[llvm] r310123 - Revert r310055, it caused PR34074.

Nico Weber via llvm-commits llvm-commits at lists.llvm.org
Fri Aug 4 13:40:38 PDT 2017


Author: nico
Date: Fri Aug  4 13:40:38 2017
New Revision: 310123

URL: http://llvm.org/viewvc/llvm-project?rev=310123&view=rev
Log:
Revert r310055, it caused PR34074.

Removed:
    llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores-big-endian.ll
    llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp
    llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll
    llvm/trunk/test/Transforms/DeadStoreElimination/combined-partial-overwrites.ll

Modified: llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp?rev=310123&r1=310122&r2=310123&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp Fri Aug  4 13:40:38 2017
@@ -34,7 +34,6 @@
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/LLVMContext.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
@@ -50,18 +49,12 @@ STATISTIC(NumRedundantStores, "Number of
 STATISTIC(NumFastStores, "Number of stores deleted");
 STATISTIC(NumFastOther , "Number of other instrs removed");
 STATISTIC(NumCompletePartials, "Number of stores dead by later partials");
-STATISTIC(NumModifiedStores, "Number of stores modified");
 
 static cl::opt<bool>
 EnablePartialOverwriteTracking("enable-dse-partial-overwrite-tracking",
   cl::init(true), cl::Hidden,
   cl::desc("Enable partial-overwrite tracking in DSE"));
 
-static cl::opt<bool>
-EnablePartialStoreMerging("enable-dse-partial-store-merging",
-  cl::init(true), cl::Hidden,
-  cl::desc("Enable partial store merging in DSE"));
-
 
 //===----------------------------------------------------------------------===//
 // Helper functions
@@ -294,22 +287,14 @@ static uint64_t getPointerSize(const Val
 }
 
 namespace {
-enum OverwriteResult {
-  OW_Begin,
-  OW_Complete,
-  OW_End,
-  OW_PartialEarlierWithFullLater,
-  OW_Unknown
-};
+enum OverwriteResult { OW_Begin, OW_Complete, OW_End, OW_Unknown };
 }
 
 /// Return 'OW_Complete' if a store to the 'Later' location completely
 /// overwrites a store to the 'Earlier' location, 'OW_End' if the end of the
 /// 'Earlier' location is completely overwritten by 'Later', 'OW_Begin' if the
-/// beginning of the 'Earlier' location is overwritten by 'Later'.
-/// 'OW_PartialEarlierWithFullLater' means that an earlier (big) store was
-/// overwritten by a latter (smaller) store which doesn't write outside the big
-/// store's memory locations. Returns 'OW_Unknown' if nothing can be determined.
+/// beginning of the 'Earlier' location is overwritten by 'Later', or
+/// 'OW_Unknown' if nothing can be determined.
 static OverwriteResult isOverwrite(const MemoryLocation &Later,
                                    const MemoryLocation &Earlier,
                                    const DataLayout &DL,
@@ -442,19 +427,6 @@ static OverwriteResult isOverwrite(const
     }
   }
 
