[X86][SSE] Combine shuffle nodes with multiple uses if all the users are being combined.

Currently we only combine shuffle nodes if they have a single user to prevent us from causing code bloat by splitting the shuffles into several different combines.

We don't take into account that in some cases we will already have combined all the users during recursively calling up the shuffle tree.

This patch keeps a list of all the shuffle nodes that have been combined so far and permits combining of further shuffle nodes if all its users are in that list.

Differential Revision: https://reviews.llvm.org/D29399

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@294183 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index a512c44..4630541 100644 (file)
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -737,6 +737,10 @@ public:
     return false;
   }
 
+  /// Return true if all the users of N are contained in Nodes.
+  /// NOTE: Requires at least one match, but doesn't require them all.
+  static bool areOnlyUsersOf(ArrayRef<const SDNode *> Nodes, const SDNode *N);
+
   /// Return the number of values used by this operation.
   unsigned getNumOperands() const { return NumOperands; }
 

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 46dde01..dc5c8ba 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -7125,6 +7125,21 @@ bool SDNode::isOnlyUserOf(const SDNode *N) const {
   return Seen;
 }
 
+/// Return true if the only users of N are contained in Nodes.
+bool SDNode::areOnlyUsersOf(ArrayRef<const SDNode *> Nodes, const SDNode *N) {
+  bool Seen = false;
+  for (SDNode::use_iterator I = N->use_begin(), E = N->use_end(); I != E; ++I) {
+    SDNode *User = *I;
+    if (llvm::any_of(Nodes,
+                     [&User](const SDNode *Node) { return User == Node; }))
+      Seen = true;
+    else
+      return false;
+  }
+
+  return Seen;
+}
+
 /// isOperand - Return true if this node is an operand of N.
 ///
 bool SDValue::isOperandOf(const SDNode *N) const {

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index af06cd3..83b340a 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -27333,6 +27333,7 @@ static bool combineX86ShufflesConstants(const SmallVectorImpl<SDValue> &Ops,
 static bool combineX86ShufflesRecursively(ArrayRef<SDValue> SrcOps,
                                           int SrcOpIndex, SDValue Root,
                                           ArrayRef<int> RootMask,
+                                          ArrayRef<const SDNode*> SrcNodes,
                                           int Depth, bool HasVariableMask,
                                           SelectionDAG &DAG,
                                           TargetLowering::DAGCombinerInfo &DCI,
@@ -27469,11 +27470,20 @@ static bool combineX86ShufflesRecursively(ArrayRef<SDValue> SrcOps,
 
   HasVariableMask |= isTargetShuffleVariableMask(Op.getOpcode());
 
-  // See if we can recurse into each shuffle source op (if it's a target shuffle).
+  // Update the list of shuffle nodes that have been combined so far.
+  SmallVector<const SDNode *, 8> CombinedNodes(SrcNodes.begin(),
+                                               SrcNodes.end());
+  CombinedNodes.push_back(Op.getNode());
+
+  // See if we can recurse into each shuffle source op (if it's a target
+  // shuffle). The source op should only be combined if it either has a
+  // single use (i.e. current Op) or all its users have already been combined.
   for (int i = 0, e = Ops.size(); i < e; ++i)
-    if (Ops[i].getNode()->hasOneUse() || Op->isOnlyUserOf(Ops[i].getNode()))
-      if (combineX86ShufflesRecursively(Ops, i, Root, Mask, Depth + 1,
-                                        HasVariableMask, DAG, DCI, Subtarget))
+    if (Ops[i].getNode()->hasOneUse() ||
+        SDNode::areOnlyUsersOf(CombinedNodes, Ops[i].getNode()))
+      if (combineX86ShufflesRecursively(Ops, i, Root, Mask, CombinedNodes,
+                                        Depth + 1, HasVariableMask, DAG, DCI,
+                                        Subtarget))
         return true;
 
