Commit Graph

3 Commits

Author SHA1 Message Date
Rafael Espindola a22b082e46 Always create a .got on mips.
The _gp* family of symbols is defined as an offset in .got, and it is
not at all clear what should happen when .got is not defined.

This will allow some simplifications on how these symbols are handled.

llvm-svn: 266063
2016-04-12 13:21:13 +00:00
Simon Atanasyan 2cd670da02 [ELF][MIPS] Fix calculation of the R_MIPS_HI16 relocation
llvm-svn: 255451
2015-12-13 06:49:01 +00:00
Simon Atanasyan 09b3e3685f [ELF] MIPS paired R_MIPS_HI16/LO16 relocations support
Some MIPS relocations including `R_MIPS_HI16/R_MIPS_LO16` use combined
addends. Such addend is calculated using addends of both paired relocations.
Each `R_MIPS_HI16` relocation is paired with the next `R_MIPS_LO16`
relocation. ABI requires to compute such combined addend in case of REL
relocation record format only.

For details see p. 4-17 at
ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf

This patch implements lookup of the next paired relocation suing new
`InputSectionBase::findPairedRelocLocation` method. The primary
disadvantage of this approach is that we put MIPS specific logic into
the common code. The next disadvantage is that we lookup `R_MIPS_LO16`
for each `R_MIPS_HI16` relocation, while in fact multiple `R_MIPS_HI16`
might be paired with the single `R_MIPS_LO16`. From the other side
this way allows us to keep `MipsTargetInfo` class stateless and implement
later relocation handling in parallel.

This patch does not support `R_MIPS_HI16/R_MIPS_LO16` relocations against
`_gp_disp` symbol. In that case the relocations use a special formula for
the calculation. That will be implemented later.

Differential Revision: http://reviews.llvm.org/D15112

llvm-svn: 254461
2015-12-01 21:24:45 +00:00