fix ABS

Shoreshen · Shoreshen · commit 6fdc26302c9b · 2025-07-17T13:08:32.000+08:00
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5570,6 +5570,9 @@ bool SelectionDAG::canCreateUndefOrPoison(SDValue Op, const APInt &DemandedElts,
   case ISD::BUILD_PAIR:
   case ISD::SPLAT_VECTOR:
   case ISD::FABS:
+  case ISD::ABS:
+    // ISD::ABS defines abs(INT_MIN) -> INT_MIN and never generates poison.
+    // Different to Intrinsic::abs.
     return false;
 
   case ISD::ADDC:
