[Attributor] Use `changeUseAfterManifest` in AAValueSimplify manifest

[uenoku]

Summary

This patch makes AAValueSimplify use changeUsesAfterManifest in manifest. This will invoke simple folding after the manifest.

[jdoerfert]

LGTM. FWIW, the improved AAVAlueSimplify does fold on its own.

[uenoku]

In D71972#1798221, @jdoerfert wrote:

LGTM. FWIW, the improved AAVAlueSimplify does fold on its own.

Yes, I'm looking forward to seeing D68934 :).

llvm/include/llvm/Transforms/IPO/Attributor.h

if (V && (V->stripPointerCasts() == NV.stripPointerCasts() ||
               isa_and_nonnull<UndefValue>(V)))
       return false;
     assert((!V || V == &NV || isa<UndefValue>(NV)) &&
            "Use was registered twice for replacement with different values!");
     V = &NV;
     return true;
   }
 
+  /// Helper function to replace all uses of \p V with \p NV. Return true if
+  /// there is any change.
+  bool changeValueAfterManifest(Value &V, Value &NV) {
+    bool Changed = false;
+    for (auto &U : V.uses())
+      Changed |= changeUseAfterManifest(U, NV);
+
+    return Changed;
+  }
+
   /// Get pointer operand of memory accessing instruction. If \p I is
   /// not a memory accessing instruction, return nullptr. If \p AllowVolatile,
   /// is set to false and the instruction is volatile, return nullptr.
   static const Value *getPointerOperand(const Instruction *I,
                                         bool AllowVolatile) {
     if (auto *LI = dyn_cast<LoadInst>(I)) {
       if (!AllowVolatile && LI->isVolatile())
         return nullptr;

llvm/lib/Transforms/IPO/Attributor.cpp

if (auto *I = dyn_cast<Instruction>(&V))
         A.deleteAfterManifest(*I);
         return ChangeStatus::CHANGED;
       }
 
     if (V.use_empty())
       return ChangeStatus::UNCHANGED;
 
     UndefValue &UV = *UndefValue::get(V.getType());
-    bool AnyChange = false;
-    for (Use &U : V.uses())
-      AnyChange |= A.changeUseAfterManifest(U, UV);
+    bool AnyChange = A.changeValueAfterManifest(V, UV);
     return AnyChange ? ChangeStatus::CHANGED : ChangeStatus::UNCHANGED;
   }
 
   /// See AbstractAttribute::trackStatistics()
   void trackStatistics() const override {
     STATS_DECLTRACK_FLOATING_ATTR(IsDead)
   }
 };
if (!SimplifiedAssociatedValue.hasValue() ||
       return Changed;
 
     if (auto *C = dyn_cast<Constant>(SimplifiedAssociatedValue.getValue())) {
       // We can replace the AssociatedValue with the constant.
       Value &V = getAssociatedValue();
       if (!V.user_empty() && &V != C && V.getType() == C->getType()) {
         LLVM_DEBUG(dbgs() << "[Attributor][ValueSimplify] " << V << " -> " << *C
                           << "\n");
-        replaceAllInstructionUsesWith(V, *C);
+        A.changeValueAfterManifest(V, *C);
         Changed = ChangeStatus::CHANGED;
       }
     }
 
     return Changed | AAValueSimplify::manifest(A);
   }
 
   /// See AbstractState::indicatePessimisticFixpoint(...).

llvm/test/Transforms/Attributor/ArgumentPromotion/2008-07-02-array-indexing.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes
 ; RUN: opt -passes=attributor -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=3 -S < %s | FileCheck %s
 ; PR2498
 
 ; This test tries to convince CHECK about promoting the load from %A + 2,
 ; because there is a load of %A in the entry block
 define internal i32 @callee(i1 %C, i32* %A) {
 ; CHECK-LABEL: define {{[^@]+}}@callee
 ; CHECK-SAME: (i1 [[C:%.*]], i32* noalias nocapture nofree nonnull readonly dereferenceable(4) [[A:%.*]])
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[A_0:%.*]] = load i32, i32* null
-; CHECK-NEXT:    br i1 false, label [[T:%.*]], label [[F:%.*]]
+; CHECK-NEXT:    br label [[F:%.*]]
 ; CHECK:       T:
 ; CHECK-NEXT:    unreachable
 ; CHECK:       F:
 ; CHECK-NEXT:    [[A_2:%.*]] = getelementptr i32, i32* null, i32 2
 ; CHECK-NEXT:    [[R:%.*]] = load i32, i32* [[A_2]]
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
 entry:

llvm/test/Transforms/Attributor/ArgumentPromotion/control-flow.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes
 ; RUN: opt -S -passes='attributor' -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=2 < %s | FileCheck %s
 
