===================================================================
@@ -685,19 +685,27 @@ DEFTREECODE (MULT_HIGHPART_EXPR, "mult_h
/* Division for integer result that rounds the quotient toward zero. */
DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2)
-/* Division for integer result that rounds the quotient toward infinity. */
+/* Division for integer result that rounds it toward plus infinity. */
DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2)
-/* Division for integer result that rounds toward minus infinity. */
+/* Division for integer result that rounds it toward minus infinity. */
DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2)
-/* Division for integer result that rounds toward nearest integer. */
+/* Division for integer result that rounds it toward nearest integer. */
DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2)
-/* Four kinds of remainder that go with the four kinds of division. */
+/* Four kinds of remainder that go with the four kinds of division: */
+
+/* The sign of the remainder is that of the dividend. */
DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2)
+
+/* The sign of the remainder is the opposite of that of the divisor. */
DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2)
+
+/* The sign of the remainder is that of the divisor. */
DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2)
+
+/* The sign of the remainder is not predictable. */
DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2)
/* Division for real result. */
===================================================================
@@ -12929,11 +12929,13 @@ tree_binary_nonnegative_warnv_p (enum tr
return RECURSE (op0) && RECURSE (op1);
case TRUNC_MOD_EXPR:
- case CEIL_MOD_EXPR:
- case FLOOR_MOD_EXPR:
- case ROUND_MOD_EXPR:
return RECURSE (op0);
+ case FLOOR_MOD_EXPR:
+ return RECURSE (op1);
+
+ case CEIL_MOD_EXPR:
+ case ROUND_MOD_EXPR:
default:
return tree_simple_nonnegative_warnv_p (code, type);
}
> Maybe add the comments to tree.def instead. Good idea, revised patch attached. * tree.def (CEIL_DIV_EXPR, FLOOR_DIV_EXPR, ROUND_DIV_EXPR): Tweak comments. (TRUNC_MOD_EXPR, CEIL_MOD_EXPR, FLOOR_MOD_EXPR, ROUND_MOD_EXPR): Add comments on sign of the result. * fold-const.c (tree_binary_nonnegative_warnv_p) <FLOOR_MOD_EXPR>: Recurse on operand #1 instead of operand #0. <CEIL_MOD_EXPR>: Do not recurse. <ROUND_MOD_EXPR>: Likewise.