Re-apply 97040 with fix. This survives a ppc self-host llvm-gcc bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97310 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 186 insertions, 35 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 7da7848930..0447e3b828 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4655,7 +4655,8 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
             DAG.DeleteNode(Trunc);
           }
           // Replace the uses of SRL with SETCC
-          DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
+          WorkListRemover DeadNodes(*this);
+          DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
           removeFromWorkList(N1.getNode());
           DAG.DeleteNode(N1.getNode());
           return SDValue(N, 0);   // Return N so it doesn't get rechecked!
@@ -4663,6 +4664,56 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
       }
     }
   }
+  
+  // Transform br(xor(x, y)) -> br(x != y)
+  // Transform br(xor(xor(x,y), 1)) -> br (x == y)
+  if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
+    SDNode *TheXor = N1.getNode();
+    SDValue Op0 = TheXor->getOperand(0);
+    SDValue Op1 = TheXor->getOperand(1);
+    if (Op0.getOpcode() == Op1.getOpcode()) {
+      // Avoid missing important xor optimizations.
+      SDValue Tmp = visitXOR(TheXor);
+      if (Tmp.getNode()) {
+        DEBUG(dbgs() << "\nReplacing.8 ";
+              TheXor->dump(&DAG);
+              dbgs() << "\nWith: ";
+              Tmp.getNode()->dump(&DAG);
+              dbgs() << '\n');
+        WorkListRemover DeadNodes(*this);
+        DAG.ReplaceAllUsesOfValueWith(N1, Tmp, &DeadNodes);
+        removeFromWorkList(TheXor);
+        DAG.DeleteNode(TheXor);
+        return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
+                           MVT::Other, Chain, Tmp, N2);
+      }
+    }
+
+    if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
+      bool Equal = false;
+      if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
+        if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
+            Op0.getOpcode() == ISD::XOR) {
+          TheXor = Op0.getNode();
+          Equal = true;
+        }
+
+      EVT SetCCVT = N1.getValueType();
+      if (LegalTypes)
+        SetCCVT = TLI.getSetCCResultType(SetCCVT);
+      SDValue SetCC = DAG.getSetCC(TheXor->getDebugLoc(),
+                                   SetCCVT,
+                                   Op0, Op1,
+                                   Equal ? ISD::SETEQ : ISD::SETNE);
+      // Replace the uses of XOR with SETCC
+      WorkListRemover DeadNodes(*this);
+      DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
+      removeFromWorkList(N1.getNode());
+      DAG.DeleteNode(N1.getNode());
+      return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
+                         MVT::Other, Chain, SetCC, N2);
+    }
+  }
 
