Clarify rules for reserved regs, fix aarch64 ones.

No test case necessary as the problematic condition is checked with the
newly introduced assertAllSuperRegsMarked() function.

Differential Revision: https://reviews.llvm.org/D26648

llvm-svn: 288277

1 files changed, 11 insertions, 9 deletions

diff --git a/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp
index bc759dbe8cc..d995c631dd1 100644
--- a/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseRegisterInfo.cpp
@@ -167,27 +167,29 @@ getReservedRegs(const MachineFunction &MF) const {
 
   // FIXME: avoid re-calculating this every time.
   BitVector Reserved(getNumRegs());
-  Reserved.set(ARM::SP);
-  Reserved.set(ARM::PC);
-  Reserved.set(ARM::FPSCR);
-  Reserved.set(ARM::APSR_NZCV);
+  markSuperRegs(Reserved, ARM::SP);
+  markSuperRegs(Reserved, ARM::PC);
+  markSuperRegs(Reserved, ARM::FPSCR);
+  markSuperRegs(Reserved, ARM::APSR_NZCV);
   if (TFI->hasFP(MF))
-    Reserved.set(getFramePointerReg(STI));
+    markSuperRegs(Reserved, getFramePointerReg(STI));
   if (hasBasePointer(MF))
-    Reserved.set(BasePtr);
+    markSuperRegs(Reserved, BasePtr);
   // Some targets reserve R9.
   if (STI.isR9Reserved())
-    Reserved.set(ARM::R9);
+    markSuperRegs(Reserved, ARM::R9);
   // Reserve D16-D31 if the subtarget doesn't support them.
   if (!STI.hasVFP3() || STI.hasD16()) {
     static_assert(ARM::D31 == ARM::D16 + 15, "Register list not consecutive!");
-    Reserved.set(ARM::D16, ARM::D31 + 1);
+    for (unsigned R = 0; R < 16; ++R)
+      markSuperRegs(Reserved, ARM::D16 + R);
   }
   const TargetRegisterClass *RC  = &ARM::GPRPairRegClass;
   for(TargetRegisterClass::iterator I = RC->begin(), E = RC->end(); I!=E; ++I)
     for (MCSubRegIterator SI(*I, this); SI.isValid(); ++SI)
-      if (Reserved.test(*SI)) Reserved.set(*I);
+      if (Reserved.test(*SI)) markSuperRegs(Reserved, *I);
 
+  assert(checkAllSuperRegsMarked(Reserved));
   return Reserved;
 }