4 Commits

Author	SHA1	Message	Date
Evan Cheng	b341fac05a	Disable the Thumb no-return call optimization: ... mov lr, pc b.w _foo The "mov" instruction doesn't set bit zero to one, it's putting incorrect value in lr. It messes up backtraces. rdar://12663632 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167657 91177308-0d34-0410-b5e6-96231b3b80d8	2012-11-10 02:09:05 +00:00
Bob Wilson	eb1641d54a	Add LLVM support for Swift. ... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164899 91177308-0d34-0410-b5e6-96231b3b80d8	2012-09-29 21:43:49 +00:00
Daniel Dunbar	20bd5296ce	Revert r151623 "Some ARM implementaions, e.g. A-series, does return stack prediction. ...", it is breaking the Clang build during the Compiler-RT part. ... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151630 91177308-0d34-0410-b5e6-96231b3b80d8	2012-02-28 15:36:07 +00:00
Evan Cheng	ec52aaa12f	Some ARM implementaions, e.g. A-series, does return stack prediction. That is, ... the processor keeps a return addresses stack (RAS) which stores the address and the instruction execution state of the instruction after a function-call type branch instruction. Calling a "noreturn" function with normal call instructions (e.g. bl) can corrupt RAS and causes 100% return misprediction so LLVM should use a unconditional branch instead. i.e. mov lr, pc b _foo The "mov lr, pc" is issued in order to get proper backtrace. rdar://8979299 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151623 91177308-0d34-0410-b5e6-96231b3b80d8	2012-02-28 06:42:03 +00:00