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

Craig Topper via llvm-commits llvm-commits at lists.llvm.org
Tue Jul 22 09:24:55 PDT 2025


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

None

>From 28020780baec703d903ba58c519d55694768aef1 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper at sifive.com>
Date: Tue, 22 Jul 2025 09:22:21 -0700
Subject: [PATCH] [SelectionDAG] Remove FIXME and commented out code from 20
 years ago. NFC

---
 .../lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 20 -------------------
 1 file changed, 20 deletions(-)

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.



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