Author: Timm Baeder Date: 2025-04-24T11:01:46+02:00 New Revision: 55066b83612b6bcc8c38ef6a84e5230ad116730f
URL: https://github.com/llvm/llvm-project/commit/55066b83612b6bcc8c38ef6a84e5230ad116730f DIFF: https://github.com/llvm/llvm-project/commit/55066b83612b6bcc8c38ef6a84e5230ad116730f.diff LOG: [clang][bytecode] Compute pointer differences as 64bit integers (#137128) And only convert to the target type after that. Added: clang/test/AST/ByteCode/i686.cpp Modified: clang/lib/AST/ByteCode/Interp.h Removed: ################################################################################ diff --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h index 588e0502fa88c..99b032bee9e3d 100644 --- a/clang/lib/AST/ByteCode/Interp.h +++ b/clang/lib/AST/ByteCode/Interp.h @@ -2161,16 +2161,22 @@ inline bool SubPtr(InterpState &S, CodePtr OpPC) { } } - T A = LHS.isBlockPointer() - ? (LHS.isElementPastEnd() ? T::from(LHS.getNumElems()) - : T::from(LHS.getIndex())) - : T::from(LHS.getIntegerRepresentation()); - T B = RHS.isBlockPointer() - ? (RHS.isElementPastEnd() ? T::from(RHS.getNumElems()) - : T::from(RHS.getIndex())) - : T::from(RHS.getIntegerRepresentation()); - - return AddSubMulHelper<T, T::sub, std::minus>(S, OpPC, A.bitWidth(), A, B); + int64_t A64 = + LHS.isBlockPointer() + ? (LHS.isElementPastEnd() ? LHS.getNumElems() : LHS.getIndex()) + : LHS.getIntegerRepresentation(); + + int64_t B64 = + RHS.isBlockPointer() + ? (RHS.isElementPastEnd() ? RHS.getNumElems() : RHS.getIndex()) + : RHS.getIntegerRepresentation(); + + int64_t R64 = A64 - B64; + if (static_cast<int64_t>(T::from(R64)) != R64) + return handleOverflow(S, OpPC, R64); + + S.Stk.push<T>(T::from(R64)); + return true; } //===----------------------------------------------------------------------===// diff --git a/clang/test/AST/ByteCode/i686.cpp b/clang/test/AST/ByteCode/i686.cpp new file mode 100644 index 0000000000000..ad914203d3c4b --- /dev/null +++ b/clang/test/AST/ByteCode/i686.cpp @@ -0,0 +1,14 @@ +// RUN: %clang_cc1 -triple i686-pc-linux-gnu -fexperimental-new-constant-interpreter -verify=expected,both %s +// RUN: %clang_cc1 -triple i686-pc-linux-gnu -verify=ref,both %s + + +char melchizedek[2200000000]; +typedef decltype(melchizedek[1] - melchizedek[0]) ptr diff _t; +constexpr ptr diff _t d1 = &melchizedek[0x7fffffff] - &melchizedek[0]; +constexpr ptr diff _t d2 = &melchizedek[0x80000000u] - &melchizedek[0]; // both-error {{constant expression}} \ + // both-note {{ 2147483648 }} +constexpr ptr diff _t d3 = &melchizedek[0] - &melchizedek[0x80000000u]; +constexpr ptr diff _t d4 = &melchizedek[0] - &melchizedek[0x80000001u]; // both-error {{constant expression}} \ + // both-note {{ -2147483649 }} + + _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
