[DAG][SystemZ] Define unwrapAddress for PCREL_WRAPPER.

Summary:
Like with X86, this allows better DAG-level alias analysis and
alignment inference for wrapped addresses.

Reviewers: jonpa, uweigand

Reviewed By: uweigand

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D57407

llvm-svn: 352786

diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
index 5a59a33..0f02312 100644 (file)
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -5775,6 +5775,12 @@ SDValue SystemZTargetLowering::combineIntDIVREM(
   return SDValue();
 }
 
+SDValue SystemZTargetLowering::unwrapAddress(SDValue N) const {
+  if (N->getOpcode() == SystemZISD::PCREL_WRAPPER)
+    return N->getOperand(0);
+  return N;
+}
+
 SDValue SystemZTargetLowering::PerformDAGCombine(SDNode *N,
                                                  DAGCombinerInfo &DCI) const {
   switch(N->getOpcode()) {

diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.h b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
index e456a5c..cd0e4c3 100644 (file)
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.h
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.h
@@ -598,6 +598,8 @@ private:
   SDValue combineGET_CCMASK(SDNode *N, DAGCombinerInfo &DCI) const;
   SDValue combineIntDIVREM(SDNode *N, DAGCombinerInfo &DCI) const;
 
+  SDValue unwrapAddress(SDValue N) const override;
+
   // If the last instruction before MBBI in MBB was some form of COMPARE,
   // try to replace it with a COMPARE AND BRANCH just before MBBI.
   // CCMask and Target are the BRC-like operands for the branch.