Commit Graph

3 Commits

Author SHA1 Message Date
Dylan McKay 1420f4efbe [AVR] Fix I/O instructions on XMEGA
Summary:
On XMEGA, I/O address space is same as data address space - there is no 0x20 offset,
because CPU General Purpose Registers are not mapped in data address space.

From https://en.wikipedia.org/wiki/AVR_microcontrollers
> In the XMEGA variant, the working register file is not mapped into the data address space; as such, it is not possible to treat any of the XMEGA's working registers as though they were SRAM. Instead, the I/O registers are mapped into the data address space starting at the very beginning of the address space.

Reviewers: dylanmckay

Reviewed By: dylanmckay

Subscribers: hiraditya, Jim, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77207

Patch by Vlastimil Labsky.
2020-05-17 19:46:09 +12:00
Dylan McKay f8b4e60c7f [AVR] Fix the 'avr-tiny.ll' and 'avr25.ll' subtarget feature tests
When these tests were originally written, the middle end would introduce
an unnecessary copy from r24:r23->GPR16->r24:r23, and these tests
mistakenly relied on it.

The most optimal codegen for the functions in the test cases before this patch
would be NOPs. This is because the first i16 argument always gets the same register
allocation as an i16 return value in the AVR calling convention.

These tests broke in r362963 when the codegen was improved and the
redundant copy was eliminated. After this, the test functions
were lowered to their optimal form - a 'ret' and nothing else.

This patch prepends an extra i16 operand to each of the test functions
so that a 16-bit copy must be inserted for the program to be correct.

llvm-svn: 363131
2019-06-12 08:31:07 +00:00
Dylan McKay 0d4778f841 [AVR] Add a selection of CodeGen tests
Summary: This adds all of the CodeGen tests which currently pass.

Reviewers: arsenm, kparzysz

Subscribers: japaric, wdng

Differential Revision: https://reviews.llvm.org/D26388

llvm-svn: 286418
2016-11-09 23:46:52 +00:00