[flang] Merge GEPs in substring fir.embox codegen

[jeanPerier]

Summary

When computing the base addresses of an array slice to make a
descriptor, codegen generated two LLVM GEPs. The first to compute
the address of the base character element, and a second one to
compute the substring base inside that element.
The previous code did not care about getting the result of the first
GEP right: it used the base array LLVM type as the result type.
This used to work when opaque pointer were not enabled (the actual GEP
result type was probably applied in some later pass). But with opaque
pointers, the second GEP ends-up computing an offset of len*<LLVM array
type> instead of len*<character width>. A previous attempt to fix the
issue was done in D129079, but it does not cover the cases where the
array slice contains subcomponents before the substring
(e.g: array(:)%char_field(5:10)).

This patch fix the issue by computing the actual GEP result type in
codegen. There is also enough knowledge now so that a single GEP can be
generated instead of two.

[clementval]

LGTM. Maybe one typo.

flang/lib/Optimizer/CodeGen/CodeGen.cpp

1403

typo?

[jeanPerier]

Fix comment typo.

flang/lib/Optimizer/CodeGen/CodeGen.cpp

 
 static mlir::Block *createBlock(mlir::ConversionPatternRewriter &rewriter,
                                 mlir::Block *insertBefore) {
   assert(insertBefore && "expected valid insertion block");
   return rewriter.createBlock(insertBefore->getParent(),
                               mlir::Region::iterator(insertBefore));
 }
 
+/// Extract constant from a value that must be the result of one of the
+/// ConstantOp operations.
+static int64_t getConstantIntValue(mlir::Value val) {
+  assert(val && val.dyn_cast<mlir::OpResult>() && "must not be null value");
+  mlir::Operation *defop = val.getDefiningOp();
+
+  if (auto constOp = mlir::dyn_cast<mlir::arith::ConstantIntOp>(defop))
+    return constOp.value();
+  if (auto llConstOp = mlir::dyn_cast<mlir::LLVM::ConstantOp>(defop))
+    if (auto attr = llConstOp.getValue().dyn_cast<mlir::IntegerAttr>())
+      return attr.getValue().getSExtValue();
+  fir::emitFatalError(val.getLoc(), "must be a constant");
+}
+
 namespace {
 /// FIR conversion pattern template
 template <typename FromOp>
 class FIROpConversion : public mlir::ConvertOpToLLVMPattern<FromOp> {
 public:
   explicit FIROpConversion(fir::LLVMTypeConverter &lowering,
                            const fir::FIRToLLVMPassOptions &options)
       : mlir::ConvertOpToLLVMPattern<FromOp>(lowering), options(options) {}
if (hasAddendum) {
       descriptor =
           insertField(rewriter, loc, descriptor, {typeDescFieldId}, typeDesc,
                       /*bitCast=*/true);
     }
 