   // Attempt to constant fold all of the constant source ops.
@@ -28270,7 +28280,7 @@ static SDValue combineShuffle(SDNode *N, SelectionDAG &DAG,
     // a particular chain.
     SmallVector<int, 1> NonceMask; // Just a placeholder.
     NonceMask.push_back(0);
-    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask,
+    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask, {},
                                       /*Depth*/ 1, /*HasVarMask*/ false, DAG,
                                       DCI, Subtarget))
       return SDValue(); // This routine will use CombineTo to replace N.
@@ -30541,7 +30551,7 @@ static SDValue combineVectorShift(SDNode *N, SelectionDAG &DAG,
     SDValue Op(N, 0);
     SmallVector<int, 1> NonceMask; // Just a placeholder.
     NonceMask.push_back(0);
-    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask,
+    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask, {},
                                       /*Depth*/ 1, /*HasVarMask*/ false, DAG,
                                       DCI, Subtarget))
       return SDValue(); // This routine will use CombineTo to replace N.
@@ -30582,7 +30592,7 @@ static SDValue combineVectorInsert(SDNode *N, SelectionDAG &DAG,
   SDValue Op(N, 0);
   SmallVector<int, 1> NonceMask; // Just a placeholder.
   NonceMask.push_back(0);
-  combineX86ShufflesRecursively({Op}, 0, Op, NonceMask,
+  combineX86ShufflesRecursively({Op}, 0, Op, NonceMask, {},
                                 /*Depth*/ 1, /*HasVarMask*/ false, DAG,
                                 DCI, Subtarget);
   return SDValue();
@@ -30895,7 +30905,7 @@ static SDValue combineAnd(SDNode *N, SelectionDAG &DAG,
     SDValue Op(N, 0);
     SmallVector<int, 1> NonceMask; // Just a placeholder.
     NonceMask.push_back(0);
-    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask,
+    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask, {},
                                       /*Depth*/ 1, /*HasVarMask*/ false, DAG,
                                       DCI, Subtarget))
       return SDValue(); // This routine will use CombineTo to replace N.
@@ -33053,7 +33063,7 @@ static SDValue combineAndnp(SDNode *N, SelectionDAG &DAG,
     SDValue Op(N, 0);
     SmallVector<int, 1> NonceMask; // Just a placeholder.
     NonceMask.push_back(0);
-    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask,
+    if (combineX86ShufflesRecursively({Op}, 0, Op, NonceMask, {},
                                       /*Depth*/ 1, /*HasVarMask*/ false, DAG,
                                       DCI, Subtarget))
       return SDValue(); // This routine will use CombineTo to replace N.

diff --git a/test/CodeGen/X86/clear_upper_vector_element_bits.ll b/test/CodeGen/X86/clear_upper_vector_element_bits.ll
index 6d50048..e9fad72 100644 (file)
--- a/test/CodeGen/X86/clear_upper_vector_element_bits.ll
+++ b/test/CodeGen/X86/clear_upper_vector_element_bits.ll
@@ -260,13 +260,7 @@ define <16 x i8> @_clearupper16xi8a(<16 x i8>) nounwind {
 define <2 x i64> @_clearupper2xi64b(<2 x i64>) nounwind {
 ; SSE-LABEL: _clearupper2xi64b:
 ; SSE:       # BB#0:
-; SSE-NEXT:    xorps %xmm2, %xmm2
-; SSE-NEXT:    xorps %xmm1, %xmm1
-; SSE-NEXT:    shufps {{.*#+}} xmm1 = xmm1[0,0],xmm0[0,0]
-; SSE-NEXT:    shufps {{.*#+}} xmm1 = xmm1[2,0],xmm0[2,3]
-; SSE-NEXT:    shufps {{.*#+}} xmm2 = xmm2[0,0],xmm1[2,0]
-; SSE-NEXT:    shufps {{.*#+}} xmm1 = xmm1[0,1],xmm2[2,0]
-; SSE-NEXT:    movaps %xmm1, %xmm0
+; SSE-NEXT:    andps {{.*}}(%rip), %xmm0
 ; SSE-NEXT:    retq
 ;
 ; AVX1-LABEL: _clearupper2xi64b:

