[GHC] #8816: Make SPARC registerised again.

[GHC]

#8816: Make SPARC registerised again.
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        Reporter:  kgardas          |                Owner:  (none)
            Type:  feature request  |               Status:  new
        Priority:  normal           |            Milestone:
       Component:  Compiler         |              Version:
      Resolution:                   |             Keywords:
Operating System:  Solaris          |         Architecture:  sparc
 Type of failure:  None/Unknown     |            Test Case:
      Blocked By:  8847             |             Blocking:
 Related Tickets:                   |  Differential Rev(s):
       Wiki Page:                   |
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Comment (by slyfox):

 To try NCG locally you don't even need to patch autoconf. That did the
 trick for me:
 {{{
 $ ./configure --target=sparc-unknown-linux-gnu --disable-unregisterised
 $ make
 }}}

 Unfortunately NCG for sparc needs a few more fixes.

 64-bit subtract inplementation:

 {{{
   rts_dist_HC rts/dist/build/StgStartup.o
 ghc-stage1: panic! (the 'impossible' happened)
   (GHC version 8.3.20170408 for sparc-unknown-linux):
         iselExpr64(sparc)
   I64[_c2::P32 + 64] - %MO_UU_Conv_W32_W64((Hp + 4) - I32[_c3::I32])
   Call stack:
       CallStack (from HasCallStack):
         prettyCurrentCallStack, called at
 compiler/utils/Outputable.hs:1134:58 in ghc:Outputable
         callStackDoc, called at compiler/utils/Outputable.hs:1138:37 in
 ghc:Outputable
         pprPanic, called at
 compiler/nativeGen/SPARC/CodeGen/Gen64.hs:196:6 in ghc:SPARC.CodeGen.Gen64

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}

 Something fun in register allocator WRT PIC register:

 {{{
   HC [stage 1] libraries/ghc-prim/dist-install/build/GHC/Types.o
 ghc-stage1: panic! (the 'impossible' happened)
   (GHC version 8.3.20170408 for sparc-unknown-linux):
         SPARC.CodeGen.Base.getRegisterReg: global is in memory
   PicBaseReg
   Call stack:
       CallStack (from HasCallStack):
         prettyCurrentCallStack, called at
 compiler/utils/Outputable.hs:1134:58 in ghc:Outputable
         callStackDoc, called at compiler/utils/Outputable.hs:1138:37 in
 ghc:Outputable
         pprPanic, called at
 compiler/nativeGen/SPARC/CodeGen/Base.hs:103:21 in ghc:SPARC.CodeGen.Base
 }}}

 '''-fPIC''' is not really supported by NCG:

 {{{
   rts_dist_HC rts/dist/build/Compact.thr_l_dyn_o
 ghc-stage1: panic! (the 'impossible' happened)
   (GHC version 8.3.20170408 for sparc-unknown-linux):
         MachCodeGen: sparc genSwitch PIC not finished

 CallStack (from HasCallStack):
   error, called at compiler/nativeGen/SPARC/CodeGen.hs:316:11 in
 ghc:SPARC.CodeGen
 }}}

 prof build is also broken in an interesting way:
 {{{
   HC [stage 1] libraries/ghc-prim/dist-install/build/GHC/Types.p_o
 /tmp/ghc26402_0/ghc_3.s: Assembler messages:

 /tmp/ghc26402_0/ghc_3.s:107:0: error:
      Error: can't resolve `iat6_str' {.rodata.str.iat6_str section} -
 `ghczmprim_GHCziTypes_HEqzusc_info' {.rodata.str.iat7_str section}
     |
 107 |   .long   iat6_str-(ghczmprim_GHCziTypes_HEqzusc_info)+0
     | ^
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8816#comment:4>
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