https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66552
Li Jia He <helijia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |helijia at gcc dot gnu.org
--- Comment #5 from Li Jia He <helijia at gcc dot gnu.org> ---
Could we consider doing this optimization on gimple? I use the following code
on gimple to produce optimized results on powerpc64.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index aefa91666e2..a40681b271f 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -11131,7 +11131,6 @@ fold_binary_loc (location_t loc, enum tree_code code,
tree type,
WARN_STRICT_OVERFLOW_MISC);
return fold_convert_loc (loc, type, tem);
}
-
return NULL_TREE;
case CEIL_MOD_EXPR:
@@ -11191,6 +11190,22 @@ fold_binary_loc (location_t loc, enum tree_code code,
tree type,
prec) == 0)
return fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
+ if (code == RSHIFT_EXPR
+ && (TREE_CODE (arg1) == CEIL_MOD_EXPR
+ || TREE_CODE (arg1) == FLOOR_MOD_EXPR
+ || TREE_CODE (arg1) == ROUND_MOD_EXPR
+ || TREE_CODE (arg1) == TRUNC_MOD_EXPR)
+ && TREE_CODE (TREE_OPERAND (arg1, 1)) == INTEGER_CST
+ && integer_pow2p (TREE_OPERAND (arg1, 1)))
+ {
+ tree arg10 = TREE_OPERAND (arg1, 0);
+ tree arg11 = TREE_OPERAND (arg1, 1);
+ return fold_build2_loc (loc, code, type, arg0,
+ fold_build2_loc (loc, BIT_AND_EXPR, TREE_TYPE(arg10), arg10,
+ fold_build2_loc (loc, MINUS_EXPR, TREE_TYPE(arg11), arg11,
+ build_one_cst(TREE_TYPE(arg11)))));
+ }
+
return NULL_TREE;
case MIN_EXPR:
