9 Commits

Author SHA1 Message Date
Ben Shi
f319c24570 [AVR] Reject/Reserve R0~R15 on AVRTiny.
Reviewed By: aykevl, dylanmckay

Differential Revision: https://reviews.llvm.org/D121672
2022-03-24 02:33:51 +00:00
Ben Shi
3fd9a320da [AVR] Fix incorrect calling convention for varargs functions
An i8 argument should only cost 1 byte on the stack. This is
compatible with avr-gcc.

There are also more test cases (of calling convention) are added.

Reviewed By: aykevl, dylanmckay

Differential Revision: https://reviews.llvm.org/D121767
2022-03-23 02:00:15 +00:00
Ayke van Laethem
3d59d94a20
[AVR] Mark call-clobbered registers as clobbered in interrupt handlers
I have matched the RISCV backend, which only uses the interrupt save
list in getCalleeSavedRegs, _not_ in getCallPreservedMask. I don't know
the details of these two methods, but with it, the correct amount of
registers is saved and restored.

Without this patch, practically all interrupt handlers that call a
function will miscompile.

I have added a test to verify this behavior. I've also added a very
simple test to verify that more normal interrupt operations (in this
case, incrementing a global value) behave as expected.

Differential Revision: https://reviews.llvm.org/D116551
2022-01-19 14:22:13 +01:00
Shivam Gupta
5449d2da65 [NFC] Run clang-format on llvm/lib/Trget/AVR/
The current inconsistency confuse contributors which coding guidlines to follow.
It would be better to have it consistent using clang-format tool.

Reviewed By: mhjacobson

Differential Revision: https://reviews.llvm.org/D109270
2021-09-04 20:05:15 +05:30
Dylan McKay
b9c26a9cfe [AVR] Rewrite the function calling convention.
Summary:
The previous version relied on the standard calling convention using
std::reverse() to try to force the AVR ABI. But this only works for
simple cases, it fails for example with aggregate types.

This patch rewrites the calling convention with custom C++ code, that
implements the ABI defined in https://gcc.gnu.org/wiki/avr-gcc.

To do that it adds a few 16-bit pseudo registers for unaligned argument
passing, such as R24R23. For example this function:

    define void @fun({ i8, i16 } %a)

will pass %a.0 in R22 and %a.1 in R24R23.

There are no instructions that can use these pseudo registers, so a new
register class, DREGSMOVW, is defined to make them apart.

Also the ArgCC_AVR_BUILTIN_DIV is no longer necessary, as it is
identical to the C++ behavior (actually the clobber list is more strict
for __div* functions, but that is currently unimplemented).

Reviewers: dylanmckay

Subscribers: Gaelan, Sh4rK, indirect, jwagen, efriedma, dsprenkels, hiraditya, Jim, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68524

Patch by Rodrigo Rivas Costa.
2020-06-23 21:36:18 +12:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Dylan McKay
1a55f201ef [AVR] Remove a bunch of unused variables
llvm-svn: 287416
2016-11-19 01:33:42 +00:00
Dylan McKay
1f69cdb321 [AVR] Rename the builtin calling convention names
'BUILTIN' is clearer than 'RT' in this context.

llvm-svn: 282602
2016-09-28 16:04:40 +00:00
Dylan McKay
f061e9b7b2 [AVR] Added AVRCallingConv.td
llvm-svn: 256130
2015-12-20 23:17:44 +00:00