[InstCombine][ValueTracking] Match non-uniform constant power-of-two vectors

Generalize existing constant matching to work with non-uniform constant vectors as well.

Differential Revision: https://reviews.llvm.org/D42818

llvm-svn: 324369

1 files changed, 5 insertions, 8 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 14a26b5..5a8bd4b 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -1646,14 +1646,11 @@ bool isKnownToBeAPowerOfTwo(const Value *V, bool OrZero, unsigned Depth,
                             const Query &Q) {
   assert(Depth <= MaxDepth && "Limit Search Depth");
 
-  if (const Constant *C = dyn_cast<Constant>(V)) {
-    if (C->isNullValue())
-      return OrZero;
-
-    const APInt *ConstIntOrConstSplatInt;
-    if (match(C, m_APInt(ConstIntOrConstSplatInt)))
-      return ConstIntOrConstSplatInt->isPowerOf2();
-  }
+  // Attempt to match against constants.
+  if (OrZero && match(V, m_Power2OrZero()))
+      return true;
+  if (match(V, m_Power2()))
+      return true;
 
   // 1 << X is clearly a power of two if the one is not shifted off the end.  If
   // it is shifted off the end then the result is undefined.