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| author | Richard Biener <rguenther@suse.de> | 2022-05-17 09:45:02 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-05-17 10:45:45 +0200 |
| commit | ebce0e9bd8d714a8607ae24331a3d842b0d11859 (patch) | |
| tree | 6717967b3c1211de56e2ea4c7fdf6e4c3faf84e2 | |
| parent | 33400df641d834ca3fd3f2c964ed92759f128ffa (diff) | |
| download | gcc-ebce0e9bd8d714a8607ae24331a3d842b0d11859.zip gcc-ebce0e9bd8d714a8607ae24331a3d842b0d11859.tar.gz gcc-ebce0e9bd8d714a8607ae24331a3d842b0d11859.tar.bz2 | |
tree-optimization/105618 - restore load sinking
The PR97330 fix caused some missed sinking of loads out of loops
the following patch re-instantiates.
2022-05-17 Richard Biener <rguenther@suse.de>
PR tree-optimization/105618
* tree-ssa-sink.cc (statement_sink_location): For virtual
PHI uses ignore those defining the used virtual operand.
* gcc.dg/tree-ssa/ssa-sink-19.c: New testcase.
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-19.c | 21 | ||||
| -rw-r--r-- | gcc/tree-ssa-sink.cc | 3 |
2 files changed, 24 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-19.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-19.c new file mode 100644 index 0000000..e98d13f --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-19.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-sink1-details -fdump-tree-cddce2-details" } */ + +static int b=4; +int c; + +int +main() +{ + int e[5] = {1,1,1,1,1}; + for (; b >= 0; b--) { + c = e[b]; + } + return 0; +} + +/* We should sink e[b] out of the loop which is possible after + applying store motion to c and b. */ +/* { dg-final { scan-tree-dump "Sinking # VUSE" "sink1" } } */ +/* And remove the loop after final value replacement. */ +/* { dg-final { scan-tree-dump "fix_loop_structure: removing loop" "cddce2" } } */ diff --git a/gcc/tree-ssa-sink.cc b/gcc/tree-ssa-sink.cc index 1c22640..8ce4403 100644 --- a/gcc/tree-ssa-sink.cc +++ b/gcc/tree-ssa-sink.cc @@ -390,6 +390,9 @@ statement_sink_location (gimple *stmt, basic_block frombb, with the use. */ if (gimple_code (use_stmt) == GIMPLE_PHI) { + /* If the PHI defines the virtual operand, ignore it. */ + if (gimple_phi_result (use_stmt) == gimple_vuse (stmt)) + continue; /* In case the PHI node post-dominates the current insert location we can disregard it. But make sure it is not dominating it as well as can happen in a CFG cycle. */ |