[PATCH] D150969: [AArch64] Try to convert two XTN and two SMLSL to UZP1, SMLSL and SMLSL2

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

Thanks



================
Comment at: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp:22446-22451
+    if (User->getOpcode() != ISD::EXTRACT_SUBVECTOR) {
+      HasFoundMULLow = false;
+      break;
+    }
+
+    if (!isNullConstant(User->getOperand(1))) {
----------------
These two ifs could be combined into one


================
Comment at: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp:22460
+  // Check ExtractLow's user.
+  if (HasFoundMULLow && ExtractLow->hasOneUse()) {
+    SDNode *ExtractLowUser = *ExtractLow.getNode()->use_begin();
----------------
I think this one could leave HasFoundMULLow = true but without a valid TruncLow.


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  https://reviews.llvm.org/D150969/new/

https://reviews.llvm.org/D150969