Reserve some constant values for the Swift calling convention.

Swift has a custom calling convention that also requires some new flags
on arguments and one new attribute on alloca instructions. This patch
does not include the implementation of that calling convention - that
will be provided as part of the open-source release of Swift; this only
reserves the bitcode constant values so that they are not used for
other purposes.

llvm-svn: 243379

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index c04e8b9..de91150 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -4081,6 +4081,8 @@ std::error_code BitcodeReader::parseFunctionBody(Function *F) {
       uint64_t AlignRecord = Record[3];
       const uint64_t InAllocaMask = uint64_t(1) << 5;
       const uint64_t ExplicitTypeMask = uint64_t(1) << 6;
+      // Reserve bit 7 for SwiftError flag.
+      // const uint64_t SwiftErrorMask = uint64_t(1) << 7;
       const uint64_t FlagMask = InAllocaMask | ExplicitTypeMask;
       bool InAlloca = AlignRecord & InAllocaMask;
       Type *Ty = getTypeByID(Record[0]);