LAA: handle 0 return from getPtrStride correctly (#124539)

artagnon · web-flow · commit 3a4376b8f906 · 2025-01-27T14:21:14.000Z
getPtrStride returns 0 when the PtrScev is loop-invariant, and this is
not an erroneous value: it returns std::nullopt to communicate that it
was not able to find a valid pointer stride. In analyzeLoop, we call
getPtrStride with a value_or(0) conflating the zero return value with
std::nullopt. Fix this, handling loop-invariant loads correctly.
diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1438,7 +1438,7 @@ llvm::getPtrStride(PredicatedScalarEvolution &PSE, Type *AccessTy, Value *Ptr,
                    bool Assume, bool ShouldCheckWrap) {
   const SCEV *PtrScev = replaceSymbolicStrideSCEV(PSE, StridesMap, Ptr);
   if (PSE.getSE()->isLoopInvariant(PtrScev, Lp))
-    return {0};
+    return 0;
 
   Type *Ty = Ptr->getType();
   assert(Ty->isPointerTy() && "Unexpected non-ptr");
@@ -2593,7 +2593,7 @@ bool LoopAccessInfo::analyzeLoop(AAResults *AA, const LoopInfo *LI,
     bool IsReadOnlyPtr = false;
     Type *AccessTy = getLoadStoreType(LD);
     if (Seen.insert({Ptr, AccessTy}).second ||
-        !getPtrStride(*PSE, LD->getType(), Ptr, TheLoop, SymbolicStrides).value_or(0)) {
+        !getPtrStride(*PSE, AccessTy, Ptr, TheLoop, SymbolicStrides)) {
       ++NumReads;
       IsReadOnlyPtr = true;
     }
diff --git a/llvm/test/Analysis/LoopAccessAnalysis/pointer-phis.ll b/llvm/test/Analysis/LoopAccessAnalysis/pointer-phis.ll
@@ -501,14 +501,6 @@ define void @phi_load_store_memdep_check(i1 %c, ptr %A, ptr %B, ptr %C) {
 ; CHECK-NEXT:            %lv3 = load i16, ptr %c.sink, align 2 ->
 ; CHECK-NEXT:            store i16 %add, ptr %c.sink, align 1
 ; CHECK-EMPTY:
-; CHECK-NEXT:        Unknown:
-; CHECK-NEXT:            %lv = load i16, ptr %A, align 1 ->
-; CHECK-NEXT:            store i16 %lv, ptr %A, align 1
-; CHECK-EMPTY:
-; CHECK-NEXT:        Unknown:
-; CHECK-NEXT:            store i16 %lv, ptr %A, align 1 ->
-; CHECK-NEXT:            %lv2 = load i16, ptr %A, align 1
-; CHECK-EMPTY:
 ; CHECK-NEXT:      Run-time memory checks:
 ; CHECK-NEXT:      Check 0:
 ; CHECK-NEXT:        Comparing group ([[GRP10:0x[0-9a-f]+]]):
diff --git a/llvm/test/Transforms/LoopDistribute/pointer-phi-in-loop.ll b/llvm/test/Transforms/LoopDistribute/pointer-phi-in-loop.ll
@@ -3,26 +3,73 @@
 
 ; Testcases inspired by PR50296, PR50288.
