From a8fc171b3f703ad8bda50a22e9227eee0822eeec Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Wed, 8 Feb 2012 22:37:35 +0000 Subject: [PATCH] Handle register masks in MachineCopyPropagation. For simplicity, treat calls with register masks as basic block boundaries. This means we can't copy propagate callee-saved registers across calls, but I don't think that is a big deal. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150108 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineCopyPropagation.cpp | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/lib/CodeGen/MachineCopyPropagation.cpp b/lib/CodeGen/MachineCopyPropagation.cpp index ed3f3498f5f..56be93a95bc 100644 --- a/lib/CodeGen/MachineCopyPropagation.cpp +++ b/lib/CodeGen/MachineCopyPropagation.cpp @@ -191,8 +191,11 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) { // Not a copy. SmallVector Defs; + bool HasRegMask = false; for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { MachineOperand &MO = MI->getOperand(i); + if (MO.isRegMask()) + HasRegMask = true; if (!MO.isReg()) continue; unsigned Reg = MO.getReg(); @@ -220,6 +223,20 @@ bool MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) { } } + // The instruction has a register mask operand which means that it clobbers + // a large set of registers. It is possible to use the register mask to + // prune the available copies, but treat it like a basic block boundary for + // now. + if (HasRegMask) { + // FIXME: We could possibly erase some MaybeDeadCopies if their registers + // are clobbered by the mask. + MaybeDeadCopies.clear(); + AvailCopyMap.clear(); + CopyMap.clear(); + SrcMap.clear(); + continue; + } + for (unsigned i = 0, e = Defs.size(); i != e; ++i) { unsigned Reg = Defs[i]; -- 2.34.1