Simplify store(bitconv(x)) to store(x). This allows us to compile this:
void bar(double Y, double *X) {
*X = Y;
}
to this:
bar:
save -96, %o6, %o6
st %i1, [%i2+4]
st %i0, [%i2]
restore %g0, %g0, %g0
retl
nop
instead of this:
bar:
save -104, %o6, %o6
st %i1, [%i6+-4]
st %i0, [%i6+-8]
ldd [%i6+-8], %f0
std %f0, [%i2]
restore %g0, %g0, %g0
retl
nop
on sparcv8.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24983 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f08fd10..52e8391 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2081,6 +2081,11 @@
return SDOperand(N, 0);
}
+ // If this is a store of a bit convert, store the input value.
+ if (Value.getOpcode() == ISD::BIT_CONVERT)
+ return DAG.getNode(ISD::STORE, MVT::Other, Chain, Value.getOperand(0),
+ Ptr, SrcValue);
+
return SDOperand();
}