 
-define void @phi_load_store_distribute(i1 %c, ptr %A, ptr %B, ptr %C) {
+define void @phi_load_store_distribute(i1 %cond, ptr %A, ptr %B, ptr %C) {
 ; CHECK-LABEL: @phi_load_store_distribute(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
-; CHECK:       for.body:
-; CHECK-NEXT:    [[IV:%.*]] = phi i16 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[IF_END:%.*]] ]
-; CHECK-NEXT:    [[LV:%.*]] = load i16, ptr [[A:%.*]], align 1
+; CHECK:       for.body.lver.check:
+; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 2
+; CHECK-NEXT:    [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[C:%.*]], i64 2
+; CHECK-NEXT:    [[SCEVGEP2:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 2
+; CHECK-NEXT:    [[BOUND0:%.*]] = icmp ult ptr [[A]], [[SCEVGEP1]]
+; CHECK-NEXT:    [[BOUND1:%.*]] = icmp ult ptr [[C]], [[SCEVGEP]]
+; CHECK-NEXT:    [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
+; CHECK-NEXT:    [[BOUND03:%.*]] = icmp ult ptr [[A]], [[SCEVGEP2]]
+; CHECK-NEXT:    [[BOUND14:%.*]] = icmp ult ptr [[B]], [[SCEVGEP]]
+; CHECK-NEXT:    [[FOUND_CONFLICT5:%.*]] = and i1 [[BOUND03]], [[BOUND14]]
+; CHECK-NEXT:    [[CONFLICT_RDX:%.*]] = or i1 [[FOUND_CONFLICT]], [[FOUND_CONFLICT5]]
+; CHECK-NEXT:    br i1 [[CONFLICT_RDX]], label [[ENTRY:%.*]], label [[FOR_BODY_PH_LDIST1:%.*]]
+; CHECK:       for.body.ph.lver.orig:
+; CHECK-NEXT:    br label [[FOR_BODY_LVER_ORIG:%.*]]
+; CHECK:       for.body.lver.orig:
+; CHECK-NEXT:    [[IV:%.*]] = phi i16 [ 0, [[ENTRY]] ], [ [[IV_NEXT:%.*]], [[IF_END:%.*]] ]
+; CHECK-NEXT:    [[LV:%.*]] = load i16, ptr [[A]], align 1
 ; CHECK-NEXT:    store i16 [[LV]], ptr [[A]], align 1
-; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF_THEN:%.*]], label [[IF_END]]
-; CHECK:       if.then:
+; CHECK-NEXT:    br i1 [[COND:%.*]], label [[IF_THEN:%.*]], label [[IF_END]]
+; CHECK:       if.then.lver.orig:
 ; CHECK-NEXT:    [[LV2:%.*]] = load i16, ptr [[A]], align 1
 ; CHECK-NEXT:    br label [[IF_END]]
+; CHECK:       if.end.lver.orig:
+; CHECK-NEXT:    [[C_SINK_LVER_ORIG:%.*]] = phi ptr [ [[B]], [[IF_THEN]] ], [ [[C]], [[FOR_BODY_LVER_ORIG]] ]
+; CHECK-NEXT:    [[LV3_LVER_ORIG:%.*]] = load i16, ptr [[C_SINK_LVER_ORIG]], align 2
+; CHECK-NEXT:    [[ADD_LVER_ORIG:%.*]] = add i16 [[LV3_LVER_ORIG]], 10
+; CHECK-NEXT:    store i16 [[ADD_LVER_ORIG]], ptr [[C_SINK_LVER_ORIG]], align 1
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i16 [[IV]], 1
+; CHECK-NEXT:    [[TOBOOL_NOT_LVER_ORIG:%.*]] = icmp eq i16 [[IV_NEXT]], 1000
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT_LVER_ORIG]], label [[FOR_END_LOOPEXIT_LOOPEXIT:%.*]], label [[FOR_BODY_LVER_ORIG]]
+; CHECK:       for.body.ph.ldist1:
+; CHECK-NEXT:    br label [[FOR_BODY_LDIST1:%.*]]