diff --git a/test/CodeGen/X86/select.ll b/test/CodeGen/X86/select.ll
index e6cce77..ae49a2c 100644 (file)
--- a/test/CodeGen/X86/select.ll
+++ b/test/CodeGen/X86/select.ll
@@ -639,9 +639,9 @@ CF244:
 
 define i16 @select_xor_1(i16 %A, i8 %cond) {
 ; CHECK-LABEL: select_xor_1:
-; MCU:    andl    $1, %edx\r
-; MCU-NEXT:    negl    %edx\r
-; MCU-NEXT:    andl    $43, %edx\r
+; MCU:    andl    $1, %edx
+; MCU-NEXT:    negl    %edx
+; MCU-NEXT:    andl    $43, %edx
 ; MCU-NEXT:    xorl    %edx, %eax
 entry:
  %and = and i8 %cond, 1

diff --git a/test/CodeGen/X86/vector-shuffle-combining-avx2.ll b/test/CodeGen/X86/vector-shuffle-combining-avx2.ll
index 4b23ba4..2f6267e 100644 (file)
--- a/test/CodeGen/X86/vector-shuffle-combining-avx2.ll
+++ b/test/CodeGen/X86/vector-shuffle-combining-avx2.ll
@@ -715,22 +715,12 @@ define <32 x i8> @combine_psrlq_pshufb(<4 x i64> %a0) {
 define <32 x i8> @combine_unpack_unpack_pshufb(<32 x i8> %a0) {
 ; X32-LABEL: combine_unpack_unpack_pshufb:
 ; X32:       # BB#0:
-; X32-NEXT:    vpshufd {{.*#+}} ymm1 = ymm0[0,0,0,0,4,4,4,4]
-; X32-NEXT:    vpshufd {{.*#+}} ymm2 = ymm0[1,1,2,3,5,5,6,7]
-; X32-NEXT:    vpshufd {{.*#+}} ymm0 = ymm0[2,3,2,3,6,7,6,7]
-; X32-NEXT:    vpunpcklbw {{.*#+}} ymm2 = ymm1[0],ymm2[0],ymm1[1],ymm2[1],ymm1[2],ymm2[2],ymm1[3],ymm2[3],ymm1[4],ymm2[4],ymm1[5],ymm2[5],ymm1[6],ymm2[6],ymm1[7],ymm2[7],ymm1[16],ymm2[16],ymm1[17],ymm2[17],ymm1[18],ymm2[18],ymm1[19],ymm2[19],ymm1[20],ymm2[20],ymm1[21],ymm2[21],ymm1[22],ymm2[22],ymm1[23],ymm2[23]
-; X32-NEXT:    vpunpcklbw {{.*#+}} ymm0 = ymm1[0],ymm0[0],ymm1[1],ymm0[1],ymm1[2],ymm0[2],ymm1[3],ymm0[3],ymm1[4],ymm0[4],ymm1[5],ymm0[5],ymm1[6],ymm0[6],ymm1[7],ymm0[7],ymm1[16],ymm0[16],ymm1[17],ymm0[17],ymm1[18],ymm0[18],ymm1[19],ymm0[19],ymm1[20],ymm0[20],ymm1[21],ymm0[21],ymm1[22],ymm0[22],ymm1[23],ymm0[23]
-; X32-NEXT:    vpunpcklbw {{.*#+}} ymm0 = ymm2[0],ymm0[0],ymm2[1],ymm0[1],ymm2[2],ymm0[2],ymm2[3],ymm0[3],ymm2[4],ymm0[4],ymm2[5],ymm0[5],ymm2[6],ymm0[6],ymm2[7],ymm0[7],ymm2[16],ymm0[16],ymm2[17],ymm0[17],ymm2[18],ymm0[18],ymm2[19],ymm0[19],ymm2[20],ymm0[20],ymm2[21],ymm0[21],ymm2[22],ymm0[22],ymm2[23],ymm0[23]
