commit d9e5c764bfea339fc5082bf17e558db959fd6d28
author Jakob Stoklund Olesen <stoklund@2pi.dk> Thu Jan 05 00:26:49 2012 +0000
committer Jakob Stoklund Olesen <stoklund@2pi.dk> Thu Jan 05 00:26:49 2012 +0000
tree fd5c1e5c86fda13c754e87965fb64027891a6f68
parent febaf8401779fedf8db7b02e499c5e39848fb9f5

Freeze reserved registers before starting register allocation.

The register allocators don't currently support adding reserved
registers while they are running.  Extend the MRI API to keep track of
the set of reserved registers when register allocation started.

Target hooks like hasFP() and needsStackRealignment() can look at this
set to avoid reserving more registers during register allocation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147577 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineRegisterInfo.cpp

diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index c35b154..67291a0 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -259,3 +259,7 @@
     I.getOperand().getParent()->dump();
 }
 #endif
+
+void MachineRegisterInfo::freezeReservedRegs(const MachineFunction &MF) {
+  ReservedRegs = TRI->getReservedRegs(MF);
+}

lib/CodeGen/RegAllocBasic.cpp

diff --git a/lib/CodeGen/RegAllocBasic.cpp b/lib/CodeGen/RegAllocBasic.cpp
index 5496d69..8019cf2 100644
--- a/lib/CodeGen/RegAllocBasic.cpp
+++ b/lib/CodeGen/RegAllocBasic.cpp
@@ -233,6 +233,7 @@
   MRI = &vrm.getRegInfo();
   VRM = &vrm;
   LIS = &lis;
+  MRI->freezeReservedRegs(vrm.getMachineFunction());
   RegClassInfo.runOnMachineFunction(vrm.getMachineFunction());
 
   const unsigned NumRegs = TRI->getNumRegs();

lib/CodeGen/RegAllocFast.cpp

diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index c2656c5..93f39b6 100644
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -1047,6 +1047,7 @@
   TM = &Fn.getTarget();
   TRI = TM->getRegisterInfo();
   TII = TM->getInstrInfo();
+  MRI->freezeReservedRegs(Fn);
   RegClassInfo.runOnMachineFunction(Fn);
   UsedInInstr.resize(TRI->getNumRegs());
 

lib/CodeGen/RegAllocPBQP.cpp

diff --git a/lib/CodeGen/RegAllocPBQP.cpp b/lib/CodeGen/RegAllocPBQP.cpp
index a053ccc..f8b0b9f 100644
--- a/lib/CodeGen/RegAllocPBQP.cpp
+++ b/lib/CodeGen/RegAllocPBQP.cpp
@@ -619,6 +619,7 @@
   vrm = &getAnalysis<VirtRegMap>();
   spiller.reset(createInlineSpiller(*this, MF, *vrm));
 
+  mri->freezeReservedRegs(MF);
 
   DEBUG(dbgs() << "PBQP Register Allocating for " << mf->getFunction()->getName() << "\n");