Shankara/llzk to pcl pass

.clang-format

@@ -22,16 +22,18 @@ IncludeCategories:
     Priority: 0                    # Needs to be set to 1 when we change priorities soon.
   - Regex: '^("|<)llzk-c/.*("|>)$' # LLZK C API headers 
     Priority: 1                    # Set to priority 1 and onwards in preparation for putting LLZK headers in priority 1
-  - Regex: '^<mlir/.*>$'           # MLIR headers
+  - Regex: '^<pcl/.*>$'           # PCL headers
     Priority: 2
-  - Regex: '^<mlir-c/.*>$'         # MLIR C API headers
+  - Regex: '^<mlir/.*>$'           # MLIR headers
     Priority: 3
-  - Regex: '^<llvm/.*>$'           # LLVM headers
+  - Regex: '^<mlir-c/.*>$'         # MLIR C API headers
     Priority: 4
-  - Regex: '^<.*(\.h)?>$'          # Standard library headers
+  - Regex: '^<llvm/.*>$'           # LLVM headers
     Priority: 5
-  - Regex: '^.*$'                  # Everything else
+  - Regex: '^<.*(\.h)?>$'          # Standard library headers
     Priority: 6
+  - Regex: '^.*$'                  # Everything else
+    Priority: 7
 SortIncludes: true
 InsertNewlineAtEOF: true
 ---

changelogs/unreleased/shankara__llzk-to-pcl-pass.yaml

@@ -0,0 +1,2 @@
+added:
+  - Added a pass to convert llzk to pcl

include/llzk/Transforms/LLZKTransformationPasses.h

@@ -10,6 +10,10 @@
 #pragma once
 
 #include "llzk/Pass/PassBase.h"
+#include "llzk/Transforms/Parsers.h"
+
+#include <llvm/ADT/APInt.h>
+#include <llvm/Support/CommandLine.h>
 
 namespace llzk {
 
@@ -31,6 +35,8 @@ std::unique_ptr<mlir::Pass> createInlineStructsPass();
 
 std::unique_ptr<mlir::Pass> createR1CSLoweringPass();
 
+std::unique_ptr<mlir::Pass> createPCLLoweringPass();
+
 void registerTransformationPassPipelines();
 
 void registerInliningExtensions(mlir::DialectRegistry &registry);

include/llzk/Transforms/LLZKTransformationPasses.td

@@ -108,4 +108,17 @@ def R1CSLoweringPass : LLZKPass<"llzk-r1cs-lowering"> {
   let constructor = "llzk::createR1CSLoweringPass()";
 }
 
+def PCLLoweringPass : LLZKPass<"llzk-to-pcl"> {
+  let summary = "Rewrites constraints to be compatible with PCL constraints "
+                "used by Picus";
+  let description = [{
+    Transforms LLZK constraints into an equivalent set of constraints expressed in the pcl-mlir dialect.
+  }];
+  let constructor = "llzk::createPCLLoweringPass()";
+  let options = [Option<"prime", "prime", "::llvm::APInt",
+                        "llvm::APInt(31, 2130706433)", // KoalaBear in decimal
+                        "Prime field that the constraints operate over. This "
+                        "is required by PCL">];
+}
+
 #endif // LLZK_TRANSFORMATION_PASSES_TD

include/llzk/Transforms/Parsers.h

@@ -0,0 +1,62 @@
+//===-- Parsers.h -----------------------------------------------*- C++ -*-===//
+//
+// Command line parsers for LLZK transformation passes.
+//
+// Part of the LLZK Project, under the Apache License v2.0.
+// See LICENSE.txt for license information.
+// Copyright 2025 Veridise Inc.
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#include <llvm/ADT/APInt.h>
+#include <llvm/ADT/StringExtras.h>
+#include <llvm/Support/CommandLine.h>
+
+// Custom command line parsers
+namespace llvm {
+namespace cl {
+
+// Parser for APInt
+template <> class parser<APInt> : public basic_parser<APInt> {
+public:
+  parser(Option &O) : basic_parser(O) {}
+
+  bool parse(Option &O, StringRef, StringRef Arg, APInt &Val) {
+    if (Arg.empty()) {
+      return O.error("empty integer literal");
+    }
+    // Decimal-only: allocate a safe width then shrink.
+    unsigned bits = std::max(1u, 4u * (unsigned)Arg.size());
+    APInt tmp(bits, Arg, 10);
+    unsigned active = tmp.getActiveBits();
+    if (active == 0) {
+      active = 1;
+    }
+    Val = tmp.zextOrTrunc(active);
+    return false;
+  }
+
+  // Prints how the passed option differs from the default one specified in the pass
+  // For example, if V = 17 and Default = 11 then it should print
+  // [OptionName] 17 (bits=5) (default: 11 (bits=4))
+  void printOptionDiff(
+      const Option &O, const APInt &V, OptionValue<APInt> Default, size_t GlobalWidth
+  ) const {
+    std::string Cur = llvm::toString(V, 10, false);
+    Cur += " (bits=" + std::to_string(V.getBitWidth()) + ")";
+
+    std::string Def = "<unspecified>";
+    if (Default.hasValue()) {
+      const APInt &D = Default.getValue();
+      Def = llvm::toString(D, 10, false);
+      Def += " (bits=" + std::to_string(D.getBitWidth()) + ")";
+    }
+
+    printOptionName(O, GlobalWidth);
+    llvm::outs() << Cur << " (default: " << Def << ")\n";
+  }
+};
+
+} // namespace cl
+} // namespace llvm

lib/Transforms/CMakeLists.txt

@@ -9,7 +9,8 @@ target_link_libraries(
                      LLVMHeaders MLIRHeaders
                   PRIVATE
                      LLZKDialect
-                     R1CSDialect)
+                     R1CSDialect
+                     $<$<BOOL:${LLZK_WITH_PCL_BOOL}>:PCL::PCLDialect>)
 add_dependencies(LLZKTransforms LLZKDialect LLZKDialectHeaders)
 llzk_target_add_mlir_link_settings(LLZKTransforms)