 ; Don't promote around control flow.
 define internal i32 @callee(i1 %C, i32* %P) {
 ; CHECK-LABEL: define {{[^@]+}}@callee
 ; CHECK-SAME: (i1 [[C:%.*]], i32* noalias nocapture nofree readnone [[P:%.*]])
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    br i1 true, label [[T:%.*]], label [[F:%.*]]
+; CHECK-NEXT:    br label [[T:%.*]]
 ; CHECK:       T:
 ; CHECK-NEXT:    ret i32 17
 ; CHECK:       F:
 ; CHECK-NEXT:    unreachable
 ;
 entry:
   br i1 %C, label %T, label %F
 

llvm/test/Transforms/Attributor/ArgumentPromotion/control-flow2.ll

 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes
 ; RUN: opt -S -passes='attributor' -aa-pipeline='basic-aa' -attributor-disable=false -attributor-max-iterations-verify -attributor-max-iterations=9 < %s | FileCheck %s
 
 target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
 
 define internal i32 @callee(i1 %C, i32* %P) {
 ; CHECK-LABEL: define {{[^@]+}}@callee
 ; CHECK-SAME: (i1 [[C:%.*]], i32* noalias nocapture nofree nonnull readonly align 4 dereferenceable(4) [[P:%.*]])
-; CHECK-NEXT:    br i1 false, label [[T:%.*]], label [[F:%.*]]
+; CHECK-NEXT:    br label [[F:%.*]]
 ; CHECK:       T:
 ; CHECK-NEXT:    unreachable
 ; CHECK:       F:
-; CHECK-NEXT:    [[X:%.*]] = load i32, i32* [[P]], align 4
+; CHECK-NEXT:    [[X:%.*]] = load i32, i32* [[P:%.*]], align 4
 ; CHECK-NEXT:    ret i32 [[X]]
 ;
   br i1 %C, label %T, label %F
 
 T:              ; preds = %0
   ret i32 17
 
 F:              ; preds = %0

llvm/test/Transforms/Attributor/ArgumentPromotion/reserve-tbaa.ll

 @g = global i32 0, align 4
 @c = global i64 0, align 8
 @d = global i8 0, align 1
 
 define internal fastcc void @fn(i32* nocapture readonly %p1, i64* nocapture readonly %p2) {
 ; CHECK-LABEL: define {{[^@]+}}@fn
 ; CHECK-SAME: (i32* nocapture nofree nonnull readonly align 4 dereferenceable(4) [[P1:%.*]], i64* nocapture nofree nonnull readonly align 8 dereferenceable(8) [[P2:%.*]])
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TMP0:%.*]] = load i64, i64* @c, align 8, !tbaa !0
+; CHECK-NEXT:    [[TMP0:%.*]] = load i64, i64* undef, align 8, !tbaa !0
 ; CHECK-NEXT:    [[CONV:%.*]] = trunc i64 [[TMP0]] to i32
 ; CHECK-NEXT:    [[TMP1:%.*]] = load i32, i32* @g, align 4, !tbaa !4
 ; CHECK-NEXT:    [[CONV1:%.*]] = trunc i32 [[TMP1]] to i8
 ; CHECK-NEXT:    store i8 [[CONV1]], i8* @d, align 1, !tbaa !6
 ; CHECK-NEXT:    ret void
 ;
 entry:
   %0 = load i64, i64* %p2, align 8, !tbaa !1

llvm/test/Transforms/Attributor/value-simplify.ll

 f:
   %r = call i32 @ipccp1(i32 5)
   ret i32 %r
 }
 
 define internal i1 @ipccp2i(i1 %a) {
 ; CHECK-LABEL: define {{[^@]+}}@ipccp2i
 ; CHECK-SAME: (i1 returned [[A:%.*]]) #0
-; CHECK-NEXT:    br i1 true, label [[T:%.*]], label [[F:%.*]]
+; CHECK-NEXT:    br label %t
 ; CHECK:       t:
 ; CHECK-NEXT:    ret i1 true
 ; CHECK:       f:
 ; CHECK-NEXT:    unreachable
 ;
   br i1 %a, label %t, label %f
 t:
   ret i1 %a