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| author | Jiufu Guo <guojiufu@linux.ibm.com> | 2021-09-22 13:20:29 +0800 |
|---|---|---|
| committer | Jiufu Guo <guojiufu@linux.ibm.com> | 2021-09-22 21:03:08 +0800 |
| commit | 3087d1b0a2cbe8880ccbbb67744726ff4e5d390e (patch) | |
| tree | fe5b08c9311ba6976decf4af95503040ff94e370 /gcc/tree-ssa-loop-niter.c | |
| parent | fec75ab8c02be904de2963c0adb6d1e940a59761 (diff) | |
| download | gcc-3087d1b0a2cbe8880ccbbb67744726ff4e5d390e.zip gcc-3087d1b0a2cbe8880ccbbb67744726ff4e5d390e.tar.gz gcc-3087d1b0a2cbe8880ccbbb67744726ff4e5d390e.tar.bz2 | |
Set bound/cmp/control for until wrap loop.
In patch r12-3136, niter->control, niter->bound and niter->cmp are
derived from number_of_iterations_lt. While for 'until wrap condition',
the calculation in number_of_iterations_lt is not align the requirements
on the define of them and requirements in determine_exit_conditions.
This patch calculate niter->control, niter->bound and niter->cmp in
number_of_iterations_until_wrap.
gcc/ChangeLog:
2021-09-22 Jiufu Guo <guojiufu@linux.ibm.com>
PR tree-optimization/102087
* tree-ssa-loop-niter.c (number_of_iterations_until_wrap):
Update bound/cmp/control for niter.
gcc/testsuite/ChangeLog:
2021-09-22 Jiufu Guo <guojiufu@linux.ibm.com>
* gcc.dg/pr102087.c: New test.
PR tree-optimization/102087
Diffstat (limited to 'gcc/tree-ssa-loop-niter.c')
| -rw-r--r-- | gcc/tree-ssa-loop-niter.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index 7af92d1..7510940 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -1482,7 +1482,7 @@ number_of_iterations_until_wrap (class loop *, tree type, affine_iv *iv0, affine_iv *iv1, class tree_niter_desc *niter) { tree niter_type = unsigned_type_for (type); - tree step, num, assumptions, may_be_zero; + tree step, num, assumptions, may_be_zero, span; wide_int high, low, max, min; may_be_zero = fold_build2 (LE_EXPR, boolean_type_node, iv1->base, iv0->base); @@ -1557,6 +1557,20 @@ number_of_iterations_until_wrap (class loop *, tree type, affine_iv *iv0, niter->control.no_overflow = false; + /* Update bound and exit condition as: + bound = niter * STEP + (IVbase - STEP). + { IVbase - STEP, +, STEP } != bound + Here, biasing IVbase by 1 step makes 'bound' be the value before wrap. + */ + niter->control.base = fold_build2 (MINUS_EXPR, niter_type, + niter->control.base, niter->control.step); + span = fold_build2 (MULT_EXPR, niter_type, niter->niter, + fold_convert (niter_type, niter->control.step)); + niter->bound = fold_build2 (PLUS_EXPR, niter_type, span, + fold_convert (niter_type, niter->control.base)); + niter->bound = fold_convert (type, niter->bound); + niter->cmp = NE_EXPR; + return true; } |