+; CHECK:       for.body.ldist1:
+; CHECK-NEXT:    [[IV_LDIST1:%.*]] = phi i16 [ 0, [[FOR_BODY_PH_LDIST1]] ], [ [[IV_NEXT_LDIST1:%.*]], [[IF_END_LDIST1:%.*]] ]
+; CHECK-NEXT:    [[LV_LDIST1:%.*]] = load i16, ptr [[A]], align 1, !alias.scope [[META0:![0-9]+]], !noalias [[META3:![0-9]+]]
+; CHECK-NEXT:    store i16 [[LV_LDIST1]], ptr [[A]], align 1, !alias.scope [[META0]], !noalias [[META3]]
+; CHECK-NEXT:    br i1 [[COND]], label [[IF_THEN_LDIST1:%.*]], label [[IF_END_LDIST1]]
+; CHECK:       if.then.ldist1:
+; CHECK-NEXT:    [[LV2_LDIST1:%.*]] = load i16, ptr [[A]], align 1, !alias.scope [[META0]], !noalias [[META3]]
+; CHECK-NEXT:    br label [[IF_END_LDIST1]]
+; CHECK:       if.end.ldist1:
+; CHECK-NEXT:    [[IV_NEXT_LDIST1]] = add nuw nsw i16 [[IV_LDIST1]], 1
+; CHECK-NEXT:    [[TOBOOL_NOT_LDIST1:%.*]] = icmp eq i16 [[IV_NEXT_LDIST1]], 1000
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT_LDIST1]], label [[FOR_BODY_PH:%.*]], label [[FOR_BODY_LDIST1]]
+; CHECK:       for.body.ph:
+; CHECK-NEXT:    br label [[FOR_BODY1:%.*]]
+; CHECK:       for.body:
+; CHECK-NEXT:    [[IV1:%.*]] = phi i16 [ 0, [[FOR_BODY_PH]] ], [ [[IV_NEXT1:%.*]], [[IF_END1:%.*]] ]
+; CHECK-NEXT:    br i1 [[COND]], label [[IF_THEN1:%.*]], label [[IF_END1]]
+; CHECK:       if.then:
+; CHECK-NEXT:    br label [[IF_END1]]
 ; CHECK:       if.end:
-; CHECK-NEXT:    [[C_SINK:%.*]] = phi ptr [ [[B:%.*]], [[IF_THEN]] ], [ [[C:%.*]], [[FOR_BODY]] ]
+; CHECK-NEXT:    [[C_SINK:%.*]] = phi ptr [ [[B]], [[IF_THEN1]] ], [ [[C]], [[FOR_BODY1]] ]
 ; CHECK-NEXT:    [[LV3:%.*]] = load i16, ptr [[C_SINK]], align 2
 ; CHECK-NEXT:    [[ADD:%.*]] = add i16 [[LV3]], 10
 ; CHECK-NEXT:    store i16 [[ADD]], ptr [[C_SINK]], align 1
-; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i16 [[IV]], 1
-; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i16 [[IV_NEXT]], 1000
-; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[FOR_END_LOOPEXIT:%.*]], label [[FOR_BODY]]
+; CHECK-NEXT:    [[IV_NEXT1]] = add nuw nsw i16 [[IV1]], 1
+; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i16 [[IV_NEXT1]], 1000
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[FOR_END_LOOPEXIT_LOOPEXIT6:%.*]], label [[FOR_BODY1]]
+; CHECK:       for.end.loopexit.loopexit:
+; CHECK-NEXT:    br label [[FOR_END_LOOPEXIT:%.*]]
+; CHECK:       for.end.loopexit.loopexit6:
+; CHECK-NEXT:    br label [[FOR_END_LOOPEXIT]]
 ; CHECK:       for.end.loopexit:
 ; CHECK-NEXT:    ret void
 ;
@@ -33,7 +80,7 @@ for.body:                                         ; preds = %if.end, %entry
   %iv = phi i16 [ 0, %entry ], [ %iv.next, %if.end ]
   %lv = load i16, ptr %A, align 1
   store i16 %lv, ptr %A, align 1
-  br i1 %c, label %if.then, label %if.end
+  br i1 %cond, label %if.then, label %if.end
 
