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Date: Sat, 17 May 2014 17:53:45 +0100 From: Al Viro <viro@...IV.linux.org.uk> To: Manuel Schölling <manuel.schoelling@....de> Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH] fs: Cleanup string initializations (char[] instead of char *) On Sat, May 17, 2014 at 05:00:18PM +0200, Manuel Schölling wrote: > Initializations like 'char *foo = "bar"' will create two variables: a static > string and a pointer (foo) to that static string. Instead 'char foo[] = "bar"' > will declare a single variable and will end up in shorter > assembly (according to Jeff Garzik on the KernelJanitor's TODO list). The hell it will. Compare assembler generated e.g. for 32bit x86 before and after. > { > char *dp; > char *status = "disabled"; > - const char * flags = "flags: "; > + const char flags[] = "flags: "; The first variant puts address of constant array into local variable (on stack or in a register). The second one fills local _array_ - the string itself goes on stack. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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