Fix null check elimination
The existing null check elimination mechanism suffered from the same
limitation as the SSA renaming: it took shortcuts that were valid in
a trace compilation world, but not in a method compilation world.
This CL replaces the old mechanism, and additionally takes advantage
of some the fact that "this" is always non-null, as are objects returned
from OP_NEW_* (thanks Ian!).
Two test cases added. The one for ensuring that unnecessary null checks
are elminated requires manual inspection. The other - that we don't
eliminate a necessary null check - is disabled until exceptions are working.
Change-Id: I2a9b72741f56617bf609e4d7c20244796c988f28
diff --git a/src/compiler/codegen/arm/Thumb2/Gen.cc b/src/compiler/codegen/arm/Thumb2/Gen.cc
index cd3a64a..c54a0a8 100644
--- a/src/compiler/codegen/arm/Thumb2/Gen.cc
+++ b/src/compiler/codegen/arm/Thumb2/Gen.cc
@@ -450,7 +450,7 @@
loadWordDisp(cUnit, r0, art::Field::OffsetOffset().Int32Value(), r0);
}
-static void genIGetX(CompilationUnit* cUnit, MIR* mir, OpSize size,
+static void genIGet(CompilationUnit* cUnit, MIR* mir, OpSize size,
RegLocation rlDest, RegLocation rlObj)
{
Field* fieldPtr = cUnit->method->GetDeclaringClass()->GetDexCache()->
@@ -485,7 +485,7 @@
}
}
-static void genIPutX(CompilationUnit* cUnit, MIR* mir, OpSize size,
+static void genIPut(CompilationUnit* cUnit, MIR* mir, OpSize size,
RegLocation rlSrc, RegLocation rlObj, bool isObject)
{
Field* fieldPtr = cUnit->method->GetDeclaringClass()->GetDexCache()->
@@ -521,7 +521,7 @@
}
}
-static void genIGetWideX(CompilationUnit* cUnit, MIR* mir, RegLocation rlDest,
+static void genIGetWide(CompilationUnit* cUnit, MIR* mir, RegLocation rlDest,
RegLocation rlObj)
{
Field* fieldPtr = cUnit->method->GetDeclaringClass()->GetDexCache()->
@@ -564,7 +564,7 @@
}
}
-static void genIPutWideX(CompilationUnit* cUnit, MIR* mir, RegLocation rlSrc,
+static void genIPutWide(CompilationUnit* cUnit, MIR* mir, RegLocation rlSrc,
RegLocation rlObj)
{
Field* fieldPtr = cUnit->method->GetDeclaringClass()->GetDexCache()->
@@ -886,8 +886,6 @@
for (int i = 0; i < numFPTemps; i++) {
oatMarkTemp(cUnit, fpTemps[i]);
}
- pool->nullCheckedRegs =
- oatAllocBitVector(cUnit->numSSARegs, false);
}
/*
@@ -1267,11 +1265,7 @@
loadValueDirectFixed(cUnit, rlSrc, r0);
/* null array object? */
- ArmLIR* pcrLabel = NULL;
-
- if (!(mir->OptimizationFlags & MIR_IGNORE_NULL_CHECK)) {
- pcrLabel = genNullCheck(cUnit, rlArray.sRegLow, r1, mir);
- }
+ genNullCheck(cUnit, rlArray.sRegLow, r1, mir);
loadWordDisp(cUnit, rSELF,
OFFSETOF_MEMBER(Thread, pCanPutArrayElementFromCode), rLR);
/* Get the array's clazz */
@@ -1295,7 +1289,7 @@
genRegCopy(cUnit, regPtr, rlArray.lowReg);
}
- if (!(mir->OptimizationFlags & MIR_IGNORE_RANGE_CHECK)) {
+ if (!(mir->optimizationFlags & MIR_IGNORE_RANGE_CHECK)) {
int regLen = oatAllocTemp(cUnit);
//NOTE: max live temps(4) here.
/* Get len */
@@ -1331,15 +1325,11 @@
int regPtr;
/* null object? */
- ArmLIR* pcrLabel = NULL;
-
- if (!(mir->OptimizationFlags & MIR_IGNORE_NULL_CHECK)) {
- pcrLabel = genNullCheck(cUnit, rlArray.sRegLow, rlArray.lowReg, mir);
- }
+ genNullCheck(cUnit, rlArray.sRegLow, rlArray.lowReg, mir);
regPtr = oatAllocTemp(cUnit);
- if (!(mir->OptimizationFlags & MIR_IGNORE_RANGE_CHECK)) {
+ if (!(mir->optimizationFlags & MIR_IGNORE_RANGE_CHECK)) {
int regLen = oatAllocTemp(cUnit);
/* Get len */
loadWordDisp(cUnit, rlArray.lowReg, lenOffset, regLen);
@@ -1405,13 +1395,9 @@
}
/* null object? */
- ArmLIR* pcrLabel = NULL;
+ genNullCheck(cUnit, rlArray.sRegLow, rlArray.lowReg, mir);
- if (!(mir->OptimizationFlags & MIR_IGNORE_NULL_CHECK)) {
- pcrLabel = genNullCheck(cUnit, rlArray.sRegLow, rlArray.lowReg, mir);
- }
-
- if (!(mir->OptimizationFlags & MIR_IGNORE_RANGE_CHECK)) {
+ if (!(mir->optimizationFlags & MIR_IGNORE_RANGE_CHECK)) {
int regLen = oatAllocTemp(cUnit);
//NOTE: max live temps(4) here.
/* Get len */