From 7582b90456e08729ca2570f9ef21476a95b7fda9 Mon Sep 17 00:00:00 2001 From: Hubert Tong Date: Thu, 4 Apr 2019 00:33:57 +0000 Subject: [PATCH] [AIX] SelectionDAGNodes.h: Pack bit-fields that are meant to be packed Summary: Certain classes in the subject file are expected to provide different views of a two-byte field as a collection of various bit-fields. On AIX, the canonical layout of bit-fields would cause these classes to span four bytes. Applying the `pack` pragma for compilers that employ the AIX canonical layout allows these classes to fit within the expected two bytes. In the future, the pragma would also likely need to be applied when building with Clang on AIX. Reviewers: xingxue, sfertile, jasonliu Reviewed By: xingxue Subscribers: jsji, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D60164 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357661 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/SelectionDAGNodes.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h index e562ffcefd7..4bf37b631bd 100644 --- a/include/llvm/CodeGen/SelectionDAGNodes.h +++ b/include/llvm/CodeGen/SelectionDAGNodes.h @@ -488,6 +488,17 @@ protected: // SubclassData. These are designed to fit within a uint16_t so they pack // with NodeType. +#if defined(_AIX) && (!defined(__GNUC__) || defined(__ibmxl__)) +// Except for GCC; by default, AIX compilers store bit-fields in 4-byte words +// and give the `pack` pragma push semantics. +#define BEGIN_TWO_BYTE_PACK() _Pragma("pack(2)") +#define END_TWO_BYTE_PACK() _Pragma("pack(pop)") +#else +#define BEGIN_TWO_BYTE_PACK() +#define END_TWO_BYTE_PACK() +#endif + +BEGIN_TWO_BYTE_PACK() class SDNodeBitfields { friend class SDNode; friend class MemIntrinsicSDNode; @@ -560,6 +571,9 @@ protected: LoadSDNodeBitfields LoadSDNodeBits; StoreSDNodeBitfields StoreSDNodeBits; }; +END_TWO_BYTE_PACK() +#undef BEGIN_TWO_BYTE_PACK +#undef END_TWO_BYTE_PACK // RawSDNodeBits must cover the entirety of the union. This means that all of // the union's members must have size <= RawSDNodeBits. We write the RHS as -- 2.50.1