     return {boxTy, descriptor, eleSize};
   }
 
-  /// Compute the base address of a substring given the base address of a scalar
-  /// string and the zero based string lower bound.
-  mlir::Value shiftSubstringBase(mlir::ConversionPatternRewriter &rewriter,
-                                 mlir::Location loc, mlir::Value base,
-                                 mlir::Value lowerBound) const {
-    llvm::SmallVector<mlir::Value> gepOperands;
-    auto baseType =
+  // Compute the base address of a fir.box given the indices from the slice.
+  // The indices from the "outer" dimensions (every dimension after the first
+  // one (inlcuded) that is not a compile time constant) must have been
+  // multiplied with the related extents and added together into \p outerOffset.
+  mlir::Value
+  genBoxOffsetGep(mlir::ConversionPatternRewriter &rewriter, mlir::Location loc,
+                  mlir::Value base, mlir::Value outerOffset,
+                  mlir::ValueRange cstInteriorIndices,
+                  mlir::ValueRange componentIndices,
+                  llvm::Optional<mlir::Value> substringOffset) const {
+    llvm::SmallVector<mlir::Value> gepArgs{outerOffset};
+    mlir::Type resultTy =
         base.getType().cast<mlir::LLVM::LLVMPointerType>().getElementType();
-    if (auto arrayType = baseType.dyn_cast<mlir::LLVM::LLVMArrayType>()) {
-      // FIXME: The baseType should be the array element type here, meaning
-      // there should at most be one dimension (constant length characters are
-      // lowered to LLVM as an array of length one characters.). However, using
-      // the character type in the GEP does not lead to correct GEPs when llvm
-      // opaque pointers are enabled.
-      auto idxTy = this->lowerTy().indexType();
-      gepOperands.append(getDimension(arrayType),
-                         genConstantIndex(loc, idxTy, rewriter, 0));
-      gepOperands.push_back(lowerBound);
-    } else {
-      gepOperands.push_back(lowerBound);
+    // Fortran is column major, llvm GEP is row major: reverse the indices here.
+    for (mlir::Value interiorIndex : llvm::reverse(cstInteriorIndices)) {
+      auto arrayTy = resultTy.dyn_cast<mlir::LLVM::LLVMArrayType>();
+      if (!arrayTy)
+        fir::emitFatalError(
+            loc,
+            "corrupted GEP generated being generated in fir.embox/fir.rebox");
+      resultTy = arrayTy.getElementType();
+      gepArgs.push_back(interiorIndex);
+    }
+    for (mlir::Value componentIndex : componentIndices) {
+      // Component indices can be field index to select a component, or array
+      // index, to select an element in an array component.
+      if (auto structTy = resultTy.dyn_cast<mlir::LLVM::LLVMStructType>()) {
+        std::int64_t cstIndex = getConstantIntValue(componentIndex);
+        resultTy = structTy.getBody()[cstIndex];
+      } else if (auto arrayTy =
+                     resultTy.dyn_cast<mlir::LLVM::LLVMArrayType>()) {
+        resultTy = arrayTy.getElementType();
+      } else {
+        fir::emitFatalError(loc, "corrupted component GEP generated being "
+                                 "generated in fir.embox/fir.rebox");
+      }
+      gepArgs.push_back(componentIndex);
+    }
+    if (substringOffset) {
+      if (auto arrayTy = resultTy.dyn_cast<mlir::LLVM::LLVMArrayType>()) {
+        gepArgs.push_back(*substringOffset);
+        resultTy = arrayTy.getElementType();
+      } else {
+        // If the CHARACTER length is dynamic, the whole base type should have
+        // degenerated to an llvm.ptr<i[width]>, and there should not be any
+        // cstInteriorIndices/componentIndices. The substring offset can be
+        // added to the outterOffset since it applies on the same LLVM type.
+        if (gepArgs.size() != 1)
+          fir::emitFatalError(loc,
+                              "corrupted substring GEP in fir.embox/fir.rebox");
+        mlir::Type outterOffsetTy = gepArgs[0].getType();
+        mlir::Value cast =
+            this->integerCast(loc, rewriter, outterOffsetTy, *substringOffset);
+
+        gepArgs[0] = rewriter.create<mlir::LLVM::AddOp>(loc, outterOffsetTy,
+                                                        gepArgs[0], cast);
       }
-    return this->genGEP(loc, base.getType(), rewriter, base, gepOperands);
+    }
+    resultTy = mlir::LLVM::LLVMPointerType::get(resultTy);
+    return rewriter.create<mlir::LLVM::GEPOp>(loc, resultTy, base, gepArgs);
+  }
+
+  template <typename BOX>
+  void
+  getSubcomponentIndices(BOX xbox, mlir::Value memref,
+                         mlir::ValueRange operands,
+                         mlir::SmallVectorImpl<mlir::Value> &indices) const {
+    // For each field in the path add the offset to base via the args list.
+    // In the most general case, some offsets must be computed since
+    // they are not be known until runtime.
+    if (fir::hasDynamicSize(fir::unwrapSequenceType(
+            fir::unwrapPassByRefType(memref.getType()))))
+      TODO(xbox.getLoc(),
+           "fir.embox codegen dynamic size component in derived type");
+    indices.append(operands.begin() + xbox.subcomponentOffset(),
+                   operands.begin() + xbox.subcomponentOffset() +
+                       xbox.subcomponent().size());
   }
 
