Commit Graph

2 Commits

Author SHA1 Message Date
Mikhail Maltsev 68f35bcc85 [ARM] Do not convert some vmov instructions
Summary:
Patch https://reviews.llvm.org/D44467 implements conversion of invalid
vmov instructions into valid ones. It turned out that some valid
instructions also get converted, for example

  vmov.i64 d2, #0xff00ff00ff00ff00 ->
  vmov.i16 d2, #0xff00

Such behavior is incorrect because according to the ARM ARM section
F2.7.7 Modified immediate constants in T32 and A32 Advanced SIMD
instructions, "On assembly, the data type must be matched in the table
if possible."

This patch fixes the isNEONmovReplicate check so that the above
instruction is not modified any more.

Reviewers: rengolin, olista01

Reviewed By: rengolin

Subscribers: javed.absar, kristof.beyls, rogfer01, llvm-commits

Differential Revision: https://reviews.llvm.org/D44678

llvm-svn: 329158
2018-04-04 08:54:19 +00:00
Mikhail Maltsev ed1c8bfec2 [ARM] Convert more invalid NEON immediate loads
Summary:
Currently the LLVM MC assembler is able to convert e.g.

  vmov.i32 d0, #0xabababab

(which is technically invalid) into a valid instruction

  vmov.i8 d0, #0xab

this patch adds support for vmov.i64 and for cases with the resulting
load types other than i8, e.g.:

  vmov.i32 d0, #0xab00ab00 ->
  vmov.i16 d0, #0xab00

Reviewers: olista01, rengolin

Reviewed By: rengolin

Subscribers: rengolin, javed.absar, kristof.beyls, rogfer01, llvm-commits

Differential Revision: https://reviews.llvm.org/D44467

llvm-svn: 327709
2018-03-16 14:10:56 +00:00