Bug 63427

Summary:	hwint.h:250:29: runtime error: shift exponent 64 is too large for 64-bit type 'long int'
Product:	gcc	Reporter:	Markus Trippelsdorf <trippels>
Component:	fortran	Assignee:	rsandifo <rsandifo>
Status:	RESOLVED FIXED
Severity:	normal	CC:	rsandifo, zadeck, zadeck
Priority:	P3
Version:	5.0
Target Milestone:	---
Host:		Target:
Build:		Known to work:
Known to fail:		Last reconfirmed:	2015-02-21 00:00:00
Bug Depends on:
Bug Blocks:	63426

Description Markus Trippelsdorf 2014-10-01 10:22:26 UTC

gcc build with "-fsanitize=undefined" hits the following issue 
when compiling testsuite/gfortran.dg/integer_exponentiation_5.F90:

markus@x4 gfortran % /var/tmp/gcc_build_dir_/gcc/testsuite/gfortran/../../gfortran -B/var/tmp/gcc_build_dir_/gcc/testsuite/gfortran/../../ -B/var/tmp/gcc_build_dir_/x86_64-unknown-linux-gnu/./libgfortran/ /var/tmp/gcc/gcc/testsuite/gfortran.dg/integer_exponentiation_5.F90  -fno-diagnostics-show-caret -fdiagnostics-color=never    -O0  -fno-range-check  -B/var/tmp/gcc_build_dir_/x86_64-unknown-linux-gnu/./libgfortran/.libs -L/var/tmp/gcc_build_dir_/x86_64-unknown-linux-gnu/./libgfortran/.libs -L/var/tmp/gcc_build_dir_/x86_64-unknown-linux-gnu/./libgfortran/.libs -B/var/tmp/gcc_build_dir_/x86_64-unknown-linux-gnu/./libquadmath/.libs -L/var/tmp/gcc_build_dir_/x86_64-unknown-linux-gnu/./libquadmath/.libs -L/var/tmp/gcc_build_dir_/x86_64-unknown-linux-gnu/./libquadmath/.libs  -lm    -o ./integer_exponentiation_5.exe                                                 
../../gcc/gcc/hwint.h:250:19: runtime error: shift exponent 64 is too large for 64-bit type 'long int'
../../gcc/gcc/hwint.h:250:29: runtime error: shift exponent 64 is too large for 64-bit type 'long int'

Comment 1 Kenneth Zadeck 2014-10-01 12:19:22 UTC

This failure is caused by the caller trying to sign extend something with a precision of zero.   This bug should be fixed upstream of this call.

Comment 2 Markus Trippelsdorf 2014-10-01 12:44:30 UTC

Thanks.
Backtrace shows that it is a Fortran issue:

