New utilities for induction variables.

Rationale:
Break-out CL of ART Vectorizer: 2 OF many.
The purpose is making the original CL smaller
and easier to review.

Bug: 34083438
Test: test-art-host
Change-Id: I46d297eba504af3850a5998ee279ea9f7b38bed8

1 files changed, 15 insertions, 1 deletions

diff --git a/compiler/optimizing/induction_var_range.h b/compiler/optimizing/induction_var_range.h
index 6c424b78b9..0858d73982 100644
--- a/compiler/optimizing/induction_var_range.h
+++ b/compiler/optimizing/induction_var_range.h
@@ -24,7 +24,8 @@ namespace art {
 /**
  * This class implements range analysis on expressions within loops. It takes the results
  * of induction variable analysis in the constructor and provides a public API to obtain
- * a conservative lower and upper bound value on each instruction in the HIR.
+ * a conservative lower and upper bound value or last value on each instruction in the HIR.
+ * The public API also provides a few general-purpose utility methods related to induction.
  *
  * The range analysis is done with a combination of symbolic and partial integral evaluation
  * of expressions. The analysis avoids complications with wrap-around arithmetic on the integral
@@ -154,6 +155,19 @@ class InductionVarRange {
    */
   bool IsFinite(HLoopInformation* loop, /*out*/ int64_t* tc) const;
 
+  /**
+   * Checks if instruction is a unit stride induction inside the closest enveloping loop.
+   * Returns invariant offset on success.
+   */
+  bool IsUnitStride(HInstruction* instruction, /*out*/ HInstruction** offset) const;
+
+  /**
+   * Generates the trip count expression for the given loop. Code is generated in given block
+   * and graph. The expression is guarded by a taken test if needed. Returns the trip count
+   * expression on success or null otherwise.
+   */
+  HInstruction* GenerateTripCount(HLoopInformation* loop, HGraph* graph, HBasicBlock* block);
+
  private:
   /*
    * Enum used in IsConstant() request.