Commit Graph

2 Commits

Author SHA1 Message Date
Daniel Sanders
7c2ef822f7 [mips][mips64r6] Use JALR for returns instead of JR (which is not available on MIPS32r6/MIPS64r6)
Summary:
RET, and RET_MM have been replaced by a pseudo named PseudoReturn.
In addition a version with a 64-bit GPR named PseudoReturn64 has been
added.

Instruction selection for a return matches RetRA, which is expanded post
register allocation to PseudoReturn/PseudoReturn64. During MipsAsmPrinter,
this PseudoReturn/PseudoReturn64 are emitted as:
- (JALR64 $zero, $rs) on MIPS64r6
- (JALR $zero, $rs) on MIPS32r6
- (JR_MM $rs) on microMIPS
- (JR $rs) otherwise

On MIPS32r6/MIPS64r6, 'jr $rs' is an alias for 'jalr $zero, $rs'. To aid
development and review (specifically, to ensure all cases of jr are
updated), these aliases are temporarily named 'r6.jr' instead of 'jr'.
A follow up patch will change them back to the correct mnemonic.

Added (JALR $zero, $rs) to MipsNaClELFStreamer's definition of an indirect
jump, and removed it from its definition of a call.
Note: I haven't accounted for MIPS64 in MipsNaClELFStreamer since it's
doesn't appear to account for any MIPS64-specifics.

The return instruction created as part of eh_return expansion is now expanded
using expandRetRA() so we use the right return instruction on MIPS32r6/MIPS64r6
('jalr $zero, $rs').

Also, fixed a misuse of isABI_N64() to detect 64-bit wide registers in
expandEhReturn().

Reviewers: jkolek, vmedic, mseaborn, zoran.jovanovic, dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D4268


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212604 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-09 10:16:07 +00:00
Daniel Sanders
8ce13cfc08 [mips] Add tests for the 'ret', 'call', and 'indirectbr' LLVM IR instruction.
Summary:
The tests in this directory are intended to test a single IR instruction
with as few dependencies on other instructions as possible. The aim is to
be very confident that each LLVM-IR instruction is implemented correctly and
with the optimal sequence of instructions, as well as to make it easy to tell
what is tested, and make it easier to bring up new ISA revisions in the
future. This gives us a good foundation on which to test bigger things.

These particular tests will allow testing that MIPS32r6/MIPS64r6 generate
the correct return instruction for returns, calls, and indirect branches.
This will be a bit tricky since the assembly text is identical but the
instruction is actually different. On MIPS32r6/MIPS64r6 'jr $rs' has been
removed in favour of the equivalent 'jalr $zero, $rs'. 'jr $rs' remains as
an alias for 'jalr $zero, $rs'.

Differential Revision: http://reviews.llvm.org/D4266


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212345 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 15:16:14 +00:00