Optimizing: Rename `As##type` to `As##type##OrNull`.

The null type check in the current implementation of
`HInstruction::As##type()` often cannot be optimized away
by clang++. It is therefore beneficial to have two functions
    HInstruction::As##type()
    HInstruction::As##type##OrNull()
where the first function never returns null but the second
one can return null. The additional text "OrNull" shall also
flag the possibility of yielding null to the developer which
may help avoid bugs similar to what we have seen previously.

This requires renaming the existing function that can return
null and introducing new function that cannot. However,
defining the new function `HInstruction::As##type()` in the
same change as renaming the old one would risk introducing
bugs by missing a rename. Therefore we simply rename the old
function here and the new function shall be introduced in a
separate change with all behavioral changes being explicit.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: buildbot-build.sh --target
Bug: 181943478
Change-Id: I4defd85038e28fe3506903ba3f33f723682b3298

1 files changed, 10 insertions, 5 deletions

diff --git a/compiler/optimizing/common_arm.h b/compiler/optimizing/common_arm.h
index 5f71cb906c..53768efad6 100644
--- a/compiler/optimizing/common_arm.h
+++ b/compiler/optimizing/common_arm.h
@@ -155,12 +155,14 @@ inline vixl::aarch32::DRegister DRegisterFromS(vixl::aarch32::SRegister s) {
 
 inline int32_t Int32ConstantFrom(HInstruction* instr) {
   if (instr->IsIntConstant()) {
-    return instr->AsIntConstant()->GetValue();
+    // TODO: Remove "OrNull".
+    return instr->AsIntConstantOrNull()->GetValue();
   } else if (instr->IsNullConstant()) {
     return 0;
   } else {
     DCHECK(instr->IsLongConstant()) << instr->DebugName();
-    const int64_t ret = instr->AsLongConstant()->GetValue();
+    // TODO: Remove "OrNull".
+    const int64_t ret = instr->AsLongConstantOrNull()->GetValue();
     DCHECK_GE(ret, std::numeric_limits<int32_t>::min());
     DCHECK_LE(ret, std::numeric_limits<int32_t>::max());
     return ret;
@@ -174,18 +176,21 @@ inline int32_t Int32ConstantFrom(Location location) {
 inline int64_t Int64ConstantFrom(Location location) {
   HConstant* instr = location.GetConstant();
   if (instr->IsIntConstant()) {
-    return instr->AsIntConstant()->GetValue();
+    // TODO: Remove "OrNull".
+    return instr->AsIntConstantOrNull()->GetValue();
   } else if (instr->IsNullConstant()) {
     return 0;
   } else {
     DCHECK(instr->IsLongConstant()) << instr->DebugName();
-    return instr->AsLongConstant()->GetValue();
+    // TODO: Remove "OrNull".
+    return instr->AsLongConstantOrNull()->GetValue();
   }
 }
 
 inline uint64_t Uint64ConstantFrom(HInstruction* instr) {
   DCHECK(instr->IsConstant()) << instr->DebugName();
-  return instr->AsConstant()->GetValueAsUint64();
+  // TODO: Remove "OrNull".
+  return instr->AsConstantOrNull()->GetValueAsUint64();
 }
 
 inline vixl::aarch32::Operand OperandFrom(Location location, DataType::Type type) {