   /// If the embox is not in a globalOp body, allocate storage for the box;
   /// store the value inside and return the generated alloca. Return the input
   /// value otherwise.
   mlir::Value
   placeInMemoryIfNotGlobalInit(mlir::ConversionPatternRewriter &rewriter,
                                mlir::Location loc, mlir::Value boxValue) const {
matchAndRewrite(fir::cg::XEmboxOp xbox, OpAdaptor adaptor,
     bool hasSlice = !xbox.slice().empty();
     unsigned sliceOffset = xbox.sliceOffset();
     mlir::Location loc = xbox.getLoc();
     mlir::Value zero = genConstantIndex(loc, i64Ty, rewriter, 0);
     mlir::Value one = genConstantIndex(loc, i64Ty, rewriter, 1);
     mlir::Value prevPtrOff = one;
     mlir::Type eleTy = boxTy.getEleTy();
     const unsigned rank = xbox.getRank();
-    llvm::SmallVector<mlir::Value> gepArgs;
+    llvm::SmallVector<mlir::Value> cstInteriorIndices;
     unsigned constRows = 0;
     mlir::Value ptrOffset = zero;
     mlir::Type memEleTy = fir::dyn_cast_ptrEleTy(xbox.memref().getType());
     assert(memEleTy.isa<fir::SequenceType>());
     auto seqTy = memEleTy.cast<fir::SequenceType>();
     mlir::Type seqEleTy = seqTy.getEleTy();
     // Adjust the element scaling factor if the element is a dependent type.
     if (fir::hasDynamicSize(seqEleTy)) {
for (unsigned di = 0, descIdx = 0; di < rank; ++di) {
       bool skipNext = false;
       if (hasSlice) {
         mlir::Value off = operands[sliceOffset];
         mlir::Value adj = one;
         if (hasShift)
           adj = operands[shiftOffset];
         auto ao = rewriter.create<mlir::LLVM::SubOp>(loc, i64Ty, off, adj);
         if (constRows > 0) {
-          gepArgs.push_back(ao);
+          cstInteriorIndices.push_back(ao);
         } else {
           auto dimOff =
               rewriter.create<mlir::LLVM::MulOp>(loc, i64Ty, ao, prevPtrOff);
           ptrOffset =
               rewriter.create<mlir::LLVM::AddOp>(loc, i64Ty, dimOff, ptrOffset);
         }
         if (mlir::isa_and_nonnull<fir::UndefOp>(
                 xbox.slice()[3 * di + 1].getDefiningOp())) {
for (unsigned di = 0, descIdx = 0; di < rank; ++di) {
       // increment iterators
       ++shapeOffset;
       if (hasShift)
         ++shiftOffset;
       if (hasSlice)
         sliceOffset += 3;
     }
     if (hasSlice || hasSubcomp || hasSubstr) {
-      llvm::SmallVector<mlir::Value> args = {ptrOffset};
-      args.append(gepArgs.rbegin(), gepArgs.rend());
-      if (hasSubcomp) {
-        // For each field in the path add the offset to base via the args list.
-        // In the most general case, some offsets must be computed since
-        // they are not be known until runtime.
-        if (fir::hasDynamicSize(fir::unwrapSequenceType(
-                fir::unwrapPassByRefType(xbox.memref().getType()))))
-          TODO(loc, "fir.embox codegen dynamic size component in derived type");
-        args.append(operands.begin() + xbox.subcomponentOffset(),
-                    operands.begin() + xbox.subcomponentOffset() +
-                        xbox.subcomponent().size());
-      }
-      base =
-          rewriter.create<mlir::LLVM::GEPOp>(loc, base.getType(), base, args);
+      // Shift the base address.
+      llvm::SmallVector<mlir::Value> fieldIndices;
+      llvm::Optional<mlir::Value> substringOffset;
+      if (hasSubcomp)
+        getSubcomponentIndices(xbox, xbox.memref(), operands, fieldIndices);
       if (hasSubstr)
-        base = shiftSubstringBase(rewriter, loc, base,
-                                  operands[xbox.substrOffset()]);
+        substringOffset = operands[xbox.substrOffset()];
+      base = genBoxOffsetGep(rewriter, loc, base, ptrOffset, cstInteriorIndices,
+                             fieldIndices, substringOffset);
     }
     dest = insertBaseAddress(rewriter, loc, dest, base);
     if (isDerivedTypeWithLenParams(boxTy))
       TODO(loc, "fir.embox codegen of derived with length parameters");
 
     mlir::Value result = placeInMemoryIfNotGlobalInit(rewriter, loc, dest);
     rewriter.replaceOp(xbox, result);
     return mlir::success();
sliceBox(fir::cg::XReboxOp rebox, mlir::Value dest, mlir::Value base,
     // Apply subcomponent and substring shift on base address.
     if (!rebox.subcomponent().empty() || !rebox.substr().empty()) {
       // Cast to inputEleTy* so that a GEP can be used.
       mlir::Type inputEleTy = getInputEleTy(rebox);
       auto llvmElePtrTy =
           mlir::LLVM::LLVMPointerType::get(convertType(inputEleTy));
       base = rewriter.create<mlir::LLVM::BitcastOp>(loc, llvmElePtrTy, base);
 
