diff options
| -rw-r--r-- | lib/CodeGen/InlineSpiller.cpp | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp index f0f69872b0..5992a3a6e3 100644 --- a/lib/CodeGen/InlineSpiller.cpp +++ b/lib/CodeGen/InlineSpiller.cpp @@ -189,6 +189,20 @@ static unsigned isFullCopyOf(const MachineInstr *MI, unsigned Reg) { return 0; } +/// isFullDefOf - Return true if MI defines the full contents of a register. +/// Since this is in the context of spilling, it does not do anything special +/// for physical registers. +static bool isFullDefOf(const MachineInstr *MI, unsigned Reg) { + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + const MachineOperand &MO = MI->getOperand(i); + if (!MO.isReg() || !MO.isDef() || MO.getSubReg()) + continue; + if (MO.getReg() == Reg) + return true; + } + return false; +} + /// isSnippet - Identify if a live interval is a snippet that should be spilled. /// It is assumed that SnipLI is a virtual register with the same original as /// Edit->getReg(). @@ -306,6 +320,7 @@ MachineInstr *InlineSpiller::traceSiblingValue(unsigned UseReg, VNInfo *UseVNI, MachineBasicBlock *SpillMBB = UseMBB; unsigned SpillDepth = Loops.getLoopDepth(SpillMBB); bool SeenOrigPHI = false; // Original PHI met. + bool SeenNonReloadDef = false; do { unsigned Reg; @@ -407,12 +422,18 @@ MachineInstr *InlineSpiller::traceSiblingValue(unsigned UseReg, VNInfo *UseVNI, } // Potential remat candidate. + SeenNonReloadDef = true; + if (!isFullDefOf(MI, Reg)) { + DEBUG(dbgs() << " partial def " << PrintReg(Reg) << ':' + << VNI->id << '@' << VNI->def << '\t' << *MI); + continue; + } DEBUG(dbgs() << " def " << PrintReg(Reg) << ':' << VNI->id << '@' << VNI->def << '\t' << *MI); SVI.DefMI = MI; } while (!WorkList.empty()); - if (SeenOrigPHI || SVI.DefMI) + if (SeenOrigPHI || SeenNonReloadDef) SVI.AllDefsAreReloads = false; DEBUG({ |