From 85bdf2e76a0351468f231f48069c64bc6938f140 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Thu, 29 Mar 2012 21:10:40 +0000
Subject: [PATCH] Handle register copies for the new ARM register classes.

ARM recently gained DPair, DTriple, and DQuad register classes.
Update copyPhysReg() to handle copies in these register classes.

No test case, it is difficult to make the register allocator emit the
odd copies reliably. The missing DPair copy caused a failure on
partialsums in the nightly test suite.

<rdar://problem/11147997>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153686 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMBaseInstrInfo.cpp | 60 ++++++++++++++++++++---------
 1 file changed, 41 insertions(+), 19 deletions(-)

diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index ccb6b16d3ac..56cd6e56e71 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -680,29 +680,51 @@ void ARMBaseInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
     return;
   }
 
-  // Generate instructions for VMOVQQ and VMOVQQQQ pseudos in place.
-  if (ARM::QQPRRegClass.contains(DestReg, SrcReg) ||
-      ARM::QQQQPRRegClass.contains(DestReg, SrcReg)) {
+  // Handle register classes that require multiple instructions.
+  unsigned BeginIdx = 0;
+  unsigned SubRegs = 0;
+  unsigned Spacing = 1;
+
+  // Use VORRq when possible.
+  if (ARM::QQPRRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VORRq, BeginIdx = ARM::qsub_0, SubRegs = 2;
+  else if (ARM::QQQQPRRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VORRq, BeginIdx = ARM::qsub_0, SubRegs = 4;
+  // Fall back to VMOVD.
+  else if (ARM::DPairRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VMOVD, BeginIdx = ARM::dsub_0, SubRegs = 2;
+  else if (ARM::DTripleRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VMOVD, BeginIdx = ARM::dsub_0, SubRegs = 3;
+  else if (ARM::DQuadRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VMOVD, BeginIdx = ARM::dsub_0, SubRegs = 4;
+
+  else if (ARM::DPairSpcRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VMOVD, BeginIdx = ARM::dsub_0, SubRegs = 2, Spacing = 2;
+  else if (ARM::DTripleSpcRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VMOVD, BeginIdx = ARM::dsub_0, SubRegs = 3, Spacing = 2;
+  else if (ARM::DQuadSpcRegClass.contains(DestReg, SrcReg))
+    Opc = ARM::VMOVD, BeginIdx = ARM::dsub_0, SubRegs = 4, Spacing = 2;
+
+  if (Opc) {
     const TargetRegisterInfo *TRI = &getRegisterInfo();
-    assert(ARM::qsub_0 + 3 == ARM::qsub_3 && "Expected contiguous enum.");
-    unsigned EndSubReg = ARM::QQPRRegClass.contains(DestReg, SrcReg) ?
-      ARM::qsub_1 : ARM::qsub_3;
-    for (unsigned i = ARM::qsub_0, e = EndSubReg + 1; i != e; ++i) {
-      unsigned Dst = TRI->getSubReg(DestReg, i);
-      unsigned Src = TRI->getSubReg(SrcReg, i);
-      MachineInstrBuilder Mov =
-        AddDefaultPred(BuildMI(MBB, I, I->getDebugLoc(), get(ARM::VORRq))
-                       .addReg(Dst, RegState::Define)
-                       .addReg(Src, getKillRegState(KillSrc))
-                       .addReg(Src, getKillRegState(KillSrc)));
-      if (i == EndSubReg) {
-        Mov->addRegisterDefined(DestReg, TRI);
-        if (KillSrc)
-          Mov->addRegisterKilled(SrcReg, TRI);
-      }
+    MachineInstrBuilder Mov;
+    for (unsigned i = 0; i != SubRegs; ++i) {
+      unsigned Dst = TRI->getSubReg(DestReg, BeginIdx + i*Spacing);
+      unsigned Src = TRI->getSubReg(SrcReg,  BeginIdx + i*Spacing);
+      assert(Dst && Src && "Bad sub-register");
+      Mov = AddDefaultPred(BuildMI(MBB, I, I->getDebugLoc(), get(Opc), Dst)
+                             .addReg(Src));
+      // VORR takes two source operands.
+      if (Opc == ARM::VORRq)
+        Mov.addReg(Src);
     }
+    // Add implicit super-register defs and kills to the last instruction.
+    Mov->addRegisterDefined(DestReg, TRI);
+    if (KillSrc)
+      Mov->addRegisterKilled(SrcReg, TRI);
     return;
   }
+
   llvm_unreachable("Impossible reg-to-reg copy");
 }