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author | Aldy Hernandez <aldyh@redhat.com> | 2023-02-02 18:08:44 +0100 |
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committer | Aldy Hernandez <aldyh@redhat.com> | 2023-02-03 21:33:07 +0100 |
commit | e261fcefb71e1270673f0457fcc73711f13d3079 (patch) | |
tree | a63c6017ebeeeb2399abb409dc07ad3291534194 /gcc | |
parent | 10bd26d6efe88a8cf03a6a325351bc470a910cab (diff) | |
download | gcc-e261fcefb71e1270673f0457fcc73711f13d3079.zip gcc-e261fcefb71e1270673f0457fcc73711f13d3079.tar.gz gcc-e261fcefb71e1270673f0457fcc73711f13d3079.tar.bz2 |
irange: Compare nonzero bits in irange with widest_int [PR108639]
The problem here is we are trying to compare two ranges with different
precisions and the == operator in wide_int is complaining.
Interestingly, the problem is not the nonzero bits, but the fact that
the entire ranges have different precisions. The reason we don't ICE
when comparing the sub-ranges, is because the code in
irange::operator== works on trees, and tree_int_cst_equal is
promoting the comparison to a widest int:
if (TREE_CODE (t1) == INTEGER_CST
&& TREE_CODE (t2) == INTEGER_CST
&& wi::to_widest (t1) == wi::to_widest (t2))
return 1;
This is why we don't see the ICE until the nonzero bits comparison is
done on wide ints. I think we should maintain the current equality
behavior, and follow suit in the nonzero bit comparison.
I have also fixed the legacy equality code, even though technically
nonzero bits shouldn't appear in legacy. But better safe than sorry.
PR tree-optimization/108639
gcc/ChangeLog:
* value-range.cc (irange::legacy_equal_p): Compare nonzero bits as
widest_int.
(irange::operator==): Same.
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/testsuite/gcc.c-torture/compile/pr108638.c | 12 | ||||
-rw-r--r-- | gcc/testsuite/gcc.c-torture/compile/pr108639.c | 11 | ||||
-rw-r--r-- | gcc/value-range.cc | 11 |
3 files changed, 32 insertions, 2 deletions
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr108638.c b/gcc/testsuite/gcc.c-torture/compile/pr108638.c new file mode 100644 index 0000000..755c151 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr108638.c @@ -0,0 +1,12 @@ +/* PR tree-optimization/108638 */ + +long long a; +int b; + +void +foo (void) +{ + for (a = 0; a < __SIZEOF_LONG_LONG__ * __CHAR_BIT__; a++) + if (b) + b |= a << a; +} diff --git a/gcc/testsuite/gcc.c-torture/compile/pr108639.c b/gcc/testsuite/gcc.c-torture/compile/pr108639.c new file mode 100644 index 0000000..ed826cc --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr108639.c @@ -0,0 +1,11 @@ +/* PR tree-optimization/108639 */ + +long long a; + +int +main () +{ + a = a ? 0 || 0 % 0 : 0; + a = a << a; + return 0; +} diff --git a/gcc/value-range.cc b/gcc/value-range.cc index 26f6f26..a535337 100644 --- a/gcc/value-range.cc +++ b/gcc/value-range.cc @@ -1259,7 +1259,10 @@ irange::legacy_equal_p (const irange &other) const other.tree_lower_bound (0)) && vrp_operand_equal_p (tree_upper_bound (0), other.tree_upper_bound (0)) - && get_nonzero_bits () == other.get_nonzero_bits ()); + && (widest_int::from (get_nonzero_bits (), + TYPE_SIGN (type ())) + == widest_int::from (other.get_nonzero_bits (), + TYPE_SIGN (other.type ())))); } bool @@ -1294,7 +1297,11 @@ irange::operator== (const irange &other) const || !operand_equal_p (ub, ub_other, 0)) return false; } - return get_nonzero_bits () == other.get_nonzero_bits (); + widest_int nz1 = widest_int::from (get_nonzero_bits (), + TYPE_SIGN (type ())); + widest_int nz2 = widest_int::from (other.get_nonzero_bits (), + TYPE_SIGN (other.type ())); + return nz1 == nz2; } /* Return TRUE if this is a symbolic range. */ |