fix rdar://9297011 - udiv by power of two causing fast-isel rejects
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129693 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 0f60cbf..d3a721f 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -990,6 +990,10 @@
if (Opcode == ISD::MUL && isPowerOf2_64(Imm)) {
Opcode = ISD::SHL;
Imm = Log2_64(Imm);
+ } else if (Opcode == ISD::UDIV && isPowerOf2_64(Imm)) {
+ // div x, 8 -> srl x, 3
+ Opcode = ISD::SRL;
+ Imm = Log2_64(Imm);
}
// Horrible hack (to be removed), check to make sure shift amounts are