From: "Alex Bennée" <alex.bennee@linaro.org>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: pbonzini@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com,
david@redhat.com
Subject: Re: [PATCH v4 03/16] qemu/compiler.h: Add optimize_away
Date: Tue, 24 Sep 2019 16:47:00 +0100 [thread overview]
Message-ID: <874l11bssr.fsf@linaro.org> (raw)
In-Reply-To: <20190923230004.9231-4-richard.henderson@linaro.org>
Richard Henderson <richard.henderson@linaro.org> writes:
> Use this as a compile-time assert that a particular
> code path is not reachable.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> ---
> include/qemu/compiler.h | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
> index 20780e722d..6604ccea92 100644
> --- a/include/qemu/compiler.h
> +++ b/include/qemu/compiler.h
> @@ -221,4 +221,19 @@
> #define QEMU_GENERIC9(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC8(x, __VA_ARGS__))
> #define QEMU_GENERIC10(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC9(x, __VA_ARGS__))
>
> +/**
> + * optimize_away()
> + *
> + * The compiler, during optimization, is expected to prove that a call
> + * to this function cannot be reached and remove it. If the compiler
> + * supports QEMU_ERROR, this will be reported at compile time; otherwise
> + * this will be reported at link time, due to the missing symbol.
> + */
> +#ifdef __OPTIMIZE__
> +extern void QEMU_NORETURN QEMU_ERROR("code path is reachable")
> + optimize_away(void);
> +#else
> +#define optimize_away() g_assert_not_reached()
> +#endif
> +
> #endif /* COMPILER_H */
--
Alex Bennée
next prev parent reply other threads:[~2019-09-24 16:58 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-23 22:59 [PATCH v4 00/16] Move rom and notdirty handling to cputlb Richard Henderson
2019-09-23 22:59 ` [PATCH v4 01/16] exec: Use TARGET_PAGE_BITS_MIN for TLB flags Richard Henderson
2019-09-24 13:53 ` Alex Bennée
2019-09-23 22:59 ` [PATCH v4 02/16] cputlb: Disable __always_inline__ without optimization Richard Henderson
2019-09-24 13:56 ` Alex Bennée
2019-09-23 22:59 ` [PATCH v4 03/16] qemu/compiler.h: Add optimize_away Richard Henderson
2019-09-24 7:47 ` David Hildenbrand
2019-09-24 17:27 ` Richard Henderson
2019-09-24 17:29 ` David Hildenbrand
2019-09-24 15:47 ` Alex Bennée [this message]
2019-09-23 22:59 ` [PATCH v4 04/16] cputlb: Use optimize_away in load/store_helpers Richard Henderson
2019-09-24 7:47 ` David Hildenbrand
2019-09-24 15:47 ` Alex Bennée
2019-09-23 22:59 ` [PATCH v4 05/16] cputlb: Split out load/store_memop Richard Henderson
2019-09-24 7:48 ` David Hildenbrand
2019-09-24 15:51 ` Alex Bennée
2019-09-23 22:59 ` [PATCH v4 06/16] cputlb: Introduce TLB_BSWAP Richard Henderson
2019-09-24 18:25 ` Alex Bennée
2019-09-25 17:36 ` Richard Henderson
2019-09-23 22:59 ` [PATCH v4 07/16] exec: Adjust notdirty tracing Richard Henderson
2019-09-24 21:53 ` Alex Bennée
2019-09-23 22:59 ` [PATCH v4 08/16] cputlb: Move ROM handling from I/O path to TLB path Richard Henderson
2019-09-25 0:16 ` Alex Bennée
2019-09-25 6:59 ` David Hildenbrand
2019-09-25 16:01 ` Alex Bennée
2019-09-25 17:01 ` Richard Henderson
2019-09-23 22:59 ` [PATCH v4 09/16] cputlb: Move NOTDIRTY " Richard Henderson
2019-09-25 16:06 ` Alex Bennée
2019-09-23 22:59 ` [PATCH v4 10/16] cputlb: Partially inline memory_region_section_get_iotlb Richard Henderson
2019-09-24 7:59 ` David Hildenbrand
2019-09-25 17:55 ` Richard Henderson
2019-09-25 19:40 ` David Hildenbrand
2019-09-25 16:12 ` Alex Bennée
2019-09-23 22:59 ` [PATCH v4 11/16] cputlb: Merge and move memory_notdirty_write_{prepare, complete} Richard Henderson
2019-09-24 8:04 ` [PATCH v4 11/16] cputlb: Merge and move memory_notdirty_write_{prepare,complete} David Hildenbrand
2019-09-25 16:15 ` Alex Bennée
2019-09-23 23:00 ` [PATCH v4 12/16] cputlb: Handle TLB_NOTDIRTY in probe_access Richard Henderson
2019-09-24 8:05 ` David Hildenbrand
2019-09-25 16:21 ` Alex Bennée
2019-09-23 23:00 ` [PATCH v4 13/16] cputlb: Remove cpu->mem_io_vaddr Richard Henderson
2019-09-25 16:22 ` Alex Bennée
2019-09-23 23:00 ` [PATCH v4 14/16] cputlb: Remove tb_invalidate_phys_page_range is_cpu_write_access Richard Henderson
2019-09-25 16:23 ` Alex Bennée
2019-09-23 23:00 ` [PATCH v4 15/16] cputlb: Pass retaddr to tb_invalidate_phys_page_fast Richard Henderson
2019-09-25 16:28 ` Alex Bennée
2019-09-23 23:00 ` [PATCH v4 16/16] cputlb: Pass retaddr to tb_check_watchpoint Richard Henderson
2019-09-25 16:30 ` Alex Bennée
2019-09-25 18:52 ` [PATCH v4 00/16] Move rom and notdirty handling to cputlb Mark Cave-Ayland
2019-09-25 18:54 ` Mark Cave-Ayland
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