diff options
| -rw-r--r-- | lib/CodeGen/IfConversion.cpp | 21 | ||||
| -rw-r--r-- | test/CodeGen/ARM/2011-04-27-IfCvtBug.ll | 59 |
2 files changed, 62 insertions, 18 deletions
diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp index db53b0473a..790200b8df 100644 --- a/lib/CodeGen/IfConversion.cpp +++ b/lib/CodeGen/IfConversion.cpp @@ -27,7 +27,6 @@ #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" -#include "llvm/ADT/DepthFirstIterator.h" #include "llvm/ADT/SmallSet.h" #include "llvm/ADT/Statistic.h" #include "llvm/ADT/STLExtras.h" @@ -146,10 +145,6 @@ namespace { : BBI(b), Kind(k), NeedSubsumption(s), NumDups(d), NumDups2(d2) {} }; - /// Roots - Basic blocks that do not have successors. These are the starting - /// points of Graph traversal. - std::vector<MachineBasicBlock*> Roots; - /// BBAnalysis - Results of if-conversion feasibility analysis indexed by /// basic block number. std::vector<BBInfo> BBAnalysis; @@ -287,11 +282,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) { MF.RenumberBlocks(); BBAnalysis.resize(MF.getNumBlockIDs()); - // Look for root nodes, i.e. blocks without successors. - for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) - if (I->succ_empty()) - Roots.push_back(I); - std::vector<IfcvtToken*> Tokens; MadeChange = false; unsigned NumIfCvts = NumSimple + NumSimpleFalse + NumTriangle + @@ -406,7 +396,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) { } Tokens.clear(); - Roots.clear(); BBAnalysis.clear(); if (MadeChange && IfCvtBranchFold) { @@ -924,13 +913,9 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB, /// candidates. void IfConverter::AnalyzeBlocks(MachineFunction &MF, std::vector<IfcvtToken*> &Tokens) { - std::set<MachineBasicBlock*> Visited; - for (unsigned i = 0, e = Roots.size(); i != e; ++i) { - for (idf_ext_iterator<MachineBasicBlock*> I=idf_ext_begin(Roots[i],Visited), - E = idf_ext_end(Roots[i], Visited); I != E; ++I) { - MachineBasicBlock *BB = *I; - AnalyzeBlock(BB, Tokens); - } + for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) { + MachineBasicBlock *BB = I; + AnalyzeBlock(BB, Tokens); } // Sort to favor more complex ifcvt scheme. diff --git a/test/CodeGen/ARM/2011-04-27-IfCvtBug.ll b/test/CodeGen/ARM/2011-04-27-IfCvtBug.ll new file mode 100644 index 0000000000..0741049cff --- /dev/null +++ b/test/CodeGen/ARM/2011-04-27-IfCvtBug.ll @@ -0,0 +1,59 @@ +; RUN: llc < %s -mtriple=thumbv7-apple-ios + +; If converter was being too cute. It look for root BBs (which don't have +; successors) and use inverse depth first search to traverse the BBs. However +; that doesn't work when the CFG has infinite loops. Simply do a linear +; traversal of all BBs work just fine. + +; rdar://9344645 + +%struct.hc = type { i32, i32, i32, i32 } + +define i32 @t(i32 %type) optsize { +entry: + br i1 undef, label %if.then, label %if.else + +if.then: + unreachable + +if.else: + br i1 undef, label %if.then15, label %if.else18 + +if.then15: + unreachable + +if.else18: + switch i32 %type, label %if.else173 [ + i32 3, label %if.then115 + i32 1, label %if.then102 + ] + +if.then102: + br i1 undef, label %cond.true10.i, label %t.exit + +cond.true10.i: + br label %t.exit + +t.exit: + unreachable + +if.then115: + br i1 undef, label %if.else163, label %if.else145 + +if.else145: + %call150 = call fastcc %struct.hc* @foo(%struct.hc* undef, i32 34865152) optsize + br label %while.body172 + +if.else163: + %call168 = call fastcc %struct.hc* @foo(%struct.hc* undef, i32 34078720) optsize + br label %while.body172 + +while.body172: + br label %while.body172 + +if.else173: + ret i32 -1 +} + +declare hidden fastcc %struct.hc* @foo(%struct.hc* nocapture, i32) nounwind optsize + |