[GlobalISel] Change representation of shuffle masks in MachineOperand.

We're planning to remove the shufflemask operand from ShuffleVectorInst
(D72467); fix GlobalISel so it doesn't depend on that Constant.

The change to prelegalizercombiner-shuffle-vector.mir happens because
the input contains a literal "-1" in the mask (so the parser/verifier
weren't really handling it properly). We now treat it as equivalent to
"undef" in all contexts.

Differential Revision: https://reviews.llvm.org/D72663

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
index b147a83cd16..4612690644f 100644
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -484,6 +484,12 @@ uint32_t *MachineFunction::allocateRegMask() {
   return Mask;
 }
 
+ArrayRef<int> MachineFunction::allocateShuffleMask(ArrayRef<int> Mask) {
+  int* AllocMask = Allocator.Allocate<int>(Mask.size());
+  copy(Mask, AllocMask);
+  return {AllocMask, Mask.size()};
+}
+
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 LLVM_DUMP_METHOD void MachineFunction::dump() const {
   print(dbgs());