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From: adr <adr@SDF.ORG>
To: 9fans@9fans.net
Subject: [9fans] Conversion of constants in C compiler
Date: Mon, 6 Jun 2022 00:35:47 +0000 (UTC)	[thread overview]
Message-ID: <3df37b2-6a4a-fdfb-7bec-218471d6cb8@SDF.ORG> (raw)

Building cmd I noticed that the case of sizeof(int) = sizeof(long)
(which is the case in all compilers) wasn't managed with my changes.
I wonder if this logic mess could be shortened without making
impossible to read the 'if' conditions without throwing up (I've
tried).

I've compiled on arm the libraries, cmd and kernel (except ape)
without any problem.

adr.

/sys/src/cmd/cc/lex.c
[...]
        vv = yylval.vval;
        if(c1 & Numvlong ||
          (uvlong)convvtox(vv, TUVLONG) > convvtox(vv, TULONG)){
                /* unsigned suffix or hex occupying the sing bit */
                if((c1 & Numuns) || convvtox(vv, TVLONG) < 0 && (c1 & Numdec) == 0) {
                        c = LUVLCONST;
                        t = TUVLONG;
                        goto nret;
                }
                c = LVLCONST;
                t = TVLONG;
                goto nret;
        }
        if(c1 & Numlong ||
          (uvlong)convvtox(vv, TULONG) > convvtox(vv, TUINT)){
                if((c1 & Numuns) || convvtox(vv, TLONG) < 0 && (c1 & Numdec) == 0) {
                        c = LULCONST;
                        t = TULONG;
                        goto nret;
                }
                /* decimal occupying the sing bit */
                if(convvtox(vv, TLONG) < 0 && (c1 & Numdec)) {
                        c = LVLCONST;
                        t = TVLONG;
                        goto nret;
                }
                c = LLCONST;
                t = TLONG;
                goto nret;
        }
        if((c1 & Numuns) || convvtox(vv, TINT) < 0 && (c1 & Numdec) == 0) {
                c = LUCONST;
                t = TUINT;
                goto nret;
        }
        if(convvtox(vv, TINT) < 0 && (c1 & Numdec)) {
                /* size(int) = size(long) */
                if(convvtox(vv, TLONG) < 0) {
                        c = LVLCONST;
                        t = TVLONG;
                        goto nret;
                }
                c = LLCONST;
                t = TLONG;
                goto nret;
        }
        c = LCONST;
        t = TINT;
        goto nret;
[...]


------------------------------------------
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             reply	other threads:[~2022-06-06  0:36 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-06  0:35 adr [this message]
  -- strict thread matches above, loose matches on Subject: below --
2022-04-20 10:19 adr
2022-04-20 11:38 ` Charles Forsyth
2022-04-20 14:37   ` adr
2022-04-20 14:37 ` ori
2022-04-21  7:54   ` adr
2022-04-21 15:29     ` ori
2022-04-28  1:10     ` ori
2022-05-01 12:03       ` adr
2022-04-28  2:43     ` ori
2022-04-28  3:12       ` ori
2022-05-01 12:35       ` adr
2022-05-09 19:31         ` adr
2022-05-10 13:06           ` adr
2022-05-10 14:48             ` adr

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