Generate taken-test during trip-count analysis.

Rationale: for loops that may not be taken, this taken-test
           can be used by clients of the induction variable
           analysis to ensure trip-count evaluation is valid.

Change-Id: Ia64749e2389b7224e69d6a49bb604b1964c11068

1 files changed, 14 insertions, 8 deletions

diff --git a/compiler/optimizing/induction_var_analysis.h b/compiler/optimizing/induction_var_analysis.h
index 7ab80cd676..cf354093f2 100644
--- a/compiler/optimizing/induction_var_analysis.h
+++ b/compiler/optimizing/induction_var_analysis.h
@@ -65,11 +65,16 @@ class HInductionVarAnalysis : public HOptimization {
     kMul,
     kDiv,
     kFetch,
-    // Trip counts (valid in full loop or only body proper; unsafe implies loop may be infinite).
-    kTripCountInLoop,
-    kTripCountInBody,
-    kTripCountInLoopUnsafe,
-    kTripCountInBodyUnsafe
+    // Trip-counts.
+    kTripCountInLoop,        // valid in full loop; loop is finite
+    kTripCountInBody,        // valid in body only; loop is finite
+    kTripCountInLoopUnsafe,  // valid in full loop; loop may be infinite
+    kTripCountInBodyUnsafe,  // valid in body only; loop may be infinite
+    // Comparisons for trip-count tests.
+    kLT,
+    kLE,
+    kGT,
+    kGE
   };
 
   /**
@@ -85,7 +90,7 @@ class HInductionVarAnalysis : public HOptimization {
    *   (4) periodic
    *         nop: a, then defined by b (repeated when exhausted)
    *   (5) trip-count:
-   *         tc: defined by b
+   *         tc: defined by a, taken-test in b
    */
   struct InductionInfo : public ArenaObject<kArenaAllocInductionVarAnalysis> {
     InductionInfo(InductionClass ic,
@@ -119,8 +124,9 @@ class HInductionVarAnalysis : public HOptimization {
     return new (graph_->GetArena()) InductionInfo(kInvariant, kFetch, nullptr, nullptr, f);
   }
 
-  InductionInfo* CreateTripCount(InductionOp op, InductionInfo* b) {
-    return new (graph_->GetArena()) InductionInfo(kInvariant, op, nullptr, b, nullptr);
+  InductionInfo* CreateTripCount(InductionOp op, InductionInfo* a, InductionInfo* b) {
+    DCHECK(a != nullptr);
+    return new (graph_->GetArena()) InductionInfo(kInvariant, op, a, b, nullptr);
   }
 
   InductionInfo* CreateInduction(InductionClass ic, InductionInfo* a, InductionInfo* b) {