-      if (!rebox.subcomponent().empty()) {
-        llvm::SmallVector<mlir::Value> gepOperands = {zero};
-        for (unsigned i = 0; i < rebox.subcomponent().size(); ++i)
-          gepOperands.push_back(operands[rebox.subcomponentOffset() + i]);
-        base = genGEP(loc, llvmElePtrTy, rewriter, base, gepOperands);
-      }
+      llvm::SmallVector<mlir::Value> fieldIndices;
+      llvm::Optional<mlir::Value> substringOffset;
+      if (!rebox.subcomponent().empty())
+        getSubcomponentIndices(rebox, rebox.box(), operands, fieldIndices);
       if (!rebox.substr().empty())
-        base = shiftSubstringBase(rewriter, loc, base,
-                                  operands[rebox.substrOffset()]);
+        substringOffset = operands[rebox.substrOffset()];
+      base = genBoxOffsetGep(rewriter, loc, base, zero,
+                             /*cstInteriorIndices=*/llvm::None, fieldIndices,
+                             substringOffset);
     }
 
     if (rebox.slice().empty())
       // The array section is of the form array[%component][substring], keep
       // the input array extents and strides.
       return finalizeRebox(rebox, dest, base, /*lbounds*/ llvm::None,
                            inputExtents, inputStrides, rewriter);
 
return rewriter.notifyMatchFailure(
         coor, "fir.coordinate_of base operand has unsupported type");
   }
 
   static unsigned getFieldNumber(fir::RecordType ty, mlir::Value op) {
     return fir::hasDynamicSize(ty)
                ? op.getDefiningOp()
                      ->getAttrOfType<mlir::IntegerAttr>("field")
                      .getInt()
-               : getIntValue(op);
-  }
-
-  static int64_t getIntValue(mlir::Value val) {
-    assert(val && val.dyn_cast<mlir::OpResult>() && "must not be null value");
-    mlir::Operation *defop = val.getDefiningOp();
-
-    if (auto constOp = mlir::dyn_cast<mlir::arith::ConstantIntOp>(defop))
-      return constOp.value();
-    if (auto llConstOp = mlir::dyn_cast<mlir::LLVM::ConstantOp>(defop))
-      if (auto attr = llConstOp.getValue().dyn_cast<mlir::IntegerAttr>())
-        return attr.getValue().getSExtValue();
-    fir::emitFatalError(val.getLoc(), "must be a constant");
+               : getConstantIntValue(op);
   }
 
   static bool hasSubDimensions(mlir::Type type) {
     return type.isa<fir::SequenceType, fir::RecordType, mlir::TupleType>();
   }
 
   /// Check whether this form of `!fir.coordinate_of` is supported. These
   /// additional checks are required, because we are not yet able to convert
for (; i < numOfCoors; ++i) {
         subEle = true;
         i += arrTy.getDimension() - 1;
         type = arrTy.getEleTy();
       } else if (auto recTy = type.dyn_cast<fir::RecordType>()) {
         subEle = true;
         type = recTy.getType(getFieldNumber(recTy, nxtOpnd));
       } else if (auto tupTy = type.dyn_cast<mlir::TupleType>()) {
         subEle = true;
-        type = tupTy.getType(getIntValue(nxtOpnd));
+        type = tupTy.getType(getConstantIntValue(nxtOpnd));
       } else {
         ptrEle = true;
       }
     }
     if (ptrEle)
       return (!subEle) && (numOfCoors == 1);
     return subEle && (i >= numOfCoors);
   }
 
