[SelectionDAG] GetDemandedBits - remove ANY_EXTEND handling

RKSimon · RKSimon · commit 47f99d2ca8ad · 2020-01-21T14:39:00.000Z
Rely on SimplifyMultipleUseDemandedBits fallback instead.
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2226,19 +2226,6 @@ SDValue SelectionDAG::GetDemandedBits(SDValue V, const APInt &DemandedBits,
     }
     break;
   }
-  case ISD::ANY_EXTEND: {
-    SDValue Src = V.getOperand(0);
-    unsigned SrcBitWidth = Src.getScalarValueSizeInBits();
-    // Being conservative here - only peek through if we only demand bits in the
-    // non-extended source (even though the extended bits are technically
-    // undef).
-    if (DemandedBits.getActiveBits() > SrcBitWidth)
-      break;
-    APInt SrcDemandedBits = DemandedBits.trunc(SrcBitWidth);
-    if (SDValue DemandedSrc = GetDemandedBits(Src, SrcDemandedBits))
-      return getNode(ISD::ANY_EXTEND, SDLoc(V), V.getValueType(), DemandedSrc);
-    break;
-  }
   }
   return SDValue();
 }

Original file line number	Diff line number	Diff line change
`@@ -2226,19 +2226,6 @@ SDValue SelectionDAG::GetDemandedBits(SDValue V, const APInt &DemandedBits,`
`2226`	`2226`	`}`
`2227`	`2227`	`break;`
`2228`	`2228`	`}`
`2229`		`- case ISD::ANY_EXTEND: {`
`2230`		`- SDValue Src = V.getOperand(0);`
`2231`		`- unsigned SrcBitWidth = Src.getScalarValueSizeInBits();`
`2232`		`- // Being conservative here - only peek through if we only demand bits in the`
`2233`		`- // non-extended source (even though the extended bits are technically`
`2234`		`- // undef).`
`2235`		`- if (DemandedBits.getActiveBits() > SrcBitWidth)`
`2236`		`- break;`
`2237`		`- APInt SrcDemandedBits = DemandedBits.trunc(SrcBitWidth);`
`2238`		`- if (SDValue DemandedSrc = GetDemandedBits(Src, SrcDemandedBits))`
`2239`		`- return getNode(ISD::ANY_EXTEND, SDLoc(V), V.getValueType(), DemandedSrc);`
`2240`		`- break;`
`2241`		`- }`
`2242`	`2229`	`}`
`2243`	`2230`	`return SDValue();`
`2244`	`2231`	`}`