In the past, AVR functions were only lowered with interrupt-specific
machine code if the function was defined with the "avr-interrupt" or
"avr-signal" calling conventions.
This patch modifies the backend so that if the function does not have a
special calling convention, but does have an "interrupt" attribute,
that function is interpreted as a function with interrupts.
This also extracts the "is this function an interrupt" logic from
several disparate places in the backend into one AVRMachineFunctionInfo
attribute.
Bug found by Wilhelm Meier.
Summary:
A lot of the pseudo instructions are required because LLVM assumes that
all integers of the same size as the pointer size are legal. This means
that it will not currently expand 16-bit instructions to their 8-bit
variants because it thinks 16-bit types are legal for the operations.
This also adds all of the CodeGen tests that required the pass to run.
Reviewers: arsenm, kparzysz
Subscribers: wdng, mgorny, modocache, llvm-commits
Differential Revision: https://reviews.llvm.org/D26577
llvm-svn: 287162
Dylan McKay