https://github.com/AmrDeveloper updated https://github.com/llvm/llvm-project/pull/169404
>From 67e56c1e4c6e15a0ce0bcf4f53a12679042ef795 Mon Sep 17 00:00:00 2001 From: Amr Hesham <[email protected]> Date: Mon, 24 Nov 2025 21:19:53 +0100 Subject: [PATCH 1/2] [CIR] CountOf VLA with Array element type --- clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp | 29 ++++++++++++++++------ clang/test/CIR/CodeGen/count-of.c | 28 +++++++++++++++++++++ 2 files changed, 49 insertions(+), 8 deletions(-) create mode 100644 clang/test/CIR/CodeGen/count-of.c diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp index 7c94743d5ffc6..feb019292715c 100644 --- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp @@ -2325,14 +2325,27 @@ mlir::Value ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( const QualType typeToSize = e->getTypeOfArgument(); const mlir::Location loc = cgf.getLoc(e->getSourceRange()); if (auto kind = e->getKind(); - kind == UETT_SizeOf || kind == UETT_DataSizeOf) { - if (cgf.getContext().getAsVariableArrayType(typeToSize)) { - cgf.getCIRGenModule().errorNYI(e->getSourceRange(), - "sizeof operator for VariableArrayType", - e->getStmtClassName()); - return builder.getConstant( - loc, cir::IntAttr::get(cgf.cgm.uInt64Ty, - llvm::APSInt(llvm::APInt(64, 1), true))); + kind == UETT_SizeOf || kind == UETT_DataSizeOf || kind == UETT_CountOf) { + if (const VariableArrayType *vat = + cgf.getContext().getAsVariableArrayType(typeToSize)) { + // For _Countof, we only want to evaluate if the extent is actually + // variable as opposed to a multi-dimensional array whose extent is + // constant but whose element type is variable. + bool evaluateExtent = true; + if (kind == UETT_CountOf && vat->getElementType()->isArrayType()) { + evaluateExtent = + !vat->getSizeExpr()->isIntegerConstantExpr(cgf.getContext()); + } + + if (evaluateExtent) { + cgf.getCIRGenModule().errorNYI( + e->getSourceRange(), + "sizeof operator for VariableArrayType & evaluateExtent", + e->getStmtClassName()); + return builder.getConstant( + loc, cir::IntAttr::get(cgf.cgm.uInt64Ty, + -llvm::APSInt(llvm::APInt(64, 1), true))); + } } } else if (e->getKind() == UETT_OpenMPRequiredSimdAlign) { cgf.getCIRGenModule().errorNYI( diff --git a/clang/test/CIR/CodeGen/count-of.c b/clang/test/CIR/CodeGen/count-of.c new file mode 100644 index 0000000000000..78c905e285969 --- /dev/null +++ b/clang/test/CIR/CodeGen/count-of.c @@ -0,0 +1,28 @@ +// RUN: %clang_cc1 -std=c2y -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-cir %s -o %t.cir +// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR +// RUN: %clang_cc1 -std=c2y -triple x86_64-unknown-linux-gnu -Wno-unused-value -fclangir -emit-llvm %s -o %t-cir.ll +// RUN: FileCheck --input-file=%t-cir.ll %s -check-prefix=LLVM +// RUN: %clang_cc1 -std=c2y -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll +// RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG + +unsigned long vla_with_array_element_type() { + long size; +#define int_arr int[5] + return _Countof(int_arr[size]); +} + +// CIR: %[[RET_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["__retval"] +// CIR: %[[SIZE_ADDR:.*]] = cir.alloca !s64i, !cir.ptr<!s64i>, ["size"] +// CIR: %[[CONST_5:.*]] = cir.const #cir.int<5> : !u64i +// CIR: cir.store %[[CONST_5]], %[[RET_ADDR]] : !u64i, !cir.ptr<!u64i> +// CIR: %[[RET_VAL:.*]] = cir.load %[[RET_ADDR]] : !cir.ptr<!u64i>, !u64i +// CIR: cir.return %[[RET_VAL]] : !u64i + +// LLVM: %[[RET_ADDR:.*]] = alloca i64, i64 1, align 8 +// LLVM: %[[SIZE_ADDR:.*]] = alloca i64, i64 1, align 8 +// LLVM: store i64 5, ptr %[[RET_ADDR]], align 8 +// LLVM: %[[RET_VAL:.*]] = load i64, ptr %[[RET_ADDR]], align 8 +// LLVM: ret i64 %[[RET_VAL]] + +// OGCG: %[[SIZE_ADDR:.