   /// Walk the abstract memory layout and determine if the path traverses any
   /// array types with unknown shape. Return true iff all the array types have a
   /// constant shape along the path.
   static bool arraysHaveKnownShape(mlir::Type type, mlir::ValueRange coors) {
     for (std::size_t i = 0, sz = coors.size(); i < sz; ++i) {
       mlir::Value nxtOpnd = coors[i];
       if (auto arrTy = type.dyn_cast<fir::SequenceType>()) {
         if (fir::sequenceWithNonConstantShape(arrTy))
           return false;
         i += arrTy.getDimension() - 1;
         type = arrTy.getEleTy();
       } else if (auto strTy = type.dyn_cast<fir::RecordType>()) {
         type = strTy.getType(getFieldNumber(strTy, nxtOpnd));
       } else if (auto strTy = type.dyn_cast<mlir::TupleType>()) {
-        type = strTy.getType(getIntValue(nxtOpnd));
+        type = strTy.getType(getConstantIntValue(nxtOpnd));
       } else {
         return true;
       }
     }
     return true;
   }
 
 private:
if (hasKnownShape || columnIsDeferred) {
           offs.push_back(nxtOpnd);
           continue;
         }
 
         // check if the i-th coordinate relates to a field
         if (auto recTy = cpnTy.dyn_cast<fir::RecordType>())
           cpnTy = recTy.getType(getFieldNumber(recTy, nxtOpnd));
         else if (auto tupTy = cpnTy.dyn_cast<mlir::TupleType>())
-          cpnTy = tupTy.getType(getIntValue(nxtOpnd));
+          cpnTy = tupTy.getType(getConstantIntValue(nxtOpnd));
         else
           cpnTy = nullptr;
 
         offs.push_back(nxtOpnd);
       }
       if (dims)
         offs.append(arrIdx.rbegin(), arrIdx.rend());
       mlir::Value base = operands[0];

flang/test/Fir/convert-to-llvm.fir

 // CHECK:         %[[EXT_ADD:.*]] = llvm.add %[[EXT_SUB]], %[[C2]]  : i64
 // CHECK:         %[[EXT_SDIV:.*]] = llvm.sdiv %[[EXT_ADD]], %[[C2]]  : i64
 // CHECK:         %[[EXT_ICMP:.*]] = llvm.icmp "sgt" %[[EXT_SDIV]], %[[ZERO]] : i64
 // CHECK:         %[[EXT_SELECT:.*]] = llvm.select %[[EXT_ICMP]], %[[EXT_SDIV]], %[[ZERO]] : i1, i64
 // CHECK:         %[[BOX7:.*]] = llvm.insertvalue %[[ONE]], %[[BOX6]][7 : i32, 0 : i32, 0 : i32] : !llvm.struct<(ptr<i32>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, array<1 x array<3 x i64>>)>
 // CHECK:         %[[BOX8:.*]] = llvm.insertvalue %[[EXT_SELECT]], %[[BOX7]][7 : i32, 0 : i32, 1 : i32] : !llvm.struct<(ptr<i32>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, array<1 x array<3 x i64>>)>
 // CHECK:         %[[STRIDE_MUL:.*]] = llvm.mul %[[PTRTOINT_DTYPE_SIZE]], %[[C2]]  : i64
 // CHECK:         %[[BOX9:.*]] = llvm.insertvalue %[[STRIDE_MUL]], %[[BOX8]][7 : i32, 0 : i32, 2 : i32] : !llvm.struct<(ptr<i32>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, array<1 x array<3 x i64>>)>
-// CHECK:         %[[BASE_PTR:.*]] = llvm.getelementptr %[[X]][%[[ZERO]], %[[ADJUSTED_OFFSET]], 0] : (!llvm.ptr<array<20 x struct<"_QFtest_dt_sliceTt", (i32, i32)>>>, i64, i64) -> !llvm.ptr<array<20 x struct<"_QFtest_dt_sliceTt", (i32, i32)>>>
-// CHECK:         %[[ADDR_BITCAST:.*]] = llvm.bitcast %[[BASE_PTR]] : !llvm.ptr<array<20 x struct<"_QFtest_dt_sliceTt", (i32, i32)>>> to !llvm.ptr<i32>
+// CHECK:         %[[BASE_PTR:.*]] = llvm.getelementptr %[[X]][%[[ZERO]], %[[ADJUSTED_OFFSET]], 0] : (!llvm.ptr<array<20 x struct<"_QFtest_dt_sliceTt", (i32, i32)>>>, i64, i64) -> !llvm.ptr<i32>
+// CHECK:         %[[ADDR_BITCAST:.*]] = llvm.bitcast %[[BASE_PTR]] : !llvm.ptr<i32> to !llvm.ptr<i32>
 // CHECK:         %[[BOX10:.*]] = llvm.insertvalue %[[ADDR_BITCAST]], %[[BOX9]][0 : i32] : !llvm.struct<(ptr<i32>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, array<1 x array<3 x i64>>)>
 // CHECK:         llvm.store %[[BOX10]], %[[ALLOCA]] : !llvm.ptr<struct<(ptr<i32>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, array<1 x array<3 x i64>>)>>
 // CHECK:         llvm.call @_QPtest_dt_callee(%1) : (!llvm.ptr<struct<(ptr<i32>, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, i{{.*}}, array<1 x array<3 x i64>>)>>) -> ()
 
