lattigo: do not use logSlots to indicate fewer used slots

lib/Target/Lattigo/LattigoEmitter.cpp

@@ -2323,20 +2323,19 @@ LogicalResult LattigoEmitter::printOperation(
   auto btParams = op.getBtParamsLiteral();
   auto paramName = getName(op.getParams());
   auto errName = getErrName();
-  auto numSlotsAttr = dyn_cast_or_null<IntegerAttr>(
-      op->getParentOfType<ModuleOp>()->getAttr(kRequestedSlotCountAttrName));
   std::string resultName = getName(op.getResult());
   os << resultName << ", " << errName
      << " := bootstrapping.NewParametersFromLiteral(";
   os << paramName << ", ";
   os << "bootstrapping.ParametersLiteral{\n";
   os.indent();
   os << "LogN: utils.Pointy(" << btParams.getLogN() << "),\n";
-  if (numSlotsAttr) {
-    int numSlots = numSlotsAttr.getInt();
-    int logNumSlots = (int)log2(numSlots);
-    os << "LogSlots: utils.Pointy(" << logNumSlots << "),\n";
-  }
+  // Deliberately no LogSlots: leave it at lattigo's default of LogN-1.
+  //
+  // LogSlots is documented as "the maximum number of slots of the ciphertext"
+  // and only sizes the CoeffsToSlots/SlotsToCoeffs matrices; the bootstrapping
+  // ring is built from LogN alone, so its LogMaxDimensions stays at LogN-1
+  // whatever LogSlots says.
   os.unindent();
   os << "})\n";
   printErrPanic(errName);

tests/Emitter/Lattigo/bootstrap_full_slots.mlir

@@ -0,0 +1,29 @@
+// RUN: heir-translate %s --emit-lattigo | FileCheck %s
+
+// A module carrying scheme.requested_slot_count (set by generate-param-ckks
+// from the requested ciphertext-degree, here 1024 in a LogN-16 ring whose
+// actual slot count is 32768) must NOT turn that hint into a sparse
+// bootstrapping LogSlots.
+
+// CHECK: bootstrapping.NewParametersFromLiteral
+// CHECK:   LogN: utils.Pointy(16)
+// CHECK-NOT: LogSlots
+// CHECK: })
+
+!params = !lattigo.ckks.parameter
+!bt_params = !lattigo.ckks.bootstrapping_parameter
+
+#paramsLiteral = #lattigo.ckks.parameters_literal<
+    logN = 16,
+    logQ = [55, 45, 45],
+    logP = [61],
+    logDefaultScale = 45
+>
+
+module attributes {scheme.ckks, scheme.requested_slot_count = 1024 : i64} {
+  func.func @make_bt_params() -> !bt_params {
+    %params = lattigo.ckks.new_parameters_from_literal {paramsLiteral = #paramsLiteral} : () -> !params
+    %bt_params = lattigo.ckks.new_bootstrapping_parameters_from_literal %params {btParamsLiteral = #lattigo.ckks.bootstrapping_parameters_literal<logN = 16>} : (!params) -> !bt_params
+    return %bt_params : !bt_params
+  }
+}

tests/Examples/lattigo/ckks/bootstrapping/bootstrap.mlir

@@ -36,7 +36,14 @@
 // CHECK-SAME: , %[[ct:\w+]]: ![[ctType]])
 // CHECK: lattigo.ckks.bootstrap %[[bEval]], %[[ct]]
 
-module attributes {backend.lattigo, ckks.schemeParam = #ckks.scheme_param<logN = 14, Q = [0x200000440001, 0x7fff80001, 0x800280001], P = [0x3ffffffb80001, 0x4000000800001], logDefaultScale = 60>, scheme.ckks} {
+// scheme.requested_slot_count is what generate-param-ckks records for a
+// requested ciphertext-degree below the ring's slot capacity (here 2048 of the
+// 8192 slots of a logN-14 ring). It must not be turned into a sparse
+// bootstrapping LogSlots: lattigo sizes only the CoeffsToSlots/SlotsToCoeffs
+// matrices from LogSlots while Bootstrap relabels its input to the full
+// LogMaxDimensions, so a sparse value mixes slot values and this test decrypts
+// to garbage.
+module attributes {backend.lattigo, ckks.schemeParam = #ckks.scheme_param<logN = 14, Q = [0x200000440001, 0x7fff80001, 0x800280001], P = [0x3ffffffb80001, 0x4000000800001], logDefaultScale = 60>, scheme.ckks, scheme.requested_slot_count = 2048 : i64} {
   func.func @bootstrap(%ct: !ct_L2) -> !ct_L13 {
     %ct_0 = ckks.bootstrap %ct : !ct_L2 -> !ct_L13
     return %ct_0 : !ct_L13

tests/Transforms/layout_optimization/pad_hoist_explicit.mlir

@@ -13,17 +13,17 @@ module attributes {backend.lattigo, scheme.ckks} {
     ^body(%input0: tensor<1x10x48xf32>):
       debug.validate %input0 {metadata = "input", name = "input", tensor_ext.layout = []} : tensor<1x10x48xf32>
       %collapsed = tensor.collapse_shape %input0 [[0, 1], [2]] {heir.kernel_info = {gap_factor = 1 : i64, result_shape = array<i64: 10, 48>}, tensor_ext.layout = #layout2} : tensor<1x10x48xf32> into tensor<10x48xf32>
-      
+
       // Pad outputs layout2
       %padded = tensor.pad %collapsed low[0, 1] high[0, 1] {
       ^bb0(%arg1: index, %arg2: index):
         tensor.yield %cst : f32
       } {heir.kernel_info = {gap_factor = 1 : i64, result_shape = array<i64: 10, 48>}, tensor_ext.layout = #layout2} : tensor<10x48xf32> to tensor<10x50xf32>
-      
+
       // Explicit convert_layout from layout2 to layout
       // CHECK-NOT: tensor_ext.convert_layout
       %converted = tensor_ext.convert_layout %padded {from_layout = #layout2, tensor_ext.layout = #layout, to_layout = #layout} : tensor<10x50xf32>
-      
+
       secret.yield %converted : tensor<10x50xf32>
     } -> (!secret.secret<tensor<10x50xf32>> {tensor_ext.layout = #layout})
     return %0 : !secret.secret<tensor<10x50xf32>>