ARM: avoid clobbering register in v6 jump-table expansion.

If we got unlucky with register allocation and actual constpool placement, we
could end up producing a tTBB_JT with an index that's already been clobbered.

Technically, we might be able to fix this situation up with a MOV, but I think
the constant islands pass is complex enough without having to deal with more
weird edge-cases.

llvm-svn: 297871

2 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index 0c694c465b6..79189e30ccd 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -332,6 +332,8 @@ bool MIRParserImpl::initializeMachineFunction(MachineFunction &MF) {
     MF.setAlignment(YamlMF.Alignment);
   MF.setExposesReturnsTwice(YamlMF.ExposesReturnsTwice);
 
+  if (YamlMF.NoVRegs)
+    MF.getProperties().set(MachineFunctionProperties::Property::NoVRegs);
   if (YamlMF.Legalized)
     MF.getProperties().set(MachineFunctionProperties::Property::Legalized);
   if (YamlMF.RegBankSelected)
diff --git a/llvm/lib/CodeGen/MIRPrinter.cpp b/llvm/lib/CodeGen/MIRPrinter.cpp
index 899973488bb..8693a9a269d 100644
--- a/llvm/lib/CodeGen/MIRPrinter.cpp
+++ b/llvm/lib/CodeGen/MIRPrinter.cpp
@@ -175,6 +175,8 @@ void MIRPrinter::print(const MachineFunction &MF) {
   YamlMF.Alignment = MF.getAlignment();
   YamlMF.ExposesReturnsTwice = MF.exposesReturnsTwice();
 
+  YamlMF.NoVRegs = MF.getProperties().hasProperty(
+      MachineFunctionProperties::Property::NoVRegs);
   YamlMF.Legalized = MF.getProperties().hasProperty(
       MachineFunctionProperties::Property::Legalized);
   YamlMF.RegBankSelected = MF.getProperties().hasProperty(