[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 4 commits: Introduce a standard thunk for allocating strings

[Marge Bot (@marge-bot)]

Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC


Commits:
86e6549e by Ömer Sinan Ağacan at 2022-10-22T07:41:30-04:00
Introduce a standard thunk for allocating strings

Currently for a top-level closure in the form

    hey = unpackCString# x

we generate code like this:

    Main.hey_entry() //  [R1]
             { info_tbls: [(c2T4,
                            label: Main.hey_info
                            rep: HeapRep static { Thunk }
                            srt: Nothing)]
               stack_info: arg_space: 8 updfr_space: Just 8
             }
         {offset
           c2T4: // global
               _rqm::P64 = R1;
               if ((Sp + 8) - 24 < SpLim) (likely: False) goto c2T5; else goto c2T6;
           c2T5: // global
               R1 = _rqm::P64;
               call (stg_gc_enter_1)(R1) args: 8, res: 0, upd: 8;
           c2T6: // global
               (_c2T1::I64) = call "ccall" arg hints:  [PtrHint,
                                                        PtrHint]  result hints:  [PtrHint] newCAF(BaseReg, _rqm::P64);
               if (_c2T1::I64 == 0) goto c2T3; else goto c2T2;
           c2T3: // global
               call (I64[_rqm::P64])() args: 8, res: 0, upd: 8;
           c2T2: // global
               I64[Sp - 16] = stg_bh_upd_frame_info;
               I64[Sp - 8] = _c2T1::I64;
               R2 = hey1_r2Gg_bytes;
               Sp = Sp - 16;
               call GHC.CString.unpackCString#_info(R2) args: 24, res: 0, upd: 24;
         }
     }

This code is generated for every string literal. Only difference between
top-level closures like this is the argument for the bytes of the string
(hey1_r2Gg_bytes in the code above).

With this patch we introduce a standard thunk in the RTS, called
stg_MK_STRING_info, that does what `unpackCString# x` does, except it
gets the bytes address from the payload. Using this, for the closure
above, we generate this:

    Main.hey_closure" {
        Main.hey_closure:
            const stg_MK_STRING_info;
            const 0; // padding for indirectee
            const 0; // static link
            const 0; // saved info
            const hey1_r1Gg_bytes; // the payload
    }

This is much smaller in code.

Metric Decrease:
    T10421
    T11195
    T12150
    T12425
    T16577
    T18282
    T18698a
    T18698b

Co-Authored By: Ben Gamari <ben at well-typed.com>

- - - - -
1937016b by Andreas Klebinger at 2022-10-22T07:42:06-04:00
hadrian: Improve error for wrong key/value errors.

- - - - -
11fe42d8 by Vladislav Zavialov at 2022-10-23T00:11:50+03:00
Class layout info (#19623)

Updates the haddock submodule.

- - - - -
dfb7fae3 by Sven Tennie at 2022-10-23T21:32:10-04:00
Pin used way for test cloneMyStack (#21977)

cloneMyStack checks the order of closures on the cloned stack. This may
change for different ways. Thus we limit this test to one way (normal).

- - - - -


30 changed files:

- compiler/GHC/Cmm.hs
- compiler/GHC/Cmm/CLabel.hs
- compiler/GHC/Cmm/Info/Build.hs
- compiler/GHC/Cmm/Parser.y
- compiler/GHC/Hs.hs
- compiler/GHC/Hs/Decls.hs
- compiler/GHC/Hs/Extension.hs
- compiler/GHC/Parser.y
- compiler/GHC/Parser/PostProcess.hs
- compiler/GHC/Parser/PostProcess/Haddock.hs
- compiler/GHC/Rename/Module.hs
- compiler/GHC/StgToCmm/Bind.hs
- compiler/GHC/StgToCmm/Heap.hs
- compiler/GHC/StgToCmm/Utils.hs
- compiler/GHC/ThToHs.hs
- compiler/GHC/Types/SrcLoc.hs
- compiler/Language/Haskell/Syntax.hs
- + compiler/Language/Haskell/Syntax/Concrete.hs
- compiler/Language/Haskell/Syntax/Decls.hs
- compiler/Language/Haskell/Syntax/Expr.hs
- compiler/Language/Haskell/Syntax/Extension.hs
- compiler/Language/Haskell/Syntax/Pat.hs
- compiler/Language/Haskell/Syntax/Type.hs
- compiler/ghc.cabal.in
- hadrian/src/Settings.hs
- rts/Prelude.h
- rts/RtsSymbols.c
- rts/StgStdThunks.cmm
- rts/include/stg/MiscClosures.h
- testsuite/tests/count-deps/CountDepsAst.stdout


The diff was not included because it is too large.


View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4384f012adcbd1713dd93d92638f12568f91eac1...dfb7fae3f239094da6d564e8be22c0a42f4acf29

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/4384f012adcbd1713dd93d92638f12568f91eac1...dfb7fae3f239094da6d564e8be22c0a42f4acf29
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