tcg: add a CONST flag to TCG helpers

A const function only reads its arguments and does not use TCG
globals variables. Hence a call to such a function does not
save TCG globals variabes back to their canonical location.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7008 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 4 insertions, 0 deletions

diff --git a/tcg/tcg.h b/tcg/tcg.h
index cb4911cde..c9b001e00 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -178,6 +178,10 @@ typedef int TCGv_i64;
    and cannot raise exceptions. Hence a call to a pure function can be
    safely suppressed if the return value is not used. */
 #define TCG_CALL_PURE           0x0010 
+/* A const function only reads its arguments and does not use TCG
+   globals variables. Hence a call to such a function does not
+   save TCG globals variabes back to their canonical location. */
+#define TCG_CALL_CONST          0x0020
 
 /* used to align parameters */
 #define TCG_CALL_DUMMY_TCGV     MAKE_TCGV_I32(-1)