[GlobalISel] Fix assert failure when legalizing non-power-2 loads.

Until we support extending loads properly we're going to fall back for these.
We already handle stores in the same way, so this is just being consistent.

llvm-svn: 324001

1 files changed, 6 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 773e51c6e34..ed1f0c9cb16 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -709,9 +709,12 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
   }
   case TargetOpcode::G_LOAD: {
-    assert(alignTo(MRI.getType(MI.getOperand(0).getReg()).getSizeInBits(), 8) ==
-               WideTy.getSizeInBits() &&
-           "illegal to increase number of bytes loaded");
+    // For some types like i24, we might try to widen to i32. To properly handle
+    // this we should be using a dedicated extending load, until then avoid
+    // trying to legalize.
+    if (alignTo(MRI.getType(MI.getOperand(0).getReg()).getSizeInBits(), 8) !=
+        WideTy.getSizeInBits())
+      return UnableToLegalize;
 
     unsigned DstExt = MRI.createGenericVirtualRegister(WideTy);
     MIRBuilder.buildLoad(DstExt, MI.getOperand(1).getReg(),