1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2025-02-01 13:11:39 +01:00
Huihui Zhang 8b112ee806 [ARM] Comply with rules on ARMv8-A thumb mode partial deprecation of IT.
Summary:
When identifing instructions that can be folded into a MOVCC instruction,
checking for a predicate operand is not enough, also need to check for
thumb2 function, with restrict-IT, is the machine instruction eligible for
ARMv8 IT or not.

Notes in ARMv8-A Architecture Reference Manual, section "Partial deprecation of IT"
  https://usermanual.wiki/Pdf/ARM20Architecture20Reference20ManualARMv8.1667877052.pdf

"ARMv8-A deprecates some uses of the T32 IT instruction. All uses of IT that apply to
instructions other than a single subsequent 16-bit instruction from a restricted set
are deprecated, as are explicit references to the PC within that single 16-bit
instruction. This permits the non-deprecated forms of IT and subsequent instructions
to be treated as a single 32-bit conditional instruction."

Reviewers: efriedma, lebedev.ri, t.p.northover, jmolloy, aemerson, compnerd, stoklund, ostannard

Reviewed By: ostannard

Subscribers: ostannard, javed.absar, kristof.beyls, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63474

llvm-svn: 363739
2019-06-18 20:55:09 +00:00
..
2019-02-15 09:04:39 +00:00