if.then21, label %for.body.i
+
+if.then21: ; preds = %entry
+ %.pr = load i32, i32* undef, align 4
+ switch i32 %.pr, label %cleanup [
+ i32 1, label %for.body.i
+ i32 3, label %if.then60
+ ]
+
+for.body.i: ; preds = %for.body.i, %if.then21, %entry
+ %1 = load i8, i8* undef, align 1
+ %cmp7.i = icmp ugt i8 %1, -17
+ br i1 %cmp7.i, label %cleanup, label %for.body.i
+
+if.then60: ; preds = %if.then21
+ %call61 = call i32 @foo(%struct.0* nonnull %0) #0
+ br label %cleanup
+
+cleanup: ; preds = %if.then60, %for.body.i, %if.then21
+ ret i32 undef
+}
+
+declare i32 @foo(%struct.0*) local_unnamed_addr #0
+
+
+attributes #0 = { nounwind }
+
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