# [PATCH] remove inline iteration variable 7 messages from 2006-08-15 to 2006-08-17. Participants: David Rientjes, Alex Riesen, Junio C Hamano. Thread: https://gitlist.dev/t/5285 ## David Rientjes, 2006-08-15 17:23 Subject: [PATCH] remove inline iteration variable Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.63.0608151022340.26891%40chino.corp.google.com ``` Remove unnecessary iteration variable in inline. David Signed-off-by: David Rientjes --- builtin-grep.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/builtin-grep.c b/builtin-grep.c index 93b7e07..6476fe1 100644 --- a/builtin-grep.c +++ b/builtin-grep.c @@ -176,8 +176,8 @@ static void compile_regexp(struct grep_p #if DEBUG static inline void indent(int in) { - int i; - for (i = 0; i < in; i++) putchar(' '); + for (; in > 0; in--) + putchar(' '); } static void dump_pattern_exp(struct grep_expr *x, int in) -- 1.4.2.rc4.gf615-dirty ``` ## Alex Riesen, 2006-08-16 07:27 Subject: Re: [PATCH] remove inline iteration variable Message-ID: <81b0412b0608160027l2ac53c10gd9a75525ca144f1d@mail.gmail.com> URL: https://gitlist.dev/e/81b0412b0608160027l2ac53c10gd9a75525ca144f1d%40mail.gmail.com In-Reply-To: ``` On 8/15/06, David Rientjes wrote: > Remove unnecessary iteration variable in inline. > - for (i = 0; i < in; i++) putchar(' '); > + for (; in > 0; in--) while(in--) putchar(' '); ``` ## David Rientjes, 2006-08-16 17:14 Subject: Re: [PATCH] remove inline iteration variable Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.63.0608161011100.20470%40chino.corp.google.com In-Reply-To: <81b0412b0608160027l2ac53c10gd9a75525ca144f1d@mail.gmail.com> ``` On Wed, 16 Aug 2006, Alex Riesen wrote: > On 8/15/06, David Rientjes wrote: > > Remove unnecessary iteration variable in inline. > > - for (i = 0; i < in; i++) putchar(' '); > > + for (; in > 0; in--) > > while(in--) putchar(' '); > That goes into an infinite loop if the argument is negative because it emits a cmpl $0, x(%ebp). Should never happen, but there's no reason not to prevent it with a for loop. David ``` ## Alex Riesen, 2006-08-16 20:10 Subject: Re: [PATCH] remove inline iteration variable Message-ID: <20060816201019.GA6083@steel.home> URL: https://gitlist.dev/e/20060816201019.GA6083%40steel.home In-Reply-To: ``` David Rientjes, Wed, Aug 16, 2006 19:14:44 +0200: > > > Remove unnecessary iteration variable in inline. > > > - for (i = 0; i < in; i++) putchar(' '); > > > + for (; in > 0; in--) > > > > while(in--) putchar(' '); > > > > That goes into an infinite loop if the argument is negative because > it emits a cmpl $0, x(%ebp). Should never happen, but there's no > reason not to prevent it with a for loop. while (in-- > 0) putchar(' '); still shorter :) ``` ## Junio C Hamano, 2006-08-16 20:16 Subject: Re: [PATCH] remove inline iteration variable Message-ID: <7vzme4307d.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vzme4307d.fsf%40assigned-by-dhcp.cox.net In-Reply-To: <20060816201019.GA6083@steel.home> ``` fork0@t-online.de (Alex Riesen) writes: > David Rientjes, Wed, Aug 16, 2006 19:14:44 +0200: >> > > Remove unnecessary iteration variable in inline. >> > > - for (i = 0; i < in; i++) putchar(' '); >> > > + for (; in > 0; in--) >> > >> > while(in--) putchar(' '); >> > >> >> That goes into an infinite loop if the argument is negative because >> it emits a cmpl $0, x(%ebp). Should never happen, but there's no >> reason not to prevent it with a for loop. > > while (in-- > 0) putchar(' '); > > still shorter :) Why do we keep talking about a usually ifdef'ed out debugging section? I'll be removing that section altogether ;-). ``` ## David Rientjes, 2006-08-16 21:41 Subject: Re: [PATCH] remove inline iteration variable Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.63.0608161441070.29566%40chino.corp.google.com In-Reply-To: <20060816201019.GA6083@steel.home> ``` On Wed, 16 Aug 2006, Alex Riesen wrote: > David Rientjes, Wed, Aug 16, 2006 19:14:44 +0200: > > > > Remove unnecessary iteration variable in inline. > > > > - for (i = 0; i < in; i++) putchar(' '); > > > > + for (; in > 0; in--) > > > > > > while(in--) putchar(' '); > > > > > > > That goes into an infinite loop if the argument is negative because > > it emits a cmpl $0, x(%ebp). Should never happen, but there's no > > reason not to prevent it with a for loop. > > while (in-- > 0) putchar(' '); > > still shorter :) > It emits a slightly rearranged assembly with the same number of instructions. David ``` ## Alex Riesen, 2006-08-17 09:11 Subject: Re: [PATCH] remove inline iteration variable Message-ID: <81b0412b0608170211p7289889av43eb7c35ba07fe02@mail.gmail.com> URL: https://gitlist.dev/e/81b0412b0608170211p7289889av43eb7c35ba07fe02%40mail.gmail.com In-Reply-To: ``` On 8/16/06, David Rientjes wrote: > > > > > Remove unnecessary iteration variable in inline. > > > > > - for (i = 0; i < in; i++) putchar(' '); > > > > > + for (; in > 0; in--) > > > > > > > > while(in--) putchar(' '); > > > > > > > > > > That goes into an infinite loop if the argument is negative because > > > it emits a cmpl $0, x(%ebp). Should never happen, but there's no > > > reason not to prevent it with a for loop. > > > > while (in-- > 0) putchar(' '); > > > > still shorter :) > > > > It emits a slightly rearranged assembly with the same number of instructions. > oops. I should've looked at the output. But the point moot anyway, Junio says :) ```