 if.then:                                          ; preds = %for.body
   %lv2 = load i16, ptr %A, align 1
@@ -55,66 +102,21 @@ for.end.loopexit:                                 ; preds = %if.end
 define void @phi_load_distribute(i1 %cond, ptr %A, ptr %B, ptr %C) {
 ; CHECK-LABEL: @phi_load_distribute(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    br label [[FOR_BODY_LVER_CHECK:%.*]]
-; CHECK:       for.body.lver.check:
-; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 2
-; CHECK-NEXT:    [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[C:%.*]], i64 2
-; CHECK-NEXT:    [[SCEVGEP2:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 2
-; CHECK-NEXT:    [[BOUND0:%.*]] = icmp ult ptr [[A]], [[SCEVGEP1]]
-; CHECK-NEXT:    [[BOUND1:%.*]] = icmp ult ptr [[C]], [[SCEVGEP]]
-; CHECK-NEXT:    [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
-; CHECK-NEXT:    [[BOUND03:%.*]] = icmp ult ptr [[A]], [[SCEVGEP2]]
-; CHECK-NEXT:    [[BOUND14:%.*]] = icmp ult ptr [[B]], [[SCEVGEP]]
-; CHECK-NEXT:    [[FOUND_CONFLICT5:%.*]] = and i1 [[BOUND03]], [[BOUND14]]
-; CHECK-NEXT:    [[CONFLICT_RDX:%.*]] = or i1 [[FOUND_CONFLICT]], [[FOUND_CONFLICT5]]
-; CHECK-NEXT:    br i1 [[CONFLICT_RDX]], label [[FOR_BODY_PH_LVER_ORIG:%.*]], label [[FOR_BODY_PH_LDIST1:%.*]]
-; CHECK:       for.body.ph.lver.orig:
 ; CHECK-NEXT:    br label [[FOR_BODY_LVER_ORIG:%.*]]
-; CHECK:       for.body.lver.orig:
-; CHECK-NEXT:    [[IV_LVER_ORIG:%.*]] = phi i16 [ 0, [[FOR_BODY_PH_LVER_ORIG]] ], [ [[IV_NEXT_LVER_ORIG:%.*]], [[IF_END_LVER_ORIG:%.*]] ]
-; CHECK-NEXT:    [[LV_LVER_ORIG:%.*]] = load i16, ptr [[A]], align 1
+; CHECK:       for.body:
+; CHECK-NEXT:    [[IV_LVER_ORIG:%.*]] = phi i16 [ 0, [[FOR_BODY_PH_LVER_ORIG:%.*]] ], [ [[IV_NEXT_LVER_ORIG:%.*]], [[IF_END_LVER_ORIG:%.*]] ]
+; CHECK-NEXT:    [[LV_LVER_ORIG:%.*]] = load i16, ptr [[A:%.*]], align 1
 ; CHECK-NEXT:    store i16 [[LV_LVER_ORIG]], ptr [[A]], align 1
 ; CHECK-NEXT:    br i1 [[COND:%.*]], label [[IF_THEN_LVER_ORIG:%.*]], label [[IF_END_LVER_ORIG]]
-; CHECK:       if.then.lver.orig:
-; CHECK-NEXT:    [[LV2_LVER_ORIG:%.*]] = load i16, ptr [[A]], align 1
-; CHECK-NEXT:    br label [[IF_END_LVER_ORIG]]
-; CHECK:       if.end.lver.orig:
-; CHECK-NEXT:    [[C_SINK_LVER_ORIG:%.*]] = phi ptr [ [[B]], [[IF_THEN_LVER_ORIG]] ], [ [[C]], [[FOR_BODY_LVER_ORIG]] ]
-; CHECK-NEXT:    [[LV3_LVER_ORIG:%.*]] = load i16, ptr [[C_SINK_LVER_ORIG]], align 2
-; CHECK-NEXT:    [[IV_NEXT_LVER_ORIG]] = add nuw nsw i16 [[IV_LVER_ORIG]], 1
-; CHECK-NEXT:    [[TOBOOL_NOT_LVER_ORIG:%.*]] = icmp eq i16 [[IV_NEXT_LVER_ORIG]], 1000
-; CHECK-NEXT:    br i1 [[TOBOOL_NOT_LVER_ORIG]], label [[FOR_END_LOOPEXIT_LOOPEXIT:%.*]], label [[FOR_BODY_LVER_ORIG]]
