[ARM] GlobalISel: Select add i32, i32
Add the minimal support necessary to select a function that returns the sum of
two i32 values.
This includes some support for argument/return lowering of i32 values through
registers, as well as the handling of copy and add instructions throughout the
GlobalISel pipeline.
Differential Revision: https://reviews.llvm.org/D26677
llvm-svn: 289940
diff --git a/llvm/lib/CodeGen/GlobalISel/InstructionSelector.cpp b/llvm/lib/CodeGen/GlobalISel/InstructionSelector.cpp
index 9149864..3b2177c 100644
--- a/llvm/lib/CodeGen/GlobalISel/InstructionSelector.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/InstructionSelector.cpp
@@ -43,6 +43,11 @@
if (TRI.isPhysicalRegister(MO.getReg()))
continue;
+ // Register operands with a value of 0 (e.g. predicate operands) don't need
+ // to be constrained.
+ if (MO.getReg() == 0)
+ continue;
+
const TargetRegisterClass *RC = TII.getRegClass(I.getDesc(), OpI, &TRI, MF);
assert(RC && "Selected inst should have regclass operand");