From 310f248c22c5a20eaa4de1e612af3338a89144f3 Mon Sep 17 00:00:00 2001 From: Tim Northover Date: Tue, 20 Nov 2012 09:56:11 +0000 Subject: Fix physical register liveness calculations: + Take account of clobbers + Give outputs priority over inputs since they happen later. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168360 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineBasicBlock.cpp | 15 +++++++++------ lib/CodeGen/MachineInstrBundle.cpp | 6 ++++-- 2 files changed, 13 insertions(+), 8 deletions(-) (limited to 'lib/CodeGen') diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 18d021d521..4406c89aba 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -982,7 +982,6 @@ MachineBasicBlock::LivenessQueryResult MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, unsigned Reg, MachineInstr *MI, unsigned Neighborhood) { - unsigned N = Neighborhood; MachineBasicBlock *MBB = MI->getParent(); @@ -997,14 +996,18 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, MachineOperandIteratorBase::PhysRegInfo Analysis = MIOperands(I).analyzePhysReg(Reg, TRI); - if (Analysis.Kills) + if (Analysis.Defines) + // Outputs happen after inputs so they take precedence if both are + // present. + return Analysis.DefinesDead ? LQR_Dead : LQR_Live; + + if (Analysis.Kills || Analysis.Clobbers) // Register killed, so isn't live. return LQR_Dead; - else if (Analysis.DefinesOverlap || Analysis.ReadsOverlap) + else if (Analysis.ReadsOverlap) // Defined or read without a previous kill - live. - return (Analysis.Defines || Analysis.Reads) ? - LQR_Live : LQR_OverlappingLive; + return Analysis.Reads ? LQR_Live : LQR_OverlappingLive; } while (I != MBB->begin() && --N > 0); } @@ -1036,7 +1039,7 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, return (Analysis.Reads) ? LQR_Live : LQR_OverlappingLive; - else if (Analysis.DefinesOverlap) + else if (Analysis.Clobbers || Analysis.Defines) // Defined (but not read) therefore cannot have been live. return LQR_Dead; } diff --git a/lib/CodeGen/MachineInstrBundle.cpp b/lib/CodeGen/MachineInstrBundle.cpp index 1f7fbfc719..70f97dedaa 100644 --- a/lib/CodeGen/MachineInstrBundle.cpp +++ b/lib/CodeGen/MachineInstrBundle.cpp @@ -281,7 +281,7 @@ MachineOperandIteratorBase::PhysRegInfo MachineOperandIteratorBase::analyzePhysReg(unsigned Reg, const TargetRegisterInfo *TRI) { bool AllDefsDead = true; - PhysRegInfo PRI = {false, false, false, false, false, false, false}; + PhysRegInfo PRI = {false, false, false, false, false, false}; assert(TargetRegisterInfo::isPhysicalRegister(Reg) && "analyzePhysReg not given a physical register!"); @@ -305,7 +305,9 @@ MachineOperandIteratorBase::analyzePhysReg(unsigned Reg, // Reg or a super-reg is read, and perhaps killed also. PRI.Reads = true; PRI.Kills = MO.isKill(); - } if (IsRegOrOverlapping && MO.readsReg()) { + } + + if (IsRegOrOverlapping && MO.readsReg()) { PRI.ReadsOverlap = true;// Reg or an overlapping register is read. } -- cgit v1.2.3