-; CHECK:       for.body.ph.ldist1:
-; CHECK-NEXT:    br label [[FOR_BODY_LDIST1:%.*]]
-; CHECK:       for.body.ldist1:
-; CHECK-NEXT:    [[IV_LDIST1:%.*]] = phi i16 [ 0, [[FOR_BODY_PH_LDIST1]] ], [ [[IV_NEXT_LDIST1:%.*]], [[IF_END_LDIST1:%.*]] ]
-; CHECK-NEXT:    [[LV_LDIST1:%.*]] = load i16, ptr [[A]], align 1, !alias.scope [[META0:![0-9]+]], !noalias [[META3:![0-9]+]]
-; CHECK-NEXT:    store i16 [[LV_LDIST1]], ptr [[A]], align 1, !alias.scope [[META0]], !noalias [[META3]]
-; CHECK-NEXT:    br i1 [[COND]], label [[IF_THEN_LDIST1:%.*]], label [[IF_END_LDIST1]]
-; CHECK:       if.then.ldist1:
-; CHECK-NEXT:    [[LV2_LDIST1:%.*]] = load i16, ptr [[A]], align 1, !alias.scope [[META0]], !noalias [[META3]]
-; CHECK-NEXT:    br label [[IF_END_LDIST1]]
-; CHECK:       if.end.ldist1:
-; CHECK-NEXT:    [[IV_NEXT_LDIST1]] = add nuw nsw i16 [[IV_LDIST1]], 1
-; CHECK-NEXT:    [[TOBOOL_NOT_LDIST1:%.*]] = icmp eq i16 [[IV_NEXT_LDIST1]], 1000
-; CHECK-NEXT:    br i1 [[TOBOOL_NOT_LDIST1]], label [[FOR_BODY_PH:%.*]], label [[FOR_BODY_LDIST1]]
-; CHECK:       for.body.ph:
-; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
-; CHECK:       for.body:
-; CHECK-NEXT:    [[IV:%.*]] = phi i16 [ 0, [[FOR_BODY_PH]] ], [ [[IV_NEXT:%.*]], [[IF_END:%.*]] ]
-; CHECK-NEXT:    br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_END]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    br label [[IF_END]]
+; CHECK-NEXT:    [[LV2:%.*]] = load i16, ptr [[A]], align 1
+; CHECK-NEXT:    br label [[IF_END_LVER_ORIG]]
 ; CHECK:       if.end:
-; CHECK-NEXT:    [[C_SINK:%.*]] = phi ptr [ [[B]], [[IF_THEN]] ], [ [[C]], [[FOR_BODY]] ]
+; CHECK-NEXT:    [[C_SINK:%.*]] = phi ptr [ [[B:%.*]], [[IF_THEN_LVER_ORIG]] ], [ [[C:%.*]], [[FOR_BODY_LVER_ORIG]] ]
 ; CHECK-NEXT:    [[LV3:%.*]] = load i16, ptr [[C_SINK]], align 2
-; CHECK-NEXT:    [[IV_NEXT]] = add nuw nsw i16 [[IV]], 1
-; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i16 [[IV_NEXT]], 1000
-; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[FOR_END_LOOPEXIT_LOOPEXIT6:%.*]], label [[FOR_BODY]]
-; CHECK:       for.end.loopexit.loopexit:
-; CHECK-NEXT:    br label [[FOR_END_LOOPEXIT:%.*]]
-; CHECK:       for.end.loopexit.loopexit6:
-; CHECK-NEXT:    br label [[FOR_END_LOOPEXIT]]
+; CHECK-NEXT:    [[IV_NEXT_LVER_ORIG]] = add nuw nsw i16 [[IV_LVER_ORIG]], 1
+; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i16 [[IV_NEXT_LVER_ORIG]], 1000
+; CHECK-NEXT:    br i1 [[TOBOOL_NOT]], label [[FOR_END_LOOPEXIT:%.*]], label [[FOR_BODY_LVER_ORIG]]
 ; CHECK:       for.end.loopexit:
 ; CHECK-NEXT:    ret void
 ;
diff --git a/llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/loop-distribute.ll b/llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/loop-distribute.ll