 // -----
 
 // Test `fircg.ext_array_coor` conversion.
 

 //CHECK:   %[[STRIDE_IDX:.*]] = llvm.mlir.constant(2 : i32) : i32
 //CHECK:   %[[SRC_STRIDE_PTR:.*]] = llvm.getelementptr %[[ARG0]][%[[ZERO_3]], 7, %[[DIM1]], %[[STRIDE_IDX]]] : (!llvm.ptr<struct<(ptr<struct<"t", (i32, array<10 x i8>)>>, i64, i32, i8, i8, i8, i8, array<1 x array<3 x i64>>, ptr<i8>, array<1 x i64>)>>, i32, i64, i32) -> !llvm.ptr<i64>
 //CHECK:   %[[SRC_STRIDE:.*]] = llvm.load %[[SRC_STRIDE_PTR]] : !llvm.ptr<i64>
 //CHECK:   %[[ZERO_4:.*]] = llvm.mlir.constant(0 : i32) : i32
 //CHECK:   %[[SRC_ARRAY_PTR:.*]] = llvm.getelementptr %[[ARG0]][%[[ZERO_4]], 0] : (!llvm.ptr<struct<(ptr<struct<"t", (i32, array<10 x i8>)>>, i64, i32, i8, i8, i8, i8, array<1 x array<3 x i64>>, ptr<i8>, array<1 x i64>)>>, i32) -> !llvm.ptr<ptr<struct<"t", (i32, array<10 x i8>)>>>
 //CHECK:   %[[SRC_ARRAY:.*]] = llvm.load %[[SRC_ARRAY_PTR]] : !llvm.ptr<ptr<struct<"t", (i32, array<10 x i8>)>>>
 //CHECK:   %[[ZERO_6:.*]] = llvm.mlir.constant(0 : i64) : i64
 //CHECK:   %[[SRC_CAST:.*]] = llvm.bitcast %[[SRC_ARRAY]] : !llvm.ptr<struct<"t", (i32, array<10 x i8>)>> to !llvm.ptr<struct<"t", (i32, array<10 x i8>)>>
-//CHECK:   %[[TMP_COMPONENT:.*]] = llvm.getelementptr %[[SRC_CAST]][%[[ZERO_6]], 1] : (!llvm.ptr<struct<"t", (i32, array<10 x i8>)>>, i64) -> !llvm.ptr<struct<"t", (i32, array<10 x i8>)>>
-//CHECK:   %[[COMPONENT:.*]] = llvm.getelementptr %[[TMP_COMPONENT]][%[[COMPONENT_OFFSET_1]]] : (!llvm.ptr<struct<"t", (i32, array<10 x i8>)>>, i64) -> !llvm.ptr<struct<"t", (i32, array<10 x i8>)>>
-//CHECK:   %[[COMPONENT_CAST:.*]] = llvm.bitcast %[[COMPONENT]] : !llvm.ptr<struct<"t", (i32, array<10 x i8>)>> to !llvm.ptr<i8>
+//CHECK:   %[[COMPONENT:.*]] = llvm.getelementptr %[[SRC_CAST]][%[[ZERO_6]], 1, %[[COMPONENT_OFFSET_1]]] : (!llvm.ptr<struct<"t", (i32, array<10 x i8>)>>, i64, i64) -> !llvm.ptr<i8>
+//CHECK:   %[[COMPONENT_CAST:.*]] = llvm.bitcast %[[COMPONENT]] : !llvm.ptr<i8> to !llvm.ptr<i8>
 //CHECK:   %[[SRC_LB:.*]] = llvm.mlir.constant(1 : i64) : i64
 //CHECK:   %[[RESULT_TMP0:.*]] = llvm.sub %[[RESULT_LB]], %[[SRC_LB]]  : i64
 //CHECK:   %[[RESULT_OFFSET_START:.*]] = llvm.mul %[[RESULT_TMP0]], %[[SRC_STRIDE]]  : i64
 //CHECK:   %[[RESULT_PTR_I8:.*]] = llvm.getelementptr %[[COMPONENT_CAST]][%[[RESULT_OFFSET_START]]] : (!llvm.ptr<i8>, i64) -> !llvm.ptr<i8>
 //CHECK:   %[[RESULT_TMP1:.*]] = llvm.sub %[[RESULT_UB]], %[[RESULT_LB]]  : i64
 //CHECK:   %[[RESULT_TMP2:.*]] = llvm.add %[[RESULT_TMP1]], %[[RESULT_STRIDE]]  : i64
 //CHECK:   %[[RESULT_TMP3:.*]] = llvm.sdiv %[[RESULT_TMP2]], %[[RESULT_STRIDE]]  : i64
 //CHECK:   %[[RESULT_TMP_PRED:.*]] = llvm.icmp "sgt" %[[RESULT_TMP3]], %[[ZERO_6]] : i64

