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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/testsuite/gcc.c-torture/execute/bitfld-1.c | |
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Diffstat (limited to 'gcc/testsuite/gcc.c-torture/execute/bitfld-1.c')
-rw-r--r-- | gcc/testsuite/gcc.c-torture/execute/bitfld-1.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.c-torture/execute/bitfld-1.c b/gcc/testsuite/gcc.c-torture/execute/bitfld-1.c new file mode 100644 index 000000000..b7e86e810 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/bitfld-1.c @@ -0,0 +1,54 @@ +/* Copyright 2002 Free Software Foundation, Inc. + + Tests correct signedness of operations on bitfields; in particular + that integer promotions are done correctly, including the case when + casts are present. + + The C front end was eliding the cast of an unsigned bitfield to + unsigned as a no-op, when in fact it forces a conversion to a + full-width unsigned int. (At the time of writing, the C++ front end + has a different bug; it erroneously promotes the uncast unsigned + bitfield to an unsigned int). + + Source: Neil Booth, 25 Jan 2002, based on PR 3325 (and 3326, which + is a different manifestation of the same bug). +*/ + +extern void abort (); + +int +main(int argc, char *argv[]) +{ + struct x { signed int i : 7; unsigned int u : 7; } bit; + + unsigned int u; + int i; + unsigned int unsigned_result = -13U % 61; + int signed_result = -13 % 61; + + bit.u = 61, u = 61; + bit.i = -13, i = -13; + + if (i % u != unsigned_result) + abort (); + if (i % (unsigned int) u != unsigned_result) + abort (); + + /* Somewhat counter-intuitively, bit.u is promoted to an int, making + the operands and result an int. */ + if (i % bit.u != signed_result) + abort (); + + if (bit.i % bit.u != signed_result) + abort (); + + /* But with a cast to unsigned int, the unsigned int is promoted to + itself as a no-op, and the operands and result are unsigned. */ + if (i % (unsigned int) bit.u != unsigned_result) + abort (); + + if (bit.i % (unsigned int) bit.u != unsigned_result) + abort (); + + return 0; +} |