-  // Check for an earlier store which writes to all the memory locations that
-  // the later store writes to.
-  if (EnablePartialStoreMerging && LaterOff >= EarlierOff &&
-      int64_t(EarlierOff + Earlier.Size) > LaterOff &&
-      uint64_t(LaterOff - EarlierOff) + Later.Size <= Earlier.Size) {
-    DEBUG(dbgs() << "DSE: Partial overwrite an earlier load [" << EarlierOff
-                 << ", " << int64_t(EarlierOff + Earlier.Size)
-                 << ") by a later store [" << LaterOff << ", "
-                 << int64_t(LaterOff + Later.Size) << ")\n");
-    // TODO: Maybe come up with a better name?
-    return OW_PartialEarlierWithFullLater;
-  }
-
   // Another interesting case is if the later store overwrites the end of the
   // earlier store.
   //
@@ -1122,8 +1094,6 @@ static bool eliminateDeadStores(BasicBlo
       // If we find a write that is a) removable (i.e., non-volatile), b) is
       // completely obliterated by the store to 'Loc', and c) which we know that
       // 'Inst' doesn't load from, then we can remove it.
-      // Also try to merge two stores if a latter one only touches memory
-      // written to by the earlier one.
       if (isRemovable(DepWrite) &&
           !isPossibleSelfRead(Inst, Loc, DepWrite, *TLI, *AA)) {
         int64_t InstWriteOffset, DepWriteOffset;
@@ -1153,73 +1123,6 @@ static bool eliminateDeadStores(BasicBlo
           bool IsOverwriteEnd = (OR == OW_End);
           MadeChange |= tryToShorten(DepWrite, DepWriteOffset, EarlierSize,
                                     InstWriteOffset, LaterSize, IsOverwriteEnd);
-        } else if (EnablePartialStoreMerging &&
-                   OR == OW_PartialEarlierWithFullLater) {
-          auto *Earlier = dyn_cast<StoreInst>(DepWrite);
-          auto *Later = dyn_cast<StoreInst>(Inst);
-          if (Earlier && isa<ConstantInt>(Earlier->getValueOperand()) &&
-              Later && isa<ConstantInt>(Later->getValueOperand())) {
-            // If the store we find is:
-            //   a) partially overwritten by the store to 'Loc'
-            //   b) the latter store is fully contained in the earlier one and
-            //   c) They both have a contant value
-            // Merge the two stores, replacing the earlier store's value with a
-            // merge of both values.
-            // TODO: Deal with other constant types (vectors, etc), and probably
-            // some mem intrinsics (if needed)
-
-            APInt EarlierValue =
-                cast<ConstantInt>(Earlier->getValueOperand())->getValue();
-            APInt LaterValue =
-                cast<ConstantInt>(Later->getValueOperand())->getValue();
-            unsigned LaterBits = LaterValue.getBitWidth();
-            assert(EarlierValue.getBitWidth() > LaterValue.getBitWidth());
-            LaterValue = LaterValue.zext(EarlierValue.getBitWidth());
-
-            // Offset of the smaller store inside the larger store
-            unsigned BitOffsetDiff = (InstWriteOffset - DepWriteOffset) * 8;
-            unsigned LShiftAmount =
-                DL.isBigEndian()
-                    ? EarlierValue.getBitWidth() - BitOffsetDiff - LaterBits
-                    : BitOffsetDiff;
-            APInt Mask =
-                APInt::getBitsSet(EarlierValue.getBitWidth(), LShiftAmount,
-                                  LShiftAmount + LaterBits);
-            // Clear the bits we'll be replacing, then OR with the smaller
-            // store, shifted appropriately.
-            APInt Merged =
-                (EarlierValue & ~Mask) | (LaterValue << LShiftAmount);
-            DEBUG(dbgs() << "DSE: Merge Stores:\n  Earlier: " << *DepWrite
-                         << "\n  Later: " << *Inst
-                         << "\n  Merged Value: " << Merged << '\n');
-
-            auto *SI = new StoreInst(
-                ConstantInt::get(Earlier->getValueOperand()->getType(), Merged),
-                Earlier->getPointerOperand(), false, Earlier->getAlignment(),
-                Earlier->getOrdering(), Earlier->getSyncScopeID(), DepWrite);
-
-            unsigned MDToKeep[] = {LLVMContext::MD_dbg, LLVMContext::MD_tbaa,
-                                   LLVMContext::MD_alias_scope,
-                                   LLVMContext::MD_noalias,
-                                   LLVMContext::MD_nontemporal};
-            SI->copyMetadata(*DepWrite, MDToKeep);
-            ++NumModifiedStores;
-
-            // Remove earlier, wider, store
-            size_t Idx = InstrOrdering.lookup(DepWrite);
-            InstrOrdering.erase(DepWrite);
-            InstrOrdering.insert(std::make_pair(SI, Idx));
-
-            // Delete the old stores and now-dead instructions that feed them.
-            deleteDeadInstruction(Inst, &BBI, *MD, *TLI, IOL, &InstrOrdering);
-            deleteDeadInstruction(DepWrite, &BBI, *MD, *TLI, IOL,
-                                  &InstrOrdering);
-            MadeChange = true;
-
-            //// We erased DepWrite; start over.
-            InstDep = MD->getDependency(SI);
-            continue;
-          }
         }
       }
 