*]] = alloca i64, align 8 +// OGCG: ret i64 5 >From 8eede9c71ab10cb21bc21157fae8543e572215ed Mon Sep 17 00:00:00 2001 From: Amr Hesham <[email protected]> Date: Tue, 25 Nov 2025 19:58:55 +0100 Subject: [PATCH 2/2] Address code review comments --- clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp | 18 +++++++++++++ clang/lib/CIR/CodeGen/CIRGenFunction.cpp | 8 ++++++ clang/lib/CIR/CodeGen/CIRGenFunction.h | 4 +++ clang/test/CIR/CodeGen/count-of.c | 30 +++++++++++++++++++--- 4 files changed, 57 insertions(+), 3 deletions(-) diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp index feb019292715c..a8c2061ddbd6c 100644 --- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp @@ -2338,6 +2338,24 @@ mlir::Value ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr( } if (evaluateExtent) { + if (e->isArgumentType()) { + // sizeof(type) - make sure to emit the VLA size. + cgf.emitVariablyModifiedType(typeToSize); + } else { + // C99 6.5.3.4p2: If the argument is an expression of type + // VLA, it is evaluated. + cgf.getCIRGenModule().errorNYI( + e->getSourceRange(), + "sizeof operator for VariableArrayType & evaluateExtent " + "ignoredExpr", + e->getStmtClassName()); + return {}; + } + + // For _Countof, we just want to return the size of a single dimension. + if (kind == UETT_CountOf) + return cgf.getVLAElements1D(vat).numElts; + cgf.getCIRGenModule().errorNYI( e->getSourceRange(), "sizeof operator for VariableArrayType & evaluateExtent", diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp index 33bdfa315a9ea..5150a1682f712 100644 --- a/clang/lib/CIR/CodeGen/CIRGenFunction.cpp +++ b/clang/lib/CIR/CodeGen/CIRGenFunction.cpp @@ -1138,6 +1138,14 @@ CIRGenFunction::getVLASize(const VariableArrayType *type) { return {numElements, elementType}; } +CIRGenFunction::VlaSizePair +CIRGenFunction::getVLAElements1D(const VariableArrayType *vla) { + mlir::Value vlaSize = vlaSizeMap[vla->getSizeExpr()]; + assert(vlaSize && "no size for VLA!"); + assert(vlaSize->getType() == sizeTy); + return {vlaSize, vla->getElementType()}; +} + // TODO(cir): Most of this function can be shared between CIRGen // and traditional LLVM codegen void CIRGenFunction::emitVariablyModifiedType(QualType type) { diff --git a/clang/lib/CIR/CodeGen/CIRGenFunction.h b/clang/lib/CIR/CodeGen/CIRGenFunction.h index 9adac089ea28b..b6926bb88ac85 100644 --- a/clang/lib/CIR/CodeGen/CIRGenFunction.h +++ b/clang/lib/CIR/CodeGen/CIRGenFunction.h @@ -498,6 +498,10 @@ class CIRGenFunction : public CIRGenTypeCache { VlaSizePair(mlir::Value num, QualType ty) : numElts(num), type(ty) {} }; + /// Return the number of elements for a single dimension + /// for the given array type. + VlaSizePair getVLAElements1D(const VariableArrayType *vla); + /// Returns an MLIR::Value+QualType pair that corresponds to the size, /// in non-variably-sized elements, of a variable length array type, /// plus that largest non-variably-sized element type. Assumes that diff --git a/clang/test/CIR/CodeGen/count-of.c b/clang/test/CIR/CodeGen/count-of.c index 78c905e285969..1fd1290c42e6b 100644 --- a/clang/test/CIR/CodeGen/count-of.c +++ b/clang/test/CIR/CodeGen/count-of.c @@ -5,10 +5,9 @@ // RUN: %clang_cc1 -std=c2y -triple x86_64-unknown-linux-gnu -Wno-unused-value -emit-llvm %s -o %t.ll // RUN: FileCheck --input-file=%t.ll %s -check-prefix=OGCG -unsigned long vla_with_array_element_type() { +unsigned long vla_with_array_element_type_with_const_size() { long size; -#define int_arr int[5] - return _Countof(int_arr[size]); + return _Countof(int[5][size]); } // CIR: %[[RET_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["__retval"] @@ -26,3 +25,28 @@ unsigned long vla_with_array_element_type() { // OGCG: %[[SIZE_ADDR:.*]] = alloca i64, align 8 // OGCG: ret i64 5 + +unsigned long vla_with_array_element_type_non_const_size() { + long size; + return _Countof(int[size][size]); +} + +// CIR: %[[REET_ADDR:.*]] = cir.alloca !u64i, !cir.ptr<!u64i>, ["__retval"] +// CIR: %[[SIZE_ADDR:.*]] = cir.alloca !s64i, !cir.ptr<!s64i>, ["size"] +// CIR: %[[TMP_SIZE:.*]] = cir.load {{.*}} %[[SIZE_ADDR]] : !cir.ptr<!s64i>, !s64i +// CIR: %[[TMP_SIZE_U64:.*]] = cir.cast integral %[[TMP_SIZE]] : !s64i -> !u64i +// CIR: cir.store %[[TMP_SIZE_U64]], %[[RET_ADDR]] : !u64i, !cir.ptr<!u64i> +// CIR: %[[TMP_RET:.*]] = cir.load %[[RET_ADDR]] : !cir.ptr<!u64i>, !u64i +// CIR: cir.return %[[TMP_RET]] : !u64i + +// LLVM: %[[RET_ADDR:.*]] = alloca i64, i64 1, align 8 +// LLVM: %[[SIZE_ADDR:.*]] = alloca i64, i64 1, align 8 +// LLVM: %[[TMP_SIZE:.*]] = load i64, ptr %[[SIZE_ADDR]], align 8 +// LLVM: store i64 %[[TMP_SIZE]], ptr %[[RET_ADDR]], align 8 +// LLVM: %[[TMP_RET:.*]] = load i64, ptr %[[RET_ADDR]], align 8 +// LLVM: ret i64 %[[TMP_RET]] + +// OGCG: %[[SIZE_ADDR:.*]] = alloca i64, align 8 +// OGCG: %[[TMP_SIZE:.*]] = load i64, ptr %[[SIZE_ADDR]], align 8 +// OGCG: %[[TMP_SIZE_2:.*]] = load i64, ptr %[[SIZE_ADDR]], align 8 +// OGCG: ret i64 %[[TMP_SIZE]] _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
