Although the register scavenger can often find a spare register, an emergency
spill slot is needed to guarantee success. Reserve this slot in cases where
the function is known to have a large stack (meaning the scavenger may be
needed when forming stack addresses).
llvm-svn: 322269
Includes support for expanding va_copy. Also adds support for using 'aligned'
registers when necessary for vararg calls, and ensure the frame pointer always
points to the bottom of the vararg spill region. This is necessary to ensure
that the saved return address and stack pointer are always available at fixed
known offsets of the frame pointer.
Differential Revision: https://reviews.llvm.org/D40805
llvm-svn: 322215
As frame pointer elimination isn't implemented until a later patch and we make
extensive use of update_llc_test_checks.py, this changes touches a lot of the
RISC-V tests.
Differential Revision: https://reviews.llvm.org/D39849
llvm-svn: 320357
Introduces the AddrFI "addressing mode", which is necessary simply because
it's not possible to write a pattern that directly matches a frameindex.
Ensure callee-saved registers are accessed relative to the stackpointer. This
is necessary as callee-saved register spills are performed before the frame
pointer is set.
Move HexagonDAGToDAGISel::isOrEquivalentToAdd to SelectionDAGISel, so we can
make use of it in the RISC-V backend.
Differential Revision: https://reviews.llvm.org/D39848
llvm-svn: 320353
This adds the minimum necessary to support codegen for simple ALU operations
on RV32. Prolog and epilog insertion, support for memory operations etc etc
follow in future patches.
Leave guessInstructionProperties=1 until https://reviews.llvm.org/D37065 is
reviewed and lands.
Differential Revision: https://reviews.llvm.org/D29933
llvm-svn: 316188
