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-rw-r--r--compiler/optimizing/load_store_analysis.cc179
1 files changed, 99 insertions, 80 deletions
diff --git a/compiler/optimizing/load_store_analysis.cc b/compiler/optimizing/load_store_analysis.cc
index 5a8ac59195..8b1812a6de 100644
--- a/compiler/optimizing/load_store_analysis.cc
+++ b/compiler/optimizing/load_store_analysis.cc
@@ -22,111 +22,130 @@ namespace art {
// The number of heap locations for most of the methods stays below this threshold.
constexpr size_t kMaxNumberOfHeapLocations = 32;
-// Check if array indices array[idx1 +/- CONST] and array[idx2] MAY alias.
-static bool BinaryOpAndIndexMayAlias(const HBinaryOperation* idx1, const HInstruction* idx2) {
- DCHECK(idx1 != nullptr);
- DCHECK(idx2 != nullptr);
+// Test if two integer ranges [l1,h1] and [l2,h2] overlap.
+// Note that the ranges are inclusive on both ends.
+// l1|------|h1
+// l2|------|h2
+static bool CanIntegerRangesOverlap(int64_t l1, int64_t h1, int64_t l2, int64_t h2) {
+ return std::max(l1, l2) <= std::min(h1, h2);
+}
- if (!idx1->IsAdd() && !idx1->IsSub()) {
+static bool IsAddOrSub(const HInstruction* instruction) {
+ return instruction->IsAdd() || instruction->IsSub();
+}
+
+static bool CanBinaryOpAndIndexAlias(const HBinaryOperation* idx1,
+ const size_t vector_length1,
+ const HInstruction* idx2,
+ const size_t vector_length2) {
+ if (!IsAddOrSub(idx1)) {
// We currently only support Add and Sub operations.
return true;
}
-
- HConstant* cst = idx1->GetConstantRight();
- if (cst == nullptr || cst->IsArithmeticZero()) {
+ if (idx1->AsBinaryOperation()->GetLeastConstantLeft() != idx2) {
+ // Cannot analyze [i+CONST1] and [j].
return true;
}
-
- if (idx1->GetLeastConstantLeft() == idx2) {
- // for example, array[idx1 + 1] and array[idx1]
- return false;
+ if (!idx1->GetConstantRight()->IsIntConstant()) {
+ return true;
}
- return true;
+ // Since 'i' are the same in [i+CONST] and [i],
+ // further compare [CONST] and [0].
+ int64_t l1 = idx1->IsAdd() ?
+ idx1->GetConstantRight()->AsIntConstant()->GetValue() :
+ -idx1->GetConstantRight()->AsIntConstant()->GetValue();
+ int64_t l2 = 0;
+ int64_t h1 = l1 + (vector_length1 - 1);
+ int64_t h2 = l2 + (vector_length2 - 1);
+ return CanIntegerRangesOverlap(l1, h1, l2, h2);
}
-// Check if Add and Sub MAY alias when used as indices in arrays.
-static bool BinaryOpsMayAlias(const HBinaryOperation* idx1, const HBinaryOperation* idx2) {
- DCHECK(idx1!= nullptr);
- DCHECK(idx2 != nullptr);
-
- HConstant* idx1_cst = idx1->GetConstantRight();
- HInstruction* idx1_other = idx1->GetLeastConstantLeft();
- HConstant* idx2_cst = idx2->GetConstantRight();
- HInstruction* idx2_other = idx2->GetLeastConstantLeft();
-
- if (idx1_cst == nullptr || idx1_other == nullptr ||
- idx2_cst == nullptr || idx2_other == nullptr) {
- // We only analyze patterns like [i +/- CONST].
+static bool CanBinaryOpsAlias(const HBinaryOperation* idx1,
+ const size_t vector_length1,
+ const HBinaryOperation* idx2,
+ const size_t vector_length2) {
+ if (!IsAddOrSub(idx1) || !IsAddOrSub(idx2)) {
+ // We currently only support Add and Sub operations.
return true;
}
-
- if (idx1_other != idx2_other) {
- // For example, [j+1] and [k+1] MAY alias.
+ if (idx1->AsBinaryOperation()->GetLeastConstantLeft() !=
+ idx2->AsBinaryOperation()->GetLeastConstantLeft()) {
+ // Cannot analyze [i+CONST1] and [j+CONST2].
return true;
}
-
- if ((idx1->IsAdd() && idx2->IsAdd()) ||
- (idx1->IsSub() && idx2->IsSub())) {
- return idx1_cst->AsIntConstant()->GetValue() == idx2_cst->AsIntConstant()->GetValue();
- }
-
- if ((idx1->IsAdd() && idx2->IsSub()) ||
- (idx1->IsSub() && idx2->IsAdd())) {
- // [i + CONST1] and [i - CONST2] MAY alias iff CONST1 == -CONST2.
- // By checking CONST1 == -CONST2, following cases are handled:
- // - Zero constants case [i+0] and [i-0] is handled.
- // - Overflow cases are handled, for example:
- // [i+0x80000000] and [i-0x80000000];
- // [i+0x10] and [i-0xFFFFFFF0].
- // - Other cases [i+CONST1] and [i-CONST2] without any overflow is handled.
