Enhance logic in X86DAGToDAGISel::PreprocessForRMW which move load inside callseq_start to allow it to be folded into a call. It was not considering the cases where a token factor is between the load and the callseq_start.

llvm-svn: 63022
This commit is contained in:
Evan Cheng 2009-01-26 18:43:34 +00:00
parent cdf60c96c8
commit ec03e0cd3b
2 changed files with 72 additions and 8 deletions

View File

@ -432,14 +432,27 @@ static bool isRMWLoad(SDValue N, SDValue Chain, SDValue Address,
/// MoveBelowCallSeqStart - Replace CALLSEQ_START operand with load's chain
/// operand and move load below the call's chain operand.
static void MoveBelowCallSeqStart(SelectionDAG *CurDAG, SDValue Load,
SDValue Call, SDValue Chain) {
SDValue Call, SDValue CallSeqStart) {
SmallVector<SDValue, 8> Ops;
for (unsigned i = 0, e = Chain.getNode()->getNumOperands(); i != e; ++i)
if (Load.getNode() == Chain.getOperand(i).getNode())
Ops.push_back(Load.getOperand(0));
else
Ops.push_back(Chain.getOperand(i));
CurDAG->UpdateNodeOperands(Chain, &Ops[0], Ops.size());
SDValue Chain = CallSeqStart.getOperand(0);
if (Chain.getNode() == Load.getNode())
Ops.push_back(Load.getOperand(0));
else {
assert(Chain.getOpcode() == ISD::TokenFactor &&
"Unexpected CallSeqStart chain operand");
for (unsigned i = 0, e = Chain.getNumOperands(); i != e; ++i)
if (Chain.getOperand(i).getNode() == Load.getNode())
Ops.push_back(Load.getOperand(0));
else
Ops.push_back(Chain.getOperand(i));
SDValue NewChain =
CurDAG->getNode(ISD::TokenFactor, MVT::Other, &Ops[0], Ops.size());
Ops.clear();
Ops.push_back(NewChain);
}
for (unsigned i = 1, e = CallSeqStart.getNumOperands(); i != e; ++i)
Ops.push_back(CallSeqStart.getOperand(i));
CurDAG->UpdateNodeOperands(CallSeqStart, &Ops[0], Ops.size());
CurDAG->UpdateNodeOperands(Load, Call.getOperand(0),
Load.getOperand(1), Load.getOperand(2));
Ops.clear();
@ -468,7 +481,13 @@ static bool isCalleeLoad(SDValue Callee, SDValue &Chain) {
return false;
Chain = Chain.getOperand(0);
}
return Chain.getOperand(0).getNode() == Callee.getNode();
if (Chain.getOperand(0).getNode() == Callee.getNode())
return true;
if (Chain.getOperand(0).getOpcode() == ISD::TokenFactor &&
Callee.getValue(1).isOperandOf(Chain.getOperand(0).getNode()))
return true;
return false;
}

View File

@ -0,0 +1,45 @@
; RUN: llvm-as < %s | llc -mtriple=x86_64-apple-darwin | grep call | grep 560
; rdar://6522427
%"struct.clang::Action" = type { %"struct.clang::ActionBase" }
%"struct.clang::ActionBase" = type { i32 (...)** }
%"struct.clang::ActionBase::ActionResult<0u>" = type { i8*, i8 }
@NumTrials = internal global i32 10000000 ; <i32*> [#uses=2]
@llvm.used = appending global [1 x i8*] [ i8* bitcast (void (i8*, %"struct.clang::Action"*)* @_Z25RawPointerPerformanceTestPvRN5clang6ActionE to i8*) ], section "llvm.metadata" ; <[1 x i8*]*> [#uses=0]
define void @_Z25RawPointerPerformanceTestPvRN5clang6ActionE(i8* %Val, %"struct.clang::Action"* %Actions) nounwind {
entry:
%0 = alloca %"struct.clang::ActionBase::ActionResult<0u>", align 8 ; <%"struct.clang::ActionBase::ActionResult<0u>"*> [#uses=3]
%1 = load i32* @NumTrials, align 4 ; <i32> [#uses=1]
%2 = icmp eq i32 %1, 0 ; <i1> [#uses=1]
br i1 %2, label %return, label %bb.nph
bb.nph: ; preds = %entry
%3 = getelementptr %"struct.clang::Action"* %Actions, i64 0, i32 0, i32 0 ; <i32 (...)***> [#uses=1]
%mrv_gep = bitcast %"struct.clang::ActionBase::ActionResult<0u>"* %0 to i64* ; <i64*> [#uses=1]
%mrv_gep1 = getelementptr %"struct.clang::ActionBase::ActionResult<0u>"* %0, i64 0, i32 1 ; <i8*> [#uses=1]
%4 = bitcast i8* %mrv_gep1 to i64* ; <i64*> [#uses=1]
%5 = getelementptr %"struct.clang::ActionBase::ActionResult<0u>"* %0, i64 0, i32 0 ; <i8**> [#uses=1]
br label %bb
bb: ; preds = %bb, %bb.nph
%Trial.01 = phi i32 [ 0, %bb.nph ], [ %12, %bb ] ; <i32> [#uses=1]
%Val_addr.02 = phi i8* [ %Val, %bb.nph ], [ %11, %bb ] ; <i8*> [#uses=1]
%6 = load i32 (...)*** %3, align 8 ; <i32 (...)**> [#uses=1]
%7 = getelementptr i32 (...)** %6, i64 70 ; <i32 (...)**> [#uses=1]
%8 = load i32 (...)** %7, align 8 ; <i32 (...)*> [#uses=1]
%9 = bitcast i32 (...)* %8 to { i64, i64 } (%"struct.clang::Action"*, i8*)* ; <{ i64, i64 } (%"struct.clang::Action"*, i8*)*> [#uses=1]
%10 = call { i64, i64 } %9(%"struct.clang::Action"* %Actions, i8* %Val_addr.02) nounwind ; <{ i64, i64 }> [#uses=2]
%mrv_gr = extractvalue { i64, i64 } %10, 0 ; <i64> [#uses=1]
store i64 %mrv_gr, i64* %mrv_gep
%mrv_gr2 = extractvalue { i64, i64 } %10, 1 ; <i64> [#uses=1]
store i64 %mrv_gr2, i64* %4
%11 = load i8** %5, align 8 ; <i8*> [#uses=1]
%12 = add i32 %Trial.01, 1 ; <i32> [#uses=2]
%13 = load i32* @NumTrials, align 4 ; <i32> [#uses=1]
%14 = icmp ult i32 %12, %13 ; <i1> [#uses=1]
br i1 %14, label %bb, label %return
return: ; preds = %bb, %entry
ret void
}