Fix infinite loop after r331115
There are two separate fixes here:
* The lowering code for non-extending loads should report UnableToLegalize instead of emitting the same instruction.
* The target should not be requesting lowering of non-extending loads.
llvm-svn: 331201
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index e4e5e0c..b1e7943 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -1042,6 +1042,10 @@
auto &MMO = **MI.memoperands_begin();
if (DstTy.getSizeInBits() == MMO.getSize() /* in bytes */ * 8) {
+ // In the case of G_LOAD, this was a non-extending load already and we're
+ // about to lower to the same instruction.
+ if (MI.getOpcode() == TargetOpcode::G_LOAD)
+ return UnableToLegalize;
MIRBuilder.buildLoad(DstReg, PtrReg, MMO);
MI.eraseFromParent();
return Legalized;