Thanks Simon, primops worked fine, but not I'm getting assembler errors(even though -dcore-lint, -dstg-lint and -dcmm-lint are all passing).
The error is caused by this STG expression: case (#,#) [ds_gX8 ds_gX9] of _ { (#,#) tag_gWR ubx_gWS -> case tag_gWR of tag_gWR { __DEFAULT -> GHC.Err.undefined; 1# -> let { sat_sWD :: [GHC.Types.Char] = \u srt:SRT:[roK :-> GHC.Show.$fShowInt] [] let { sat_sWC :: GHC.Types.Int = NO_CCS GHC.Types.I#! [ubx_gWS]; } in GHC.Show.show GHC.Show.$fShowInt sat_sWC; } in let { sat_sWB :: [GHC.Types.Char] = \u srt:SRT:[0k :-> GHC.CString.unpackCString#] [] GHC.CString.unpackCString# "Left "#; } in GHC.Base.++ sat_sWB sat_sWD; 2# -> let { co_gWT :: GHC.Prim.Float# = sat-only \s [] int2Float# [ubx_gWS]; } in let { sat_sWH :: [GHC.Types.Char] = \u srt:SRT:[rd2 :-> GHC.Float.$fShowFloat] [] let { sat_sWG :: GHC.Types.Float = NO_CCS GHC.Types.F#! [co_gWT]; } in GHC.Show.show GHC.Float.$fShowFloat sat_sWG; } in let { sat_sWF :: [GHC.Types.Char] = \u srt:SRT:[0k :-> GHC.CString.unpackCString#] [] GHC.CString.unpackCString# "Right "#; } in GHC.Base.++ sat_sWF sat_sWH; }; }; In the first case(when the tag is 1#) I'm not doing any coercions, second argument of the tuple is directly used. In the second case(when the tag is 2#), I'm generating this let-binding: let { co_gWT :: GHC.Prim.Float# = sat-only \s [] int2Float# [ubx_gWS]; } And then in the RHS of case alternative I'm using co_gWT instead of ubx_gWS, but for some reason GHC is generating invalid assembly for this expression: /tmp/ghc2889_0/ghc_2.s: Assembler messages: /tmp/ghc2889_0/ghc_2.s:125:0: error: Error: `16(%xmm1)' is not a valid base/index expression `gcc' failed in phase `Assembler'. (Exit code: 1) The assembly seems to be: ==================== Asm code ==================== .section .text .align 8 .quad 4294967296 .quad 18 co_gWT_info: _cY7: _cY9: movq 16(%xmm1),%rax cvtsi2ssq %rax,%xmm0 movss %xmm0,%xmm1 jmp *(%rbp) .size co_gWT_info, .-co_gWT_info Do you have any ideas why this may be happening? 2015-12-07 7:23 GMT-05:00 Simon Peyton Jones <simo...@microsoft.com>: > If memory serves, there are primops for converting between unboxed values of > different widths. > > Certainly converting between a float and a non-float will require an > instruction on some architectures, since they use different register sets. > > Re (2) I have no idea. You'll need to get more information... pprTrace or > something. > > Simon > > | -----Original Message----- > | From: ghc-devs [mailto:ghc-devs-boun...@haskell.org] On Behalf Of Ömer > | Sinan Agacan > | Sent: 06 December 2015 18:25 > | To: ghc-devs <ghc-devs@haskell.org> > | Subject: question about coercions between primitive types in STG level > | > | Hi all, > | > | In my compiler pass(D1559, see ElimUbxSums.hs) I'm doing some unsafe > | coercions at the STG level. It works fine for lifted types, but for > | unlifted ones I'm having some problems. What I'm trying to do is given > | a number of primitive types I'm finding the one with biggest size, and > | then generating a constructor that takes this biggest primitive type > | as argument. > | > | The problem is that this is not working very well - GHC is generating > | illegal instructions that try to load a F32 value to a register > | allocated for I64, using movss instruction. > | > | CoreLint is catching this error and printing this: > | > | Cmm lint error: > | in basic block c1hF > | in assignment: > | _g16W::I64 = 4.5 :: W32; // CmmAssign > | Reg ty: I64 > | Rhs ty: F32 > | > | So I have two questions about this: > | > | 1. Is there a way to safely do this? What are my options here? What > | I'm trying > | to do is to use a single data constructor field for different > | primitive > | types. The field is guaranteed to be as big as necessary. > | > | 2. In the Cmm code shown above, the type annotation is showing `W32` > | but in the > | error message it says `F32`. I'm confused about this, is this error > | message > | given because the sizes don't match? (64bits vs 32bits) Why the > | type > | annotation says W32 while the value has type F32? > | > | Thanks.. > | _______________________________________________ > | ghc-devs mailing list > | ghc-devs@haskell.org > | https://na01.safelinks.protection.outlook.com/?url=http%3a%2f%2fmail.h > | askell.org%2fcgi-bin%2fmailman%2flistinfo%2fghc- > | devs&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7ced6a1fbfa6254e5 > | 2a7d808d2fe6a9a63%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=7j3fQs4 > | ox67SZbA4jv4uPVVdvp5X5yUUuMaqp4sh%2fpg%3d _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs