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| author | Jakub Jelinek <jakub@redhat.com> | 2020-02-27 10:45:30 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-02-27 10:45:30 +0100 |
| commit | 1956773cc655dfcba8d310066d3f6585dd4b8972 (patch) | |
| tree | 97912090e49accaad698355da78281533048d1a0 | |
| parent | 5f9cd512c4278621435cce486dd00248ea2e821c (diff) | |
| download | gcc-1956773cc655dfcba8d310066d3f6585dd4b8972.zip gcc-1956773cc655dfcba8d310066d3f6585dd4b8972.tar.gz gcc-1956773cc655dfcba8d310066d3f6585dd4b8972.tar.bz2 | |
gimplify: Don't optimize register const vars to static [PR93949]
The following testcase is rejected, while it was accepted in 3.4 and earlier
(before tree-ssa merge).
The problem is that we decide to promote the const variable to TREE_STATIC,
but TREE_STATIC DECL_REGISTER VAR_DECLs may only be the global register vars
and so assemble_variable/make_decl_rtl diagnoses it.
Either we do what the following patch does, where we could consider
register as a hint the user doesn't want such optimization, because if
something is forced static, it is not "register" anymore and register static
is not valid in C either, or we could clear DECL_REGISTER instead, but would
still need to punt at least on DECL_HARD_REGISTER cases.
2020-02-27 Jakub Jelinek <jakub@redhat.com>
PR c/93949
* gimplify.c (gimplify_init_constructor): Don't promote readonly
DECL_REGISTER variables to TREE_STATIC.
* gcc.c-torture/compile/pr93949.c: New test.
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/gimplify.c | 1 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 3 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/compile/pr93949.c | 7 |
4 files changed, 15 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 38bfbb9..d8cfd09 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,9 @@ 2020-02-27 Jakub Jelinek <jakub@redhat.com> + PR c/93949 + * gimplify.c (gimplify_init_constructor): Don't promote readonly + DECL_REGISTER variables to TREE_STATIC. + PR tree-optimization/93582 PR tree-optimization/93945 * tree-ssa-sccvn.c (vn_reference_lookup_3): Handle memset with diff --git a/gcc/gimplify.c b/gcc/gimplify.c index a6205d6..ef531f3 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -4923,6 +4923,7 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p, && num_nonzero_elements > 1 && TREE_READONLY (object) && VAR_P (object) + && !DECL_REGISTER (object) && (flag_merge_constants >= 2 || !TREE_ADDRESSABLE (object)) /* For ctors that have many repeated nonzero elements represented through RANGE_EXPRs, prefer initializing diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 70897c5..3cc13f9 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,8 @@ 2020-02-27 Jakub Jelinek <jakub@redhat.com> + PR c/93949 + * gcc.c-torture/compile/pr93949.c: New test. + PR tree-optimization/93582 PR tree-optimization/93945 * gcc.dg/tree-ssa/pr93582-9.c: New test. diff --git a/gcc/testsuite/gcc.c-torture/compile/pr93949.c b/gcc/testsuite/gcc.c-torture/compile/pr93949.c new file mode 100644 index 0000000..bbda020 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/pr93949.c @@ -0,0 +1,7 @@ +/* PR c/93949 */ + +void +foo (void) +{ + register const double d[3] = { 0., 1., 2. }; +} |