maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[MemorySSA] Rename uses in blocks with Phis. 

Renaming should include blocks with existing Phis.

Resolves PR45927.

Differential Revision: https://reviews.llvm.org/D87661
This commit is contained in:
Alina Sbirlea 2020-09-14 18:07:44 -07:00
parent e30371d99d
commit 344a3d0bc0
2 changed files with 85 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
llvm/lib/Analysis/MemorySSAUpdater.cpp
View File

@ -342,6 +342,8 @@ void MemorySSAUpdater::insertDef(MemoryDef *MD, bool RenameUses) {
SmallVector<WeakVH, 8> FixupList(InsertedPHIs.begin(), InsertedPHIs.end());
SmallSet<WeakVH, 8> ExistingPhis;
// Remember the index where we may insert new phis.
unsigned NewPhiIndex = InsertedPHIs.size();
if (!DefBeforeSameBlock) {
@ -382,6 +384,8 @@ void MemorySSAUpdater::insertDef(MemoryDef *MD, bool RenameUses) {
if (!MPhi) {
MPhi = MSSA->createMemoryPhi(BBIDF);
NewInsertedPHIs.push_back(MPhi);
} else {
ExistingPhis.insert(MPhi);
}
// Add the phis created into the IDF blocks to NonOptPhis, so they are not
// optimized out as trivial by the call to getPreviousDefFromEnd below.
@ -447,6 +451,13 @@ void MemorySSAUpdater::insertDef(MemoryDef *MD, bool RenameUses) {
if (Phi)
MSSA->renamePass(Phi->getBlock(), nullptr, Visited);
}
// Existing Phi blocks may need renaming too, if an access was previously
// optimized and the inserted Defs "covers" the Optimized value.
for (auto &MP : ExistingPhis) {
MemoryPhi *Phi = dyn_cast_or_null<MemoryPhi>(MP);
if (Phi)
MSSA->renamePass(Phi->getBlock(), nullptr, Visited);
}
}
}
@ -1322,6 +1333,7 @@ void MemorySSAUpdater::removeMemoryAccess(MemoryAccess *MA, bool OptimizePhis) {
// Note: We assume MemorySSA is not used in metadata since it's not really
// part of the IR.
assert(NewDefTarget != MA && "Going into an infinite loop");
while (!MA->use_empty()) {
Use &U = *MA->use_begin();
if (auto *MUD = dyn_cast<MemoryUseOrDef>(U.getUser()))

73
llvm/test/Analysis/MemorySSA/pr45927.ll Normal file
View File

@ -0,0 +1,73 @@
; RUN: opt -disable-output -loop-simplify -lcssa -licm -print-memoryssa < %s 2>&1 | FileCheck %s
; RUN: opt -disable-output -aa-pipeline=basic-aa -passes='loop-mssa(licm),print<memoryssa>' < %s 2>&1 | FileCheck %s
@a = external dso_local global i16, align 1
@c = external dso_local global i16, align 1
; CHECK-LABEL: @main()
; CHECK: entry:
; CHECK-NEXT: %res.addr.i = alloca i16
; CHECK-NEXT: ; MemoryUse(liveOnEntry)
; CHECK-NEXT: %c.promoted = load i16, i16* @c
; CHECK-NEXT: br label %for.cond.i
; CHECK: for.cond.i:
; CHECK-NEXT: ; [[NO5:.*]] = MemoryPhi({entry,liveOnEntry},{f.exit.i,[[NO5]]})
; CHECK-NEXT: %inc.i1 = phi i16 [ %inc.i, %f.exit.i ], [ %c.promoted, %entry ]
; CHECK-NEXT: %inc.i = add nsw i16 %inc.i1, 1
; CHECK-NEXT: br i1 false, label %f.exit.thread.i, label %f.exit.i
; CHECK: f.exit.thread.i:
; CHECK-NEXT: %inc.i.lcssa = phi i16 [ %inc.i, %for.cond.i ]
; CHECK-NEXT: ; [[NO6:.*]] = MemoryDef([[NO5]])
; CHECK-NEXT: store i16 %inc.i.lcssa, i16* @c, align 1
; CHECK-NEXT: ; [[NO2:.*]] = MemoryDef([[NO6]])
; CHECK-NEXT: store i16 1, i16* @a, align 1
; CHECK-NEXT: ; MemoryUse([[NO2]])
; CHECK-NEXT: %tmp2 = load i16, i16* @c, align 1
; CHECK-NEXT: br label %g.exit
; CHECK: f.exit.i
; CHECK-NEXT: br i1 false, label %g.exit.loopexit, label %for.cond.i
; CHECK: g.exit.loopexit:
; CHECK-NEXT: %inc.i.lcssa2 = phi i16 [ %inc.i, %f.exit.i ]
; CHECK-NEXT: ; [[NO7:.*]] = MemoryDef([[NO5]])
; CHECK-NEXT: store i16 %inc.i.lcssa2, i16* @c, align 1
; CHECK-NEXT: br label %g.exit
; CHECK: g.exit
; CHECK-NEXT: ; [[NO4:.*]] = MemoryPhi({f.exit.thread.i,[[NO2]]},{g.exit.loopexit,[[NO7]]})
; CHECK-NEXT: ; MemoryUse([[NO4]])
; CHECK-NEXT: %tmp1 = load i16, i16* @c, align 1
; CHECK-NEXT: ; [[NO3:.*]] = MemoryDef([[NO4]])
; CHECK-NEXT: store i16 %tmp1, i16* %res.addr.i, align 1
; CHECK-NEXT: ret void
define dso_local void @main() {
entry:
%res.addr.i = alloca i16, align 1
br label %for.cond.i
for.cond.i: ; preds = %f.exit.i, %entry
%tmp0 = load i16, i16* @c, align 1
%inc.i = add nsw i16 %tmp0, 1
store i16 %inc.i, i16* @c, align 1
br i1 false, label %f.exit.thread.i, label %f.exit.i
f.exit.thread.i: ; preds = %for.cond.i
store i16 1, i16* @a, align 1
%tmp2 = load i16, i16* @c, align 1
br label %g.exit
f.exit.i: ; preds = %for.cond.i
br i1 false, label %g.exit, label %for.cond.i
g.exit: ; preds = %f.exit.i, %f.exit.thread.i
%tmp1 = load i16, i16* @c, align 1
store i16 %tmp1, i16* %res.addr.i, align 1
ret void
}