[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #8 from jakub at gcc dot gnu dot org 2008-10-02 09:11 --- *** Bug 37666 has been marked as a duplicate of this bug. *** -- jakub at gcc dot gnu dot org changed: What|Removed |Added CC||joel at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #9 from jakub at gcc dot gnu dot org 2008-10-02 09:12 --- *** Bug 35874 has been marked as a duplicate of this bug. *** -- jakub at gcc dot gnu dot org changed: What|Removed |Added CC||mstein dot lists at ||googlemail dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #5 from rguenth at gcc dot gnu dot org 2008-10-01 13:20 ---
Note that after tuples we always have a default label again, just the default
label isn't a default label. I have a patch to fix that, sort of
Index: tree-vrp.c
===
*** tree-vrp.c (revision 140810)
--- tree-vrp.c (working copy)
*** execute_vrp (void)
*** 7149,7157
--- 7149,7164
{
size_t j;
size_t n = TREE_VEC_LENGTH (su-vec);
+ tree label;
gimple_switch_set_num_labels (su-stmt, n);
for (j = 0; j n; j++)
gimple_switch_set_label (su-stmt, j, TREE_VEC_ELT (su-vec, j));
+ /* As we may have replaced the default label with a regular one
+make sure to make it a real default label again. This ensures
+optimal expansion. */
+ label = gimple_switch_default_label (su-stmt);
+ CASE_LOW (label) = NULL_TREE;
+ CASE_HIGH (label) = NULL_TREE;
}
if (VEC_length (edge, to_remove_edges) 0)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
-- rguenth at gcc dot gnu dot org changed: What|Removed |Added AssignedTo|unassigned at gcc dot gnu |rguenth at gcc dot gnu dot |dot org |org Status|NEW |ASSIGNED Last reconfirmed|2008-08-31 11:59:27 |2008-10-01 13:27:26 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #6 from rguenth at gcc dot gnu dot org 2008-10-01 15:09 --- Fixed. -- rguenth at gcc dot gnu dot org changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #7 from rguenth at gcc dot gnu dot org 2008-10-01 15:11 --- Subject: Bug 37285 Author: rguenth Date: Wed Oct 1 15:09:26 2008 New Revision: 140814 URL: http://gcc.gnu.org/viewcvs?root=gccview=revrev=140814 Log: 2008-10-01 Richard Guenther [EMAIL PROTECTED] PR middle-end/37285 * tree-vrp.c (execute_vrp): If we optimized away the default case make sure to promote the label that got in place of it to a default case label. * gcc.c-torture/compile/pr37285.c: New testcase. Added: trunk/gcc/testsuite/gcc.c-torture/compile/pr37285.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-vrp.c -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
-- jsm28 at gcc dot gnu dot org changed: What|Removed |Added Priority|P3 |P1 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #4 from rguenth at gcc dot gnu dot org 2008-08-31 11:59 ---
The code in purge_dead_edges looks broken.
/* If we don't see a jump insn, we don't know exactly why the block would
have been broken at this point. Look for a simple, non-fallthru edge,
as these are only created by conditional branches. If we find such an
edge we know that there used to be a jump here and can then safely
remove all non-fallthru edges. */
but for switches we never have an edge with fallthru set (at least not on
the tree level, even before VRP runs).
