diff options
Diffstat (limited to 'REORG.TODO/sysdeps/sparc/sparc64/dl-plt.h')
| -rw-r--r-- | REORG.TODO/sysdeps/sparc/sparc64/dl-plt.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/sparc/sparc64/dl-plt.h b/REORG.TODO/sysdeps/sparc/sparc64/dl-plt.h new file mode 100644 index 0000000000..daad1063b3 --- /dev/null +++ b/REORG.TODO/sysdeps/sparc/sparc64/dl-plt.h @@ -0,0 +1,167 @@ +/* PLT fixups. Sparc 64-bit version. + Copyright (C) 1997-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _DL_PLT_H +#define _DL_PLT_H + +/* We have 4 cases to handle. And we code different code sequences + for each one. I love V9 code models... */ +static inline void __attribute__ ((always_inline)) +sparc64_fixup_plt (struct link_map *map, const Elf64_Rela *reloc, + Elf64_Addr *reloc_addr, Elf64_Addr value, + Elf64_Addr high, int t) +{ + unsigned int *insns = (unsigned int *) reloc_addr; + Elf64_Addr plt_vaddr = (Elf64_Addr) reloc_addr; + Elf64_Sxword disp = value - plt_vaddr; + + /* 't' is '0' if we are resolving this PLT entry for RTLD bootstrap, + in which case we'll be resolving all PLT entries and thus can + optimize by overwriting instructions starting at the first PLT entry + instruction and we need not be mindful of thread safety. + + Otherwise, 't' is '1'. + + Now move plt_vaddr up to the call instruction. */ + plt_vaddr += ((t + 1) * 4); + + /* PLT entries .PLT32768 and above look always the same. */ + if (__builtin_expect (high, 0) != 0) + { + *reloc_addr = value - map->l_addr; + } + /* Near destination. */ + else if (disp >= -0x800000 && disp < 0x800000) + { + unsigned int insn; + + /* ba,a */ + insn = 0x30800000 | ((disp >> 2) & 0x3fffff); + + if (disp >= -0x100000 && disp < 0x100000) + { + /* ba,a,pt %icc */ + insn = 0x30480000 | ((disp >> 2) & 0x07ffff); + } + + /* As this is just one instruction, it is thread safe and so we + can avoid the unnecessary sethi FOO, %g1. Each 64-bit PLT + entry is 8 instructions long, so we can't run into the 'jmp' + delay slot problems 32-bit PLTs can. */ + insns[0] = insn; + __asm __volatile ("flush %0" : : "r" (insns)); + } + /* 32-bit Sparc style, the target is in the lower 32-bits of + address space. */ + else if (insns += t, (value >> 32) == 0) + { + /* sethi %hi(target), %g1 + jmpl %g1 + %lo(target), %g0 */ + + insns[1] = 0x81c06000 | (value & 0x3ff); + __asm __volatile ("flush %0 + 4" : : "r" (insns)); + + insns[0] = 0x03000000 | ((unsigned int)(value >> 10)); + __asm __volatile ("flush %0" : : "r" (insns)); + } + /* We can also get somewhat simple sequences if the distance between + the target and the PLT entry is within +/- 2GB. */ + else if ((plt_vaddr > value + && ((plt_vaddr - value) >> 31) == 0) + || (value > plt_vaddr + && ((value - plt_vaddr) >> 31) == 0)) + { + unsigned int displacement; + + if (plt_vaddr > value) + displacement = (0 - (plt_vaddr - value)); + else + displacement = value - plt_vaddr; + + /* mov %o7, %g1 + call displacement + mov %g1, %o7 */ + + insns[2] = 0x9e100001; + __asm __volatile ("flush %0 + 8" : : "r" (insns)); + + insns[1] = 0x40000000 | (displacement >> 2); + __asm __volatile ("flush %0 + 4" : : "r" (insns)); + + insns[0] = 0x8210000f; + __asm __volatile ("flush %0" : : "r" (insns)); + } + /* Worst case, ho hum... */ + else + { + unsigned int high32 = (value >> 32); + unsigned int low32 = (unsigned int) value; + + /* ??? Some tricks can be stolen from the sparc64 egcs backend + constant formation code I wrote. -DaveM */ + + if (__glibc_unlikely (high32 & 0x3ff)) + { + /* sethi %hh(value), %g1 + sethi %lm(value), %g5 + or %g1, %hm(value), %g1 + or %g5, %lo(value), %g5 + sllx %g1, 32, %g1 + jmpl %g1 + %g5, %g0 + nop */ + + insns[5] = 0x81c04005; + __asm __volatile ("flush %0 + 20" : : "r" (insns)); + + insns[4] = 0x83287020; + __asm __volatile ("flush %0 + 16" : : "r" (insns)); + + insns[3] = 0x8a116000 | (low32 & 0x3ff); + __asm __volatile ("flush %0 + 12" : : "r" (insns)); + + insns[2] = 0x82106000 | (high32 & 0x3ff); + } + else + { + /* sethi %hh(value), %g1 + sethi %lm(value), %g5 + sllx %g1, 32, %g1 + or %g5, %lo(value), %g5 + jmpl %g1 + %g5, %g0 + nop */ + + insns[4] = 0x81c04005; + __asm __volatile ("flush %0 + 16" : : "r" (insns)); + + insns[3] = 0x8a116000 | (low32 & 0x3ff); + __asm __volatile ("flush %0 + 12" : : "r" (insns)); + + insns[2] = 0x83287020; + } + + __asm __volatile ("flush %0 + 8" : : "r" (insns)); + + insns[1] = 0x0b000000 | (low32 >> 10); + __asm __volatile ("flush %0 + 4" : : "r" (insns)); + + insns[0] = 0x03000000 | (high32 >> 10); + __asm __volatile ("flush %0" : : "r" (insns)); + } +} + +#endif /* dl-plt.h */ |