From a3f5054b1a215a140e40a408bc13208196fb3d5d Mon Sep 17 00:00:00 2001 From: Aurelien Jarno Date: Fri, 5 Mar 2010 22:48:03 +0100 Subject: tcg: update README with const and pure helpers Signed-off-by: Aurelien Jarno --- tcg/README | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'tcg/README') diff --git a/tcg/README b/tcg/README index f0e21a1c1d..281c1143f3 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. -- cgit v1.2.1