Revert r138794, "Do not try to rematerialize a value from a partial definition."

The problem is fixed for all register allocators by r138944, so this
patch is no longer necessary.

<rdar://problem/10032939>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138945 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2011-09-01 17:25:18 +00:00
parent 9d548d0343
commit ae779eea27

View File

@ -189,20 +189,6 @@ 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().
@ -320,7 +306,6 @@ 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;
@ -422,18 +407,12 @@ 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 || SeenNonReloadDef)
if (SeenOrigPHI || SVI.DefMI)
SVI.AllDefsAreReloads = false;
DEBUG({