   return SDValue();
 }
@@ -5012,7 +5063,7 @@ SDValue DAGCombiner::visitLOAD(SDNode *N) {
       assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
       if (N->hasNUsesOfValue(0, 0) && N->hasNUsesOfValue(0, 1)) {
         SDValue Undef = DAG.getUNDEF(N->getValueType(0));
-        DEBUG(dbgs() << "\nReplacing.6 ";
+        DEBUG(dbgs() << "\nReplacing.7 ";
               N->dump(&DAG);
               dbgs() << "\nWith: ";
               Undef.getNode()->dump(&DAG);
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index e88af4f3e0..2762ce8d57 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1775,7 +1775,7 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
         break;   // todo, be more careful with signed comparisons
       }
     } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
-                (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
+               (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
       EVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
       unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits();
       EVT ExtDstTy = N0.getValueType();
@@ -1809,22 +1809,21 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
                           Cond);
     } else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) &&
                 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
-      
       // SETCC (SETCC), [0|1], [EQ|NE]  -> SETCC
-      if (N0.getOpcode() == ISD::SETCC) {
+      if (N0.getOpcode() == ISD::SETCC &&
+          isTypeLegal(VT) && VT.bitsLE(N0.getValueType())) {
         bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getAPIntValue() != 1);
         if (TrueWhenTrue)
-          return N0;
-        
+          return DAG.getNode(ISD::TRUNCATE, dl, VT, N0);        
         // Invert the condition.
         ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
         CC = ISD::getSetCCInverse(CC, 
                                   N0.getOperand(0).getValueType().isInteger());
         return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
       }
-      
+
       if ((N0.getOpcode() == ISD::XOR ||
-            (N0.getOpcode() == ISD::AND && 
+           (N0.getOpcode() == ISD::AND && 
             N0.getOperand(0).getOpcode() == ISD::XOR &&
             N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
           isa<ConstantSDNode>(N0.getOperand(1)) &&
@@ -1847,9 +1846,36 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
                               N0.getOperand(0).getOperand(0),
                               N0.getOperand(1));
           }
+
           return DAG.getSetCC(dl, VT, Val, N1,
                               Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
         }
+      } else if (N1C->getAPIntValue() == 1 &&
+                 (VT == MVT::i1 ||
+                  getBooleanContents() == ZeroOrOneBooleanContent)) {
+        SDValue Op0 = N0;
+        if (Op0.getOpcode() == ISD::TRUNCATE)
+          Op0 = Op0.getOperand(0);
+
+        if ((Op0.getOpcode() == ISD::XOR) &&
+            Op0.getOperand(0).getOpcode() == ISD::SETCC &&
+            Op0.getOperand(1).getOpcode() == ISD::SETCC) {
+          // (xor (setcc), (setcc)) == / != 1 -> (setcc) != / == (setcc)
+          Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ;
+          return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1),
+                              Cond);
+        } else if (Op0.getOpcode() == ISD::AND &&
+                isa<ConstantSDNode>(Op0.getOperand(1)) &&
+                cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
+          // If this is (X&1) == / != 1, normalize it to (X&1) != / == 0.
+          if (Op0.getValueType() != VT)
+            Op0 = DAG.getNode(ISD::AND, dl, VT,
+                          DAG.getNode(ISD::TRUNCATE, dl, VT, Op0.getOperand(0)),
+                          DAG.getConstant(1, VT));
+          return DAG.getSetCC(dl, VT, Op0,
+                              DAG.getConstant(0, Op0.getValueType()),
+                              Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
+        }
       }
     }
     
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index eb0a995432..b0a1bff04c 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -5883,26 +5883,31 @@ SDValue X86TargetLowering::EmitCmp(SDValue Op0, SDValue Op1, unsigned X86CC,
 
 /// LowerToBT - Result of 'and' is compared against zero. Turn it into a BT node
 /// if it's possible.
-static SDValue LowerToBT(SDValue Op0, ISD::CondCode CC,
+static SDValue LowerToBT(SDValue And, ISD::CondCode CC,
                          DebugLoc dl, SelectionDAG &DAG) {
+  SDValue Op0 = And.getOperand(0);
+  SDValue Op1 = And.getOperand(1);
+  if (Op0.getOpcode() == ISD::TRUNCATE)
+    Op0 = Op0.getOperand(0);
+  if (Op1.getOpcode() == ISD::TRUNCATE)
+    Op1 = Op1.getOperand(0);
+
   SDValue LHS, RHS;
-  if (Op0.getOperand(1).getOpcode() == ISD::SHL) {
-    if (ConstantSDNode *Op010C =
-        dyn_cast<ConstantSDNode>(Op0.getOperand(1).getOperand(0)))
-      if (Op010C->getZExtValue() == 1) {
-        LHS = Op0.getOperand(0);
-        RHS = Op0.getOperand(1).getOperand(1);
+  if (Op1.getOpcode() == ISD::SHL) {
+    if (ConstantSDNode *And10C = dyn_cast<ConstantSDNode>(Op1.getOperand(0)))
+      if (And10C->getZExtValue() == 1) {
+        LHS = Op0;
+        RHS = Op1.getOperand(1);
       }
-  } else if (Op0.getOperand(0).getOpcode() == ISD::SHL) {
-    if (ConstantSDNode *Op000C =
-        dyn_cast<ConstantSDNode>(Op0.getOperand(0).getOperand(0)))
-      if (Op000C->getZExtValue() == 1) {
-        LHS = Op0.getOperand(1);
-        RHS = Op0.getOperand(0).getOperand(1);
+  } else if (Op0.getOpcode() == ISD::SHL) {
+    if (ConstantSDNode *And00C = dyn_cast<ConstantSDNode>(Op0.getOperand(0)))
+      if (And00C->getZExtValue() == 1) {
+        LHS = Op1;
+        RHS = Op0.getOperand(1);
       }
-  } else if (Op0.getOperand(1).getOpcode() == ISD::Constant) {
-    ConstantSDNode *AndRHS = cast<ConstantSDNode>(Op0.getOperand(1));
-    SDValue AndLHS = Op0.getOperand(0);
+  } else if (Op1.getOpcode() == ISD::Constant) {
+    ConstantSDNode *AndRHS = cast<ConstantSDNode>(Op1);
+    SDValue AndLHS = Op0;
     if (AndRHS->getZExtValue() == 1 && AndLHS.getOpcode() == ISD::SRL) {
       LHS = AndLHS.getOperand(0);
       RHS = AndLHS.getOperand(1);
@@ -5952,6 +5957,21 @@ SDValue X86TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) {
       return NewSetCC;
   }
 
