Commit Graph

2 Commits

Author SHA1 Message Date
Sameer AbuAsal e01e711c64 [RISCV] Tail calls don't need to save return address
Summary:
 When expanding the PseudoTail in expandFunctionCall() we were using X6
 to save the return address. Since this is a tail call the return
 address is not needed, this patch replaces it with X0 to be ignored.

 This matches the behaviour listed in the ISA V2.2 document page 110.
 tail offset -----> jalr x0, x6, offset

 GCC exhibits the same behavior.

Reviewers: apazos, asb, mgrang

Reviewed By: asb

Subscribers: rbar, johnrusso, simoncook, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01

Differential Revision: https://reviews.llvm.org/D48343

llvm-svn: 335239
2018-06-21 14:37:09 +00:00
Mandeep Singh Grang ef0ebf2806 [RISCV] Implement MC layer support for the tail pseudoinstruction
Summary:
This patch implements MC support for tail psuedo instruction.
A follow-up patch implements the codegen support as well as handling of the indirect tail pseudo instruction.

Reviewers: asb, apazos

Reviewed By: asb

Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, llvm-commits

Differential Revision: https://reviews.llvm.org/D46221

llvm-svn: 332634
2018-05-17 17:31:27 +00:00