Breakpoint 1, 0x00007ffff6e33160 in __ubsan::Diag::~Diag() () from /usr/lib/gcc/x86_64-pc-linux-gnu/5.0.0/libubsan.so.0
(gdb) bt
#0  0x00007ffff6e33160 in __ubsan::Diag::~Diag() () from /usr/lib/gcc/x86_64-pc-linux-gnu/5.0.0/libubsan.so.0
#1  0x00007ffff6e35e1a in handleShiftOutOfBoundsImpl(__ubsan::ShiftOutOfBoundsData*, unsigned long, unsigned long, __ubsan::ReportOptions) ()
   from /usr/lib/gcc/x86_64-pc-linux-gnu/5.0.0/libubsan.so.0
#2  0x00007ffff6e36613 in __ubsan_handle_shift_out_of_bounds () from /usr/lib/gcc/x86_64-pc-linux-gnu/5.0.0/libubsan.so.0
#3  0x00000000019d5e10 in sext_hwi (prec=<optimized out>, src=<optimized out>) at ../../gcc/gcc/hwint.h:250
#4  set_len (is_sign_extended=<optimized out>, l=<optimized out>, this=<optimized out>) at ../../gcc/gcc/wide-int.h:1075
#5  wi::from_mpz (type=0x11, x=0x53b5e20, wrap=64, wrap@entry=true) at ../../gcc/gcc/wide-int.cc:265
#6  0x00000000007633a5 in gfc_conv_mpz_to_tree (i=0x53b5e20, kind=8) at ../../gcc/gcc/fortran/trans-const.c:206
#7  0x0000000000764c38 in gfc_conv_constant (se=0x7fffffffd760, expr=0x53b5da0) at ../../gcc/gcc/fortran/trans-const.c:403
#8  0x00000000007aec0b in gfc_conv_expr (se=se@entry=0x7fffffffd760, expr=expr@entry=0x53b5da0) at ../../gcc/gcc/fortran/trans-expr.c:6520
#9  0x00000000007ba908 in gfc_conv_expr_reference (se=0x7fffffffd760, expr=0x53b5da0) at ../../gcc/gcc/fortran/trans-expr.c:6651
#10 0x00000000007a0ccf in gfc_conv_procedure_call (se=0x7fffffffd170, se@entry=0x7fffffffd8b0, sym=0x4396944, args=0x7fffffffd1f0, args@entry=0x53aa0d0, expr=0x40, 
    expr@entry=0x0, append_args=0x4396940, append_args@entry=0x0) at ../../gcc/gcc/fortran/trans-expr.c:4429
#11 0x0000000000831728 in gfc_trans_call (code=code@entry=0x53b5e70, dependency_check=<optimized out>, mask=mask@entry=0x0, count1=count1@entry=0x0, 
    invert=invert@entry=false) at ../../gcc/gcc/fortran/trans-stmt.c:408
#12 0x0000000000726aca in trans_code (code=0x53b5e70, cond=cond@entry=0x0) at ../../gcc/gcc/fortran/trans.c:1717
#13 0x000000000072a277 in gfc_trans_code (code=<optimized out>) at ../../gcc/gcc/fortran/trans.c:1928
#14 0x0000000000789f34 in gfc_generate_function_code (ns=<optimized out>) at ../../gcc/gcc/fortran/trans-decl.c:5789
#15 0x000000000072a2a5 in gfc_generate_code (ns=<optimized out>) at ../../gcc/gcc/fortran/trans.c:1945
#16 0x000000000068148b in translate_all_program_units (gfc_global_ns_list=0x53a48b0) at ../../gcc/gcc/fortran/parse.c:4947
#17 gfc_parse_file () at ../../gcc/gcc/fortran/parse.c:5144
#18 0x0000000000715db8 in gfc_be_parse_file () at ../../gcc/gcc/fortran/f95-lang.c:212
#19 0x000000000129d388 in compile_file () at ../../gcc/gcc/toplev.c:551
#20 0x00000000012a0aab in do_compile () at ../../gcc/gcc/toplev.c:1946
#21 toplev_main (argc=20, argv=0x7fffffffe038) at ../../gcc/gcc/toplev.c:2022
#22 0x00007ffff6ae1fd0 in __libc_start_main () from /lib/libc.so.6
#23 0x000000000058d3a1 in _start ()
(gdb)

Comment 3 rsandifo@gcc.gnu.org 2015-02-21 14:16:46 UTC

Caused by wi::from_mpz mishandling the wrap operation.
Related, a testcase like:

program test
  write (*), (2_8 ** 64009999_2) / 2
end program test

(compiled with -fno-range-check) writes way beyond the buffer.

Comment 4 rsandifo@gcc.gnu.org 2015-02-23 23:03:22 UTC

Author: rsandifo
Date: Mon Feb 23 23:02:50 2015
New Revision: 220921

URL: https://gcc.gnu.org/viewcvs?rev=220921&root=gcc&view=rev
Log:
gcc/
	PR fortran/63427
	* wide-int.cc (wi::from_mpz): Cope with unwrapped values that are
	too big for a wide_int.  Implement missing wrapping operation.

gcc/testsuite/
	PR fortran/63427
	* gfortran.dg/integer_exponentiation_6.F90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/integer_exponentiation_6.F90
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/wide-int.cc

Comment 5 Markus Trippelsdorf 2016-01-21 11:24:22 UTC

closing as fixed