with '-mframe-pointer'
After D56351 and D64294, frame pointer handling is migrated to tri-state
(all, non-leaf, none) in clang driver and on the function attribute.
This patch makes the frame pointer handling cc1 option tri-state.
Reviewers: chandlerc, rnk, t.p.northover, MaskRay
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D56353
llvm-svn: 366645
The Windows on ARM ABI recommends that FPO be disabled. This is since the
Windows on ARM ABI uses the FP for fast stack walking. By paying the slight
cost of the loss of registers, a much faster backtrace is possible by using the
frame pointer since the pdata need not be consulted. Furthermore, even if pdata
is not available, you can still more easily reconstruct the stack.
llvm-svn: 249227
Yuanfang Chen