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Groups > linux.kernel > #1228240
| From | Andrew Morton <akpm@linux-foundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 0/3] Add __ioread32_copy() and use it |
| Date | 2015-09-18 21:20 +0200 |
| Message-ID | <qa9mq-3gO-19@gated-at.bofh.it> (permalink) |
| References | <q94oN-6wV-1@gated-at.bofh.it> <q97mG-2Ru-13@gated-at.bofh.it> <q9aNA-7V0-15@gated-at.bofh.it> <q9aXg-86m-1@gated-at.bofh.it> <q9b6W-8hW-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, 16 Sep 2015 04:55:46 +0200 Andi Kleen <andi@firstfloor.org> wrote: > > Under what circumstances will the compiler (or linker?) do this? > > Compiler. > > > LTO enabled? > > Yes it's for LTO. The optimization allows the compiler to drop unused > functions, which is very popular with users (a lot use it to get smaller > kernel images) > Does this look truthful and complete? --- a/include/linux/compiler-gcc.h~a +++ a/include/linux/compiler-gcc.h @@ -205,7 +205,10 @@ #if GCC_VERSION >= 40600 /* - * Tell the optimizer that something else uses this function or variable. + * When used with Link Time Optimization, gcc can optimize away C functions or + * variables which are referenced only from assembly code. __visible tells the + * optimizer that something else uses this function or variable, thus preventing + * this. */ #define __visible __attribute__((externally_visible)) #endif _ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.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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[PATCH 0/3] Add __ioread32_copy() and use it Stephen Boyd <sboyd@codeaurora.org> - 2015-09-15 21:50 +0200
[PATCH 1/3] lib: iomap_copy: Add __ioread32_copy() Stephen Boyd <sboyd@codeaurora.org> - 2015-09-15 21:50 +0200
[PATCH 3/3] FIRMWARE: bcm47xx_nvram: Use __ioread32_copy() instead of open-coding Stephen Boyd <sboyd@codeaurora.org> - 2015-09-15 21:50 +0200
[PATCH 2/3] soc: qcom: smd: Use __ioread32_copy() instead of open-coding it Stephen Boyd <sboyd@codeaurora.org> - 2015-09-15 21:50 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Andrew Morton <akpm@linux-foundation.org> - 2015-09-16 01:00 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Stephen Boyd <sboyd@codeaurora.org> - 2015-09-16 03:00 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Andrew Morton <akpm@linux-foundation.org> - 2015-09-17 00:10 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Andi Kleen <andi@firstfloor.org> - 2015-09-16 04:40 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Andrew Morton <akpm@linux-foundation.org> - 2015-09-16 04:50 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Andi Kleen <andi@firstfloor.org> - 2015-09-16 05:00 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Andrew Morton <akpm@linux-foundation.org> - 2015-09-18 21:20 +0200
Re: [PATCH 0/3] Add __ioread32_copy() and use it Andi Kleen <andi@firstfloor.org> - 2015-09-19 22:20 +0200
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