+; X32-NEXT:    vpshufb {{.*#+}} ymm0 = ymm0[0,0,4,8,1,1,5,9,2,2,6,10,3,3,7,11,16,16,20,24,17,17,21,25,18,18,22,26,19,19,23,27]
 ; X32-NEXT:    retl
 ;
 ; X64-LABEL: combine_unpack_unpack_pshufb:
 ; X64:       # BB#0:
-; X64-NEXT:    vpshufd {{.*#+}} ymm1 = ymm0[0,0,0,0,4,4,4,4]
-; X64-NEXT:    vpshufd {{.*#+}} ymm2 = ymm0[1,1,2,3,5,5,6,7]
-; X64-NEXT:    vpshufd {{.*#+}} ymm0 = ymm0[2,3,2,3,6,7,6,7]
-; X64-NEXT:    vpunpcklbw {{.*#+}} ymm2 = ymm1[0],ymm2[0],ymm1[1],ymm2[1],ymm1[2],ymm2[2],ymm1[3],ymm2[3],ymm1[4],ymm2[4],ymm1[5],ymm2[5],ymm1[6],ymm2[6],ymm1[7],ymm2[7],ymm1[16],ymm2[16],ymm1[17],ymm2[17],ymm1[18],ymm2[18],ymm1[19],ymm2[19],ymm1[20],ymm2[20],ymm1[21],ymm2[21],ymm1[22],ymm2[22],ymm1[23],ymm2[23]
-; X64-NEXT:    vpunpcklbw {{.*#+}} ymm0 = ymm1[0],ymm0[0],ymm1[1],ymm0[1],ymm1[2],ymm0[2],ymm1[3],ymm0[3],ymm1[4],ymm0[4],ymm1[5],ymm0[5],ymm1[6],ymm0[6],ymm1[7],ymm0[7],ymm1[16],ymm0[16],ymm1[17],ymm0[17],ymm1[18],ymm0[18],ymm1[19],ymm0[19],ymm1[20],ymm0[20],ymm1[21],ymm0[21],ymm1[22],ymm0[22],ymm1[23],ymm0[23]
-; X64-NEXT:    vpunpcklbw {{.*#+}} ymm0 = ymm2[0],ymm0[0],ymm2[1],ymm0[1],ymm2[2],ymm0[2],ymm2[3],ymm0[3],ymm2[4],ymm0[4],ymm2[5],ymm0[5],ymm2[6],ymm0[6],ymm2[7],ymm0[7],ymm2[16],ymm0[16],ymm2[17],ymm0[17],ymm2[18],ymm0[18],ymm2[19],ymm0[19],ymm2[20],ymm0[20],ymm2[21],ymm0[21],ymm2[22],ymm0[22],ymm2[23],ymm0[23]
+; X64-NEXT:    vpshufb {{.*#+}} ymm0 = ymm0[0,0,4,8,1,1,5,9,2,2,6,10,3,3,7,11,16,16,20,24,17,17,21,25,18,18,22,26,19,19,23,27]
 ; X64-NEXT:    retq
   %1 = shufflevector <32 x i8> %a0, <32 x i8> undef, <32 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3, i32 16, i32 17, i32 18, i32 19, i32 16, i32 17, i32 18, i32 19, i32 16, i32 17, i32 18, i32 19, i32 16, i32 17, i32 18, i32 19>
   %2 = shufflevector <32 x i8> %a0, <32 x i8> undef, <32 x i32> <i32 4, i32 5, i32 6, i32 7, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 20, i32 21, i32 22, i32 23, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>

