Refined range rule for ABS(x)

Rationale;
ABS(minint) = minint prevents assuming >=0 always.
With a fail-before(sig11)/pass-after regression test.

Test: 623
Change-Id: If5fb1580b207c7cdd964f7498849d1768bb1589d

1 files changed, 4 insertions, 2 deletions

diff --git a/compiler/optimizing/induction_var_range.cc b/compiler/optimizing/induction_var_range.cc
index f35aace3a9..089340e715 100644
--- a/compiler/optimizing/induction_var_range.cc
+++ b/compiler/optimizing/induction_var_range.cc
@@ -87,8 +87,10 @@ static bool IsGEZero(HInstruction* instruction) {
                IsGEZero(instruction->InputAt(1));
       case Intrinsics::kMathAbsInt:
       case Intrinsics::kMathAbsLong:
-        // Instruction ABS(x) is >= 0.
-        return true;
+        // Instruction ABS(>=0) is >= 0.
+        // NOTE: ABS(minint) = minint prevents assuming
+        //       >= 0 without looking at the argument.
+        return IsGEZero(instruction->InputAt(0));
       default:
         break;
     }