And the splitting code now splits
;; basic block 3, loop depth 0, count 0
;; prev block 12, next block 4
;; pred: 12 [100.0%] (fallthru)
;; succ: 5 [61.0%] 4 [39.0%]
(note 17 51 18 3 [bb 3] NOTE_INSN_BASIC_BLOCK)
(insn 18 17 19 3 t.i:5 (set (reg:DI 3 3)
(reg/v:DI 120 [ l_symndx ])) -1 (nil))
(insn 19 18 20 3 t.i:5 (set (reg:DI 5 5)
(const_int 1 [0x1])) -1 (nil))
(call_insn/u 20 19 21 3 t.i:5 (parallel [
(set (reg:SI 3 3)
(call (mem:SI (symbol_ref:SI (__ucmpdi2) [flags 0x41]) [0 S4
A8])
(const_int 0 [0x0])))
(use (const_int 16 [0x10]))
(clobber (reg:SI 65 lr))
]) -1 (expr_list:REG_EH_REGION (const_int 0 [0x0])
(nil))
(expr_list:REG_DEP_TRUE (use (reg:DI 5 5))
(expr_list:REG_DEP_TRUE (use (reg:DI 3 3))
(nil
(insn 21 20 22 3 t.i:5 (set (reg:CCUNS 125)
(compare:CCUNS (reg:SI 3 3)
(const_int 1 [0x1]))) -1 (nil))
(jump_insn 22 21 23 3 t.i:5 (set (pc)
(if_then_else (leu (reg:CCUNS 125)
(const_int 0 [0x0]))
(label_ref 36)
(pc))) -1 (nil))
(insn 23 22 24 3 t.i:5 (set (reg:CC 126)
(compare:CC (subreg:SI (reg/v:DI 120 [ l_symndx ]) 0)
(const_int 0 [0x0]))) -1 (nil))
(jump_insn 24 23 25 3 t.i:5 (set (pc)
(if_then_else (ne (reg:CC 126)
(const_int 0 [0x0]))
(label_ref 29)
(pc))) -1 (nil))
(insn 25 24 26 3 t.i:5 (set (reg:CC 127)
(compare:CC (subreg:SI (reg/v:DI 120 [ l_symndx ]) 4)
(const_int 2 [0x2]))) -1 (nil))
(jump_insn 26 25 27 3 t.i:5 (set (pc)
(if_then_else (ne (reg:CC 127)
(const_int 0 [0x0]))
(label_ref 29)
(pc))) -1 (nil))
(jump_insn 27 26 28 3 t.i:5 (set (pc)
(label_ref 30)) -1 (nil))
(barrier 28 27 29)
(code_label 29 28 30 3 5 [2 uses])
at the jump target (code_label 29 28 30 3 5 [2 uses]) so we enter
purge_dead_edges with
;; basic block 16, loop depth 0, count 0
;; prev block 15, next block 4
;; pred:
;; succ: 5 [61.0%] 4 [39.0%]
(code_label 29 28 55 16 5 [2 uses])
(note 55 29 30 16 [bb 16] NOTE_INSN_BASIC_BLOCK)
so in the end it looks like we can remove the assert which leaves us with
(IMHO, my ppc fu is not too great) correct assembly generated.
Proposed patch:
Index: gcc/cfgrtl.c
===
--- gcc/cfgrtl.c(revision 139823)
+++ gcc/cfgrtl.c(working copy)
@@ -2324,10 +2324,11 @@ purge_dead_edges (basic_block bb)
ei_next (ei);
}
- gcc_assert (single_succ_p (bb));
-
- single_succ_edge (bb)-probability = REG_BR_PROB_BASE;
- single_succ_edge (bb)-count = bb-count;
+ if (single_succ_p (bb))
+{
+ single_succ_edge (bb)-probability = REG_BR_PROB_BASE;
+ single_succ_edge (bb)-count = bb-count;
+}
if (dump_file)
fprintf (dump_file, Purged non-fallthru edges from bb %i\n,
But this also shows a missed optimization as we now no longer merge
the case 0 ...1 range with the default case. Before VRP we have
switch (l_symndx_1(D)) default: L4, case 0 ... 1: L4, case 2: L3
so we could easily detect this.
Can you verify the generated assembly is correct with the proposed patch?
Thanks.
--
rguenth at gcc dot gnu dot org changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|-00-00 00:00:00 |2008-08-31 11:59:27
date||
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #1 from rguenth at gcc dot gnu dot org 2008-08-30 14:10 --- What is the ICE? and with what options? I get the same IL on i?86 but no ICE. -- rguenth at gcc dot gnu dot org changed: What|Removed |Added Status|UNCONFIRMED |WAITING http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #2 from pinskia at gcc dot gnu dot org 2008-08-30 22:17 --- ../../src/bfd/xcofflink.c: In function '_bfd_xcoff_canonicalize_dynamic_reloc': ../../src/bfd/xcofflink.c:399: internal compiler error: in purge_dead_edges, at cfgrtl.c:2327 Please submit a full bug report, with preprocessed source if appropriate. See http://gcc.gnu.org/bugs.html for instructions. -O1 -ftree-vrp is enough to reproduce the bug which shows the middle-end is not ready for the IR changes that are done by VRP. -- pinskia at gcc dot gnu dot org changed: What|Removed |Added Status|WAITING |UNCONFIRMED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
--- Comment #3 from pinskia at gcc dot gnu dot org 2008-08-30 22:27 --- One more thing I forgot to mention is that the ICE is during expand time. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
[Bug middle-end/37285] [4.4 Regression] ICE while building binutils on ppc
-- pinskia at gcc dot gnu dot org changed: What|Removed |Added Severity|normal |blocker Target Milestone|--- |4.4.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37285
