Correct struct pointer offset calc (#279)

* Correct struct pointer offset calc

* fix test

* fix test

Author: ivanradanov

tools/cgeist/Lib/clang-mlir.cc

@@ -2740,12 +2740,20 @@ ValueCategory MLIRScanner::VisitBinaryOperator(clang::BinaryOperator *BO) {
     auto lhs_v = lhs.getValue(loc, builder);
     auto rhs_v = rhs.getValue(loc, builder);
     if (auto mt = lhs_v.getType().dyn_cast<mlir::MemRefType>()) {
+      mlir::Type innerType = mt.getElementType();
+      auto shape = mt.getShape();
+      for (size_t i = 1; i < shape.size(); i++)
+        innerType = LLVM::LLVMArrayType::get(innerType, shape[i]);
       lhs_v = builder.create<polygeist::Memref2PointerOp>(
-          loc, LLVM::LLVMPointerType::get(mt.getElementType()), lhs_v);
+          loc, LLVM::LLVMPointerType::get(innerType), lhs_v);
     }
     if (auto mt = rhs_v.getType().dyn_cast<mlir::MemRefType>()) {
+      mlir::Type innerType = mt.getElementType();
+      auto shape = mt.getShape();
+      for (size_t i = 1; i < shape.size(); i++)
+        innerType = LLVM::LLVMArrayType::get(innerType, shape[i]);
       rhs_v = builder.create<polygeist::Memref2PointerOp>(
-          loc, LLVM::LLVMPointerType::get(mt.getElementType()), rhs_v);
+          loc, LLVM::LLVMPointerType::get(innerType), rhs_v);
     }
     if (lhs_v.getType().isa<mlir::FloatType>()) {
       assert(rhs_v.getType() == lhs_v.getType());

tools/cgeist/Test/Verification/memrefsubstract.c

@@ -0,0 +1,34 @@
+// RUN: cgeist %s --function=* -S | FileCheck %s
+
+struct latLong
+{
+  int lat;
+  int lng;
+};
+
+int foo(struct latLong *a, struct latLong *b) {
+  return a - b;
+}
+struct latLong *bar(struct latLong *a, int b) {
+  return a - b;
+}
+
+// CHECK:  func.func @foo(%arg0: memref<?x2xi32>, %arg1: memref<?x2xi32>) -> i32
+// CHECK-NEXT:    %c8_i64 = arith.constant 8 : i64
+// CHECK-DAG:    %[[i0:.*]] = "polygeist.memref2pointer"(%arg0) : (memref<?x2xi32>) -> !llvm.ptr<array<2 x i32>>
+// CHECK-DAG:    %[[i1:.*]] = "polygeist.memref2pointer"(%arg1) : (memref<?x2xi32>) -> !llvm.ptr<array<2 x i32>>
+// CHECK-DAG:    %[[i2:.*]] = llvm.ptrtoint %[[i0]] : !llvm.ptr<array<2 x i32>> to i64
+// CHECK-DAG:    %[[i3:.*]] = llvm.ptrtoint %[[i1]] : !llvm.ptr<array<2 x i32>> to i64
+// CHECK-NEXT:    %4 = arith.subi %[[i2]], %[[i3]] : i64
+// CHECK-NEXT:    %5 = arith.divsi %4, %c8_i64 : i64
+// CHECK-NEXT:    %6 = arith.trunci %5 : i64 to i32
+// CHECK-NEXT:    return %6 : i32
+// CHECK-NEXT:  }
+// CHECK:  func.func @bar(%arg0: memref<?x2xi32>, %arg1: i32) -> memref<?x2xi32>
+// CHECK-NEXT:    %c0_i32 = arith.constant 0 : i32
+// CHECK-NEXT:    %0 = "polygeist.memref2pointer"(%arg0) : (memref<?x2xi32>) -> !llvm.ptr<array<2 x i32>>
+// CHECK-NEXT:    %1 = arith.subi %c0_i32, %arg1 : i32
+// CHECK-NEXT:    %2 = llvm.getelementptr %0[%1] : (!llvm.ptr<array<2 x i32>>, i32) -> !llvm.ptr<array<2 x i32>>
+// CHECK-NEXT:    %3 = "polygeist.pointer2memref"(%2) : (!llvm.ptr<array<2 x i32>>) -> memref<?x2xi32>
+// CHECK-NEXT:    return %3 : memref<?x2xi32>
+// CHECK-NEXT:  }