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| author | Vladimir N. Makarov <vmakarov@redhat.com> | 2023-09-25 16:19:50 -0400 |
|---|---|---|
| committer | Vladimir N. Makarov <vmakarov@redhat.com> | 2023-09-25 16:20:09 -0400 |
| commit | 3c23defed384cf17518ad6c817d94463a445d21b (patch) | |
| tree | b777ee78775055a3fe170d9ffc09403f82d2b6ba /gcc/lra.cc | |
| parent | 19df06f67c982b4e5427c4a056319d6a51c03481 (diff) | |
| download | gcc-3c23defed384cf17518ad6c817d94463a445d21b.zip gcc-3c23defed384cf17518ad6c817d94463a445d21b.tar.gz gcc-3c23defed384cf17518ad6c817d94463a445d21b.tar.bz2 | |
[PR111497][LRA]: Copy substituted equivalence
When we substitute the equivalence and it becomes shared, we can fail
to correctly update reg info used by LRA. This can result in wrong
code generation, e.g. because of incorrect live analysis. It can also
result in compiler crash as the pseudo survives RA. This is what
exactly happened for the PR. This patch solves this problem by
unsharing substituted equivalences.
gcc/ChangeLog:
PR middle-end/111497
* lra-constraints.cc (lra_constraints): Copy substituted
equivalence.
* lra.cc (lra): Change comment for calling unshare_all_rtl_again.
gcc/testsuite/ChangeLog:
PR middle-end/111497
* g++.target/i386/pr111497.C: new test.
Diffstat (limited to 'gcc/lra.cc')
| -rw-r--r-- | gcc/lra.cc | 5 |
1 files changed, 2 insertions, 3 deletions
@@ -2579,9 +2579,8 @@ lra (FILE *f) if (inserted_p) commit_edge_insertions (); - /* Replacing pseudos with their memory equivalents might have - created shared rtx. Subsequent passes would get confused - by this, so unshare everything here. */ + /* Subsequent passes expect that rtl is unshared, so unshare everything + here. */ unshare_all_rtl_again (get_insns ()); if (flag_checking) |