Messages in this thread | | | Subject | Re: [PATCH v2 1/2] scripts: Add a recorduidiv program | From | Michal Marek <> | Date | Mon, 30 Nov 2015 16:11:16 +0100 |
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On 2015-11-26 00:47, Russell King - ARM Linux wrote: > On Wed, Nov 25, 2015 at 01:51:03PM -0800, Stephen Boyd wrote: >> The ARM compiler inserts calls to __aeabi_uidiv() and >> __aeabi_idiv() when it needs to perform division on signed and >> unsigned integers. If a processor has support for the udiv and >> sdiv division instructions the calls to these support routines >> can be replaced with those instructions. Therefore, record the >> location of calls to these library functions into two sections >> (one for udiv and one for sdiv) similar to how we trace calls to >> mcount. When the kernel boots up it will check to see if the >> processor supports the instructions and then patch the call sites >> with the instruction. > > Do we have any resolution on these programs which modify the object > files in-place, rather than breaking any hard-links which may be > present (eg, as a result of using ccache in hard-link mode) ?
Good point, but I do not think anybody is using CCACHE_HARDLINK with the kernel. As the manpage says, it is going to confuse make, so the time saved by ccache would be offset by make trying to recompile all *.c files each time.
Michal
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