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[ELF][MIPS] Create PLT entry specific for MIPS ABI version R6 

llvm-svn: 276173
This commit is contained in:
Simon Atanasyan 2016-07-20 20:15:33 +00:00
parent f463709d7d
commit a088bce959
2 changed files with 46 additions and 1 deletions
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9
lld/ELF/Target.cpp
View File

@ -1957,6 +1957,12 @@ static void writeMipsLo16(uint8_t *Loc, uint64_t V) {
write32<E>(Loc, (Instr & 0xffff0000) | (V & 0xffff));
}
template <class ELFT> static bool isMipsR6() {
const auto &FirstObj = cast<ELFFileBase<ELFT>>(*Config->FirstElf);
uint32_t Arch = FirstObj.getObj().getHeader()->e_flags & EF_MIPS_ARCH;
return Arch == EF_MIPS_ARCH_32R6 || Arch == EF_MIPS_ARCH_64R6;
}
template <class ELFT>
void MipsTargetInfo<ELFT>::writePltHeader(uint8_t *Buf) const {
const endianness E = ELFT::TargetEndianness;
@ -1981,7 +1987,8 @@ void MipsTargetInfo<ELFT>::writePlt(uint8_t *Buf, uint64_t GotEntryAddr,
const endianness E = ELFT::TargetEndianness;
write32<E>(Buf, 0x3c0f0000); // lui $15, %hi(.got.plt entry)
write32<E>(Buf + 4, 0x8df90000); // l[wd] $25, %lo(.got.plt entry)($15)
write32<E>(Buf + 8, 0x03200008); // jr $25
// jr $25
write32<E>(Buf + 8, isMipsR6<ELFT>() ? 0x03200009 : 0x03200008);
write32<E>(Buf + 12, 0x25f80000); // addiu $24, $15, %lo(.got.plt entry)
writeMipsHi16<E>(Buf, GotEntryAddr);
writeMipsLo16<E>(Buf + 4, GotEntryAddr);

38
lld/test/ELF/mips-plt-r6.s Normal file
View File

@ -0,0 +1,38 @@
# Check PLT entries generation in case of R6 ABI version.
# RUN: llvm-mc -filetype=obj -triple=mips-unknown-linux \
# RUN: -mcpu=mips32r6 %s -o %t1.o
# RUN: llvm-mc -filetype=obj -triple=mips-unknown-linux \
# RUN: -mcpu=mips32r6 %S/Inputs/mips-dynamic.s -o %t2.o
# RUN: ld.lld %t2.o -shared -o %t.so
# RUN: ld.lld %t1.o %t.so -o %t.exe
# RUN: llvm-objdump -d %t.exe | FileCheck %s
# REQUIRES: mips
# CHECK: Disassembly of section .text:
# CHECK-NEXT: __start:
# CHECK-NEXT: 20000: 0c 00 80 0c jal 131120
# ^-- 0x20030 gotplt[foo0]
# CHECK-NEXT: 20004: 00 00 00 00 nop
#
# CHECK-NEXT: Disassembly of section .plt:
# CHECK-NEXT: .plt:
# CHECK-NEXT: 20010: 3c 1c 00 04 aui $zero, $gp, 4
# CHECK-NEXT: 20014: 8f 99 00 04 lw $25, 4($gp)
# CHECK-NEXT: 20018: 27 9c 00 04 addiu $gp, $gp, 4
# CHECK-NEXT: 2001c: 03 1c c0 23 subu $24, $24, $gp
# CHECK-NEXT: 20020: 03 e0 78 25 move $15, $ra
# CHECK-NEXT: 20024: 00 18 c0 82 srl $24, $24, 2
# CHECK-NEXT: 20028: 03 20 f8 09 jalr $25
# CHECK-NEXT: 2002c: 27 18 ff fe addiu $24, $24, -2
# CHECK-NEXT: 20030: 3c 0f 00 04 aui $zero, $15, 4
# CHECK-NEXT: 20034: 8d f9 00 0c lw $25, 12($15)
# CHECK-NEXT: 20038: 03 20 00 09 jr $25
# CHECK-NEXT: 2003c: 25 f8 00 0c addiu $24, $15, 12
.text
.global __start
__start:
jal foo0 # R_MIPS_26 against 'foo0' from DSO