Modified: llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll?rev=310123&r1=310122&r2=310123&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/PartialStore.ll Fri Aug  4 13:40:38 2017
@@ -1,4 +1,4 @@
-; RUN: opt < %s -basicaa -dse -enable-dse-partial-store-merging=false -S | FileCheck %s
+; RUN: opt < %s -basicaa -dse -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"
 
 ; Ensure that the dead store is deleted in this case.  It is wholely

Modified: llvm/trunk/test/Transforms/DeadStoreElimination/combined-partial-overwrites.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/combined-partial-overwrites.ll?rev=310123&r1=310122&r2=310123&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/combined-partial-overwrites.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/combined-partial-overwrites.ll Fri Aug  4 13:40:38 2017
@@ -1,4 +1,4 @@
-; RUN: opt -S -dse -enable-dse-partial-store-merging=false < %s | FileCheck %s
+; RUN: opt -S -dse < %s | FileCheck %s
 target datalayout = "E-m:e-i64:64-n32:64"
 target triple = "powerpc64-bgq-linux"
 

Removed: llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores-big-endian.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores-big-endian.ll?rev=310122&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores-big-endian.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores-big-endian.ll (removed)
@@ -1,173 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -dse -enable-dse-partial-store-merging -S < %s | FileCheck %s
-target datalayout = "E-m:e-i64:64-i128:128-n32:64-S128"
-
-define void @byte_by_byte_replacement(i32 *%ptr) {
-; CHECK-LABEL: @byte_by_byte_replacement(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i32 151653132, i32* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  ;; This store's value should be modified as it should be better to use one
-  ;; larger store than several smaller ones.
-  ;; store will turn into 0x090A0B0C == 151653132
-  store i32 305419896, i32* %ptr  ; 0x12345678
-  %bptr = bitcast i32* %ptr to i8*
-  %bptr1 = getelementptr inbounds i8, i8* %bptr, i64 1
-  %bptr2 = getelementptr inbounds i8, i8* %bptr, i64 2
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-
-  ;; We should be able to merge these four stores with the i32 above
-  ; value (and bytes) stored before  ; 0x12345678
-  store i8 9, i8* %bptr              ;   09
-  store i8 10, i8* %bptr1            ;     0A
-  store i8 11, i8* %bptr2            ;       0B
-  store i8 12, i8* %bptr3            ;         0C
-  ;                                    0x090A0B0C
-
-  ret void
-}
-
-define void @word_replacement(i64 *%ptr) {
-; CHECK-LABEL: @word_replacement(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 72638273700655232, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 72623859790382856, i64* %ptr  ; 0x0102030405060708
-
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr1 = getelementptr inbounds i16, i16* %wptr, i64 1
-  %wptr2 = getelementptr inbounds i16, i16* %wptr, i64 2
-  %wptr3 = getelementptr inbounds i16, i16* %wptr, i64 3
-
-  ;; We should be able to merge these two stores with the i64 one above
-  ; value (and bytes) stored before  ; 0x0102030405060708
-  store i16  4128, i16* %wptr1       ;       1020
-  store i16 28800, i16* %wptr3       ;               7080
-  ;                                    0x0102102005067080
-
-  ret void
-}
-
-
-define void @differently_sized_replacements(i64 *%ptr) {
-; CHECK-LABEL: @differently_sized_replacements(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 289077004501059343, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 579005069656919567, i64* %ptr  ; 0x08090a0b0c0d0e0f
