[CIR][Lower][MLIR] Handle pointer decay of higher dimensions arrays

Author: keryell

clang/lib/CIR/Lowering/ThroughMLIR/LowerCIRToMLIR.cpp

@@ -48,6 +48,7 @@
 #include "mlir/IR/ValueRange.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Pass/PassManager.h"
+#include "mlir/Support/LLVM.h"
 #include "mlir/Support/LogicalResult.h"
 #include "mlir/Target/LLVMIR/Dialect/Builtin/BuiltinToLLVMIRTranslation.h"
 #include "mlir/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.h"
@@ -121,6 +122,17 @@ mlir::Type lowerArrayType(cir::ArrayType type, bool hasValueSemantics,
   return convertToReferenceType(shape, elementType);
 }
 
+// Compute the identity stride for the default layout of a memref
+static llvm::SmallVector<std::int64_t> identityStrides(mlir::MemRefType t) {
+  llvm::SmallVector<std::int64_t> strides(t.getShape().size());
+  if (!strides.empty())
+    strides.back() = 1;
+  // To replace by range algorithms with an exclusive scan...
+  for (auto i = strides.size(); i > 1; --i)
+    strides[i - 2] = t.getShape()[i - 1] * strides[i - 1];
+  return strides;
+}
+
 class CIRReturnLowering : public mlir::OpConversionPattern<cir::ReturnOp> {
 public:
   using OpConversionPattern<cir::ReturnOp>::OpConversionPattern;
@@ -174,7 +186,7 @@ class CIRCallOpLowering : public mlir::OpConversionPattern<cir::CallOp> {
 };
 
 /// Emits the value from memory as expected by its users. Should be called when
-/// the memory represetnation of a CIR type is not equal to its scalar
+/// the memory representation of a CIR type is not equal to its scalar
 /// representation.
 static mlir::Value emitFromMemory(mlir::ConversionPatternRewriter &rewriter,
                                   cir::LoadOp op, mlir::Value value) {
@@ -1289,7 +1301,8 @@ class CIRCastOpLowering : public mlir::OpConversionPattern<cir::CastOp> {
     case CIR::array_to_ptrdecay: {
       auto newDstType = mlir::cast<mlir::MemRefType>(convertTy(dstType));
       rewriter.replaceOpWithNewOp<mlir::memref::ReinterpretCastOp>(
-          op, newDstType, src, 0, std::nullopt, std::nullopt);
+          op, newDstType, src, 0, newDstType.getShape(),
+          identityStrides(newDstType));
       return mlir::success();
     }
     case CIR::bitcast: {
@@ -1447,7 +1460,7 @@ class CIRPtrStrideOpLowering
   //        memref.reinterpret_cast (%base, %stride)
   //
   // MemRef Dialect doesn't have GEP-like operation. memref.reinterpret_cast
-  // only been used to propogate %base and %stride to memref.load/store and
+  // only been used to propagate %base and %stride to memref.load/store and
   // should be erased after the conversion.
   mlir::LogicalResult
   matchAndRewrite(cir::PtrStrideOp op, OpAdaptor adaptor,

clang/test/CIR/Lowering/ThroughMLIR/cast.cpp

@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-clangir-direct-lowering -emit-mlir %s -o %t.mlir
+// RUN: FileCheck --input-file=%t.mlir %s
+
+
+int main() {
+  int a[10];
+  int b[4][7];
+  int *aa = a;
+  int *p = &a[0];
+  auto *ap = &a;
+  *ap[3] = 7;
+  auto *ap10 = (int (*)[10]) p;
+
+  auto v15 = b[1][5];
+  int *bpd = b[0];
+  auto pb36 = &b[3][6];
+  auto pb2 = &b[2];
+  auto pb2a = b[2];
+
+  return a[3];
+
+  // CHECK: %[[ALLOCA:.+]] = memref.alloca() {alignment = 8 : i64} : memref<!named_tuple.named_tuple<"s", [i32, f64, i8, tensor<5xf32>]>>
+  // CHECK: %[[C_7:.+]] = arith.constant 7 : i32/home/rkeryell/Xilinx/Projects/LLVM/worktrees/clangir/build/bin/clang -cc1 -internal-isystem /home/rkeryell/Xilinx/Projects/LLVM/worktrees/clangir/build/lib/clang/20/include -nostdsysteminc -triple x86_64-unknown-linux-gnu -fno-clangir-direct-lowering -emit-mlir /home/rkeryell/Xilinx/Projects/LLVM/worktrees/clangir/clang/test/CIR/Lowering/ThroughMLIR/cast.cpp -o 
+  // CHECK: %[[I8_EQUIV_A:.+]] = named_tuple.cast %[[ALLOCA]] : memref<!named_tuple.named_tuple<"s", [i32, f64, i8, tensor<5xf32>]>> to memref<40xi8>
+  // CHECK: %[[OFFSET_A:.+]] = arith.constant 0 : index
+  // CHECK: %[[VIEW_A:.+]] = memref.view %[[I8_EQUIV_A]][%[[OFFSET_A]]][] : memref<40xi8> to memref<i32>
+  // CHECK: memref.store %[[C_7]], %[[VIEW_A]][] : memref<i32>
+ }

mlir/utils/emacs/mlir-lsp-client.el

@@ -1,4 +1,4 @@
-;;; mlir-lsp-clinet.el --- LSP clinet for the MLIR.
+;;; mlir-lsp-client.el --- LSP clinet for the MLIR.
 
 ;; Copyright (C) 2022 The MLIR Authors.
 ;;
@@ -18,7 +18,7 @@
 
 ;;; Commentary:
 
-;; LSP clinet to use with `mlir-mode' that uses `mlir-lsp-server' or any
+;; LSP client to use with `mlir-mode' that uses `mlir-lsp-server' or any
 ;; user made compatible server.
 
 ;;; Code: