[PATCH] D105764: [InstCombine] Fold lshr/ashr(or(neg(x), x), bw-1) --> zext/sext(icmp_ne(x,0)) (PR50816)

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri accepted this revision.
lebedev.ri added a comment.
This revision is now accepted and ready to land.

LG



================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp:1144-1145
+      if (match(Op0, m_OneUse(m_c_Or(m_Neg(m_Value(X)), m_Deferred(X))))) {
+        Constant *Zero = ConstantInt::get(Ty, 0);
+        return new ZExtInst(Builder.CreateICmpNE(X, Zero), Ty);
+      }
----------------
Could use `Builder.CreateIsNotNull()`


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp:1335-1336
+      if (match(Op0, m_OneUse(m_c_Or(m_Neg(m_Value(X)), m_Deferred(X))))) {
+        Constant *Zero = ConstantInt::get(Ty, 0);
+        return new SExtInst(Builder.CreateICmpNE(X, Zero), Ty);
+      }
----------------
Same


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D105764/new/

https://reviews.llvm.org/D105764