[AArch64][MachineLegalizer] Mark more G_BITCAST as legal.

Basically any vector types that fits in a 32-bit register is also valid
as far as copies are concerned.

llvm-svn: 284089

1 files changed, 8 insertions, 1 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64MachineLegalizer.cpp b/llvm/lib/Target/AArch64/AArch64MachineLegalizer.cpp
index 4f921e8d8ef..46261bca67c 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineLegalizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64MachineLegalizer.cpp
@@ -181,14 +181,21 @@ AArch64MachineLegalizer::AArch64MachineLegalizer() {
     setAction({G_BITCAST, 1, Ty}, Legal);
   }
 
+  // For the sake of copying bits around, the type does not really
+  // matter as long as it fits a register.
   for (int EltSize = 8; EltSize <= 64; EltSize *= 2) {
     setAction({G_BITCAST, 0, LLT::vector(128/EltSize, EltSize)}, Legal);
     setAction({G_BITCAST, 1, LLT::vector(128/EltSize, EltSize)}, Legal);
-    if (EltSize == 64)
+    if (EltSize >= 64)
       continue;
 
     setAction({G_BITCAST, 0, LLT::vector(64/EltSize, EltSize)}, Legal);
     setAction({G_BITCAST, 1, LLT::vector(64/EltSize, EltSize)}, Legal);
+    if (EltSize >= 32)
+      continue;
+
+    setAction({G_BITCAST, 0, LLT::vector(32/EltSize, EltSize)}, Legal);
+    setAction({G_BITCAST, 1, LLT::vector(32/EltSize, EltSize)}, Legal);
   }
 
   computeTables();