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| author | Richard Biener <rguenther@suse.de> | 2021-08-09 13:12:08 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2021-08-11 16:24:08 +0200 |
| commit | e8426554e1375fec2d119ba9cc5feb263db84559 (patch) | |
| tree | 9ff9e1b439f38fbb24e1a3d687143f183bdbc8e6 /gcc/tree-ssa-operands.c | |
| parent | cecdff844ac3a4a1790794ce4aa17d7fa50ee3eb (diff) | |
| download | gcc-e8426554e1375fec2d119ba9cc5feb263db84559.zip gcc-e8426554e1375fec2d119ba9cc5feb263db84559.tar.gz gcc-e8426554e1375fec2d119ba9cc5feb263db84559.tar.bz2 | |
Adjust volatile handling of the operand scanner
The GIMPLE SSA operand scanner handles COMPONENT_REFs that are
not marked TREE_THIS_VOLATILE but have a TREE_THIS_VOLATILE
FIELD_DECL as volatile. That's inconsistent in how TREE_THIS_VOLATILE
testing on GENERIC refs works which requires operand zero of
component references to mirror TREE_THIS_VOLATILE to the ref
so that testing TREE_THIS_VOLATILE on the outermost reference
is enough to determine the volatileness.
The following patch thus removes FIELD_DECL scanning from
the GIMPLE SSA operand scanner, possibly leaving fewer stmts
marked as gimple_has_volatile_ops.
It shows we miss at least one case in the fortran frontend, though
there's a suspicious amount of COMPONENT_REF creation compared
to little setting of TREE_THIS_VOLATILE. This fixes the FAIL
of gfortran.dg/volatile11.f90 that would otherwise occur.
Visually inspecting fortran/ reveals a bunch of likely to fix
cases but I don't know the constraints of 'volatile' uses in
the fortran language to assess whether some of these are not
necessary.
2021-08-09 Richard Biener <rguenther@suse.de>
gcc/
* tree-ssa-operands.c (operands_scanner::get_expr_operands):
Do not look at COMPONENT_REF FIELD_DECLs TREE_THIS_VOLATILE
to determine has_volatile_ops.
gcc/fortran/
* trans-common.c (create_common): Set TREE_THIS_VOLATILE on the
COMPONENT_REF if the field is volatile.
Diffstat (limited to 'gcc/tree-ssa-operands.c')
| -rw-r--r-- | gcc/tree-ssa-operands.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c index c155754..ebf7eea 100644 --- a/gcc/tree-ssa-operands.c +++ b/gcc/tree-ssa-operands.c @@ -834,12 +834,7 @@ operands_scanner::get_expr_operands (tree *expr_p, int flags) get_expr_operands (&TREE_OPERAND (expr, 0), flags); if (code == COMPONENT_REF) - { - if (!(flags & opf_no_vops) - && TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1))) - gimple_set_has_volatile_ops (stmt, true); - get_expr_operands (&TREE_OPERAND (expr, 2), uflags); - } + get_expr_operands (&TREE_OPERAND (expr, 2), uflags); else if (code == ARRAY_REF || code == ARRAY_RANGE_REF) { get_expr_operands (&TREE_OPERAND (expr, 1), uflags); |