teach codegen to turn trunc(zextload) into load when possible.
This doesn't occur much at all, it only seems to formed in the case
when the trunc optimization kicks in due to phase ordering. In that
case it is saves a few bytes on x86-32.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101350 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 5974aff..69a2616 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3637,7 +3637,7 @@
// Do not generate loads of non-round integer types since these can
// be expensive (and would be wrong if the type is not byte sized).
if (isa<LoadSDNode>(N0) && N0.hasOneUse() && ExtVT.isRound() &&
- cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits() > EVTBits &&
+ cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits() >= EVTBits &&
// Do not change the width of a volatile load.
!cast<LoadSDNode>(N0)->isVolatile()) {
LoadSDNode *LN0 = cast<LoadSDNode>(N0);