- return idx1_cst->AsIntConstant()->GetValue() == -(idx2_cst->AsIntConstant()->GetValue());
+ if (!idx1->GetConstantRight()->IsIntConstant() ||
+ !idx2->GetConstantRight()->IsIntConstant()) {
+ return true;
}
- // All other cases, MAY alias.
- return true;
+ // Since 'i' are the same in [i+CONST1] and [i+CONST2],
+ // further compare [CONST1] and [CONST2].
+ int64_t l1 = idx1->IsAdd() ?
+ idx1->GetConstantRight()->AsIntConstant()->GetValue() :
+ -idx1->GetConstantRight()->AsIntConstant()->GetValue();
+ int64_t l2 = idx2->IsAdd() ?
+ idx2->GetConstantRight()->AsIntConstant()->GetValue() :
+ -idx2->GetConstantRight()->AsIntConstant()->GetValue();
+ int64_t h1 = l1 + (vector_length1 - 1);
+ int64_t h2 = l2 + (vector_length2 - 1);
+ return CanIntegerRangesOverlap(l1, h1, l2, h2);
}
-// The following array index cases are handled:
-// [i] and [i]
-// [CONST1] and [CONST2]
-// [i] and [i+CONST]
-// [i] and [i-CONST]
-// [i+CONST1] and [i+CONST2]
-// [i-CONST1] and [i-CONST2]
-// [i+CONST1] and [i-CONST2]
-// [i-CONST1] and [i+CONST2]
-// For other complicated cases, we rely on other passes like GVN and simpilfier
-// to optimize these cases before this pass.
-// For example: [i+j+k+10] and [i+k+10+j] shall be optimized to [i7+10] and [i7+10].
-bool HeapLocationCollector::CanArrayIndicesAlias(const HInstruction* idx1,
- const HInstruction* idx2) const {
+bool HeapLocationCollector::CanArrayElementsAlias(const HInstruction* idx1,
+ const size_t vector_length1,
+ const HInstruction* idx2,
+ const size_t vector_length2) const {
DCHECK(idx1 != nullptr);
DCHECK(idx2 != nullptr);
+ DCHECK_GE(vector_length1, HeapLocation::kScalar);
+ DCHECK_GE(vector_length2, HeapLocation::kScalar);
+ // [i] and [i].
if (idx1 == idx2) {
- // [i] and [i]
return true;
}
- if (idx1->IsIntConstant() && idx2->IsIntConstant()) {
- // [CONST1] and [CONST2]
- return idx1->AsIntConstant()->GetValue() == idx2->AsIntConstant()->GetValue();
- }
-
- if (idx1->IsBinaryOperation() && !BinaryOpAndIndexMayAlias(idx1->AsBinaryOperation(), idx2)) {
- // [i] and [i+/-CONST]
- return false;
- }
- if (idx2->IsBinaryOperation() && !BinaryOpAndIndexMayAlias(idx2->AsBinaryOperation(), idx1)) {
- // [i+/-CONST] and [i]
- return false;
- }
- if (idx1->IsBinaryOperation() && idx2->IsBinaryOperation()) {
- // [i+/-CONST1] and [i+/-CONST2]
- if (!BinaryOpsMayAlias(idx1->AsBinaryOperation(), idx2->AsBinaryOperation())) {
- return false;
- }
+ // [CONST1] and [CONST2].
+ if (idx1->IsIntConstant() && idx2->IsIntConstant()) {
+ int64_t l1 = idx1->AsIntConstant()->GetValue();
+ int64_t l2 = idx2->AsIntConstant()->GetValue();
+ // To avoid any overflow in following CONST+vector_length calculation,
+ // use int64_t instead of int32_t.
+ int64_t h1 = l1 + (vector_length1 - 1);
+ int64_t h2 = l2 + (vector_length2 - 1);
+ return CanIntegerRangesOverlap(l1, h1, l2, h2);
+ }
+
+ // [i+CONST] and [i].
+ if (idx1->IsBinaryOperation() &&
+ idx1->AsBinaryOperation()->GetConstantRight() != nullptr &&
+ idx1->AsBinaryOperation()->GetLeastConstantLeft() == idx2) {
+ return CanBinaryOpAndIndexAlias(idx1->AsBinaryOperation(),
+ vector_length1,
+ idx2,
+ vector_length2);
+ }
+
+ // [i] and [i+CONST].
+ if (idx2->IsBinaryOperation() &&
+ idx2->AsBinaryOperation()->GetConstantRight() != nullptr &&
+ idx2->AsBinaryOperation()->GetLeastConstantLeft() == idx1) {
+ return CanBinaryOpAndIndexAlias(idx2->AsBinaryOperation(),
+ vector_length2,
+ idx1,
+ vector_length1);
+ }
+
+ // [i+CONST1] and [i+CONST2].
+ if (idx1->IsBinaryOperation() &&
+ idx1->AsBinaryOperation()->GetConstantRight() != nullptr &&
+ idx2->IsBinaryOperation() &&
+ idx2->AsBinaryOperation()->GetConstantRight() != nullptr) {
+ return CanBinaryOpsAlias(idx1->AsBinaryOperation(),
+ vector_length1,
+ idx2->AsBinaryOperation(),
+ vector_length2);
}
// By default, MAY alias.
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-03 22:16:31 +0000