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[PowerPC] Rework TLS call operand processing

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As part of the global-dynamic and local-dynamic TLS sequences, we need
to use a special form of the call instruction:

 bl __tls_get_addr(sym@tlsld)
 bl __tls_get_addr(sym@tlsgd)

which generates two fixups.  The current implementation of this causes
problems with recognizing this form in the asm parser.  To fix this,
this patch reworks operand processing for this special form by using
a single operand to hold both __tls_get_addr and sym@tlsld and defining
a print method to output the above form, and an encoding method to
generate the two fixups.

As a side simplification, the patch replaces the two instruction
patterns BL8_NOP_TLSGD and BL8_NOP_TLSLD by a single BL8_NOP_TLS,
since the patterns already operate in an identical fashion (whether
we have a local-dynamic or global-dynamic symbol is already encoded
in the symbol modifier).

No change in code generation intended.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185477 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Ulrich Weigand
2013-07-02 21:31:04 +00:00
parent 58fc1f52ce
commit a17a7e1868
6 changed files with 40 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
View File

@@ -60,6 +60,8 @@ public:
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getTLSRegEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getTLSCallEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
@@ -80,7 +82,7 @@ public:
unsigned Size = 4; // FIXME: Have Desc.getSize() return the correct value!
unsigned Opcode = MI.getOpcode();
if (Opcode == PPC::BL8_NOP || Opcode == PPC::BLA8_NOP ||
Opcode == PPC::BL8_NOP_TLSGD || Opcode == PPC::BL8_NOP_TLSLD)
Opcode == PPC::BL8_NOP_TLS)
Size = 8;
// Output the constant in big endian byte order.
@@ -113,17 +115,6 @@ getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
// Add a fixup for the branch target.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_br24));
// For special TLS calls, add another fixup for the symbol. Apparently
// BL8_NOP, BL8_NOP_TLSGD, and BL8_NOP_TLSLD are sufficiently
// similar that TblGen will not generate a separate case for the latter
// two, so this is the only way to get the extra fixup generated.
unsigned Opcode = MI.getOpcode();
if (Opcode == PPC::BL8_NOP_TLSGD || Opcode == PPC::BL8_NOP_TLSLD) {
const MCOperand &MO2 = MI.getOperand(OpNo+1);
Fixups.push_back(MCFixup::Create(0, MO2.getExpr(),
(MCFixupKind)PPC::fixup_ppc_nofixup));
}
return 0;
}
@@ -222,6 +213,17 @@ unsigned PPCMCCodeEmitter::getTLSRegEncoding(const MCInst &MI, unsigned OpNo,
return CTX.getRegisterInfo()->getEncodingValue(PPC::X13);
}
unsigned PPCMCCodeEmitter::getTLSCallEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
// For special TLS calls, we need two fixups; one for the branch target
// (__tls_get_addr), which we create via getDirectBrEncoding as usual,
// and one for the TLSGD or TLSLD symbol, which is emitted here.
const MCOperand &MO = MI.getOperand(OpNo+1);
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_nofixup));
return getDirectBrEncoding(MI, OpNo, Fixups);
}
unsigned PPCMCCodeEmitter::
get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {