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| author | Artem Serov <artem.serov@linaro.org> | 2019-12-04 21:02:09 +0000 |
|---|---|---|
| committer | Treehugger Robot <treehugger-gerrit@google.com> | 2020-04-14 10:26:59 +0000 |
| commit | b47b978486572492140b63b0c8c5daa58dc28d41 (patch) | |
| tree | 546c065d9396ef25bbd08b02d5ef4f6d269babfc /compiler/optimizing/loop_optimization.cc | |
| parent | e778fa6ead79e9cb26810d484c5a594e9612de9b (diff) | |
ART: Fix vectorizer HalvingAdd idiom.
IsAddConst2 function tried to extract addition chains
for the halving add idiom: (A + B) >> 1. The problem
was that regular shift right (x >> 1) was accepted for the
idiom (with {A: x, B: 0}) and not processed as a shift - which
broke the assumptions on shifts right and operand signedness.
This CL fixes that.
Test: 646-checker-simd-hadd.
Test: test-art-target.
Change-Id: Icf71e1a8e8c54e68114d7d5d6c4aa8a47ea5234d
Diffstat (limited to 'compiler/optimizing/loop_optimization.cc')
| -rw-r--r-- | compiler/optimizing/loop_optimization.cc | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/compiler/optimizing/loop_optimization.cc b/compiler/optimizing/loop_optimization.cc index 770a011550..b72fbb07c4 100644 --- a/compiler/optimizing/loop_optimization.cc +++ b/compiler/optimizing/loop_optimization.cc @@ -305,7 +305,8 @@ static bool IsAddConst2(HGraph* graph, /*out*/ HInstruction** a, /*out*/ HInstruction** b, /*out*/ int64_t* c) { - if (IsAddConst(instruction, a, b, c) && *a != nullptr) { + // We want an actual add/sub and not the trivial case where {b: 0, c: 0}. + if (IsAddOrSub(instruction) && IsAddConst(instruction, a, b, c) && *a != nullptr) { if (*b == nullptr) { // Constant is usually already present, unless accumulated. *b = graph->GetConstant(instruction->GetType(), (*c)); |