[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060 --- Comment #7 from Jakub Jelinek jakub at gcc dot gnu.org --- Author: jakub Date: Tue May 13 08:28:53 2014 New Revision: 210352 URL: http://gcc.gnu.org/viewcvs?rev=210352root=gccview=rev Log: PR target/61060 * config/i386/i386.c (ix86_expand_set_or_movmem): If count_exp is const0_rtx, return immediately. Don't test count == 0 when it is always true. * gcc.dg/pr61060.c: New test. Added: trunk/gcc/testsuite/gcc.dg/pr61060.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/i386.c trunk/gcc/testsuite/ChangeLog
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060 --- Comment #8 from Jakub Jelinek jakub at gcc dot gnu.org --- Author: jakub Date: Tue May 13 08:31:29 2014 New Revision: 210353 URL: http://gcc.gnu.org/viewcvs?rev=210353root=gccview=rev Log: PR target/61060 * config/i386/i386.c (ix86_expand_set_or_movmem): If count_exp is const0_rtx, return immediately. Don't test count == 0 when it is always true. * gcc.dg/pr61060.c: New test. Added: branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/pr61060.c Modified: branches/gcc-4_9-branch/gcc/ChangeLog branches/gcc-4_9-branch/gcc/config/i386/i386.c branches/gcc-4_9-branch/gcc/testsuite/ChangeLog
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060 Jakub Jelinek jakub at gcc dot gnu.org changed: What|Removed |Added Status|NEW |RESOLVED Known to work||4.10.0, 4.9.1 Resolution|--- |FIXED Known to fail|4.10.0, 4.9.1 |4.9.0 --- Comment #9 from Jakub Jelinek jakub at gcc dot gnu.org --- Should be fixed now for 4.9.1+.
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060
--- Comment #4 from Richard Biener rguenth at gcc dot gnu.org ---
At -O0? Well... it seems the expander doesn't yet see it's zero:
/* If the LEN parameter is zero, return DEST. */
if (integer_zerop (len))
{
/* Evaluate and ignore VAL in case it has side-effects. */
expand_expr (val, const0_rtx, VOIDmode, EXPAND_NORMAL);
return expand_expr (dest, target, mode, EXPAND_NORMAL);
that is because len is len_5 at -O0 (no CCP), but it is TERed and thus
len_5 = 0 is expanded in-place.
I'd say the backend should better deal with this. Or we have to
double-check (or delay) the zero-length check until after
len_rtx = expand_normal (len);
sth like
Index: gcc/builtins.c
===
--- gcc/builtins.c (revision 209890)
+++ gcc/builtins.c (working copy)
@@ -3685,20 +3685,20 @@ expand_builtin_memset_args (tree dest, t
if (expected_align dest_align)
expected_align = dest_align;
+ /* Stabilize the arguments in case we fail. */
+ dest = builtin_save_expr (dest);
+ val = builtin_save_expr (val);
+ len = builtin_save_expr (len);
+
+ len_rtx = expand_normal (len);
/* If the LEN parameter is zero, return DEST. */
- if (integer_zerop (len))
+ if (len_rtx == const0_rtx)
{
/* Evaluate and ignore VAL in case it has side-effects. */
expand_expr (val, const0_rtx, VOIDmode, EXPAND_NORMAL);
return expand_expr (dest, target, mode, EXPAND_NORMAL);
}
- /* Stabilize the arguments in case we fail. */
- dest = builtin_save_expr (dest);
- val = builtin_save_expr (val);
- len = builtin_save_expr (len);
-
- len_rtx = expand_normal (len);
determine_block_size (len, len_rtx, min_size, max_size,
probable_max_size);
dest_mem = get_memory_rtx (dest, len);
probably applies to almost all builtin expansions.
But I'd say the backend should be more fault-tolerant here. It can't
simply reserve len == 0 for itself.
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060
--- Comment #5 from Jan Hubicka hubicka at ucw dot cz ---
I'd say the backend should better deal with this. Or we have to
double-check (or delay) the zero-length check until after
len_rtx = expand_normal (len);
sth like
This looks good to me indeed. Thanks for explanation concerning TER.