+  // Look for "(setcc) == / != 1" to avoid unncessary setcc.
+  if (Op0.getOpcode() == X86ISD::SETCC &&
+      Op1.getOpcode() == ISD::Constant &&
+      (cast<ConstantSDNode>(Op1)->getZExtValue() == 1 ||
+       cast<ConstantSDNode>(Op1)->isNullValue()) &&
+      (CC == ISD::SETEQ || CC == ISD::SETNE)) {
+    X86::CondCode CCode = (X86::CondCode)Op0.getConstantOperandVal(0);
+    bool Invert = (CC == ISD::SETNE) ^
+      cast<ConstantSDNode>(Op1)->isNullValue();
+    if (Invert)
+      CCode = X86::GetOppositeBranchCondition(CCode);
+    return DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
+                       DAG.getConstant(CCode, MVT::i8), Op0.getOperand(1));
+  }
+
   bool isFP = Op.getOperand(1).getValueType().isFloatingPoint();
   unsigned X86CC = TranslateX86CC(CC, isFP, Op0, Op1, DAG);
   if (X86CC == X86::COND_INVALID)
diff --git a/test/CodeGen/X86/2010-02-23-DAGCombineBug.ll b/test/CodeGen/X86/2010-02-23-DAGCombineBug.ll
new file mode 100644
index 0000000000..6a58e9e551
--- /dev/null
+++ b/test/CodeGen/X86/2010-02-23-DAGCombineBug.ll
@@ -0,0 +1,18 @@
+; RUN: llc < %s -march=x86 | FileCheck %s
+
+define i32* @t() nounwind optsize ssp {
+entry:
+; CHECK: t:
+; CHECK: testl %eax, %eax
+; CHECK: js
+  %cmp = icmp slt i32 undef, 0                    ; <i1> [#uses=1]
+  %outsearch.0 = select i1 %cmp, i1 false, i1 true ; <i1> [#uses=1]
+  br i1 %outsearch.0, label %if.then27, label %if.else29
+
+if.then27:                                        ; preds = %entry
+  ret i32* undef
+
+if.else29:                                        ; preds = %entry
+  unreachable
+}
+
diff --git a/test/CodeGen/X86/critical-edge-split.ll b/test/CodeGen/X86/critical-edge-split.ll
index 4fe554de75..f29cbf323e 100644
--- a/test/CodeGen/X86/critical-edge-split.ll
+++ b/test/CodeGen/X86/critical-edge-split.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=i386-apple-darwin -tailcallopt=false -stats -info-output-file - | grep asm-printer | grep 31
+; RUN: llc < %s -mtriple=i386-apple-darwin -stats -info-output-file - | grep asm-printer | grep 29
 
 	%CC = type { %Register }
 	%II = type { %"struct.XX::II::$_74" }
diff --git a/test/CodeGen/X86/ins_subreg_coalesce-3.ll b/test/CodeGen/X86/ins_subreg_coalesce-3.ll
index 627edc51c1..8c1c409766 100644
--- a/test/CodeGen/X86/ins_subreg_coalesce-3.ll
+++ b/test/CodeGen/X86/ins_subreg_coalesce-3.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -march=x86-64 | grep mov | count 5
+; RUN: llc < %s -march=x86-64 | grep mov | count 3
 
