Correct a problem with the ISA bit being stripped from the addend of
compressed branch relocations, affecting RELA targets. It has been
there since microMIPS support has been added, with:
commit df58fc944d
Author: Richard Sandiford <rdsandiford@googlemail.com>
Date: Sun Jul 24 14:20:15 2011 +0000
<https://sourceware.org/ml/binutils/2011-07/msg00198.html>, ("MIPS:
microMIPS ASE support") and R_MICROMIPS_PC7_S1, R_MICROMIPS_PC10_S1 and
R_MICROMIPS_PC16_S1 relocations originally affected, and the
R_MIPS16_PC16_S1 relocation recently added with commit c9775dde32
("MIPS16: Add R_MIPS16_PC16_S1 branch relocation support") actually
triggering a linker error, due to its heightened processing strictness
level:
$ cat test.s
.text
.set mips16
foo:
b bar
.set bar, 0x1235
.align 4, 0
$ as -EB -n32 -o test.o test.s
$ objdump -dr test.o
test.o: file format elf32-ntradbigmips
Disassembly of section .text:
00000000 <foo>:
0: f000 1000 b 4 <foo+0x4>
0: R_MIPS16_PC16_S1 *ABS*+0x1230
...
$ ld -melf32btsmipn32 -Ttext 0 -e 0 -o test test.o
test.o: In function `foo':
(.text+0x0): Branch to a non-instruction-aligned address
$
This is because the ISA bit of the branch target does not match the ISA
bit of the referring branch, hardwired to 1 of course.
Retain the ISA bit then, so that the linker knows this is really MIPS16
code referred:
$ objdump -dr fixed.o
fixed.o: file format elf32-ntradbigmips
Disassembly of section .text:
00000000 <foo>:
0: f000 1000 b 4 <foo+0x4>
0: R_MIPS16_PC16_S1 *ABS*+0x1231
...
$ ld -melf32btsmipn32 -Ttext 0 -e 0 -o fixed fixed.o
$
Add a set of MIPS16 tests to cover the relevant cases, excluding linker
tests though which would overflow the in-place addend on REL targets and
use them as dump patterns for RELA targets only.
gas/
* config/tc-mips.c (md_apply_fix) <BFD_RELOC_MIPS16_16_PCREL_S1>
<BFD_RELOC_MICROMIPS_7_PCREL_S1, BFD_RELOC_MICROMIPS_10_PCREL_S1>
<BFD_RELOC_MICROMIPS_16_PCREL_S1>: Keep the ISA bit in the
addend calculated.
* testsuite/gas/mips/mips16-branch-absolute.s: Set the ISA bit
in `bar', export `foo'.
* testsuite/gas/mips/mips16-branch-absolute.d: Adjust
accordingly.
* testsuite/gas/mips/mips16-branch-absolute-n32.d: Likewise.
* testsuite/gas/mips/mips16-branch-absolute-n64.d: Likewise.
* testsuite/gas/mips/mips16-branch-absolute-addend-n32.d:
Likewise.
* testsuite/gas/mips/mips16-branch-absolute-addend-n64.d:
Likewise.
ld/
* testsuite/ld-mips-elf/mips16-branch-absolute.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n32.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-n64.d: New test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n32.d: New
test.
* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n64.d: New
test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests, except
from `mips16-branch-absolute' and
`mips16-branch-absolute-addend', referred indirectly only.