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptr6 = getelementptr inbounds i8, i8* %bptr, i64 6
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr2 = getelementptr inbounds i16, i16* %wptr, i64 2
-  %dptr = bitcast i64* %ptr to i32*
-
-  ;; We should be able to merge all these stores with the i64 one above
-  ; value (and bytes) stored before  ; 0x08090a0b0c0d0e0f
-  store i8         7, i8*  %bptr6    ;               07
-  store i16     1541, i16* %wptr2    ;           0605
-  store i32 67305985, i32* %dptr     ;   04030201
-  ;                                    0x040302010605070f
-  ret void
-}
-
-
-define void @multiple_replacements_to_same_byte(i64 *%ptr) {
-; CHECK-LABEL: @multiple_replacements_to_same_byte(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 289077004602248719, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 579005069656919567, i64* %ptr  ; 0x08090a0b0c0d0e0f
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr1 = getelementptr inbounds i16, i16* %wptr, i64 1
-  %dptr = bitcast i64* %ptr to i32*
-
-  ;; We should be able to merge all these stores with the i64 one above
-  ; value (and bytes) stored before  ; 0x08090a0b0c0d0e0f
-  store i8         7, i8*  %bptr3    ;         07
-  store i16     1541, i16* %wptr1    ;       0605
-  store i32 67305985, i32* %dptr     ;   04030201
-  ;                                    0x040302010c0d0e0f
-  ret void
-}
-
-define void @merged_merges(i64 *%ptr) {
-; CHECK-LABEL: @merged_merges(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 289081428418563599, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 579005069656919567, i64* %ptr  ; 0x08090a0b0c0d0e0f
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr1 = getelementptr inbounds i16, i16* %wptr, i64 1
-  %dptr = bitcast i64* %ptr to i32*
-
-  ;; We should be able to merge all these stores with the i64 one above
-  ; value (not bytes) stored before  ; 0x08090a0b0c0d0e0f
-  store i32 67305985, i32* %dptr     ;   04030201
-  store i16     1541, i16* %wptr1    ;       0605
-  store i8         7, i8*  %bptr3    ;         07
-  ;                                    0x040306070c0d0e0f
-  ret void
-}
-
-define signext i8 @shouldnt_merge_since_theres_a_full_overlap(i64 *%ptr) {
-; CHECK-LABEL: @shouldnt_merge_since_theres_a_full_overlap(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[BPTR:%.*]] = bitcast i64* [[PTR:%.*]] to i8*
-; CHECK-NEXT:    [[BPTRM1:%.*]] = getelementptr inbounds i8, i8* [[BPTR]], i64 -1
-; CHECK-NEXT:    [[BPTR3:%.*]] = getelementptr inbounds i8, i8* [[BPTR]], i64 3
-; CHECK-NEXT:    [[DPTR:%.*]] = bitcast i8* [[BPTRM1]] to i32*
-; CHECK-NEXT:    [[QPTR:%.*]] = bitcast i8* [[BPTR3]] to i64*
-; CHECK-NEXT:    store i32 1234, i32* [[DPTR]], align 1
-; CHECK-NEXT:    store i64 5678, i64* [[QPTR]], align 1
-; CHECK-NEXT:    ret i8 0
-;
-entry:
-
-  store i64 0, i64* %ptr
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptrm1 = getelementptr inbounds i8, i8* %bptr, i64 -1
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-  %dptr = bitcast i8* %bptrm1 to i32*
-  %qptr = bitcast i8* %bptr3 to i64*
-
-  store i32 1234, i32* %dptr, align 1
-  store i64 5678, i64* %qptr, align 1
-
-  ret i8 0
-}
-
-;; Test case from PR31777
-%union.U = type { i64 }
-
-define void @foo(%union.U* nocapture %u) {
-; CHECK-LABEL: @foo(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[I:%.*]] = getelementptr inbounds [[UNION_U:%.*]], %union.U* [[U:%.*]], i64 0, i32 0
-; CHECK-NEXT:    store i64 11821949021847552, i64* [[I]], align 8
-; CHECK-NEXT:    ret void
-;
-entry:
-  %i = getelementptr inbounds %union.U, %union.U* %u, i64 0, i32 0
-  store i64 0, i64* %i, align 8
-  %s = bitcast %union.U* %u to i16*
-  store i16 42, i16* %s, align 8
-  ret void
-}