 	%struct.COMPOSITE = type { i8, i16, i16 }
 	%struct.FILE = type { i8*, i32, i32, i16, i16, %struct.__sbuf, i32, i8*, i32 (i8*)*, i32 (i8*, i8*, i32)*, i64 (i8*, i64, i32)*, i32 (i8*, i8*, i32)*, %struct.__sbuf, %struct.__sFILEX*, i32, [3 x i8], [1 x i8], %struct.__sbuf, i32, i64 }
diff --git a/test/CodeGen/X86/trunc-to-bool.ll b/test/CodeGen/X86/trunc-to-bool.ll
index bfab1aef90..6062084106 100644
--- a/test/CodeGen/X86/trunc-to-bool.ll
+++ b/test/CodeGen/X86/trunc-to-bool.ll
@@ -3,13 +3,14 @@
 ; value and as the operand of a branch.
 ; RUN: llc < %s -march=x86 | FileCheck %s
 
-define i1 @test1(i32 %X) zeroext {
+define i1 @test1(i32 %X) zeroext nounwind {
     %Y = trunc i32 %X to i1
     ret i1 %Y
 }
+; CHECK: test1:
 ; CHECK: andl $1, %eax
 
-define i1 @test2(i32 %val, i32 %mask) {
+define i1 @test2(i32 %val, i32 %mask) nounwind {
 entry:
     %shifted = ashr i32 %val, %mask
     %anded = and i32 %shifted, 1
@@ -20,9 +21,10 @@ ret_true:
 ret_false:
     ret i1 false
 }
-; CHECK: testb $1, %al
+; CHECK: test2:
+; CHECK: btl %eax
 
-define i32 @test3(i8* %ptr) {
+define i32 @test3(i8* %ptr) nounwind {
     %val = load i8* %ptr
     %tmp = trunc i8 %val to i1
     br i1 %tmp, label %cond_true, label %cond_false
@@ -31,9 +33,10 @@ cond_true:
 cond_false:
     ret i32 42
 }
-; CHECK: testb $1, %al
+; CHECK: test3:
+; CHECK: testb $1, (%eax)
 
-define i32 @test4(i8* %ptr) {
+define i32 @test4(i8* %ptr) nounwind {
     %tmp = ptrtoint i8* %ptr to i1
     br i1 %tmp, label %cond_true, label %cond_false
 cond_true:
@@ -41,9 +44,10 @@ cond_true:
 cond_false:
     ret i32 42
 }
-; CHECK: testb $1, %al
+; CHECK: test4:
+; CHECK: testb $1, 4(%esp)
 
-define i32 @test6(double %d) {
+define i32 @test5(double %d) nounwind {
     %tmp = fptosi double %d to i1
     br i1 %tmp, label %cond_true, label %cond_false
 cond_true:
@@ -51,4 +55,5 @@ cond_true:
 cond_false:
     ret i32 42
 }
+; CHECK: test5:
 ; CHECK: testb $1
diff --git a/test/CodeGen/X86/xor-icmp.ll b/test/CodeGen/X86/xor-icmp.ll
index a6bdb13ec6..2d75c5d762 100644
--- a/test/CodeGen/X86/xor-icmp.ll
+++ b/test/CodeGen/X86/xor-icmp.ll
@@ -1,5 +1,6 @@
 ; RUN: llc < %s -march=x86    | FileCheck %s -check-prefix=X32
 ; RUN: llc < %s -march=x86-64 | FileCheck %s -check-prefix=X64
+; rdar://7367229
 
 define i32 @t(i32 %a, i32 %b) nounwind ssp {
 entry:
@@ -34,3 +35,33 @@ bb1:                                              ; preds = %entry
 declare i32 @foo(...)
 
 declare i32 @bar(...)
+
+define i32 @t2(i32 %x, i32 %y) nounwind ssp {
+; X32: t2:
+; X32: cmpl
+; X32: sete
+; X32: cmpl
+; X32: sete
+; X32-NOT: xor
+; X32: je
+
+; X64: t2:
+; X64: testl
+; X64: sete
+; X64: testl
+; X64: sete
+; X64-NOT: xor
+; X64: je
+entry:
+  %0 = icmp eq i32 %x, 0                          ; <i1> [#uses=1]
+  %1 = icmp eq i32 %y, 0                          ; <i1> [#uses=1]
+  %2 = xor i1 %1, %0                              ; <i1> [#uses=1]
+  br i1 %2, label %bb, label %return
+
+bb:                                               ; preds = %entry
+  %3 = tail call i32 (...)* @foo() nounwind       ; <i32> [#uses=0]
+  ret i32 undef
+
+return:                                           ; preds = %entry
+  ret i32 undef
+}