[llvm] [SelectionDAG] Remove FIXME and commented out code from 20 years ago. NFC (PR #150055)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/150055.diff


1 Files Affected:

- (modified) llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (-20) 


``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index e471d2276a0ba..fe8f22f7a1132 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -10860,26 +10860,6 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, SDVTList VTList,
            (Ops[2]->getAsZExtVal() == 0 || Ops[2]->getAsZExtVal() == 1) &&
            "Invalid STRICT_FP_ROUND!");
     break;
-#if 0
-  // FIXME: figure out how to safely handle things like
-  // int foo(int x) { return 1 << (x & 255); }
-  // int bar() { return foo(256); }
-  case ISD::SRA_PARTS:
-  case ISD::SRL_PARTS:
-  case ISD::SHL_PARTS:
-    if (N3.getOpcode() == ISD::SIGN_EXTEND_INREG &&
-        cast<VTSDNode>(N3.getOperand(1))->getVT() != MVT::i1)
-      return getNode(Opcode, DL, VT, N1, N2, N3.getOperand(0));
-    else if (N3.getOpcode() == ISD::AND)
-      if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N3.getOperand(1))) {
-        // If the and is only masking out bits that cannot effect the shift,
-        // eliminate the and.
-        unsigned NumBits = VT.getScalarSizeInBits()*2;
-        if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1)
-          return getNode(Opcode, DL, VT, N1, N2, N3.getOperand(0));
-      }
-    break;
-#endif
   }
 
   // Memoize the node unless it returns a glue result.

``````````

</details>


https://github.com/llvm/llvm-project/pull/150055