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| author | Geoff Keating <geoffk@cygnus.com> | 2000-07-18 00:23:50 +0000 |
|---|---|---|
| committer | Geoffrey Keating <geoffk@gcc.gnu.org> | 2000-07-18 00:23:50 +0000 |
| commit | dd40655a26cbe76bdb06db0e3184635f63c4acc8 (patch) | |
| tree | c87034f77402afc1ffe5f2431783be7a58cbbd65 /gcc | |
| parent | 5b1a6de4de1d2f82e9ea03218ea07bc6a3d18c7b (diff) | |
| download | gcc-dd40655a26cbe76bdb06db0e3184635f63c4acc8.zip gcc-dd40655a26cbe76bdb06db0e3184635f63c4acc8.tar.gz gcc-dd40655a26cbe76bdb06db0e3184635f63c4acc8.tar.bz2 | |
extend.texi (Extended Asm): Mention that a memory clobber does not count as a side-effect.
* extend.texi (Extended Asm): Mention that a memory clobber
does not count as a side-effect.
From-SVN: r35110
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 3 | ||||
| -rw-r--r-- | gcc/extend.texi | 5 |
2 files changed, 7 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8597b35..142e387 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,8 @@ 2000-07-17 Geoffrey Keating <geoffk@cygnus.com> + * extend.texi (Extended Asm): Mention that a memory clobber + does not count as a side-effect. + * unroll.c (copy_loop_body): Fix one instance of using host arithmetic on the target; fixes loop-4 on a 32-bit -> 64-bit cross-compile. diff --git a/gcc/extend.texi b/gcc/extend.texi index 3b8899b..6eefa62 100644 --- a/gcc/extend.texi +++ b/gcc/extend.texi @@ -2558,7 +2558,10 @@ effect. But it is valid no matter what the machine. If your assembler instruction modifies memory in an unpredictable fashion, add @samp{memory} to the list of clobbered registers. This will cause GNU CC to not keep memory values cached in registers across -the assembler instruction. +the assembler instruction. You will also want to add the +@code{volatile} keyword if the memory affected is not listed in the +inputs or outputs of the @code{asm}, as the @samp{memory} clobber does +not count as a side-effect of the @code{asm}. You can put multiple assembler instructions together in a single @code{asm} template, separated either with newlines (written as |