[llvm] 0722f3d - Revert rGb803294cf78714303db2d3647291a2308347ef23 : "[InstCombine] Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) (PR50183)"

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2021-07-14T11:48:37+01:00
New Revision: 0722f3d0fad16d2427acf66a591bf3597fd0e0d8

URL: https://github.com/llvm/llvm-project/commit/0722f3d0fad16d2427acf66a591bf3597fd0e0d8
DIFF: https://github.com/llvm/llvm-project/commit/0722f3d0fad16d2427acf66a591bf3597fd0e0d8.diff

LOG: Revert rGb803294cf78714303db2d3647291a2308347ef23 : "[InstCombine] Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) (PR50183)"

Missed some BPF test changes that need addressing

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
    llvm/test/Transforms/InstCombine/select-gep.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index fb9750d59e656..eadc826c7190d 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -2933,33 +2933,6 @@ Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
   if (Instruction *I = foldSelectExtConst(SI))
     return I;
 
-  // Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0))
-  // Fold (select C, Ptr, (gep Ptr, Idx)) -> (gep Ptr, (select C, 0, Idx))
-  auto SelectGepWithBase = [&](GetElementPtrInst *Gep, Value *Base,
-                               bool Swap) -> GetElementPtrInst * {
-    Value *Ptr = Gep->getPointerOperand();
-    if (Gep->getNumOperands() != 2 || Gep->getPointerOperand() != Base ||
-        !Gep->hasOneUse())
-      return nullptr;
-    Type *ElementType = Gep->getResultElementType();
-    Value *Idx = Gep->getOperand(1);
-    Value *NewT = Idx;
-    Value *NewF = Constant::getNullValue(Idx->getType());
-    if (Swap)
-      std::swap(NewT, NewF);
-    Value *NewSI =
-        Builder.CreateSelect(CondVal, NewT, NewF, SI.getName() + ".idx", &SI);
-    return Gep->isInBounds()
-               ? GetElementPtrInst::CreateInBounds(ElementType, Ptr, {NewSI})
-               : GetElementPtrInst::Create(ElementType, Ptr, {NewSI});
-  };
-  if (auto *TrueGep = dyn_cast<GetElementPtrInst>(TrueVal))
-    if (auto *NewGep = SelectGepWithBase(TrueGep, FalseVal, false))
-      return NewGep;
-  if (auto *FalseGep = dyn_cast<GetElementPtrInst>(FalseVal))
-    if (auto *NewGep = SelectGepWithBase(FalseGep, TrueVal, true))
-      return NewGep;
-
   // See if we can fold the select into one of our operands.
   if (SelType->isIntOrIntVectorTy() || SelType->isFPOrFPVectorTy()) {
     if (Instruction *FoldI = foldSelectIntoOp(SI, TrueVal, FalseVal))

diff  --git a/llvm/test/Transforms/InstCombine/select-gep.ll b/llvm/test/Transforms/InstCombine/select-gep.ll
index bba67091b3fa2..77710cee416d2 100644
--- a/llvm/test/Transforms/InstCombine/select-gep.ll
+++ b/llvm/test/Transforms/InstCombine/select-gep.ll
@@ -74,9 +74,9 @@ define i32* @test2(i32* %p, i64 %x, i64 %y) {
 ; PR50183
 define i32* @test2a(i32* %p, i64 %x, i64 %y) {
 ; CHECK-LABEL: @test2a(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[SELECT_IDX:%.*]] = select i1 [[CMP]], i64 [[X]], i64 0
-; CHECK-NEXT:    [[SELECT:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 [[SELECT_IDX]]
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y:%.*]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[GEP]], i32* [[P]]
 ; CHECK-NEXT:    ret i32* [[SELECT]]
 ;
   %gep = getelementptr inbounds i32, i32* %p, i64 %x
@@ -88,9 +88,9 @@ define i32* @test2a(i32* %p, i64 %x, i64 %y) {
 ; PR50183
 define i32* @test2b(i32* %p, i64 %x, i64 %y) {
 ; CHECK-LABEL: @test2b(
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[SELECT_IDX:%.*]] = select i1 [[CMP]], i64 0, i64 [[X]]
-; CHECK-NEXT:    [[SELECT:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 [[SELECT_IDX]]
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i32, i32* [[P:%.*]], i64 [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y:%.*]]
+; CHECK-NEXT:    [[SELECT:%.*]] = select i1 [[CMP]], i32* [[P]], i32* [[GEP]]
 ; CHECK-NEXT:    ret i32* [[SELECT]]
 ;
   %gep = getelementptr inbounds i32, i32* %p, i64 %x