tcg: update README with const and pure helpers

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Aurelien Jarno 2010-03-05 22:48:03 +01:00
parent 4e17eae9f2
commit a3f5054b1a
1 changed files with 7 additions and 4 deletions

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@ -75,10 +75,13 @@ destroyed, but local temporaries and globals are preserved.
* Helpers:
Using the tcg_gen_helper_x_y it is possible to call any function
taking i32, i64 or pointer types. Before calling an helper, all
globals are stored at their canonical location and it is assumed that
the function can modify them. In the future, function modifiers will
be allowed to tell that the helper does not read or write some globals.
taking i32, i64 or pointer types. By default, before calling an helper,
all globals are stored at their canonical location and it is assumed
that the function can modify them. This can be overriden by the
TCG_CALL_CONST function modifier. By default, the helper is allowed to
modify the CPU state or raise an exception. This can be overriden by
the TCG_CALL_PURE function modifier, in which case the call to the
function is removed if the return value is not used.
On some TCG targets (e.g. x86), several calling conventions are
supported.