[CodeGenPrepare] The instruction to be sunk should be inserted before its user in a block

In current implementation, the instruction to be sunk will be inserted before the target instruction without considering the def-use tree,
which may case Instruction does not dominate all uses error. We need to choose a suitable location to insert according to the use chain

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D107262

Author: huhu233

llvm/lib/CodeGen/CodeGenPrepare.cpp

@@ -6950,16 +6950,26 @@ bool CodeGenPrepare::tryToSinkFreeOperands(Instruction *I) {
   BasicBlock *TargetBB = I->getParent();
   bool Changed = false;
   SmallVector<Use *, 4> ToReplace;
+  Instruction *InsertPoint = I;
+  DenseMap<const Instruction *, unsigned long> InstOrdering;
+  unsigned long InstNumber = 0;
+  for (const auto &I : *TargetBB)
+    InstOrdering[&I] = InstNumber++;
+
   for (Use *U : reverse(OpsToSink)) {
     auto *UI = cast<Instruction>(U->get());
-    if (UI->getParent() == TargetBB || isa<PHINode>(UI))
+    if (isa<PHINode>(UI))
+      continue;
+    if (UI->getParent() == TargetBB) {
+      if (InstOrdering[UI] < InstOrdering[InsertPoint])
+        InsertPoint = UI;
       continue;
+    }
     ToReplace.push_back(U);
   }
 
   SetVector<Instruction *> MaybeDead;
   DenseMap<Instruction *, Instruction *> NewInstructions;
-  Instruction *InsertPoint = I;
   for (Use *U : ToReplace) {
     auto *UI = cast<Instruction>(U->get());
     Instruction *NI = UI->clone();

llvm/test/Transforms/CodeGenPrepare/AArch64/sink-free-instructions-inseltpoison.ll

