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| author | Jakub Jelinek <jakub@redhat.com> | 2023-11-21 09:32:37 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2023-11-21 09:32:37 +0100 |
| commit | 8a8a6d60c670c5153c5109df5fe68deb6fcf466d (patch) | |
| tree | a29901a239bdaa4cb0972956ee2f76f5446a096b /gcc | |
| parent | 7ad308bd4cca871e7509a5eeaef83ee68678820f (diff) | |
| download | gcc-8a8a6d60c670c5153c5109df5fe68deb6fcf466d.zip gcc-8a8a6d60c670c5153c5109df5fe68deb6fcf466d.tar.gz gcc-8a8a6d60c670c5153c5109df5fe68deb6fcf466d.tar.bz2 | |
builtins: Fix fold_builtin_query clzg/ctzg side-effects handling [PR112639]
As the testcase shows, I've missed one spot where initially the code thinks
it could use 2 argument IFN_CLZ/IFN_CTZ form, but then verifies it can't
because it doesn't have the right target value and turns it into the
arg0 ? arg1 : .C[LT]Z (arg0)
form. That form evaluates the argument twice though and so needs save_expr,
which I've missed to call in that case. In other cases where it is known
from the beginning that it will be needed (e.g. the __builtin_clzg case
on types smaller than unsigned int where we'll need to add an addend
to the clz value) or the unsigned __int128 expansion called save_expr
before.
2023-11-21 Jakub Jelinek <jakub@redhat.com>
PR middle-end/112639
* builtins.cc (fold_builtin_bit_query): If arg0 has side-effects, arg1
is specified but cleared, call save_expr on arg0.
* gcc.dg/torture/pr112639.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/builtins.cc | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr112639.c | 34 |
2 files changed, 36 insertions, 0 deletions
diff --git a/gcc/builtins.cc b/gcc/builtins.cc index a489ef1..6af2a0b 100644 --- a/gcc/builtins.cc +++ b/gcc/builtins.cc @@ -9819,6 +9819,8 @@ fold_builtin_bit_query (location_t loc, enum built_in_function fcode, if (!direct_internal_fn_supported_p (ifn, arg0_type, OPTIMIZE_FOR_BOTH)) arg2 = NULL_TREE; + if (arg2 == NULL_TREE) + arg0 = save_expr (arg0); } if (fcodei == END_BUILTINS || arg2) call = build_call_expr_internal_loc (loc, ifn, integer_type_node, diff --git a/gcc/testsuite/gcc.dg/torture/pr112639.c b/gcc/testsuite/gcc.dg/torture/pr112639.c new file mode 100644 index 0000000..9450d88 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr112639.c @@ -0,0 +1,34 @@ +/* PR middle-end/112639 */ +/* { dg-do run } */ + +unsigned long long b = 0; + +int +foo (void) +{ + return __builtin_clzg (b++, __SIZEOF_LONG_LONG__ * __CHAR_BIT__); +} + +int +bar (void) +{ + return __builtin_ctzg (b++, __SIZEOF_LONG_LONG__ * __CHAR_BIT__); +} + +int +main () +{ + if (foo () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ || b != 1) + __builtin_abort (); + if (foo () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ - 1 || b != 2) + __builtin_abort (); + if (foo () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ - 2 || b != 3) + __builtin_abort (); + b = 0; + if (bar () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ || b != 1) + __builtin_abort (); + if (bar () != 0 || b != 2) + __builtin_abort (); + if (bar () != 1 || b != 3) + __builtin_abort (); +} |