@@ -1,15 +1,15 @@
 ; RUN: opt -passes=loop-distribute -enable-loop-distribute \
 ; RUN:   -debug-only=loop-distribute -disable-output 2>&1 %s | FileCheck %s
 
-define void @ldist(i1 %c, ptr %A, ptr %B, ptr %C) {
+define void @ldist(i1 %cond, ptr %A, ptr %B, ptr %C) {
 entry:
   br label %for.body
 
 for.body:                                         ; preds = %if.end, %entry
   %iv = phi i16 [ 0, %entry ], [ %iv.next, %if.end ]
   %lv = load i16, ptr %A, align 1
   store i16 %lv, ptr %A, align 1
-  br i1 %c, label %if.then, label %if.end
+  br i1 %cond, label %if.then, label %if.end
 
 if.then:                                          ; preds = %for.body
   %lv2 = load i16, ptr %A, align 1
@@ -18,6 +18,8 @@ if.then:                                          ; preds = %for.body
 if.end:                                           ; preds = %if.then, %for.body
   %c.sink = phi ptr [ %B, %if.then ], [ %C, %for.body ]
   %lv3 = load i16, ptr %c.sink
+  %add = add i16 %lv3, 10
+  store i16 %add, ptr %c.sink, align 1
   %iv.next = add nuw nsw i16 %iv, 1
   %tobool.not = icmp eq i16 %iv.next, 1000
   br i1 %tobool.not, label %for.end.loopexit, label %for.body
diff --git a/llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/loop-distribute.ll.expected b/llvm/test/tools/UpdateTestChecks/update_analyze_test_checks/Inputs/loop-distribute.ll.expected
@@ -2,51 +2,55 @@
 ; RUN: opt -passes=loop-distribute -enable-loop-distribute \
 ; RUN:   -debug-only=loop-distribute -disable-output 2>&1 %s | FileCheck %s
 
-define void @ldist(i1 %c, ptr %A, ptr %B, ptr %C) {
+define void @ldist(i1 %cond, ptr %A, ptr %B, ptr %C) {
 ; CHECK-LABEL: 'ldist'
 ; CHECK-NEXT:  LDist: Found a candidate loop: for.body
 ; CHECK-NEXT:  LDist: Backward dependences:
 ; CHECK-NEXT:    Unknown:
-; CHECK-NEXT:        %lv = load i16, ptr %A, align 1 ->
-; CHECK-NEXT:        store i16 %lv, ptr %A, align 1
+; CHECK-NEXT:        %lv3 = load i16, ptr %c.sink, align 2 ->
+; CHECK-NEXT:        store i16 %add, ptr %c.sink, align 1
 ; CHECK-NEXT:    Unknown:
-; CHECK-NEXT:        store i16 %lv, ptr %A, align 1 ->
-; CHECK-NEXT:        %lv2 = load i16, ptr %A, align 1
+; CHECK-NEXT:        %lv3 = load i16, ptr %c.sink, align 2 ->
+; CHECK-NEXT:        store i16 %add, ptr %c.sink, align 1
 ; CHECK-NEXT:  LDist: Seeded partitions:
-; CHECK-NEXT:  LDist: Partition 0: (cycle)
+; CHECK-NEXT:  LDist: Partition 0:
 ; CHECK-NEXT:    for.body: %lv = load i16, ptr %A, align 1
-; CHECK-NEXT:    for.body: store i16 %lv, ptr %A, align 1
-; CHECK-NEXT:    if.then: %lv2 = load i16, ptr %A, align 1
 ; CHECK-NEXT:  LDist: Partition 1:
-; CHECK-NEXT:    if.end: %lv3 = load i16, ptr %c.sink, align 2
+; CHECK-NEXT:    for.body: store i16 %lv, ptr %A, align 1
