https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61375
Bug ID: 61375
Summary: ICE in int_cst_value at -O3 in tree-ssa pass when
compiling a reference to an __int128 value
Product: gcc
Version: 4.10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: gary at intrepid dot com
CC: nenad at intrepid dot com
Target: x86_64
Created attachment 32880
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32880&action=edit
pre-processed "C" source, generates ICE at -O3 in tree-ssa
When compiling the attached pre-processed source file at -O3, the following
stack trace is generated.
$ gcc -O3 -fpreprocessed -c ice-int_cst_value-int128.i
ice-int_cst_value-int128.i: In function ‘test15’:
ice-int_cst_value-int128.i:442:1: internal compiler error: in int_cst_value, at
tree.c:10492
test15 ()
^
0xe3fb99 int_cst_value(tree_node const*)
/eng/upc/dev/gary/gupc-gcc-trunk/src/gcc/tree.c:10492
0xd03709 find_bswap_or_nop_1
/eng/upc/dev/gary/gupc-gcc-trunk/src/gcc/tree-ssa-math-opts.c:1848
0xd0354c find_bswap_or_nop_1
/eng/upc/dev/gary/gupc-gcc-trunk/src/gcc/tree-ssa-math-opts.c:1815
0xd0354c find_bswap_or_nop_1
/eng/upc/dev/gary/gupc-gcc-trunk/src/gcc/tree-ssa-math-opts.c:1815
0xd039a9 find_bswap_or_nop_1
/eng/upc/dev/gary/gupc-gcc-trunk/src/gcc/tree-ssa-math-opts.c:1916
0xd03f6a find_bswap_or_nop
/eng/upc/dev/gary/gupc-gcc-trunk/src/gcc/tree-ssa-math-opts.c:2034
0xd04ac3 execute
/eng/upc/dev/gary/gupc-gcc-trunk/src/gcc/tree-ssa-math-opts.c:2322
The compiler is based on:
Last Changed Rev: 211071
Last Changed Date: 2014-05-29 17:17:10 -0700
The test case can likely be reduced. The issue seems to relate to an attempt
to simplify an expression that mixes an address and an __int128 value.
The ICE triggered here:
10488 unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
10489 unsigned HOST_WIDE_INT val = TREE_INT_CST_LOW (x);
10490
10491 /* Make sure the sign-extended value will fit in a HOST_WIDE_INT. */
10492 gcc_assert (cst_and_fits_in_hwi (x));
where 'x' is:
<integer_cst 0x7ffff19ab0e0 type <integer_type 0x7ffff19be690
upcr_pshared_ptr_t> constant 0x0fffff00000000000>
and the type is a 128 bit integer:
<integer_type 0x7ffff19be690 upcr_pshared_ptr_t sizes-gimplified public
unsigned TI
size <integer_cst 0x7ffff189d6c0 type <integer_type 0x7ffff189f150
bitsizetype> constant 128>
unit size <integer_cst 0x7ffff189d6d8 type <integer_type 0x7ffff189f0a8
sizetype> constant 16>
align 128 symtab 0 alias set -1 canonical type 0x7ffff189fb28 precision 128
min <integer_cst 0x7ffff189d9a8 0> max <integer_cst 0x7ffff189c668
0xffffffffffffffffffffffffffffffff> context <translation_unit_decl
0x7ffff19c3b80 D.1942>
pointer_to_this <pointer_type 0x7ffff19c97e0>>
The gimple statement being simplified looks like this:
_15 = array.0_8 & 18446726481523507200
(gdb) p/x 18446726481523507200
$4 = 0xfffff00000000000
