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| author | Eric Botcazou <ebotcazou@adacore.com> | 2022-11-04 11:23:12 +0100 |
|---|---|---|
| committer | Eric Botcazou <ebotcazou@adacore.com> | 2022-11-04 15:14:50 +0100 |
| commit | 0bdf10bdf1b2c9f31e7e764dec4d56ea6044f943 (patch) | |
| tree | 25b2ac3b00d05621a82a46657a3dd214fe1d3a72 /gcc/fold-const.cc | |
| parent | 3e2bdf2460a34a2389dee813a2ba8ecf976f2ec9 (diff) | |
| download | gcc-0bdf10bdf1b2c9f31e7e764dec4d56ea6044f943.zip gcc-0bdf10bdf1b2c9f31e7e764dec4d56ea6044f943.tar.gz gcc-0bdf10bdf1b2c9f31e7e764dec4d56ea6044f943.tar.bz2 | |
Fix recent thinko in operand_equal_p
There is a thinko in a recent improvement made to operand_equal_p where
the code just looks at operand 2 of COMPONENT_REF, if it is present, to
compare addresses. That's wrong because operand 2 contains the number of
DECL_OFFSET_ALIGN-bit-sized words so, when DECL_OFFSET_ALIGN > 8, not all
the bytes are included and some of them are in DECL_FIELD_BIT_OFFSET, see
get_inner_reference for the model computation.
In other words, you would need to compare operand 2 and DECL_OFFSET_ALIGN
and DECL_FIELD_BIT_OFFSET in this situation, but I'm not sure this is worth
the hassle in practice so the fix just removes this alternate handling.
gcc/
* fold-const.cc (operand_compare::operand_equal_p) <COMPONENT_REF>:
Do not take into account operand 2.
(operand_compare::hash_operand) <COMPONENT_REF>: Likewise.
gcc/testsuite/
* gnat.dg/opt99.adb: New test.
* gnat.dg/opt99_pkg1.ads, gnat.dg/opt99_pkg1.adb: New helper.
* gnat.dg/opt99_pkg2.ads: Likewise.
Diffstat (limited to 'gcc/fold-const.cc')
| -rw-r--r-- | gcc/fold-const.cc | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc index 7e1ea58..b89cac9 100644 --- a/gcc/fold-const.cc +++ b/gcc/fold-const.cc @@ -3377,9 +3377,6 @@ operand_compare::operand_equal_p (const_tree arg0, const_tree arg1, if (compare_address && (flags & OEP_ADDRESS_OF_SAME_FIELD) == 0) { - if (TREE_OPERAND (arg0, 2) - || TREE_OPERAND (arg1, 2)) - return OP_SAME_WITH_NULL (2); tree field0 = TREE_OPERAND (arg0, 1); tree field1 = TREE_OPERAND (arg1, 1); @@ -3890,17 +3887,10 @@ operand_compare::hash_operand (const_tree t, inchash::hash &hstate, if (sflags & OEP_ADDRESS_OF) { hash_operand (TREE_OPERAND (t, 0), hstate, flags); - if (TREE_OPERAND (t, 2)) - hash_operand (TREE_OPERAND (t, 2), hstate, - flags & ~OEP_ADDRESS_OF); - else - { - tree field = TREE_OPERAND (t, 1); - hash_operand (DECL_FIELD_OFFSET (field), - hstate, flags & ~OEP_ADDRESS_OF); - hash_operand (DECL_FIELD_BIT_OFFSET (field), - hstate, flags & ~OEP_ADDRESS_OF); - } + hash_operand (DECL_FIELD_OFFSET (TREE_OPERAND (t, 1)), + hstate, flags & ~OEP_ADDRESS_OF); + hash_operand (DECL_FIELD_BIT_OFFSET (TREE_OPERAND (t, 1)), + hstate, flags & ~OEP_ADDRESS_OF); return; } break; |