For stack frames on the size of a register in x86, a code size optimization
emits "push rax/eax" instead of "sub" for stack allocation. For example:
foo:
.cfi_startproc
BB#0:
pushq %rax
Ltmp0:
.cfi_def_cfa_offset 16
...
.cfi_endproc
However, we are falling back to DWARF in this case because we cannot
encode %rax as a saved register.
This requirement is wrong, since we don't care about the contents of
%rax, it is the equivalent of a sub.
In order to specify that we care about the contents of %rax, we would
need a .cfi_offset %rax, <offset>.
It's also overzealous in the case where there are pushes for callee saved
registers followed by a "push rax/eax" instead of "sub", in which case we should
also be able to encode the callee saved regs and everything else using compact
unwind.
Patch authored by Bruno Cardoso Lopes.
Differential Revision: https://reviews.llvm.org/D13793
llvm-svn: 350623
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.
The MIR printer prints the IR name of a MBB only for block definitions.
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix
Differential Revision: https://reviews.llvm.org/D40422
llvm-svn: 319665
Fix a compact unwind encoding logic bug which would try to encode
more callee saved registers than it should, leading to early bail out
in the encoding logic and abusive use of DWARF frame mode unnecessarily.
Also remove no-compact-unwind.ll which was testing the wrong thing
based on this bug and move it to valid 'compact unwind' tests. Added
other few more tests too.
llvm-svn: 223676
Francis Visoiu Mistrih