https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55212
--- Comment #115 from Oleg Endo <olegendo at gcc dot gnu.org> ---
It seems that it's already enough to set the cost for I08 from 0 to 1:
Index: gcc/config/sh/sh.c
===================================================================
--- gcc/config/sh/sh.c (revision 227958)
+++ gcc/config/sh/sh.c (working copy)
@@ -3574,7 +3574,7 @@
return true;
}
if (CONST_OK_FOR_I08 (INTVAL (x)))
- *total = 0;
+ *total = 1;
else if ((outer_code == AND || outer_code == IOR || outer_code == XOR)
&& CONST_OK_FOR_K08 (INTVAL (x)))
*total = 1;
This will reduce the rematerializations and thus increase reg live ranges in
other places.
attachment 36363 and attachment 36364 are CSiBE comparistions with and without
LRA.
Without LRA: sum: 3347407 -> 3345667 -1740 / -0.051981 %
With LRA: sum: 3348933 -> 3347433 -1500 / -0.044790 %
Although there are quite some increases, overall it seems beneficial...
