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| author | Richard Biener <rguenther@suse.de> | 2024-01-31 11:28:50 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2024-01-31 12:29:19 +0100 |
| commit | 724b64304ff5c8ac08a913509afd6fde38d7b767 (patch) | |
| tree | a9919753900b9f3b5fa99781d921c6641169b86c | |
| parent | b59775b642bb2b1ecd2e6d52c988b9c432117bc8 (diff) | |
| download | gcc-724b64304ff5c8ac08a913509afd6fde38d7b767.zip gcc-724b64304ff5c8ac08a913509afd6fde38d7b767.tar.gz gcc-724b64304ff5c8ac08a913509afd6fde38d7b767.tar.bz2 | |
tree-optimization/113630 - invalid code hoisting
The following avoids code hoisting (but also PRE insertion) of
expressions that got value-numbered to another one that are not
a valid replacement (but still compute the same value). This time
because the access path ends in a structure with different size,
meaning we consider a related access as not trapping because of the
size of the base of the access.
PR tree-optimization/113630
* tree-ssa-pre.cc (compute_avail): Avoid registering a
reference with a representation with not matching base
access size.
* gcc.dg/torture/pr113630.c: New testcase.
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr113630.c | 4 | ||||
| -rw-r--r-- | gcc/tree-ssa-pre.cc | 14 |
2 files changed, 18 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr113630.c b/gcc/testsuite/gcc.dg/torture/pr113630.c new file mode 100644 index 0000000..72ebdef --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr113630.c @@ -0,0 +1,4 @@ +/* { dg-do run { target { { *-*-linux* *-*-gnu* *-*-uclinux* } && mmap } } } */ +/* { dg-additional-options "-fno-strict-aliasing" } */ + +#include "pr110799.c" diff --git a/gcc/tree-ssa-pre.cc b/gcc/tree-ssa-pre.cc index e72592d..d29214d 100644 --- a/gcc/tree-ssa-pre.cc +++ b/gcc/tree-ssa-pre.cc @@ -4281,6 +4281,20 @@ compute_avail (function *fun) = wide_int_to_tree (ptr_type_node, wi::to_wide (ref1->op2)); } + /* We also need to make sure that the access path + ends in an access of the same size as otherwise + we might assume an access may not trap while in + fact it might. That's independent of whether + TBAA is in effect. */ + if (TYPE_SIZE (ref1->type) != TYPE_SIZE (ref2->type) + && (! TYPE_SIZE (ref1->type) + || ! TYPE_SIZE (ref2->type) + || ! operand_equal_p (TYPE_SIZE (ref1->type), + TYPE_SIZE (ref2->type)))) + { + operands.release (); + continue; + } operands.release (); result = get_or_alloc_expr_for_reference |