E.g.
bar (int x)
{
char p[x];
push outgoing variables for foo.
call foo
}
We need to generate stack adjustment instructions for outgoing arguments by
eliminateCallFramePseudoInstr when the function contains variable size
objects to avoid outgoing variables corrupt the variable size object.
Default hasReservedCallFrame will return !hasFP().
We don't want to generate extra sp adjustment instructions when hasFP()
return true, So We override hasReservedCallFrame as !hasVarSizedObjects().
Differential Revision: https://reviews.llvm.org/D43752
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327938 91177308-0d34-0410-b5e6-96231b3b80d8
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).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322269 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@322215 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320353 91177308-0d34-0410-b5e6-96231b3b80d8
