Allow the register scavenger to spill multiple registers

This patch lets the register scavenger make use of multiple spill slots in
order to guarantee that it will be able to provide multiple registers
simultaneously.

To support this, the RS's API has changed slightly: setScavengingFrameIndex /
getScavengingFrameIndex have been replaced by addScavengingFrameIndex /
isScavengingFrameIndex / getScavengingFrameIndices.

In forthcoming commits, the PowerPC backend will use this capability in order
to implement the spilling of condition registers, and some special-purpose
registers, without relying on r0 being reserved. In some cases, spilling these
registers requires two GPRs: one for addressing and one to hold the value being
transferred.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177774 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 7 insertions, 7 deletions

diff --git a/lib/Target/AArch64/AArch64FrameLowering.cpp b/lib/Target/AArch64/AArch64FrameLowering.cpp
index 572617cc07..dc41f2f605 100644
--- a/lib/Target/AArch64/AArch64FrameLowering.cpp
+++ b/lib/Target/AArch64/AArch64FrameLowering.cpp
@@ -396,7 +396,7 @@ AArch64FrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
     // helpfully places it near either SP or FP for us to avoid
     // infinitely-regression during scavenging.
     const TargetRegisterClass *RC = &AArch64::GPR64RegClass;
-    RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+    RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
                                                        RC->getAlignment(),
                                                        false));
   }
diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index abdd251743..b6b27f849a 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -680,7 +680,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   // means the stack pointer cannot be used to access the emergency spill slot
   // when !hasReservedCallFrame().
 #ifndef NDEBUG
-  if (RS && FrameReg == ARM::SP && FrameIndex == RS->getScavengingFrameIndex()){
+  if (RS && FrameReg == ARM::SP && RS->isScavengingFrameIndex(FrameIndex)){
     assert(TFI->hasReservedCallFrame(MF) &&
            "Cannot use SP to access the emergency spill slot in "
            "functions without a reserved call frame");
diff --git a/lib/Target/ARM/ARMFrameLowering.cpp b/lib/Target/ARM/ARMFrameLowering.cpp
index 3b12408768..7a02adf246 100644
--- a/lib/Target/ARM/ARMFrameLowering.cpp
+++ b/lib/Target/ARM/ARMFrameLowering.cpp
@@ -1368,7 +1368,7 @@ ARMFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
         // note: Thumb1 functions spill to R12, not the stack.  Reserve a slot
         // closest to SP or frame pointer.
         const TargetRegisterClass *RC = &ARM::GPRRegClass;
-        RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+        RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
                                                            RC->getAlignment(),
                                                            false));
       }
diff --git a/lib/Target/ARM/Thumb1RegisterInfo.cpp b/lib/Target/ARM/Thumb1RegisterInfo.cpp
index 609d502aa5..7452fb776e 100644
--- a/lib/Target/ARM/Thumb1RegisterInfo.cpp
+++ b/lib/Target/ARM/Thumb1RegisterInfo.cpp
@@ -588,7 +588,7 @@ Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   // means the stack pointer cannot be used to access the emergency spill slot
   // when !hasReservedCallFrame().
 #ifndef NDEBUG
-  if (RS && FrameReg == ARM::SP && FrameIndex == RS->getScavengingFrameIndex()){
+  if (RS && FrameReg == ARM::SP && RS->isScavengingFrameIndex(FrameIndex)){
     assert(MF.getTarget().getFrameLowering()->hasReservedCallFrame(MF) &&
            "Cannot use SP to access the emergency spill slot in "
            "functions without a reserved call frame");
diff --git a/lib/Target/Mips/MipsSEFrameLowering.cpp b/lib/Target/Mips/MipsSEFrameLowering.cpp
index 0dd671376f..c67e1adef6 100644
--- a/lib/Target/Mips/MipsSEFrameLowering.cpp
+++ b/lib/Target/Mips/MipsSEFrameLowering.cpp
@@ -295,7 +295,7 @@ processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
     &Mips::CPU64RegsRegClass : &Mips::CPURegsRegClass;
   int FI = MF.getFrameInfo()->CreateStackObject(RC->getSize(),
                                                 RC->getAlignment(), false);
-  RS->setScavengingFrameIndex(FI);
+  RS->addScavengingFrameIndex(FI);
 }
 
 const MipsFrameLowering *
diff --git a/lib/Target/PowerPC/PPCFrameLowering.cpp b/lib/Target/PowerPC/PPCFrameLowering.cpp
index 0108f7256e..707c2a5d26 100644
--- a/lib/Target/PowerPC/PPCFrameLowering.cpp
+++ b/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -1086,7 +1086,7 @@ PPCFrameLowering::addScavengingSpillSlot(MachineFunction &MF,
     const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
     const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
     const TargetRegisterClass *RC = Subtarget.isPPC64() ? G8RC : GPRC;
-    RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+    RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
                                                        RC->getAlignment(),
                                                        false));
   }
diff --git a/lib/Target/XCore/XCoreFrameLowering.cpp b/lib/Target/XCore/XCoreFrameLowering.cpp
index 019c4570d9..6b6480e4b4 100644
--- a/lib/Target/XCore/XCoreFrameLowering.cpp
+++ b/lib/Target/XCore/XCoreFrameLowering.cpp
@@ -409,7 +409,7 @@ XCoreFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
   }
   if (RegInfo->requiresRegisterScavenging(MF)) {
     // Reserve a slot close to SP or frame pointer.
-    RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+    RS->addScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
                                                        RC->getAlignment(),
                                                        false));
   }