Author: arphaman Date: Wed Jan 31 13:59:02 2018 New Revision: 323921 URL: http://llvm.org/viewvc/llvm-project?rev=323921&view=rev Log: [PR32482] Fix bitfield layout for -mms-bitfield and pragma pack
The patch ensures that a new storage unit is created when the new bitfield's size is wider than the available bits. rdar://36343145 Differential Revision: https://reviews.llvm.org/D42660 Modified: cfe/trunk/lib/AST/RecordLayoutBuilder.cpp cfe/trunk/test/CodeGen/mms-bitfields.c cfe/trunk/test/Sema/mms-bitfields.c Modified: cfe/trunk/lib/AST/RecordLayoutBuilder.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/RecordLayoutBuilder.cpp?rev=323921&r1=323920&r2=323921&view=diff ============================================================================== --- cfe/trunk/lib/AST/RecordLayoutBuilder.cpp (original) +++ cfe/trunk/lib/AST/RecordLayoutBuilder.cpp Wed Jan 31 13:59:02 2018 @@ -1504,9 +1504,10 @@ void ItaniumRecordLayoutBuilder::LayoutB FieldAlign = TypeSize; // If the previous field was not a bitfield, or was a bitfield - // with a different storage unit size, we're done with that - // storage unit. - if (LastBitfieldTypeSize != TypeSize) { + // with a different storage unit size, or if this field doesn't fit into + // the current storage unit, we're done with that storage unit. + if (LastBitfieldTypeSize != TypeSize || + UnfilledBitsInLastUnit < FieldSize) { // Also, ignore zero-length bitfields after non-bitfields. if (!LastBitfieldTypeSize && !FieldSize) FieldAlign = 1; Modified: cfe/trunk/test/CodeGen/mms-bitfields.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/mms-bitfields.c?rev=323921&r1=323920&r2=323921&view=diff ============================================================================== --- cfe/trunk/test/CodeGen/mms-bitfields.c (original) +++ cfe/trunk/test/CodeGen/mms-bitfields.c Wed Jan 31 13:59:02 2018 @@ -20,3 +20,46 @@ struct s3 { } s3; // CHECK: %struct.s3 = type { i32, [4 x i8], %struct.s1 } + +// PR32482: + +#pragma pack (push,1) + +typedef unsigned int UINT32; + +struct Inner { + UINT32 A : 1; + UINT32 B : 1; + UINT32 C : 1; + UINT32 D : 30; +} Inner; + +#pragma pack (pop) + +// CHECK: %struct.Inner = type { i32, i32 } + +// CHECK: %struct.A = type { i32, i32, i32 } + +#pragma pack(push, 1) + +union HEADER { + struct A { + int : 3; // Bits 2:0 + int a : 9; // Bits 11:3 + int : 12; // Bits 23:12 + int b : 17; // Bits 40:24 + int : 7; // Bits 47:41 + int c : 4; // Bits 51:48 + int : 4; // Bits 55:52 + int d : 3; // Bits 58:56 + int : 5; // Bits 63:59 + } Bits; +} HEADER; + +#pragma pack(pop) + +struct Inner variable = { 1,0,1, 21 }; +union HEADER hdr = {{1,2,3,4}}; + +// CHECK: @variable = global { i8, [3 x i8], i8, i8, i8, i8 } { i8 5, [3 x i8] undef, i8 21, i8 0, i8 0, i8 0 }, align 1 +// CHECK: @hdr = global { { i8, i8, [2 x i8], i8, i8, i8, i8, i8, [3 x i8] } } { { i8, i8, [2 x i8], i8, i8, i8, i8, i8, [3 x i8] } { i8 8, i8 0, [2 x i8] undef, i8 2, i8 0, i8 0, i8 3, i8 4, [3 x i8] undef } }, align 1 Modified: cfe/trunk/test/Sema/mms-bitfields.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/mms-bitfields.c?rev=323921&r1=323920&r2=323921&view=diff ============================================================================== --- cfe/trunk/test/Sema/mms-bitfields.c (original) +++ cfe/trunk/test/Sema/mms-bitfields.c Wed Jan 31 13:59:02 2018 @@ -11,3 +11,18 @@ struct // MS pads out bitfields between different types. static int arr[(sizeof(t) == 8) ? 1 : -1]; + +#pragma pack (push,1) + +typedef unsigned int UINT32; + +struct Inner { + UINT32 A : 1; + UINT32 B : 1; + UINT32 C : 1; + UINT32 D : 30; +} Inner; + +#pragma pack (pop) + +static int arr2[(sizeof(Inner) == 8) ? 1 : -1]; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