@@ -9,13 +9,13 @@ define <8 x i16> @sink_zext(<8 x i8> %a, <8 x i8> %b, i1 %c) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[ZB_1:%.*]] = zext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP0:%.*]] = zext <8 x i8> [[A:%.*]] to <8 x i16>
+; CHECK-NEXT:    [[ZB_1:%.*]] = zext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[RES_1:%.*]] = add <8 x i16> [[TMP0]], [[ZB_1]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES_1]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[ZB_2:%.*]] = zext <8 x i8> [[B]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP1:%.*]] = zext <8 x i8> [[A]] to <8 x i16>
+; CHECK-NEXT:    [[ZB_2:%.*]] = zext <8 x i8> [[B]] to <8 x i16>
 ; CHECK-NEXT:    [[RES_2:%.*]] = sub <8 x i16> [[TMP1]], [[ZB_2]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES_2]]
 ;
@@ -39,13 +39,13 @@ define <8 x i16> @sink_sext(<8 x i8> %a, <8 x i8> %b, i1 %c) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[ZB_1:%.*]] = sext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP0:%.*]] = sext <8 x i8> [[A:%.*]] to <8 x i16>
+; CHECK-NEXT:    [[ZB_1:%.*]] = sext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[RES_1:%.*]] = add <8 x i16> [[TMP0]], [[ZB_1]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES_1]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[ZB_2:%.*]] = sext <8 x i8> [[B]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP1:%.*]] = sext <8 x i8> [[A]] to <8 x i16>
+; CHECK-NEXT:    [[ZB_2:%.*]] = sext <8 x i8> [[B]] to <8 x i16>
 ; CHECK-NEXT:    [[RES_2:%.*]] = sub <8 x i16> [[TMP1]], [[ZB_2]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES_2]]
 ;
@@ -69,8 +69,8 @@ define <8 x i16> @do_not_sink_nonfree_zext(<8 x i8> %a, <8 x i8> %b, i1 %c) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[ZB_1:%.*]] = sext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP0:%.*]] = sext <8 x i8> [[A:%.*]] to <8 x i16>
+; CHECK-NEXT:    [[ZB_1:%.*]] = sext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[RES_1:%.*]] = add <8 x i16> [[TMP0]], [[ZB_1]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES_1]]
 ; CHECK:       if.else:
@@ -96,8 +96,8 @@ define <8 x i16> @do_not_sink_nonfree_sext(<8 x i8> %a, <8 x i8> %b, i1 %c) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[ZB_1:%.*]] = sext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP0:%.*]] = sext <8 x i8> [[A:%.*]] to <8 x i16>
+; CHECK-NEXT:    [[ZB_1:%.*]] = sext <8 x i8> [[B:%.*]] to <8 x i16>
 ; CHECK-NEXT:    [[RES_1:%.*]] = add <8 x i16> [[TMP0]], [[ZB_1]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES_1]]
 ; CHECK:       if.else:
@@ -124,13 +124,13 @@ define <8 x i16> @sink_shufflevector_umull(<16 x i8> %a, <16 x i8> %b) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 undef, label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[S2:%.*]] = shufflevector <16 x i8> [[B:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
 ; CHECK-NEXT:    [[TMP0:%.*]] = shufflevector <16 x i8> [[A:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    [[S2:%.*]] = shufflevector <16 x i8> [[B:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
 ; CHECK-NEXT:    [[VMULL0:%.*]] = tail call <8 x i16> @llvm.aarch64.neon.umull.v8i16(<8 x i8> [[TMP0]], <8 x i8> [[S2]])
 ; CHECK-NEXT:    ret <8 x i16> [[VMULL0]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[S4:%.*]] = shufflevector <16 x i8> [[B]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
 ; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <16 x i8> [[A]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; CHECK-NEXT:    [[S4:%.*]] = shufflevector <16 x i8> [[B]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
 ; CHECK-NEXT:    [[VMULL1:%.*]] = tail call <8 x i16> @llvm.aarch64.neon.umull.v8i16(<8 x i8> [[TMP1]], <8 x i8> [[S4]])
 ; CHECK-NEXT:    ret <8 x i16> [[VMULL1]]
 ;
@@ -156,17 +156,17 @@ define <8 x i16> @sink_shufflevector_ext_subadd(<16 x i8> %a, <16 x i8> %b) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br i1 undef, label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[S2:%.*]] = shufflevector <16 x i8> [[B:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
-; CHECK-NEXT:    [[Z2:%.*]] = zext <8 x i8> [[S2]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP0:%.*]] = shufflevector <16 x i8> [[A:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
 ; CHECK-NEXT:    [[TMP1:%.*]] = zext <8 x i8> [[TMP0]] to <8 x i16>
+; CHECK-NEXT:    [[S2:%.*]] = shufflevector <16 x i8> [[B:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    [[Z2:%.*]] = zext <8 x i8> [[S2]] to <8 x i16>
 ; CHECK-NEXT:    [[RES1:%.*]] = add <8 x i16> [[TMP1]], [[Z2]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES1]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[S4:%.*]] = shufflevector <16 x i8> [[B]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
-; CHECK-NEXT:    [[Z4:%.*]] = sext <8 x i8> [[S4]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <16 x i8> [[A]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
 ; CHECK-NEXT:    [[TMP3:%.*]] = sext <8 x i8> [[TMP2]] to <8 x i16>
+; CHECK-NEXT:    [[S4:%.*]] = shufflevector <16 x i8> [[B]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; CHECK-NEXT:    [[Z4:%.*]] = sext <8 x i8> [[S4]] to <8 x i16>
 ; CHECK-NEXT:    [[RES2:%.*]] = sub <8 x i16> [[TMP3]], [[Z4]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES2]]
 ;
@@ -202,17 +202,17 @@ define <8 x i16> @sink_shufflevector_ext_subadd_multiuse(<16 x i8> %a, <16 x i8>
 ; CHECK-NEXT:    call void @user1(<8 x i16> [[Z3]])
 ; CHECK-NEXT:    br i1 undef, label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[S2:%.*]] = shufflevector <16 x i8> [[B:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
-; CHECK-NEXT:    [[Z2:%.*]] = zext <8 x i8> [[S2]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP0:%.*]] = shufflevector <16 x i8> [[A]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
 ; CHECK-NEXT:    [[TMP1:%.*]] = zext <8 x i8> [[TMP0]] to <8 x i16>
+; CHECK-NEXT:    [[S2:%.*]] = shufflevector <16 x i8> [[B:%.*]], <16 x i8> poison, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    [[Z2:%.*]] = zext <8 x i8> [[S2]] to <8 x i16>
 ; CHECK-NEXT:    [[RES1:%.*]] = add <8 x i16> [[TMP1]], [[Z2]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES1]]
 ; CHECK:       if.else:
-; CHECK-NEXT:    [[S4:%.*]] = shufflevector <16 x i8> [[B]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
-; CHECK-NEXT:    [[Z4:%.*]] = sext <8 x i8> [[S4]] to <8 x i16>
 ; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <16 x i8> [[A]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
 ; CHECK-NEXT:    [[TMP3:%.*]] = sext <8 x i8> [[TMP2]] to <8 x i16>
+; CHECK-NEXT:    [[S4:%.*]] = shufflevector <16 x i8> [[B]], <16 x i8> poison, <8 x i32> <i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
+; CHECK-NEXT:    [[Z4:%.*]] = sext <8 x i8> [[S4]] to <8 x i16>
 ; CHECK-NEXT:    [[RES2:%.*]] = sub <8 x i16> [[TMP3]], [[Z4]]
 ; CHECK-NEXT:    ret <8 x i16> [[RES2]]
 ;