flang/test/Fir/embox.fir

func.func @emboxSubstring(%arg0: !fir.ref<!fir.array<2x3x!fir.char<1,4>>>) {
   %c2 = arith.constant 2 : index
   %c3 = arith.constant 3 : index
   %c1 = arith.constant 1 : index
   %c1_i64 = arith.constant 1 : i64
   %c2_i64 = arith.constant 2 : i64
   %0 = fir.shape %c2, %c3 : (index, index) -> !fir.shape<2>
   %1 = fir.slice %c1, %c2, %c1, %c1, %c3, %c1 substr %c1_i64, %c2_i64 : (index, index, index, index, index, index, i64, i64) -> !fir.slice<2>
   %2 = fir.embox %arg0(%0) [%1] : (!fir.ref<!fir.array<2x3x!fir.char<1,4>>>, !fir.shape<2>, !fir.slice<2>) -> !fir.box<!fir.array<?x?x!fir.char<1,?>>>
-  // CHECK: %[[addr:.*]] = getelementptr [3 x [2 x [4 x i8]]], ptr %[[arg0]], i64 0, i64 0, i64 0
-  // CHECK: %[[substringAddr:.*]] = getelementptr {{.*}}, ptr %[[addr]], i64 0, i64 0, i64 0, i64 1
+  // CHECK: %[[addr:.*]] = getelementptr [3 x [2 x [4 x i8]]], ptr %[[arg0]], i64 0, i64 0, i64 0, i64 1
   // CHECK: insertvalue {[[descriptorType:.*]]} { ptr undef, i64 2, i32 20180515, i8 2, i8 40, i8 0, i8 0,
   // CHECK-SAME: [2 x [3 x i64]] [{{\[}}3 x i64] [i64 1, i64 2, i64 4], [3 x i64] [i64 1, i64 3, i64 8]] },
-  // CHECK-SAME: ptr %[[substringAddr]], 0
+  // CHECK-SAME: ptr %[[addr]], 0
 
   fir.call @takesRank2CharBox(%2) : (!fir.box<!fir.array<?x?x!fir.char<1,?>>>) -> ()
   return
 }
 
 func.func private @do_something(!fir.box<!fir.array<?xf32>>) -> ()
 // CHECK: define void @fir_dev_issue_1416
 // CHECK-SAME: ptr %[[base_addr:.*]], i64 %[[low:.*]], i64 %[[up:.*]], i64 %[[at:.*]])

flang/test/Fir/rebox-susbtring.fir

 
 // CHECK:         %[[VAL_4:.*]] = llvm.mlir.constant(1 : i64) : i64
 // CHECK:         %[[VAL_7:.*]] = llvm.mlir.constant(0 : i32) : i32
 // CHECK:         %[[VAL_30:.*]] = llvm.mlir.constant(0 : i64) : i64
 
