From 79dc217688a774fc532584f6551a0aec8b45bc4a Mon Sep 17 00:00:00 2001
From: Vladimir Marko <vmarko@google.com>
Date: Wed, 5 Apr 2023 10:33:07 +0000
Subject: 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
---
 compiler/optimizing/code_generator.h | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

(limited to 'compiler/optimizing/code_generator.h')

diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index 9872efaa4a..59ae213960 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -552,37 +552,45 @@ class CodeGenerator : public DeletableArenaObject<kArenaAllocCodeGenerator> {
 
   static int8_t GetInt8ValueOf(HConstant* constant) {
     DCHECK(constant->IsIntConstant());
-    return constant->AsIntConstant()->GetValue();
+    // TODO: Remove "OrNull".
+    return constant->AsIntConstantOrNull()->GetValue();
   }
 
   static int16_t GetInt16ValueOf(HConstant* constant) {
     DCHECK(constant->IsIntConstant());
-    return constant->AsIntConstant()->GetValue();
+    // TODO: Remove "OrNull".
+    return constant->AsIntConstantOrNull()->GetValue();
   }
 
   static int32_t GetInt32ValueOf(HConstant* constant) {
     if (constant->IsIntConstant()) {
-      return constant->AsIntConstant()->GetValue();
+      // TODO: Remove "OrNull".
+      return constant->AsIntConstantOrNull()->GetValue();
     } else if (constant->IsNullConstant()) {
       return 0;
     } else {
       DCHECK(constant->IsFloatConstant());
-      return bit_cast<int32_t, float>(constant->AsFloatConstant()->GetValue());
+      // TODO: Remove "OrNull".
+      return bit_cast<int32_t, float>(constant->AsFloatConstantOrNull()->GetValue());
     }
   }
 
   static int64_t GetInt64ValueOf(HConstant* constant) {
     if (constant->IsIntConstant()) {
-      return constant->AsIntConstant()->GetValue();
+      // TODO: Remove "OrNull".
+      return constant->AsIntConstantOrNull()->GetValue();
     } else if (constant->IsNullConstant()) {
       return 0;
     } else if (constant->IsFloatConstant()) {
-      return bit_cast<int32_t, float>(constant->AsFloatConstant()->GetValue());
+      // TODO: Remove "OrNull".
+      return bit_cast<int32_t, float>(constant->AsFloatConstantOrNull()->GetValue());
     } else if (constant->IsLongConstant()) {
-      return constant->AsLongConstant()->GetValue();
+      // TODO: Remove "OrNull".
+      return constant->AsLongConstantOrNull()->GetValue();
     } else {
       DCHECK(constant->IsDoubleConstant());
-      return bit_cast<int64_t, double>(constant->AsDoubleConstant()->GetValue());
+      // TODO: Remove "OrNull".
+      return bit_cast<int64_t, double>(constant->AsDoubleConstantOrNull()->GetValue());
     }
   }
 
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