Simplify ReduceLoadWidth's logic: it doesn't need several different

special cases after producing the new reduced-width load, because the
new load already has the needed adjustments built into it. This fixes
several bugs due to the special cases, including PR3317.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62692 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-01-21 15:17:51 +00:00
parent 1ef4d8f7ee
commit 764fd0cbc8
2 changed files with 56 additions and 19 deletions

View File

@ -511,6 +511,9 @@ SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
DOUT << "\nReplacing.1 "; DEBUG(N->dump(&DAG));
DOUT << "\nWith: "; DEBUG(To[0].getNode()->dump(&DAG));
DOUT << " and " << NumTo-1 << " other values\n";
DEBUG(for (unsigned i = 0, e = NumTo; i != e; ++i)
assert(N->getValueType(i) == To[i].getValueType() &&
"Cannot combine value to value of different type!"));
WorkListRemover DeadNodes(*this);
DAG.ReplaceAllUsesWith(N, To, &DeadNodes);
@ -3310,7 +3313,7 @@ SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
SDValue N0 = N->getOperand(0);
MVT VT = N->getValueType(0);
MVT EVT = N->getValueType(0);
MVT EVT = VT;
// This transformation isn't valid for vector loads.
if (VT.isVector())
@ -3327,7 +3330,6 @@ SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
unsigned EVTBits = EVT.getSizeInBits();
unsigned ShAmt = 0;
bool CombineSRL = false;
if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
ShAmt = N01->getZExtValue();
@ -3336,7 +3338,6 @@ SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
N0 = N0.getOperand(0);
if (N0.getValueType().getSizeInBits() <= EVTBits)
return SDValue();
CombineSRL = true;
}
}
}
@ -3368,22 +3369,12 @@ SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
: DAG.getExtLoad(ExtType, VT, LN0->getChain(), NewPtr,
LN0->getSrcValue(), LN0->getSrcValueOffset() + PtrOff,
EVT, LN0->isVolatile(), NewAlign);
AddToWorkList(Load.getNode());
if (CombineSRL) {
WorkListRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1),
&DeadNodes);
CombineTo(N->getOperand(0).getNode(), Load);
} else
CombineTo(N0.getNode(), Load, Load.getValue(1));
if (ShAmt) {
if (Opc == ISD::SIGN_EXTEND_INREG)
return DAG.getNode(Opc, VT, Load, N->getOperand(1));
else
return DAG.getNode(Opc, VT, Load);
}
return SDValue(N, 0); // Return N so it doesn't get rechecked!
// Replace the old load's chain with the new load's chain.
WorkListRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1),
&DeadNodes);
// Return the new loaded value.
return Load;
}
return SDValue();

View File

@ -0,0 +1,46 @@
; RUN: llvm-as < %s | llc -march=x86
; PR3317
%ArraySInt16 = type { %JavaObject, i8*, [0 x i16] }
%ArraySInt8 = type { %JavaObject, i8*, [0 x i8] }
%Attribut = type { %ArraySInt16*, i32, i32 }
%CacheNode = type { i8*, %JavaCommonClass*, %CacheNode*, %Enveloppe* }
%Enveloppe = type { %CacheNode*, %ArraySInt16*, %ArraySInt16*, i8, %JavaClass*, %CacheNode }
%JavaArray = type { %JavaObject, i8* }
%JavaClass = type { %JavaCommonClass, i32, %VT*, [1 x %TaskClassMirror], i8*, %JavaField*, i16, %JavaField*, i16, %JavaMethod*, i16, %JavaMethod*, i16, i8*, %ArraySInt8*, i8*, %Attribut*, i16, %JavaClass**, i16, %JavaClass*, i16, i8, i32, i32, i8*, void (i8*)* }
%JavaCommonClass = type { %JavaCommonClass**, i32, [1 x %JavaObject*], i16, %JavaClass**, i16, %ArraySInt16*, %JavaClass*, i8* }
%JavaField = type { i8*, i16, %ArraySInt16*, %ArraySInt16*, %Attribut*, i16, %JavaClass*, i32, i16, i8* }
%JavaMethod = type { i8*, i16, %Attribut*, i16, %Enveloppe*, i16, %JavaClass*, %ArraySInt16*, %ArraySInt16*, i8, i8*, i32, i8* }
%JavaObject = type { %VT*, %JavaCommonClass*, i8* }
%TaskClassMirror = type { i32, i8* }
%UTF8 = type { %JavaObject, i8*, [0 x i16] }
%VT = type [0 x i32 (...)*]
declare void @jnjvmNullPointerException()
define i32 @JnJVM_java_rmi_activation_ActivationGroupID_hashCode__(%JavaObject* nocapture) nounwind {
start:
%1 = getelementptr %JavaObject* %0, i64 1, i32 1 ; <%JavaCommonClass**> [#uses=1]
%2 = load %JavaCommonClass** %1 ; <%JavaCommonClass*> [#uses=4]
%3 = icmp eq %JavaCommonClass* %2, null ; <i1> [#uses=1]
br i1 %3, label %verifyNullExit1, label %verifyNullCont2
verifyNullExit1: ; preds = %start
tail call void @jnjvmNullPointerException()
unreachable
verifyNullCont2: ; preds = %start
%4 = bitcast %JavaCommonClass* %2 to { %JavaObject, i16, i32, i64 }* ; <{ %JavaObject, i16, i32, i64 }*> [#uses=1]
%5 = getelementptr { %JavaObject, i16, i32, i64 }* %4, i64 0, i32 2 ; <i32*> [#uses=1]
%6 = load i32* %5 ; <i32> [#uses=1]
%7 = getelementptr %JavaCommonClass* %2, i64 0, i32 4 ; <%JavaClass***> [#uses=1]
%8 = bitcast %JavaClass*** %7 to i64* ; <i64*> [#uses=1]
%9 = load i64* %8 ; <i64> [#uses=1]
%10 = trunc i64 %9 to i32 ; <i32> [#uses=1]
%11 = getelementptr %JavaCommonClass* %2, i64 0, i32 3 ; <i16*> [#uses=1]
%12 = load i16* %11 ; <i16> [#uses=1]
%13 = sext i16 %12 to i32 ; <i32> [#uses=1]
%14 = xor i32 %10, %6 ; <i32> [#uses=1]
%15 = xor i32 %14, %13 ; <i32> [#uses=1]
ret i32 %15
}