 // CHECK:         %[[VAL_37:.*]] = llvm.getelementptr %[[VAL_0]]{{\[}}%[[VAL_7]], 0] : (!llvm.ptr<[[char20_descriptor_t]]>)>>, i32) -> !llvm.ptr<ptr<array<20 x i8>>>
 // CHECK:         %[[VAL_38:.*]] = llvm.load %[[VAL_37]] : !llvm.ptr<ptr<array<20 x i8>>>
 // CHECK:         %[[VAL_39:.*]] = llvm.bitcast %[[VAL_38]] : !llvm.ptr<array<20 x i8>> to !llvm.ptr<array<20 x i8>>
-// CHECK:         %[[VAL_40:.*]] = llvm.getelementptr %[[VAL_39]]{{\[}}%[[VAL_30]], %[[VAL_4]]] : (!llvm.ptr<array<20 x i8>>, i64, i64) -> !llvm.ptr<array<20 x i8>>
-// CHECK:         llvm.bitcast %[[VAL_40]] : !llvm.ptr<array<20 x i8>> to !llvm.ptr<i8>
+// CHECK:         %[[VAL_40:.*]] = llvm.getelementptr %[[VAL_39]]{{\[}}%[[VAL_30]], %[[VAL_4]]] : (!llvm.ptr<array<20 x i8>>, i64, i64) -> !llvm.ptr<i8>
+// CHECK:         llvm.bitcast %[[VAL_40]] : !llvm.ptr<i8> to !llvm.ptr<i8>
 
 // More offset computation with descriptor strides and triplets that is not character specific ...
 
   %2 = fir.rebox %arg0 [%1] : (!fir.box<!fir.array<?x!fir.char<1,20>>>, !fir.slice<1>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
   fir.call @bar(%2) : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> ()
   return
 }
 

 // CHECK:         %[[VAL_1:.*]] = llvm.mlir.constant(1 : i32) : i32
 // CHECK:         %[[VAL_4:.*]] = llvm.mlir.constant(1 : i64) : i64
 // CHECK:         %[[VAL_17:.*]] = llvm.mlir.constant(0 : i32) : i32
 // CHECK:         %[[VAL_21:.*]] = llvm.mlir.constant(0 : i64) : i64
 
 // CHECK:         %[[VAL_30:.*]] = llvm.getelementptr %[[VAL_0]]{{\[}}%[[VAL_17]], 0] : (!llvm.ptr<[[struct_t_descriptor:.*]]>, i32) -> !llvm.ptr<ptr<[[struct_t]]>>
 // CHECK:         %[[VAL_31:.*]] = llvm.load %[[VAL_30]] : !llvm.ptr<ptr<[[struct_t]]>>
 // CHECK:         %[[VAL_32:.*]] = llvm.bitcast %[[VAL_31]] : !llvm.ptr<[[struct_t]]> to !llvm.ptr<[[struct_t]]>
-// CHECK:         %[[VAL_33:.*]] = llvm.getelementptr %[[VAL_32]]{{\[}}%[[VAL_21]], 1] : (!llvm.ptr<[[struct_t]]>, i64) -> !llvm.ptr<[[struct_t]]>
-// CHECK:         %[[VAL_34:.*]] = llvm.getelementptr %[[VAL_33]]{{\[}}%[[VAL_4]]] : (!llvm.ptr<[[struct_t]]>, i64) -> !llvm.ptr<[[struct_t]]>
-// CHECK:         llvm.bitcast %[[VAL_34]] : !llvm.ptr<[[struct_t]]> to !llvm.ptr<i8>
+// CHECK:         %[[VAL_33:.*]] = llvm.getelementptr %[[VAL_32]]{{\[}}%[[VAL_21]], 1, %[[VAL_4]]] : (!llvm.ptr<[[struct_t]]>, i64, i64) -> !llvm.ptr<i8>
+// CHECK:         llvm.bitcast %[[VAL_33]] : !llvm.ptr<i8> to !llvm.ptr<i8>
 
 // More offset computation with descriptor strides and triplets that is not character specific ...
 
   %2 = fir.rebox %arg0 [%1] : (!fir.box<!fir.array<?x!fir.type<t{i:i32,c:!fir.char<1,10>}>>>, !fir.slice<1>) -> !fir.box<!fir.array<?x!fir.char<1,?>>>
   fir.call @bar(%2) : (!fir.box<!fir.array<?x!fir.char<1,?>>>) -> ()
   return
 }