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| author | Aldy Hernandez <aldyh@redhat.com> | 2021-10-28 11:44:13 +0200 |
|---|---|---|
| committer | Aldy Hernandez <aldyh@redhat.com> | 2021-10-28 14:30:06 +0200 |
| commit | 113dab2b9d511f3aadc30a6a921fc30bd5f93706 (patch) | |
| tree | 6cb4c293fa0eccb941dfac4e7cb36c5bad5aaa4a | |
| parent | 7f6c22585229b43b13fc9c8d3c08aedd9f7c493a (diff) | |
| download | gcc-113dab2b9d511f3aadc30a6a921fc30bd5f93706.zip gcc-113dab2b9d511f3aadc30a6a921fc30bd5f93706.tar.gz gcc-113dab2b9d511f3aadc30a6a921fc30bd5f93706.tar.bz2 | |
Improve backward threading with switches.
We've been essentially using find_taken_edge_switch_expr() in the
backward threader, but this is suboptimal because said function only
works with singletons. VRP has a much smarter find_case_label_range
that works with ranges.
Tested on x86-64 Linux with:
a) Bootstrap & regtests.
b) Verifying we get more threads than before.
c) Asserting that the new code catches everything the old one
code caught (over a set of bootstrap .ii files).
gcc/ChangeLog:
* tree-ssa-threadbackward.c
(back_threader::find_taken_edge_switch): Use find_case_label_range
instead of find_taken_edge.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/vrp106.c: Adjust for threading.
* gcc.dg/tree-ssa/vrp113.c: Same.
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/vrp106.c | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/vrp113.c | 2 | ||||
| -rw-r--r-- | gcc/tree-ssa-threadbackward.c | 8 |
3 files changed, 6 insertions, 8 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c index f25ea9c..dc5021a 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp106.c @@ -1,6 +1,6 @@ /* PR tree-optimization/18046 */ -/* { dg-options "-O2 -fdump-tree-vrp-thread1-details" } */ -/* { dg-final { scan-tree-dump-times "Threaded jump" 1 "vrp-thread1" } } */ +/* { dg-options "-O2 -fdump-tree-ethread-details" } */ +/* { dg-final { scan-tree-dump-times "Registering jump thread" 1 "ethread" } } */ /* During VRP we expect to thread the true arm of the conditional through the switch and to the BB that corresponds to the 7 ... 9 case label. */ extern void foo (void); diff --git a/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c b/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c index ab8d91e..dfe4989 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/vrp113.c @@ -13,5 +13,3 @@ int f(int a) { case 7: return 19; } } - -/* { dg-final { scan-tree-dump "return 3;" "vrp1" { xfail *-*-* } } } */ diff --git a/gcc/tree-ssa-threadbackward.c b/gcc/tree-ssa-threadbackward.c index 6c1b159..456effc 100644 --- a/gcc/tree-ssa-threadbackward.c +++ b/gcc/tree-ssa-threadbackward.c @@ -195,11 +195,11 @@ back_threader::find_taken_edge_switch (const vec<basic_block> &path, if (r.varying_p ()) return NULL; - tree val; - if (r.singleton_p (&val)) - return ::find_taken_edge (gimple_bb (sw), val); + tree label = find_case_label_range (sw, &r); + if (!label) + return NULL; - return NULL; + return find_edge (gimple_bb (sw), label_to_block (cfun, CASE_LABEL (label))); } // Same as find_taken_edge, but for paths ending in a GIMPLE_COND. |