From bed353d0163a6b17beecc20c23b67de9b06e7b5c Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Tue, 10 Feb 2009 23:29:38 +0000 Subject: [PATCH] Consider any instruction that modifies the stack pointer to be a scheduling region boundary. This isn't necessary for correctness; it helps with compile time, as it avoids the need for data- and anti-dependencies from all spills and reloads on the stack-pointer modification. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64255 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/PostRASchedulerList.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/lib/CodeGen/PostRASchedulerList.cpp b/lib/CodeGen/PostRASchedulerList.cpp index 617b4ac1ec2..fd7135f3627 100644 --- a/lib/CodeGen/PostRASchedulerList.cpp +++ b/lib/CodeGen/PostRASchedulerList.cpp @@ -28,6 +28,7 @@ #include "llvm/CodeGen/MachineLoopInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/ScheduleHazardRecognizer.h" +#include "llvm/Target/TargetLowering.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Target/TargetInstrInfo.h" #include "llvm/Target/TargetRegisterInfo.h" @@ -221,6 +222,15 @@ static bool isSchedulingBoundary(const MachineInstr *MI, if (MI->getDesc().isTerminator() || MI->isLabel()) return true; + // Don't attempt to schedule around any instruction that modifies + // a stack-oriented pointer, as it's unlikely to be profitable. This + // saves compile time, because it doesn't require every single + // stack slot reference to depend on the instruction that does the + // modification. + const TargetLowering &TLI = *MF.getTarget().getTargetLowering(); + if (MI->modifiesRegister(TLI.getStackPointerRegisterToSaveRestore())) + return true; + return false; }