 ; CHECK-NEXT:  LDist: Partition 2:
+; CHECK-NEXT:    if.then: %lv2 = load i16, ptr %A, align 1
+; CHECK-NEXT:  LDist: Partition 3: (cycle)
 ; CHECK-NEXT:    if.end: %lv3 = load i16, ptr %c.sink, align 2
+; CHECK-NEXT:    if.end: store i16 %add, ptr %c.sink, align 1
 ; CHECK-NEXT:  LDist: Merged partitions:
-; CHECK-NEXT:  LDist: Partition 0: (cycle)
+; CHECK-NEXT:  LDist: Partition 0:
 ; CHECK-NEXT:    for.body: %lv = load i16, ptr %A, align 1
 ; CHECK-NEXT:    for.body: store i16 %lv, ptr %A, align 1
 ; CHECK-NEXT:    if.then: %lv2 = load i16, ptr %A, align 1
-; CHECK-NEXT:  LDist: Partition 1:
+; CHECK-NEXT:  LDist: Partition 1: (cycle)
 ; CHECK-NEXT:    if.end: %lv3 = load i16, ptr %c.sink, align 2
+; CHECK-NEXT:    if.end: store i16 %add, ptr %c.sink, align 1
 ; CHECK-NEXT:  LDist: Populated partitions:
-; CHECK-NEXT:  LDist: Partition 0: (cycle)
+; CHECK-NEXT:  LDist: Partition 0:
 ; CHECK-NEXT:    for.body: %lv = load i16, ptr %A, align 1
 ; CHECK-NEXT:    for.body: store i16 %lv, ptr %A, align 1
 ; CHECK-NEXT:    if.then: %lv2 = load i16, ptr %A, align 1
-; CHECK-NEXT:    for.body: br i1 %c, label %if.then, label %if.end
+; CHECK-NEXT:    for.body: br i1 %cond, label %if.then, label %if.end
 ; CHECK-NEXT:    if.then: br label %if.end
 ; CHECK-NEXT:    if.end: br i1 %tobool.not, label %for.end.loopexit, label %for.body
 ; CHECK-NEXT:    if.end: %tobool.not = icmp eq i16 %iv.next, 1000
 ; CHECK-NEXT:    if.end: %iv.next = add nuw nsw i16 %iv, 1
 ; CHECK-NEXT:    for.body: %iv = phi i16 [ 0, %entry ], [ %iv.next, %if.end ]
-; CHECK-NEXT:  LDist: Partition 1:
+; CHECK-NEXT:  LDist: Partition 1: (cycle)
 ; CHECK-NEXT:    if.end: %lv3 = load i16, ptr %c.sink, align 2
-; CHECK-NEXT:    for.body: br i1 %c, label %if.then, label %if.end
+; CHECK-NEXT:    if.end: store i16 %add, ptr %c.sink, align 1
+; CHECK-NEXT:    for.body: br i1 %cond, label %if.then, label %if.end
 ; CHECK-NEXT:    if.then: br label %if.end
 ; CHECK-NEXT:    if.end: br i1 %tobool.not, label %for.end.loopexit, label %for.body
 ; CHECK-NEXT:    if.end: %tobool.not = icmp eq i16 %iv.next, 1000
 ; CHECK-NEXT:    if.end: %iv.next = add nuw nsw i16 %iv, 1
 ; CHECK-NEXT:    for.body: %iv = phi i16 [ 0, %entry ], [ %iv.next, %if.end ]
+; CHECK-NEXT:    if.end: %add = add i16 %lv3, 10
 ; CHECK-NEXT:    if.end: %c.sink = phi ptr [ %B, %if.then ], [ %C, %for.body ]
 ; CHECK-NEXT:  LDist: Distributing loop: for.body
 ; CHECK-NEXT:  LDist: Pointers:
@@ -56,19 +60,21 @@ define void @ldist(i1 %c, ptr %A, ptr %B, ptr %C) {
 ; CHECK-NEXT:    ptr %A
 ; CHECK-NEXT:    Against group ([[GRP2:0x[0-9a-f]+]]):
 ; CHECK-NEXT:    ptr %C
+; CHECK-NEXT:    ptr %C
 ; CHECK-NEXT:  Check 1:
 ; CHECK-NEXT:    Comparing group ([[GRP1]]):
