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author | Bruno Cardoso Lopes <bruno.cardoso@gmail.com> | 2011-12-07 00:28:57 +0000 |
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committer | Bruno Cardoso Lopes <bruno.cardoso@gmail.com> | 2011-12-07 00:28:57 +0000 |
commit | e3d3572e282733bd7aa5ac14115ed0804174e426 (patch) | |
tree | e1b5dc1b31e9d97b63000ee6997f982b276cbd6a /lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp | |
parent | 2068215e8515203ab4839ee494cdc53dfd0cdf02 (diff) | |
download | external_llvm-e3d3572e282733bd7aa5ac14115ed0804174e426.zip external_llvm-e3d3572e282733bd7aa5ac14115ed0804174e426.tar.gz external_llvm-e3d3572e282733bd7aa5ac14115ed0804174e426.tar.bz2 |
Add a few moreLocal/Global R_MIPS_GOT related fixups and
make the addend fixup code a bit more generic
Patch by Jack Carter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145998 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp')
-rw-r--r-- | lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp | 74 |
1 files changed, 32 insertions, 42 deletions
diff --git a/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp b/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp index 8a8e36a..60ff4fe 100644 --- a/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp +++ b/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp @@ -29,13 +29,19 @@ #include "llvm/Support/ELF.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" + using namespace llvm; +// Prepare value for the target space for it static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) { // Add/subtract and shift switch (Kind) { default: + return 0; + case FK_GPRel_4: + case FK_Data_4: + case Mips::fixup_Mips_LO16: break; case Mips::fixup_Mips_PC16: // So far we are only using this type for branches. @@ -52,25 +58,10 @@ static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) { // address range. Value >>= 2; break; - } - - // Mask off value for placement as an operand - switch (Kind) { - default: - break; - case FK_GPRel_4: - case FK_Data_4: - Value &= 0xffffffff; - break; - case Mips::fixup_Mips_26: - Value &= 0x03ffffff; - break; - case Mips::fixup_Mips_LO16: - case Mips::fixup_Mips_PC16: - Value &= 0x0000ffff; - break; case Mips::fixup_Mips_HI16: - Value >>= 16; + case Mips::fixup_Mips_GOT_Local: + // Get the higher 16-bits. Also add 1 if bit 15 is 1. + Value = (Value >> 16) + ((Value & 0x8000) != 0); break; } @@ -96,42 +87,40 @@ public: /// fixup kind as appropriate. void ApplyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize, uint64_t Value) const { - unsigned Kind = (unsigned)Fixup.getKind(); - Value = adjustFixupValue(Kind, Value); + MCFixupKind Kind = Fixup.getKind(); + Value = adjustFixupValue((unsigned)Kind, Value); if (!Value) - return; // Doesn't change encoding. + return; // Doesn't change encoding. unsigned Offset = Fixup.getOffset(); - switch (Kind) { - default: - llvm_unreachable("Unknown fixup kind!"); - case Mips::fixup_Mips_GOT16: // This will be fixed up at link time - break; - case FK_GPRel_4: - case FK_Data_4: - case Mips::fixup_Mips_26: - case Mips::fixup_Mips_LO16: - case Mips::fixup_Mips_PC16: - case Mips::fixup_Mips_HI16: - // For each byte of the fragment that the fixup touches, mask i - // the fixup value. The Value has been "split up" into the appr - // bitfields above. - for (unsigned i = 0; i != 4; ++i) // FIXME - Need to support 2 and 8 bytes - Data[Offset + i] += uint8_t((Value >> (i * 8)) & 0xff); - break; + // FIXME: The below code will not work across endian models + // How many bytes/bits are we fixing up? + unsigned NumBytes = ((getFixupKindInfo(Kind).TargetSize-1)/8)+1; + uint64_t Mask = ((uint64_t)1 << getFixupKindInfo(Kind).TargetSize) - 1; + + // Grab current value, if any, from bits. + uint64_t CurVal = 0; + for (unsigned i = 0; i != NumBytes; ++i) + CurVal |= ((uint8_t)Data[Offset + i]) << (i * 8); + + CurVal = (CurVal & ~Mask) | ((CurVal + Value) & Mask); + + // Write out the bytes back to the code/data bits. + // First the unaffected bits and then the fixup. + for (unsigned i = 0; i != NumBytes; ++i) { + Data[Offset + i] = uint8_t((CurVal >> (i * 8)) & 0xff); } - } +} unsigned getNumFixupKinds() const { return Mips::NumTargetFixupKinds; } const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const { const static MCFixupKindInfo Infos[Mips::NumTargetFixupKinds] = { - // This table *must* be in the order that the fixup_* kinds a + // This table *must* be in same the order of fixup_* kinds in // MipsFixupKinds.h. // // name offset bits flags - { "fixup_Mips_NONE", 0, 0, 0 }, { "fixup_Mips_16", 0, 16, 0 }, { "fixup_Mips_32", 0, 32, 0 }, { "fixup_Mips_REL32", 0, 32, 0 }, @@ -140,7 +129,8 @@ public: { "fixup_Mips_LO16", 0, 16, 0 }, { "fixup_Mips_GPREL16", 0, 16, 0 }, { "fixup_Mips_LITERAL", 0, 16, 0 }, - { "fixup_Mips_GOT16", 0, 16, 0 }, + { "fixup_Mips_GOT_Global", 0, 16, 0 }, + { "fixup_Mips_GOT_Local", 0, 16, 0 }, { "fixup_Mips_PC16", 0, 16, MCFixupKindInfo::FKF_IsPCRel }, { "fixup_Mips_CALL16", 0, 16, 0 }, { "fixup_Mips_GPREL32", 0, 32, 0 }, |