Commit Graph

6 Commits

Author SHA1 Message Date
David Green f4c5cadbcb [ARM] Select f32 constants with vmov.f16
This adds lowering for f32 values using the vmov.f16, which zeroes the
top bits whilst setting the lower bits to a pattern. This range of
values does not often come up, except where a f16 constant value has
been converted to a f32.

Differential Revision: https://reviews.llvm.org/D87790
2020-09-21 11:10:47 +01:00
David Green 29bd8ea110 [ARM] Constant fold VMOVrh
This adds simple constant folding for VMOVrh, to constant fold fp16
constants to integer values. It can help especially with soft calling
conventions, but some of the results are not optimal as we end up
loading using a vldr. This will be improved in a follow up patch.

Differential Revision: https://reviews.llvm.org/D87789
2020-09-20 21:32:51 +01:00
Lucas Prates 92ad6d57c2 [ARM] Moving CMSE handling of half arguments and return to the backend
Summary:
As half-precision floating point arguments and returns were previously
coerced to either float or int32 by clang's codegen, the CMSE handling
of those was also performed in clang's side by zeroing the unused MSBs
of the coercer values.

This patch moves this handling to the backend's calling convention
lowering, making sure the high bits of the registers used by
half-precision arguments and returns are zeroed.

Reviewers: chill, rjmccall, ostannard

Reviewed By: ostannard

Subscribers: kristof.beyls, hiraditya, danielkiss, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D81428
2020-06-18 13:16:29 +01:00
Momchil Velikov bc2e572f51 Re-commit: [ARM] CMSE code generation
This patch implements the final bits of CMSE code generation:

* emit special linker symbols

* restrict parameter passing to no use memory

* emit BXNS and BLXNS instructions for returns from non-secure entry
  functions, and non-secure function calls, respectively

* emit code to save/restore secure floating-point state around calls
  to non-secure functions

* emit code to save/restore non-secure floating-pointy state upon
  entry to non-secure entry function, and return to non-secure state

* emit code to clobber registers not used for arguments and returns

* when switching to no-secure state

Patch by Momchil Velikov, Bradley Smith, Javed Absar, David Green,
possibly others.

Differential Revision: https://reviews.llvm.org/D76518
2020-05-14 16:46:16 +01:00
Momchil Velikov fb18dffaeb Revert "[ARM] CMSE code generation"
This reverts commit 7cbbf89d23.

The regression tests fail with the expensive checks.
2020-05-05 19:05:40 +01:00
Momchil Velikov 7cbbf89d23 [ARM] CMSE code generation
This patch implements the final bits of CMSE code generation:

* emit special linker symbols

* restrict parameter passing to not use memory

* emit BXNS and BLXNS instructions for returns from non-secure entry
  functions, and non-secure function calls, respectively

* emit code to save/restore secure floating-point state around calls
  to non-secure functions

* emit code to save/restore non-secure floating-pointy state upon
  entry to non-secure entry function, and return to non-secure state

* emit code to clobber registers not used for arguments and returns
  when switching to no-secure state

Patch by Momchil Velikov, Bradley Smith, Javed Absar, David Green,
possibly others.

Differential Revision: https://reviews.llvm.org/D76518
2020-05-05 18:23:28 +01:00