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  1. Dec 12, 2012
  2. Dec 11, 2012
    • Nadav Rotem's avatar
    • Tom Stellard's avatar
      Add R600 backend · 75aadc28
      Tom Stellard authored
      A new backend supporting AMD GPUs: Radeon HD2XXX - HD7XXX
      
      llvm-svn: 169915
      75aadc28
    • Bill Schmidt's avatar
      This patch implements the general dynamic TLS model for 64-bit PowerPC. · c56f1d34
      Bill Schmidt authored
      Given a thread-local symbol x with global-dynamic access, the generated
      code to obtain x's address is:
      
           Instruction                            Relocation            Symbol
        addis ra,r2,x@got@tlsgd@ha           R_PPC64_GOT_TLSGD16_HA       x
        addi  r3,ra,x@got@tlsgd@l            R_PPC64_GOT_TLSGD16_L        x
        bl __tls_get_addr(x@tlsgd)           R_PPC64_TLSGD                x
                                             R_PPC64_REL24           __tls_get_addr
        nop
        <use address in r3>
      
      The implementation borrows from the medium code model work for introducing
      special forms of ADDIS and ADDI into the DAG representation.  This is made
      slightly more complicated by having to introduce a call to the external
      function __tls_get_addr.  Using the full call machinery is overkill and,
      more importantly, makes it difficult to add a special relocation.  So I've
      introduced another opcode GET_TLS_ADDR to represent the function call, and
      surrounded it with register copies to set up the parameter and return value.
      
      Most of the code is pretty straightforward.  I ran into one peculiarity
      when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like
      BL8_NOP_ELF except that it takes another parameter to represent the symbol
      ("x" above) that requires a relocation on the call.  Something in the 
      TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated
      identically during the emit phase, so this second operand was never
      visited to generate relocations.  This is the reason for the slightly
      messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding().
      
      Two new tests are included to demonstrate correct external assembly and
      correct generation of relocations using the integrated assembler.
      
      Comments welcome!
      
      Thanks,
      Bill
      
      llvm-svn: 169910
      c56f1d34
    • Eric Christopher's avatar
      Update some comments. · d692c1db
      Eric Christopher authored
      llvm-svn: 169907
      d692c1db
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