Index: gcc/builtins.c
===
--- gcc/builtins.c (revision 209890)
+++ gcc/builtins.c (working copy)
@@ -3685,20 +3685,20 @@ expand_builtin_memset_args (tree dest, t
if (expected_align dest_align)
expected_align = dest_align;
+ /* Stabilize the arguments in case we fail. */
+ dest = builtin_save_expr (dest);
+ val = builtin_save_expr (val);
+ len = builtin_save_expr (len);
+
+ len_rtx = expand_normal (len);
/* If the LEN parameter is zero, return DEST. */
- if (integer_zerop (len))
+ if (len_rtx == const0_rtx)
{
/* Evaluate and ignore VAL in case it has side-effects. */
expand_expr (val, const0_rtx, VOIDmode, EXPAND_NORMAL);
return expand_expr (dest, target, mode, EXPAND_NORMAL);
}
- /* Stabilize the arguments in case we fail. */
- dest = builtin_save_expr (dest);
- val = builtin_save_expr (val);
- len = builtin_save_expr (len);
-
- len_rtx = expand_normal (len);
determine_block_size (len, len_rtx, min_size, max_size,
probable_max_size);
dest_mem = get_memory_rtx (dest, len);
probably applies to almost all builtin expansions.
But I'd say the backend should be more fault-tolerant here. It can't
simply reserve len == 0 for itself.
OK, I think I can just add early return to the expander functions then (or an
assert - still it seems more like middle-end's bug as it only wastes time even
at -O0)
Honza
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Priority|P3 |P2 Component|rtl-optimization|target Target Milestone|--- |4.9.1
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060 Uroš Bizjak ubizjak at gmail dot com changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2014-05-05 Ever confirmed|0 |1 --- Comment #1 from Uroš Bizjak ubizjak at gmail dot com --- Confirmed, modeless (const_int 0) leaks to line 24181. (gdb) f 7 #7 0x00c4fc71 in ix86_expand_set_or_movmem (dst=0x719c5d50, src=0x10048e0 int_mode_for_mode(machine_mode)::__FUNCTION__, src@entry=0x0, count_exp=0x718a5470, val_exp=0x190, val_exp@entry=0x718a5510, align_exp=0x64, align_exp@entry=0x718a5480, expected_align_exp=0x7ff9f00, expected_align_exp@entry=0x718a5480, expected_size_exp=0x718a5460, min_size_exp=0x0, max_size_exp=0x190, max_size_exp@entry=0x718a5510, probable_max_size_exp=0x10048e0 int_mode_for_mode(machine_mode)::__FUNCTION__, probable_max_size_exp@entry=0x0, issetmem=true) at /home/uros/gcc-svn/trunk/gcc/config/i386/i386.c:24182 24182 count_exp = copy_to_mode_reg (GET_MODE (count_exp), count_exp); (gdb) p debug_rtx (count_exp) (const_int 0 [0]) $9 = void (gdb) list 24177creating of promoted vector value is very cheap in this case. */ 24178 if (issetmem alg == vector_loop val_exp != const0_rtx) 24179 alg = unrolled_loop; 24180 24181 if (!count) 24182 count_exp = copy_to_mode_reg (GET_MODE (count_exp), count_exp); 24183 destreg = ix86_copy_addr_to_reg (XEXP (dst, 0)); 24184 if (!issetmem) 24185 srcreg = ix86_copy_addr_to_reg (XEXP (src, 0)); 24186
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060 Uroš Bizjak ubizjak at gmail dot com changed: What|Removed |Added CC||hubicka at ucw dot cz --- Comment #2 from Uroš Bizjak ubizjak at gmail dot com --- The code in ix86_expand_set_or_movmem assumes that !count implies non-const_int count_exp: unsigned HOST_WIDE_INT count = 0; ... if (CONST_INT_P (count_exp)) min_size = max_size = probable_max_size = count = expected_size = INTVAL (count_exp); ... if (!count) count_exp = copy_to_mode_reg (GET_MODE (count_exp), count_exp); However, when count_exp is (const_int 0), the assumption breaks, and the code tries to determine the mode of modeless (const_int 0) count_exp RTX. CC author of the code.
[Bug target/61060] [4.9/4.10 Regression] ICE: in int_mode_for_mode, at stor-layout.c:400 with -free-ter
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61060 --- Comment #3 from Jan Hubicka hubicka at ucw dot cz --- if (CONST_INT_P (count_exp)) min_size = max_size = probable_max_size = count = expected_size = INTVAL (count_exp); ... if (!count) count_exp = copy_to_mode_reg (GET_MODE (count_exp), count_exp); However, when count_exp is (const_int 0), the assumption breaks, and the code tries to determine the mode of modeless (const_int 0) count_exp RTX. CC author of the code. I would say it is job of middle-end to not expand obviously pointless stringops...
