On Tue, Apr 20, 2004 at 02:56:36PM +0200, Ketil Malde wrote:
> Bernard James POPE <[EMAIL PROTECTED]> writes:
>
> > Note each program was compiled with ghc 6.2 with -O2 on debian linux.
> :
> > main = print $ loop 100000000 0
>
> Isn't this going to be optimized away to a constant with -O2?
Here's the final stg code, obtained by:
ghc -ddump-stg -O2 --make MainPure.hs -o pure
==================== STG syntax: ====================
Main.$wloop =
\r [ww ww1]
case ww of ds {
__DEFAULT ->
case +# [ww1 ds] of sat_s2pI {
__DEFAULT ->
case -# [ds 1] of sat_s2pE {
__DEFAULT -> Main.$wloop sat_s2pE sat_s2pI;
};
};
0 -> ww1;
};
SRT(Main.$wloop): []
Main.loop =
\r [w w1]
case w of w2 {
GHC.Base.I# ww ->
case w1 of w3 {
GHC.Base.I# ww1 ->
case Main.$wloop ww ww1 of ww2 { __DEFAULT -> GHC.Base.I# [ww2]; };
};
};
SRT(Main.loop): []
Main.eta =
\u []
case Main.$wloop 100000000 0 of ww {
__DEFAULT -> GHC.Base.I# [ww];
};
SRT(Main.eta): []
Main.lvl =
\u srt:(0,*bitmap*) []
case Main.eta of w {
GHC.Base.I# ww -> GHC.Show.$wshowSignedInt 0 ww GHC.Base.[];
};
SRT(Main.lvl): [Main.eta]
Main.main =
\r srt:(0,*bitmap*) [s]
case GHC.IO.hGetLine GHC.Handle.stdin s of wild {
GHC.Prim.(#,#) new_s a41 ->
case GHC.IO.hPutStr GHC.Handle.stdout Main.lvl new_s of wild1 {
GHC.Prim.(#,#) new_s1 a411 ->
GHC.IO.$whPutChar GHC.Handle.stdout '\n' new_s1;
};
};
SRT(Main.main): [GHC.Handle.stdout, GHC.IO.$whPutChar,
GHC.IO.hPutStr, GHC.Handle.stdin, GHC.IO.hGetLine, Main.lvl]
:Main.main =
\r srt:(0,*bitmap*) [eta1]
catch# [Main.main GHC.TopHandler.topHandler eta1];
SRT(:Main.main): [Main.main, GHC.TopHandler.topHandler]
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