Removed: llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores.ll?rev=310122&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores.ll (original)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/merge-stores.ll (removed)
@@ -1,205 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -dse -enable-dse-partial-store-merging -S < %s | FileCheck %s
-target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-f128:128:128-n8:16:32:64"
-
-define void @byte_by_byte_replacement(i32 *%ptr) {
-; CHECK-LABEL: @byte_by_byte_replacement(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i32 202050057, i32* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  ;; This store's value should be modified as it should be better to use one
-  ;; larger store than several smaller ones.
-  ;; store will turn into 0x0C0B0A09 == 202050057
-  store i32 305419896, i32* %ptr  ; 0x12345678
-  %bptr = bitcast i32* %ptr to i8*
-  %bptr1 = getelementptr inbounds i8, i8* %bptr, i64 1
-  %bptr2 = getelementptr inbounds i8, i8* %bptr, i64 2
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-
-  ;; We should be able to merge these four stores with the i32 above
-  ; value (and bytes) stored before  ; 0x12345678
-  store i8 9, i8* %bptr              ;         09
-  store i8 10, i8* %bptr1            ;       0A
-  store i8 11, i8* %bptr2            ;     0B
-  store i8 12, i8* %bptr3            ;   0C
-  ;                                    0x0C0B0A09
-  ret void
-}
-
-define void @word_replacement(i64 *%ptr) {
-; CHECK-LABEL: @word_replacement(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 8106482645252179720, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 72623859790382856, i64* %ptr  ; 0x0102030405060708
-
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr1 = getelementptr inbounds i16, i16* %wptr, i64 1
-  %wptr2 = getelementptr inbounds i16, i16* %wptr, i64 2
-  %wptr3 = getelementptr inbounds i16, i16* %wptr, i64 3
-
-  ;; We should be able to merge these two stores with the i64 one above
-  ; value (not bytes) stored before  ; 0x0102030405060708
-  store i16  4128, i16* %wptr1       ;           1020
-  store i16 28800, i16* %wptr3       ;   7080
-  ;                                    0x7080030410200708
-  ret void
-}
-
-
-define void @differently_sized_replacements(i64 *%ptr) {
-; CHECK-LABEL: @differently_sized_replacements(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 578437695752307201, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 579005069656919567, i64* %ptr  ; 0x08090a0b0c0d0e0f
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptr6 = getelementptr inbounds i8, i8* %bptr, i64 6
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr2 = getelementptr inbounds i16, i16* %wptr, i64 2
-  %dptr = bitcast i64* %ptr to i32*
-
-  ;; We should be able to merge all these stores with the i64 one above
-  ; value (not bytes) stored before  ; 0x08090a0b0c0d0e0f
-  store i8         7, i8*  %bptr6    ;     07
-  store i16     1541, i16* %wptr2    ;       0605
-  store i32 67305985, i32* %dptr     ;           04030201
-  ;                                    0x0807060504030201
-  ret void
-}
-
-
-define void @multiple_replacements_to_same_byte(i64 *%ptr) {
-; CHECK-LABEL: @multiple_replacements_to_same_byte(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 579005069522043393, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 579005069656919567, i64* %ptr  ; 0x08090a0b0c0d0e0f
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr1 = getelementptr inbounds i16, i16* %wptr, i64 1
-  %dptr = bitcast i64* %ptr to i32*
-
-  ;; We should be able to merge all these stores with the i64 one above
-  ; value (not bytes) stored before  ; 0x08090a0b0c0d0e0f
-  store i8         7, i8*  %bptr3    ;           07
-  store i16     1541, i16* %wptr1    ;           0605
-  store i32 67305985, i32* %dptr     ;           04030201
-  ;                                    0x08090a0b04030201
-  ret void
-}
-
-define void @merged_merges(i64 *%ptr) {
-; CHECK-LABEL: @merged_merges(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    store i64 579005069572506113, i64* [[PTR:%.*]]
