The BKPT instruction is specified to cause a software breakpoint,
and at least on Linux results in a SIGTRAP. This makes it more
suitable for implementing debugtrap than TRAP (aka UDF #254), which
is specified to cause an undefined instruction exception and results
in a SIGILL on Linux.
Moreover, BKPT is not marked as a terminator, which is not only
consistent with the IR instruction but allows the analyzeBlock
function to correctly analyze a basic block containing the instruction,
which fixes an assertion failure in the machine block placement pass
previously triggered by the included test case.
Because BKPT is only supported starting with ARMv5T, we continue to
use UDF #254 when targeting v4T.
Differential Revision: https://reviews.llvm.org/D53614
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345171 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
There are a number of files in the tree which have been accidentally checked in with DOS line endings. Convert these to native line endings.
There are also a few files which have DOS line endings on purpose, and I have set the svn:eol-style property to 'CRLF' on those.
Reviewers: joerg, aaron.ballman
Subscribers: aaron.ballman, sanjoy, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D15848
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256707 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When ARMFrameLowering::emitPopInst generates a "pop" instruction to restore the callee saved registers, it checks if the LR register is among them. If so, the function may decide to remove the basic block's terminator and replace it with a "pop" to the PC register instead of LR.
This leads to a problem when the block's terminator is preceded by a "llvm.debugtrap" call. The MI iterator points to the trap in such a case, which is also a terminator. If the function decides to restore LR to PC, it erroneously removes the trap.
Reviewers: asl, rengolin
Subscribers: aemerson, jfb, rengolin, dschuff, llvm-commits
Differential Revision: http://reviews.llvm.org/D13672
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251123 91177308-0d34-0410-b5e6-96231b3b80d8
