[llvm] [SelectionDAG][RISCV] Teach computeKnownBits to use range metadata for atomic_load. (PR #137119)

[Craig Topper via llvm-commits]

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@@ -4382,6 +4382,38 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts,
     Known.Zero |= APInt::getBitsSetFrom(BitWidth, VT.getScalarSizeInBits());
     break;
   }
+  case ISD::ATOMIC_LOAD: {
+    // If we are looking at the loaded value.
+    if (Op.getResNo() == 0) {
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topperc wrote:

I was keeping consistency with ISD::LOAD. Maybe we should change all of them at once?

https://github.com/llvm/llvm-project/pull/137119