 ; CHECK-NEXT:    ptr %A
 ; CHECK-NEXT:    ptr %A
 ; CHECK-NEXT:    Against group ([[GRP3:0x[0-9a-f]+]]):
 ; CHECK-NEXT:    ptr %B
+; CHECK-NEXT:    ptr %B
 ; CHECK-NEXT:  LDist: After removing unused Instrs:
 ; CHECK-NEXT:  LDist: Partition 0:
 ; CHECK-NEXT:  for.body.ldist1: ; preds = %if.end.ldist1, %for.body.ph.ldist1
 ; CHECK-NEXT:    %iv.ldist1 = phi i16 [ 0, %for.body.ph.ldist1 ], [ %iv.next.ldist1, %if.end.ldist1 ]
 ; CHECK-NEXT:    %lv.ldist1 = load i16, ptr %A, align 1, !alias.scope !0, !noalias !3
 ; CHECK-NEXT:    store i16 %lv.ldist1, ptr %A, align 1, !alias.scope !0, !noalias !3
-; CHECK-NEXT:    br i1 %c, label %if.then.ldist1, label %if.end.ldist1
+; CHECK-NEXT:    br i1 %cond, label %if.then.ldist1, label %if.end.ldist1
 ; CHECK-EMPTY:
 ; CHECK-NEXT:  if.then.ldist1: ; preds = %for.body.ldist1
 ; CHECK-NEXT:    %lv2.ldist1 = load i16, ptr %A, align 1, !alias.scope !0, !noalias !3
@@ -81,14 +87,16 @@ define void @ldist(i1 %c, ptr %A, ptr %B, ptr %C) {
 ; CHECK-NEXT:  LDist: Partition 1:
 ; CHECK-NEXT:  for.body: ; preds = %if.end, %for.body.ph
 ; CHECK-NEXT:    %iv = phi i16 [ 0, %for.body.ph ], [ %iv.next, %if.end ]
-; CHECK-NEXT:    br i1 %c, label %if.then, label %if.end
+; CHECK-NEXT:    br i1 %cond, label %if.then, label %if.end
 ; CHECK-EMPTY:
 ; CHECK-NEXT:  if.then: ; preds = %for.body
 ; CHECK-NEXT:    br label %if.end
 ; CHECK-EMPTY:
 ; CHECK-NEXT:  if.end: ; preds = %if.then, %for.body
 ; CHECK-NEXT:    %c.sink = phi ptr [ %B, %if.then ], [ %C, %for.body ]
 ; CHECK-NEXT:    %lv3 = load i16, ptr %c.sink, align 2
+; CHECK-NEXT:    %add = add i16 %lv3, 10
+; CHECK-NEXT:    store i16 %add, ptr %c.sink, align 1
 ; CHECK-NEXT:    %iv.next = add nuw nsw i16 %iv, 1
 ; CHECK-NEXT:    %tobool.not = icmp eq i16 %iv.next, 1000
 ; CHECK-NEXT:    br i1 %tobool.not, label %for.end.loopexit.loopexit6, label %for.body
@@ -100,7 +108,7 @@ for.body:                                         ; preds = %if.end, %entry
   %iv = phi i16 [ 0, %entry ], [ %iv.next, %if.end ]
   %lv = load i16, ptr %A, align 1
   store i16 %lv, ptr %A, align 1
-  br i1 %c, label %if.then, label %if.end
+  br i1 %cond, label %if.then, label %if.end
 
 if.then:                                          ; preds = %for.body
   %lv2 = load i16, ptr %A, align 1
@@ -109,6 +117,8 @@ if.then:                                          ; preds = %for.body
 if.end:                                           ; preds = %if.then, %for.body
   %c.sink = phi ptr [ %B, %if.then ], [ %C, %for.body ]
   %lv3 = load i16, ptr %c.sink
+  %add = add i16 %lv3, 10
+  store i16 %add, ptr %c.sink, align 1
   %iv.next = add nuw nsw i16 %iv, 1
   %tobool.not = icmp eq i16 %iv.next, 1000
   br i1 %tobool.not, label %for.end.loopexit, label %for.body
