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| author | Jakub Jelinek <jakub@redhat.com> | 2022-01-03 13:47:53 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2022-01-03 13:47:53 +0100 |
| commit | 91031bffa42fdea3c985727d042cd1882a64be9c (patch) | |
| tree | 77c152759b6dbb0787713ed52737e8461731a4f7 /gcc/tree-ssa-structalias.c | |
| parent | 814c221c9eb350dc636556738f37aa73ebba8fdc (diff) | |
| download | gcc-91031bffa42fdea3c985727d042cd1882a64be9c.zip gcc-91031bffa42fdea3c985727d042cd1882a64be9c.tar.gz gcc-91031bffa42fdea3c985727d042cd1882a64be9c.tar.bz2 | |
symtab: Fold &a == &b to 0 if folding_initializer [PR94716]
On Thu, Dec 09, 2021 at 06:09:12PM -0500, Jason Merrill wrote:
> For the more general comparison of decls like your a != b example above I
> think clang is in the right; in manifestly constant-evaluated context
> (folding_initializer) we should return that they are unequal and prevent a
> later alias declaration, like we do for comparison to 0 in
> maybe_nonzero_address. It's possible that this gives a wrong answer based
> on something in another translation unit, but that's unlikely, and taking
> that chance seems better than rejecting code that needs a constant answer.
I agree. This is an incremental patch to do that.
2022-01-03 Jakub Jelinek <jakub@redhat.com>
PR c++/94716
gcc/
* symtab.c: Include fold-const.h.
(symtab_node::equal_address_to): If folding_initializer is true,
handle it like memory_accessed. Simplify.
gcc/testsuite/
* gcc.dg/init-compare-1.c: New test.
* g++.dg/cpp0x/constexpr-compare1.C: New test.
* g++.dg/cpp1y/constexpr-94716.C: New test.
* g++.dg/cpp1z/constexpr-compare1.C: New test.
Diffstat (limited to 'gcc/tree-ssa-structalias.c')
0 files changed, 0 insertions, 0 deletions