-; CHECK-NEXT:    ret void
-;
-entry:
-  store i64 579005069656919567, i64* %ptr  ; 0x08090a0b0c0d0e0f
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-  %wptr = bitcast i64* %ptr to i16*
-  %wptr1 = getelementptr inbounds i16, i16* %wptr, i64 1
-  %dptr = bitcast i64* %ptr to i32*
-
-  ;; We should be able to merge all these stores with the i64 one above
-  ; value (not bytes) stored before  ; 0x08090a0b0c0d0e0f
-  store i32 67305985, i32* %dptr     ;           04030201
-  store i16     1541, i16* %wptr1    ;           0605
-  store i8         7, i8*  %bptr3    ;           07
-  ;                                    0x08090a0b07050201
-  ret void
-}
-
-define signext i8 @shouldnt_merge_since_theres_a_full_overlap(i64 *%ptr) {
-; CHECK-LABEL: @shouldnt_merge_since_theres_a_full_overlap(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[BPTR:%.*]] = bitcast i64* [[PTR:%.*]] to i8*
-; CHECK-NEXT:    [[BPTRM1:%.*]] = getelementptr inbounds i8, i8* [[BPTR]], i64 -1
-; CHECK-NEXT:    [[BPTR3:%.*]] = getelementptr inbounds i8, i8* [[BPTR]], i64 3
-; CHECK-NEXT:    [[DPTR:%.*]] = bitcast i8* [[BPTRM1]] to i32*
-; CHECK-NEXT:    [[QPTR:%.*]] = bitcast i8* [[BPTR3]] to i64*
-; CHECK-NEXT:    store i32 1234, i32* [[DPTR]], align 1
-; CHECK-NEXT:    store i64 5678, i64* [[QPTR]], align 1
-; CHECK-NEXT:    ret i8 0
-;
-entry:
-
-  ; Also check that alias.scope metadata doesn't get dropped
-  store i64 0, i64* %ptr, !alias.scope !32
-
-  %bptr = bitcast i64* %ptr to i8*
-  %bptrm1 = getelementptr inbounds i8, i8* %bptr, i64 -1
-  %bptr3 = getelementptr inbounds i8, i8* %bptr, i64 3
-  %dptr = bitcast i8* %bptrm1 to i32*
-  %qptr = bitcast i8* %bptr3 to i64*
-
-  store i32 1234, i32* %dptr, align 1
-  store i64 5678, i64* %qptr, align 1
-
-  ret i8 0
-}
-
-;; Test case from PR31777
-%union.U = type { i64 }
-
-define void @foo(%union.U* nocapture %u) {
-; CHECK-LABEL: @foo(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[I:%.*]] = getelementptr inbounds [[UNION_U:%.*]], %union.U* [[U:%.*]], i64 0, i32 0
-; CHECK-NEXT:    store i64 42, i64* [[I]], align 8
-; CHECK-NEXT:    ret void
-;
-entry:
-  %i = getelementptr inbounds %union.U, %union.U* %u, i64 0, i32 0
-  store i64 0, i64* %i, align 8, !dbg !22, !tbaa !26, !noalias !30, !nontemporal !29
-  %s = bitcast %union.U* %u to i16*
-  store i16 42, i16* %s, align 8
-  ret void
-}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 5.0.0 (trunk 306512)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
-!1 = !DIFile(filename: "me.cpp", directory: "/compiler-explorer")
-!2 = !{}
-!7 = distinct !DISubprogram(name: "foo", linkageName: "foo(U*)", scope: !1, file: !1, line: 9, type: !8, isLocal: false, isDefinition: true, scopeLine: 9, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !20)
-!8 = !DISubroutineType(types: !9)
-!9 = !{null, !10}
-!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !11, size: 64)
-!11 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "U", file: !1, line: 4, size: 64, elements: !12, identifier: "typeinfo name for U")
-!12 = !{!13, !17}
-!13 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !11, file: !1, line: 5, baseType: !14, size: 64)
-!14 = !DIDerivedType(tag: DW_TAG_typedef, name: "uint64_t", file: !15, line: 55, baseType: !16)
-!15 = !DIFile(filename: "/usr/include/stdint.h", directory: "/compiler-explorer")
-!16 = !DIBasicType(name: "long unsigned int", size: 64, encoding: DW_ATE_unsigned)
-!17 = !DIDerivedType(tag: DW_TAG_member, name: "s", scope: !11, file: !1, line: 6, baseType: !18, size: 16)
-!18 = !DIDerivedType(tag: DW_TAG_typedef, name: "uint16_t", file: !15, line: 49, baseType: !19)
-!19 = !DIBasicType(name: "unsigned short", size: 16, encoding: DW_ATE_unsigned)
-!20 = !{!21}
-!21 = !DILocalVariable(name: "u", arg: 1, scope: !7, file: !1, line: 9, type: !10)
-!22 = !DILocation(line: 10, column: 8, scope: !7)
-
-!26 = !{!27, !27, i64 0}
-!27 = !{!"omnipotent char", !28, i64 0}
-!28 = !{!"Simple C++ TBAA"}
-
-!29 = !{i32 1}
-
-; Domains and scopes which might alias
-!30 = !{!30}
-!31 = !{!31, !30}
-
-!32 = !{!32}
-!33 = !{!33, !32}




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