Don't conditionalize Neon instructions, even in IT blocks.

This has been deprecated since ARMARM v7-AR, release C.b, published back
in 2012.

This also removes test/CodeGen/Thumb2/ifcvt-neon.ll that originally was
introduced to check that conditionalization of Neon instructions did
happen when generating Thumb2. However, the test had evolved and was no
longer testing that. Rather than trying to adapt that test, this commit
introduces test/CodeGen/Thumb2/ifcvt-neon-deprecated.mir, since we can
now use the MIR framework to write nicer/more maintainable tests.

llvm-svn: 305998

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 8715657ad5e..e0810c358f2 100644
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -665,12 +665,14 @@ bool ARMBaseInstrInfo::isPredicable(const MachineInstr &MI) const {
   const ARMFunctionInfo *AFI =
       MI.getParent()->getParent()->getInfo<ARMFunctionInfo>();
 
+  // Neon instructions in Thumb2 IT blocks are deprecated, see ARMARM.
+  // In their ARM encoding, they can't be encoded in a conditional form.
+  if ((MI.getDesc().TSFlags & ARMII::DomainMask) == ARMII::DomainNEON)
+    return false;
+
   if (AFI->isThumb2Function()) {
     if (getSubtarget().restrictIT())
       return isV8EligibleForIT(&MI);
-  } else { // non-Thumb
-    if ((MI.getDesc().TSFlags & ARMII::DomainMask) == ARMII::DomainNEON)
-      return false;
   }
 
   return true;