[KnownBits] Add bit counting methods to KnownBits struct and use them where possible

This patch adds min/max population count, leading/trailing zero/one bit counting methods.

The min methods return answers based on bits that are known without considering unknown bits. The max methods give answers taking into account the largest count that unknown bits could give.

Differential Revision: https://reviews.llvm.org/D32931

llvm-svn: 302925

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 6cc356dfa1d..1f5b94ff8fa 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -16752,7 +16752,7 @@ static SDValue LowerAndToBT(SDValue And, ISD::CondCode CC,
       if (BitWidth > AndBitWidth) {
         KnownBits Known;
         DAG.computeKnownBits(Op0, Known);
-        if (Known.Zero.countLeadingOnes() < BitWidth - AndBitWidth)
+        if (Known.countMinLeadingZeros() < BitWidth - AndBitWidth)
           return SDValue();
       }
       LHS = Op1;