From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 26 Jan 2009 18:43:34 +0000 (+0000)
Subject: Enhance logic in X86DAGToDAGISel::PreprocessForRMW which move load inside callseq_sta... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5b2e5893c62cac7f349b348400c669d40e2eeca2;p=oota-llvm.git

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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63022 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index c1d886c32f5..04ba430d2d6 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -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;
 }
 
 
diff --git a/test/CodeGen/X86/fold-call-3.ll b/test/CodeGen/X86/fold-call-3.ll
new file mode 100644
index 00000000000..824ae003da2
--- /dev/null
+++ b/test/CodeGen/X86/fold-call-3.ll
@@ -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
+}