Bug 82413

Summary: [8 Regression] -O0 crash (ICE in decompose, at tree.h:5179)
Product: gcc Reporter: Dmitry Babokin <babokin>
Component: cAssignee: Not yet assigned to anyone <unassigned>
Status: RESOLVED FIXED    
Severity: normal CC: dcb314, rsandifo, tschwinge
Priority: P1 Keywords: ice-on-valid-code
Version: 8.0   
Target Milestone: 8.0   
Host: Target:
Build: Known to work: 7.2.0
Known to fail: 8.0 Last reconfirmed: 2017-10-03 00:00:00
Bug Depends on:    
Bug Blocks: 103035    

Description Dmitry Babokin 2017-10-03 00:52:10 UTC 
GCC trunk, rev 253367, x86_64.

Rev 253307 works fine, so it's a fresh regression.

> cat f.cpp
bool a;
int b;
void c() { b &&a <= 0; }

> g++ -c f.cpp
f.cpp: In function ‘void c()’:
f.cpp:3:21: internal compiler error: in decompose, at tree.h:5179
 void c() { b &&a <= 0; }
                     ^
0x6cbe00 wi::int_traits<tree_node const*>::decompose(long*, unsigned int, tree_node const*)
        ../../gcc/gcc/tree.h:5179
0x6cbe00 wide_int_ref_storage<false>::wide_int_ref_storage<tree_node const*>(tree_node const* const&, unsigned int)
        ../../gcc/gcc/wide-int.h:976
0x6cbe00 generic_wide_int<wide_int_ref_storage<false> >::generic_wide_int<tree_node const*>(tree_node const* const&, unsigned int)
        ../../gcc/gcc/wide-int.h:753
0x6cbe00 bool wi::eq_p<generic_wide_int<wide_int_storage>, tree_node const*>(generic_wide_int<wide_int_storage> const&, tree_node const* const&)
        ../../gcc/gcc/wide-int.h:1760
0x6cbe00 bool generic_wide_int<wide_int_storage>::operator==<tree_node*>(tree_node* const&) const
        ../../gcc/gcc/wide-int.h:704
0x6cbe00 build_range_check(unsigned int, tree_node*, tree_node*, int, tree_node*, tree_node*)
        ../../gcc/gcc/fold-const.c:4854
0xcd4a08 build_range_check(unsigned int, tree_node*, tree_node*, int, tree_node*, tree_node*)
        ../../gcc/gcc/fold-const.c:4809
0xb4c404 warn_logical_operator(unsigned int, tree_code, tree_node*, tree_code, tree_node*, tree_code, tree_node*)
        ../../gcc/gcc/c-family/c-warn.c:270
0x91af33 build_new_op_1
        ../../gcc/gcc/cp/call.c:5978
0x91b42e build_new_op(unsigned int, tree_code, int, tree_node*, tree_node*, tree_node*, tree_node**, int)
        ../../gcc/gcc/cp/call.c:6051
0xabf972 build_x_binary_op(unsigned int, tree_code, tree_node*, tree_code, tree_node*, tree_code, tree_node**, int)
        ../../gcc/gcc/cp/typeck.c:3960
0xa03a2e cp_parser_binary_expression
        ../../gcc/gcc/cp/parser.c:9274
0xa04f74 cp_parser_assignment_expression
        ../../gcc/gcc/cp/parser.c:9407
0xa05678 cp_parser_expression
        ../../gcc/gcc/cp/parser.c:9576
0xa07388 cp_parser_expression_statement
        ../../gcc/gcc/cp/parser.c:11091
0xa0d543 cp_parser_statement
        ../../gcc/gcc/cp/parser.c:10907
0xa0e5f0 cp_parser_statement_seq_opt
        ../../gcc/gcc/cp/parser.c:11234
0xa0e6c7 cp_parser_compound_statement
        ../../gcc/gcc/cp/parser.c:11188
0xa2400a cp_parser_function_body
        ../../gcc/gcc/cp/parser.c:21669
0xa2400a cp_parser_ctor_initializer_opt_and_function_body
        ../../gcc/gcc/cp/parser.c:21707
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Comment 1 David Binderman 2017-10-03 07:25:08 UTC 
Bug seems to occur between revisions 253315 and 253366.
Comment 2 Martin Liška 2017-10-03 07:51:12 UTC 
Confirmed, started with r253345.
Comment 3 Thomas Schwinge 2017-10-03 11:53:16 UTC 
I'm always willing to take the blame for things I've broken ;-) but...

(In reply to Martin Liška from comment #2)
> Confirmed, started with r253345.

... that sounds very unlikely.  I had a quick look myself, and that would instead point to r253341 for this regression/ICE.
Comment 4 Martin Liška 2017-10-03 14:10:12 UTC 
(In reply to Thomas Schwinge from comment #3)
> I'm always willing to take the blame for things I've broken ;-) but...
> 
> (In reply to Martin Liška from comment #2)
> > Confirmed, started with r253345.
> 
> ... that sounds very unlikely.  I had a quick look myself, and that would
> instead point to r253341 for this regression/ICE.

Sorry, I must have some issue in my bisect script. Thanks.
Comment 5 Richard Sandiford 2017-10-04 10:50:51 UTC 
Author: rsandifo
Date: Wed Oct  4 10:50:19 2017
New Revision: 253401

URL: https://gcc.gnu.org/viewcvs?rev=253401&root=gcc&view=rev
Log:
PR82413: Mismatched precisions in build_range_check

build_range_check explicitly allows LOW and HIGH to be a different type
from EXP, so we need to use w::to_widest when comparing a value based on
HIGH with a value based on EXP's type.

2017-10-04  Richard Sandiford  <richard.sandiford@linaro.org>

gcc/
	PR tree-optimization/82413
	* fold-const.c (build_range_check): Use widest_int when comparing
	the maximum ETYPE value with HIGH.

gcc/testsuite/
	PR tree-optimization/82413
	* g++.dg/pr82413.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/pr82413.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/testsuite/ChangeLog
Comment 6 Richard Sandiford 2017-10-04 10:52:01 UTC 
Patch applied.