Currently, the interaction between the triple, the CPU, and the
supported features is a mess: the driver edits the triple to indicate
the supported architecture version, and the LLVM backend uses this to
figure out what instructions are legal. This makes it difficult to
understand what's happening, and makes it impossible to LTO together two
modules with different computed architectures.
Instead of relying on triple rewriting to get the correct target
features, we should add the right target features explicitly.
Differential Revision: https://reviews.llvm.org/D45240
llvm-svn: 330169
Summary:
The thumb-mode target feature is used to force Thumb or ARM code
generation on a per-function basis. Explicitly adding +thumb-mode to
functions for thumbxx triples enables mixed ARM/Thumb code generation in
places where compilation units with thumbxx and armxx triples are merged
together (e.g. the IR linker or LTO).
For armxx triples, -thumb-mode is added in a similar fashion.
Reviewers: echristo, t.p.northover, kristof.beyls, rengolin
Reviewed By: echristo
Subscribers: rinon, aemerson, mehdi_amini, javed.absar, cfe-commits
Differential Revision: https://reviews.llvm.org/D33448
llvm-svn: 304897
Eli Friedman