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| author | Jakub Jelinek <jakub@redhat.com> | 2009-04-22 23:57:52 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2009-04-22 23:57:52 +0200 |
| commit | 2c0eba5af00a2544e7e15bd8052a53bdb2b6f22f (patch) | |
| tree | 9490a0f1996cc98864effb946df615d1062f9693 | |
| parent | 023f059b5c168cb31e8818d2c983f5687b169df4 (diff) | |
| download | gcc-2c0eba5af00a2544e7e15bd8052a53bdb2b6f22f.zip gcc-2c0eba5af00a2544e7e15bd8052a53bdb2b6f22f.tar.gz gcc-2c0eba5af00a2544e7e15bd8052a53bdb2b6f22f.tar.bz2 | |
re PR c/39855 (Shift optimization discards operands' side effects)
PR c/39855
* fold-const.c (fold_binary) <case LSHIFT_EXPR>: When optimizing
into 0, use omit_one_operand.
* gcc.dg/torture/pr39855.c: New test.
From-SVN: r146617
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/fold-const.c | 3 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr39855.c | 24 |
4 files changed, 35 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9073054..7bc4f33 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -3,6 +3,10 @@ * alias.c (find_base_term): Move around LO_SUM case, so that CONST falls through into PLUS/MINUS handling. + PR c/39855 + * fold-const.c (fold_binary) <case LSHIFT_EXPR>: When optimizing + into 0, use omit_one_operand. + 2009-04-23 Ben Elliston <bje@au.ibm.com> * config/rs6000/linux-unwind.h (get_regs): Remove type diff --git a/gcc/fold-const.c b/gcc/fold-const.c index ca07cf1..f0ff5b6 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -11880,7 +11880,8 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1) if (code == LROTATE_EXPR || code == RROTATE_EXPR) low = low % TYPE_PRECISION (type); else if (TYPE_UNSIGNED (type) || code == LSHIFT_EXPR) - return build_int_cst (type, 0); + return omit_one_operand (type, build_int_cst (type, 0), + TREE_OPERAND (arg0, 0)); else low = TYPE_PRECISION (type) - 1; } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index e5c7010..7af7fcc 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2009-04-22 Jakub Jelinek <jakub@redhat.com> + + PR c/39855 + * gcc.dg/torture/pr39855.c: New test. + 2009-04-22 Dodji Seketeli <dodji@redhat.com> PR c++/39639 diff --git a/gcc/testsuite/gcc.dg/torture/pr39855.c b/gcc/testsuite/gcc.dg/torture/pr39855.c new file mode 100644 index 0000000..6d75c38 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr39855.c @@ -0,0 +1,24 @@ +/* PR c/39855 */ +/* { dg-do run { target { int32plus } } } */ + +extern void abort (void); + +int i, j, k; + +int +foo (void) +{ + return ++i; +} + +int +main () +{ + if (__CHAR_BIT__ != 8 || sizeof (int) != 4) + return 0; + j = foo () << 30 << 2; + k = (unsigned) foo () >> 16 >> 16; + if (i != 2 || j != 0 || k != 0) + abort (); + return 0; +} |