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author | 2015-11-29 12:17:36 +0100 | |
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committer | 2015-11-29 12:17:36 +0100 | |
commit | 8ea2eb2dc442e9d0e89e08d40283b1aaba1cc87a (patch) | |
tree | eaa63e77f9386864c26fb87a9f50f4628611abc8 /src/bitflags.rs | |
parent | bec7731473a0fae1d837a8a0fdfc902504ea9fcd (diff) | |
download | rust-x86-8ea2eb2dc442e9d0e89e08d40283b1aaba1cc87a.tar.gz rust-x86-8ea2eb2dc442e9d0e89e08d40283b1aaba1cc87a.tar.zst rust-x86-8ea2eb2dc442e9d0e89e08d40283b1aaba1cc87a.zip |
Fixing volatile and memory attributes for assembly.
For volatile:
You can prevent an asm instruction from being deleted by writing the
keyword volatile after the asm. [...] The volatile keyword indicates
that the instruction has important side-effects. GCC will not
delete a volatile asm if it is reachable.
and
An asm instruction without any output operands will be treated
identically to a volatile asm instruction.
And for memory:
This will cause GCC to not keep memory values cached in
registers across the assembler instruction and not optimize
stores or loads to that memory.
See also:
https://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/Extended-Asm.html
http://stackoverflow.com/questions/14449141/the-difference-between-asm-asm-volatile-and-clobbering-memory
Diffstat (limited to 'src/bitflags.rs')
-rw-r--r-- | src/bitflags.rs | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/src/bitflags.rs b/src/bitflags.rs index a514001..8d16e41 100644 --- a/src/bitflags.rs +++ b/src/bitflags.rs @@ -8,7 +8,6 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. -#[macro_export] macro_rules! bitflags { ($(#[$attr:meta])* flags $BitFlags:ident: $T:ty { $($(#[$Flag_attr:meta])* const $Flag:ident = $value:expr),+ |