[Bug regression/55168] New: [4.8 Regression]: gcc.c-torture/compile/pr44119.c ICE, all but -O0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55168 Bug #: 55168 Summary: [4.8 Regression]: gcc.c-torture/compile/pr44119.c ICE, all but -O0 Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Keywords: ice-on-valid-code Severity: normal Priority: P3 Component: regression AssignedTo: unassig...@gcc.gnu.org ReportedBy: h...@gcc.gnu.org CC: ste...@gcc.gnu.org Host: x86_64-unknown-linux-gnu Target: cris-axis-elf This test previously passed, now it fails. A patch in the revision range (last_known_working:first_known_failing) 193042:193049 exposed or caused this regression. Since then it fails as follows: Running /tmp/hpautotest-gcc0/gcc/gcc/testsuite/gcc.c-torture/compile/compile.exp ... FAIL: gcc.c-torture/compile/pr44119.c -O1 (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O1 (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -O2 (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O2 (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -O3 -fomit-frame-pointer (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O3 -fomit-frame-pointer (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -O3 -fomit-frame-pointer -funroll-loops (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O3 -fomit-frame-pointer -funroll-loops (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -O3 -g (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O3 -g (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -Os (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -Os (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -O2 -flto -fno-use-linker-plugin -flto-partition=none (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O2 -flto -fno-use-linker-plugin -flto-partition=none (test for excess errors) FAIL: gcc.c-torture/compile/pr44119.c -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects (internal compiler error) FAIL: gcc.c-torture/compile/pr44119.c -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects (test for excess errors) The messages in gcc.log are similar: Executing on host: /tmp/hpautotest-gcc0/cris-elf/gccobj/gcc/xgcc -B/tmp/hpautotest-gcc0/cris-elf/gccobj/gcc/ -fno-diagnostics-show-caret -O1 -w -c -isystem /tmp/hpautotest-gcc0/cris-elf/gccobj/cris-elf/./newlib/targ-include -isystem /tmp/hpautotest-gcc0/gcc/newlib/libc/include -o pr44119.o /tmp/hpautotest-gcc0/gcc/gcc/testsuite/gcc.c-torture/compile/pr44119.c (timeout = 300) /tmp/hpautotest-gcc0/gcc/gcc/testsuite/gcc.c-torture/compile/pr44119.c: In function 'func_96': /tmp/hpautotest-gcc0/gcc/gcc/testsuite/gcc.c-torture/compile/pr44119.c:45:1: internal compiler error: Floating point exception 0x84ab35 crash_signal /tmp/hpautotest-gcc0/gcc/gcc/toplev.c:333 0x7d4bbf predict_loops /tmp/hpautotest-gcc0/gcc/gcc/predict.c:1524 0x7d67b4 tree_estimate_probability() /tmp/hpautotest-gcc0/gcc/gcc/predict.c:2259 0x7d75d4 tree_estimate_probability_driver /tmp/hpautotest-gcc0/gcc/gcc/predict.c:2296 Author of only suspect patch in revision range CC:ed.
Re: [Bug regression/55168] New: [4.8 Regression]: gcc.c-torture/compile/pr44119.c ICE, all but -O0
This actually looks like a previously latent issue in predict.c For all but
estimate_num_iterations_int. It uses the funny definition of number of
iterations (i.e. 0 means that loop will exit at first invocation of the exit
condition and that is what it will be predicted with when nitercst == 1.
Index: predict.c
===
--- predict.c (revision 193062)
+++ predict.c (working copy)
@@ -1433,8 +1437,8 @@ predict_loops (void)
the loop, use it to predict this exit. */
else if (n_exits == 1)
{
- nitercst = estimated_stmt_executions_int (loop);
- if (nitercst 0)
+ nitercst = estimated_stmt_executions_int (loop) + 1;
+ if (nitercst = 0)
continue;
if (nitercst max)
nitercst = max;
