Reapply r146997, "Heed spill slot alignment on ARM."

Now that canRealignStack() understands frozen reserved registers, it is
safe to use it for aligned spill instructions.

It will only return true if the registers reserved at the beginning of
register allocation allow for dynamic stack realignment.

<rdar://problem/10625436>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147579 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 6 insertions, 6 deletions

diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index dfd9c40..13f1e66 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -765,7 +765,8 @@ storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
       break;
     case 16:
       if (ARM::QPRRegClass.hasSubClassEq(RC)) {
-        if (Align >= 16 && getRegisterInfo().needsStackRealignment(MF)) {
+        // Use aligned spills if the stack can be realigned.
+        if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
           AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VST1q64Pseudo))
                      .addFrameIndex(FI).addImm(16)
                      .addReg(SrcReg, getKillRegState(isKill))
@@ -914,7 +915,7 @@ loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
     break;
   case 16:
     if (ARM::QPRRegClass.hasSubClassEq(RC)) {
-      if (Align >= 16 && getRegisterInfo().needsStackRealignment(MF)) {
+      if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
         AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLD1q64Pseudo), DestReg)
                      .addFrameIndex(FI).addImm(16)
                      .addMemOperand(MMO));
diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index 9f46ce9..ed7ac27 100644
--- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -557,7 +557,7 @@ needsStackRealignment(const MachineFunction &MF) const {
   const MachineFrameInfo *MFI = MF.getFrameInfo();
   const Function *F = MF.getFunction();
   unsigned StackAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
-  bool requiresRealignment = ((MFI->getLocalFrameMaxAlign() > StackAlign) ||
+  bool requiresRealignment = ((MFI->getMaxAlignment() > StackAlign) ||
                                F->hasFnAttr(Attribute::StackAlignment));
 
   return requiresRealignment && canRealignStack(MF);
diff --git a/test/CodeGen/ARM/fast-isel-deadcode.ll b/test/CodeGen/ARM/fast-isel-deadcode.ll
index 1d77975..7e147c7 100644
--- a/test/CodeGen/ARM/fast-isel-deadcode.ll
+++ b/test/CodeGen/ARM/fast-isel-deadcode.ll
@@ -15,8 +15,7 @@ entry:
 ; THUMB-NOT: sxtb
 ; THUMB: movs r0, #0
 ; THUMB: movt r0, #0
-; THUMB: add sp, #32
-; THUMb: pop {r7, pc}
+; THUMB: pop
   ret i32 0
 }
 
diff --git a/test/CodeGen/Thumb2/aligned-spill.ll b/test/CodeGen/Thumb2/aligned-spill.ll
index 7340032..948c8ce 100644
--- a/test/CodeGen/Thumb2/aligned-spill.ll
+++ b/test/CodeGen/Thumb2/aligned-spill.ll
@@ -1,4 +1,4 @@
-; DONT: llc < %s -mcpu=cortex-a8 | FileCheck %s
+; RUN: llc < %s -mcpu=cortex-a8 | FileCheck %s
 ; RUN: llc < %s -mcpu=cortex-a8 -align-neon-spills | FileCheck %s --check-prefix=NEON
 target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32-S32"
 target triple = "thumbv7-apple-ios"