diff --git a/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll b/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll
index 33b22b3..792496e 100644 (file)
--- a/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll
+++ b/test/CodeGen/X86/vector-shuffle-combining-ssse3.ll
@@ -555,31 +555,12 @@ define <16 x i8> @combine_unpckl_arg1_pshufb(<16 x i8> %a0, <16 x i8> %a1) {
 define <8 x i16> @shuffle_combine_unpack_insert(<8 x i16> %a0) {
 ; SSE-LABEL: shuffle_combine_unpack_insert:
 ; SSE:       # BB#0:
-; SSE-NEXT:    pextrw $2, %xmm0, %eax
-; SSE-NEXT:    pextrw $4, %xmm0, %ecx
-; SSE-NEXT:    movdqa %xmm0, %xmm2
-; SSE-NEXT:    pinsrw $4, %eax, %xmm2
-; SSE-NEXT:    movdqa %xmm0, %xmm1
-; SSE-NEXT:    pinsrw $2, %ecx, %xmm1
-; SSE-NEXT:    movdqa %xmm2, %xmm3
-; SSE-NEXT:    punpcklwd {{.*#+}} xmm3 = xmm3[0],xmm1[0],xmm3[1],xmm1[1],xmm3[2],xmm1[2],xmm3[3],xmm1[3]
-; SSE-NEXT:    movdqa %xmm3, %xmm1
-; SSE-NEXT:    punpckhwd {{.*#+}} xmm1 = xmm1[4],xmm2[4],xmm1[5],xmm2[5],xmm1[6],xmm2[6],xmm1[7],xmm2[7]
-; SSE-NEXT:    punpckhwd {{.*#+}} xmm3 = xmm3[4],xmm0[4],xmm3[5],xmm0[5],xmm3[6],xmm0[6],xmm3[7],xmm0[7]
-; SSE-NEXT:    punpcklwd {{.*#+}} xmm1 = xmm1[0],xmm3[0],xmm1[1],xmm3[1],xmm1[2],xmm3[2],xmm1[3],xmm3[3]
-; SSE-NEXT:    movdqa %xmm1, %xmm0
+; SSE-NEXT:    pshufb {{.*#+}} xmm0 = xmm0[4,5,4,5,4,5,8,9,8,9,8,9,10,11,10,11]
 ; SSE-NEXT:    retq
 ;
 ; AVX-LABEL: shuffle_combine_unpack_insert:
 ; AVX:       # BB#0:
-; AVX-NEXT:    vpextrw $2, %xmm0, %eax
-; AVX-NEXT:    vpextrw $4, %xmm0, %ecx
-; AVX-NEXT:    vpinsrw $4, %eax, %xmm0, %xmm1
-; AVX-NEXT:    vpinsrw $2, %ecx, %xmm0, %xmm2
-; AVX-NEXT:    vpunpcklwd {{.*#+}} xmm2 = xmm1[0],xmm2[0],xmm1[1],xmm2[1],xmm1[2],xmm2[2],xmm1[3],xmm2[3]
-; AVX-NEXT:    vpunpckhwd {{.*#+}} xmm1 = xmm2[4],xmm1[4],xmm2[5],xmm1[5],xmm2[6],xmm1[6],xmm2[7],xmm1[7]
-; AVX-NEXT:    vpunpckhwd {{.*#+}} xmm0 = xmm2[4],xmm0[4],xmm2[5],xmm0[5],xmm2[6],xmm0[6],xmm2[7],xmm0[7]
-; AVX-NEXT:    vpunpcklwd {{.*#+}} xmm0 = xmm1[0],xmm0[0],xmm1[1],xmm0[1],xmm1[2],xmm0[2],xmm1[3],xmm0[3]
+; AVX-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[4,5,4,5,4,5,8,9,8,9,8,9,10,11,10,11]
 ; AVX-NEXT:    retq
   %1 = extractelement <8 x i16> %a0, i32 2
   %2 = extractelement <8 x i16> %a0, i32 4