[GlobalISel] Bail on G_PHI narrowing of odd types (PR48188)
The current narrowing code for G_PHI can only handle the case
where the size is a multiple of the narrow size. If this is not
the case, fall back to SDAG instead of asserting.
Original patch by shepmaster.
Differential Revision: https://reviews.llvm.org/D92446
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 87ab384..5fef853 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -1006,6 +1006,11 @@
Observer.changedInstr(MI);
return Legalized;
case TargetOpcode::G_PHI: {
+ // FIXME: add support for when SizeOp0 isn't an exact multiple of
+ // NarrowSize.
+ if (SizeOp0 % NarrowSize != 0)
+ return UnableToLegalize;
+
unsigned NumParts = SizeOp0 / NarrowSize;
SmallVector<Register, 2> DstRegs(NumParts);
SmallVector<SmallVector<Register, 2>, 2> SrcRegs(MI.getNumOperands() / 2);
