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| author | 2016-02-24 14:17:53 -0800 | |
|---|---|---|
| committer | 2016-02-25 09:26:57 -0800 | |
| commit | 358af839c60db9e178f0b0bb9d430711c071b82a (patch) | |
| tree | bfeb6c0fe553161a6d3df57f2e35401ea36e94ff /compiler/optimizing/induction_var_analysis.cc | |
| parent | 4e4e64511e530db37b33f450016afe49db3c4b20 (diff) | |
Recognize for (int i = 0; i != x.length; i++) loops
Rationale:
Idiom occurs in real-life and is very straightforwardly
recognized by existing induction/range machinery.
Change-Id: I965a16e9de72f3523ea5023d30ed1c4e47ed5010
Diffstat (limited to 'compiler/optimizing/induction_var_analysis.cc')
| -rw-r--r-- | compiler/optimizing/induction_var_analysis.cc | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/compiler/optimizing/induction_var_analysis.cc b/compiler/optimizing/induction_var_analysis.cc index a1e1cde9df..82a898a9f1 100644 --- a/compiler/optimizing/induction_var_analysis.cc +++ b/compiler/optimizing/induction_var_analysis.cc @@ -552,9 +552,11 @@ void HInductionVarAnalysis::VisitCondition(HLoopInformation* loop, if (!IsExact(stride_expr, &stride_value)) { return; } - // Rewrite condition i != U into i < U or i > U if end condition is reached exactly. - if (cmp == kCondNE && ((stride_value == +1 && IsTaken(lower_expr, upper_expr, kCondLT)) || - (stride_value == -1 && IsTaken(lower_expr, upper_expr, kCondGT)))) { + // Rewrite condition i != U into strict end condition i < U or i > U if this end condition + // is reached exactly (tested by verifying if the loop has a unit stride and the non-strict + // condition would be always taken). + if (cmp == kCondNE && ((stride_value == +1 && IsTaken(lower_expr, upper_expr, kCondLE)) || + (stride_value == -1 && IsTaken(lower_expr, upper_expr, kCondGE)))) { cmp = stride_value > 0 ? kCondLT : kCondGT; } // Normalize a linear loop control with a nonzero stride: |