From: Aurelien Jarno Date: Fri, 5 Mar 2010 21:48:03 +0000 (+0100) Subject: tcg: update README with const and pure helpers X-Git-Tag: TizenStudio_2.0_p2.3~5407 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=148c18af046002d314d0089565645f471a40375e;p=sdk%2Femulator%2Fqemu.git tcg: update README with const and pure helpers Signed-off-by: Aurelien Jarno --- diff --git a/tcg/README b/tcg/README index f0e21a1..281c114 100644 --- a/tcg/README +++ b/tcg/README @@ -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.