From: Eric Botcazou <ebotcazou@adacore.com>
To: Richard Biener <richard.guenther@gmail.com>
Cc: gcc-patches@gcc.gnu.org, Jeff Law <law@redhat.com>,
Joseph Myers <joseph@codesourcery.com>
Subject: Re: [patch] Fix failure of ACATS c45503c at -O2
Date: Wed, 21 Oct 2015 13:15:00 -0000 [thread overview]
Message-ID: <2100616.AKovr9yibX@polaris> (raw)
In-Reply-To: <CAFiYyc3Ne8pLSYoOm6=8paXv6MUur8M0rdaUt4p8+-RkU+nw3Q@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 488 bytes --]
> 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.
--
Eric Botcazou
[-- Attachment #2: p.diff --]
[-- Type: text/x-patch, Size: 2259 bytes --]
Index: tree.def
===================================================================
--- tree.def (revision 229123)
+++ tree.def (working copy)
@@ -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. */
Index: fold-const.c
===================================================================
--- fold-const.c (revision 229123)
+++ fold-const.c (working copy)
@@ -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);
}
next prev parent reply other threads:[~2015-10-21 13:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-20 16:38 Eric Botcazou
2015-10-20 19:04 ` Jeff Law
2015-10-20 22:10 ` Joseph Myers
2015-10-21 5:57 ` Jeff Law
2015-10-21 7:50 ` Eric Botcazou
2015-10-21 9:56 ` Richard Biener
2015-10-21 13:15 ` Eric Botcazou [this message]
2015-10-21 13:18 ` Richard Biener
2015-10-21 21:11 ` Richard Sandiford
2015-10-20 22:30 ` Eric Botcazou
2015-10-20 22:55 ` Joseph Myers
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