feat(concrete-compiler): add new ciphertext multiplication operator

compiler/include/concretelang/Dialect/FHE/IR/FHEOps.td

@@ -285,6 +285,44 @@ def FHE_MulEintIntOp : FHE_Op<"mul_eint_int", [NoSideEffect]> {
     let hasFolder = 1;
 }
 
+def FHE_MulEintOp : FHE_Op<"mul_eint", [NoSideEffect]> {
+    let summary = "Multiplies two encrypted integers";
+
+    let description = [{
+        Multiplies two encrypted integers.
+
+        The encrypted integers and the result must have the same width and
+        signedness. Also, due to the current implementation, one supplementary
+        bit of width must be provided, in addition to the number of bits needed
+        to encode the largest output value.
+
+        Example:
+        ```mlir
+        // ok
+        "FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<2>)
+        "FHE.mul_eint"(%a, %b): (!FHE.eint<3>, !FHE.eint<3>) -> (!FHE.eint<3>)
+        "FHE.mul_eint"(%a, %b): (!FHE.esint<3>, !FHE.esint<3>) -> (!FHE.esint<3>)
+
+        // error
+        "FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<3>) -> (!FHE.eint<2>)
+        "FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.eint<3>)
+        "FHE.mul_eint"(%a, %b): (!FHE.eint<2>, !FHE.eint<2>) -> (!FHE.esint<2>)
+        "FHE.mul_eint"(%a, %b): (!FHE.esint<2>, !FHE.eint<2>) -> (!FHE.eint<2>)
+        ```
+    }];
+
+    let arguments = (ins FHE_AnyEncryptedInteger:$a, FHE_AnyEncryptedInteger:$b);
+    let results = (outs FHE_AnyEncryptedInteger);
+
+    let builders = [
+        OpBuilder<(ins "Value":$a, "Value":$b), [{
+          build($_builder, $_state, a.getType(), a, b);
+        }]>
+    ];
+
+    let hasVerifier = 1;
+}
+
 def FHE_ToSignedOp : FHE_Op<"to_signed", [NoSideEffect]> {
     let summary = "Cast an unsigned integer to a signed one";
 

compiler/include/concretelang/Dialect/FHE/Transforms/CMakeLists.txt

@@ -2,3 +2,7 @@ set(LLVM_TARGET_DEFINITIONS Boolean.td)
 mlir_tablegen(Boolean.h.inc -gen-pass-decls -name Transforms)
 add_public_tablegen_target(ConcretelangFHEBooleanPassIncGen)
 add_dependencies(mlir-headers ConcretelangFHEBooleanPassIncGen)
+set(LLVM_TARGET_DEFINITIONS EncryptedMulToDoubleTLU.td)
+mlir_tablegen(EncryptedMulToDoubleTLU.h.inc -gen-pass-decls -name Transforms)
+add_public_tablegen_target(EncryptedMulToDoubleTLUPassIncGen)
+add_dependencies(mlir-headers EncryptedMulToDoubleTLUPassIncGen)

compiler/include/concretelang/Dialect/FHE/Transforms/EncryptedMulToDoubleTLU.h

@@ -0,0 +1,24 @@
+// Part of the Concrete Compiler Project, under the BSD3 License with Zama
+// Exceptions. See
+// https://github.com/zama-ai/concrete-compiler-internal/blob/main/LICENSE.txt
+// for license information.
+
+#ifndef CONCRETELANG_FHE_ENCRYPTED_MUL_TO_DOUBLE_TLU_PASS_H
+#define CONCRETELANG_FHE_ENCRYPTED_MUL_TO_DOUBLE_TLU_PASS_H
+
+#include <concretelang/Dialect/FHE/IR/FHEDialect.h>
+#include <mlir/Dialect/Func/IR/FuncOps.h>
+#include <mlir/Pass/Pass.h>
+
+#define GEN_PASS_CLASSES
+
+#include <concretelang/Dialect/FHE/Transforms/EncryptedMulToDoubleTLU.h.inc>
+
+namespace mlir {
+namespace concretelang {
+std::unique_ptr<mlir::OperationPass<mlir::func::FuncOp>>
+createEncryptedMulToDoubleTLUPass();
+} // namespace concretelang
+} // namespace mlir
+
+#endif

compiler/include/concretelang/Dialect/FHE/Transforms/EncryptedMulToDoubleTLU.td

@@ -0,0 +1,11 @@
+#ifndef CONCRETELANG_FHE_ENCRYPTED_MUL_TO_DOUBLE_TLU_PASS
+#define CONCRETELANG_FHE_ENCRYPTED_MUL_TO_DOUBLE_TLU_PASS
+
+include "mlir/Pass/PassBase.td"
+
+def EncryptedMulToDoubleTLU : Pass<"EncryptedMulToDoubleTLU", "::mlir::func::FuncOp"> {
+  let summary = "Replaces encrypted multiplication with a double table lookup.";
+  let constructor = "mlir::concretelang::createEncryptedMulToDoubleTLUPass()";
+}
+
+#endif

compiler/include/concretelang/Support/Pipeline.h

@@ -34,6 +34,10 @@ markFHELinalgForTiling(mlir::MLIRContext &context, mlir::ModuleOp &module,
                        llvm::ArrayRef<int64_t> tileSizes,
                        std::function<bool(mlir::Pass *)> enablePass);
 
+mlir::LogicalResult
+transformHighLevelFHEOps(mlir::MLIRContext &context, mlir::ModuleOp &module,
+                         std::function<bool(mlir::Pass *)> enablePass);
+
 mlir::LogicalResult
 lowerFHELinalgToFHE(mlir::MLIRContext &context, mlir::ModuleOp &module,
                     llvm::Optional<V0FHEContext> &fheContext,