enhance the load/store narrowing optimization to handle a
tokenfactor in between the load/store. This allows us to
optimize test7 into:
_test7: ## @test7
## BB#0: ## %entry
movl (%rdx), %eax
## kill: SIL<def> ESI<kill>
movb %sil, 5(%rdi)
ret
instead of:
_test7: ## @test7
## BB#0: ## %entry
movl 4(%esp), %ecx
movl $-65281, %eax ## imm = 0xFFFFFFFFFFFF00FF
andl 4(%ecx), %eax
movzbl 8(%esp), %edx
shll $8, %edx
addl %eax, %edx
movl 12(%esp), %eax
movl (%eax), %eax
movl %edx, 4(%ecx)
ret
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101355 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 69a2616..ec70a5e 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5172,12 +5172,25 @@
!ISD::isNormalLoad(V->getOperand(0).getNode()))
return Result;
- // Check the chain and pointer. The store should be chained directly to the
- // load (TODO: Or through a TF node!) since it's to the same address.
+ // Check the chain and pointer.
LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
- if (LD->getBasePtr() != Ptr ||
- V->getOperand(0).getNode() != Chain.getNode())
- return Result;
+ if (LD->getBasePtr() != Ptr) return Result; // Not from same pointer.
+
+ // The store should be chained directly to the load or be an operand of a
+ // tokenfactor.
+ if (LD == Chain.getNode())
+ ; // ok.
+ else if (Chain->getOpcode() != ISD::TokenFactor)
+ return Result; // Fail.
+ else {
+ bool isOk = false;
+ for (unsigned i = 0, e = Chain->getNumOperands(); i != e; ++i)
+ if (Chain->getOperand(i).getNode() == LD) {
+ isOk = true;
+ break;
+ }
+ if (!isOk) return Result;
+ }
// This only handles simple types.
if (V.getValueType() != MVT::i16 &&