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| author | Richard Biener <rguenther@suse.de> | 2021-07-01 12:49:45 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2021-07-01 13:38:59 +0200 |
| commit | 0a77c07b9b3fe83679358c3ef57721e09e2ad5fb (patch) | |
| tree | 27e44924fdf36ccf4e2d4bd2f277440e76d08f71 /gcc/gimple-loop-interchange.cc | |
| parent | 09a7b00ac3075e3544978027f47b68fce54adabb (diff) | |
| download | gcc-0a77c07b9b3fe83679358c3ef57721e09e2ad5fb.zip gcc-0a77c07b9b3fe83679358c3ef57721e09e2ad5fb.tar.gz gcc-0a77c07b9b3fe83679358c3ef57721e09e2ad5fb.tar.bz2 | |
tree-optimization/101280 - revise interchange fix for PR101173
The following revises the original fix for PR101173 to correctly
check for a reversed dependence rather than disallowing a zero
distance. It also adds a check from TSVC which asks for this
kind of interchange (but with a valid dependence).
2021-07-01 Richard Biener <rguenther@suse.de>
PR tree-optimization/101280
PR tree-optimization/101173
* gimple-loop-interchange.cc
(tree_loop_interchange::valid_data_dependences): Revert
previous change and instead correctly handle DDR_REVERSED_P
dependence.
* gcc.dg/tree-ssa/loop-interchange-16.c: New testcase.
Diffstat (limited to 'gcc/gimple-loop-interchange.cc')
| -rw-r--r-- | gcc/gimple-loop-interchange.cc | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/gcc/gimple-loop-interchange.cc b/gcc/gimple-loop-interchange.cc index 43045c54..43ef112 100644 --- a/gcc/gimple-loop-interchange.cc +++ b/gcc/gimple-loop-interchange.cc @@ -1043,8 +1043,11 @@ tree_loop_interchange::valid_data_dependences (unsigned i_idx, unsigned o_idx, continue; /* Be conservative, skip case if either direction at i_idx/o_idx - levels is not '=' (for the inner loop) or '<'. */ - if (dist_vect[i_idx] < 0 || dist_vect[o_idx] <= 0) + levels is not '=' or '<'. */ + if (dist_vect[i_idx] < 0 + || (DDR_REVERSED_P (ddr) && dist_vect[i_idx] > 0) + || dist_vect[o_idx] < 0 + || (DDR_REVERSED_P (ddr) && dist_vect[o_idx] > 0)) return false; } } |