summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--llvm/lib/Analysis/AliasSetTracker.cpp19
-rw-r--r--llvm/lib/Transforms/Scalar/LICM.cpp26
-rw-r--r--llvm/test/Transforms/LICM/atomics.ll5
-rw-r--r--llvm/test/Transforms/LICM/funclet.ll4
-rw-r--r--llvm/test/Transforms/LICM/promote-order.ll8
-rw-r--r--llvm/test/Transforms/LICM/store-hoisting.ll89
6 files changed, 135 insertions, 16 deletions
diff --git a/llvm/lib/Analysis/AliasSetTracker.cpp b/llvm/lib/Analysis/AliasSetTracker.cpp
index 377db8a569f..51a61e9e2d9 100644
--- a/llvm/lib/Analysis/AliasSetTracker.cpp
+++ b/llvm/lib/Analysis/AliasSetTracker.cpp
@@ -256,9 +256,22 @@ Instruction* AliasSet::getUniqueInstruction() {
if (AliasAny)
// May have collapses alias set
return nullptr;
- if (size() != 0)
- // Can't track source of pointer, might be many instruction
- return nullptr;
+ if (begin() != end()) {
+ if (!UnknownInsts.empty())
+ // Another instruction found
+ return nullptr;
+ if (std::next(begin()) != end())
+ // Another instruction found
+ return nullptr;
+ Value *Addr = begin()->getValue();
+ assert(!Addr->user_empty() &&
+ "where's the instruction which added this pointer?");
+ if (std::next(Addr->user_begin()) != Addr->user_end())
+ // Another instruction found -- this is really restrictive
+ // TODO: generalize!
+ return nullptr;
+ return cast<Instruction>(*(Addr->user_begin()));
+ }
if (1 != UnknownInsts.size())
return nullptr;
return cast<Instruction>(UnknownInsts[0]);
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index 94fcdaf3c08..ff7cb3c26c9 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -416,7 +416,8 @@ bool llvm::sinkRegion(DomTreeNode *N, AliasAnalysis *AA, LoopInfo *LI,
//
bool FreeInLoop = false;
if (isNotUsedOrFreeInLoop(I, CurLoop, SafetyInfo, TTI, FreeInLoop) &&
- canSinkOrHoistInst(I, AA, DT, CurLoop, CurAST, true, ORE)) {
+ canSinkOrHoistInst(I, AA, DT, CurLoop, CurAST, true, ORE) &&
+ !I.mayHaveSideEffects()) {
if (sink(I, LI, DT, CurLoop, SafetyInfo, ORE, FreeInLoop)) {
if (!FreeInLoop) {
++II;
@@ -604,8 +605,8 @@ namespace {
/// concerns such as aliasing or speculation safety.
bool isHoistableAndSinkableInst(Instruction &I) {
// Only these instructions are hoistable/sinkable.
- return (isa<LoadInst>(I) || isa<CallInst>(I) ||
- isa<FenceInst>(I) ||
+ return (isa<LoadInst>(I) || isa<StoreInst>(I) ||
+ isa<CallInst>(I) || isa<FenceInst>(I) ||
isa<BinaryOperator>(I) || isa<CastInst>(I) ||
isa<SelectInst>(I) || isa<GetElementPtrInst>(I) ||
isa<CmpInst>(I) || isa<InsertElementInst>(I) ||
@@ -695,6 +696,7 @@ bool llvm::canSinkOrHoistInst(Instruction &I, AAResults *AA, DominatorTree *DT,
// it's arguments with arbitrary offsets. If we can prove there are no
// writes to this memory in the loop, we can hoist or sink.
if (AliasAnalysis::onlyAccessesArgPointees(Behavior)) {
+ // TODO: expand to writeable arguments
for (Value *Op : CI->arg_operands())
if (Op->getType()->isPointerTy() &&
pointerInvalidatedByLoop(
@@ -729,6 +731,24 @@ bool llvm::canSinkOrHoistInst(Instruction &I, AAResults *AA, DominatorTree *DT,
(void)FI; //suppress unused variable warning
assert(UniqueI == FI && "AS must contain FI");
return true;
+ } else if (auto *SI = dyn_cast<StoreInst>(&I)) {
+ if (!SI->isUnordered())
+ return false; // Don't sink/hoist volatile or ordered atomic store!
+
+ // We can only hoist a store that we can prove writes a value which is not
+ // read or overwritten within the loop. For those cases, we fallback to
+ // load store promotion instead.
+ auto &AS = CurAST->getAliasSetFor(MemoryLocation::get(SI));
+
+ if (AS.isRef() || !AS.isMustAlias())
+ // Quick exit test, handled by the full path below as well.
+ return false;
+ auto *UniqueI = AS.getUniqueInstruction();
+ if (!UniqueI)
+ // other memory op, give up
+ return false;
+ assert(UniqueI == SI && "AS must contain SI");
+ return true;
}
assert(!I.mayReadOrWriteMemory() && "unhandled aliasing");
diff --git a/llvm/test/Transforms/LICM/atomics.ll b/llvm/test/Transforms/LICM/atomics.ll
index 15c461aeca2..23dc60c590a 100644
--- a/llvm/test/Transforms/LICM/atomics.ll
+++ b/llvm/test/Transforms/LICM/atomics.ll
@@ -173,10 +173,11 @@ loop:
end:
ret i32 %vala
; CHECK-LABEL: define i32 @test7b(
+; CHECK-LABEL: entry:
+; CHECK: store i32 5, i32* %x
+; CHECK-LABEL: loop:
; CHECK: load atomic i32, i32* %y monotonic
-
; CHECK-LABEL: end:
-; CHECK: store i32 5, i32* %x
; CHECK: store atomic i32 %{{.+}}, i32* %z unordered, align 4
}
diff --git a/llvm/test/Transforms/LICM/funclet.ll b/llvm/test/Transforms/LICM/funclet.ll
index 6b5f11507ed..36d2d49d9d4 100644
--- a/llvm/test/Transforms/LICM/funclet.ll
+++ b/llvm/test/Transforms/LICM/funclet.ll
@@ -97,9 +97,11 @@ else: ; preds = %postinvoke
}
; CHECK-LABEL: define void @test3(
-; CHECK: catchswitch within none
+; CHECK-LABEL: forbody.preheader:
; CHECK: store i32 1, i32* %bc, align 4
; CHECK: store i32 2, i32* %bc2, align 4
+; CHECK: catchswitch within none
+; CHECK-LABEL: forbody:
declare void @may_throw()
diff --git a/llvm/test/Transforms/LICM/promote-order.ll b/llvm/test/Transforms/LICM/promote-order.ll
index b7e0b7c6c43..79aa7899b21 100644
--- a/llvm/test/Transforms/LICM/promote-order.ll
+++ b/llvm/test/Transforms/LICM/promote-order.ll
@@ -10,6 +10,11 @@ target triple = "x86_64-apple-macosx10.8.0"
@p = external global i8*
define i32* @_Z4doiti(i32 %n, float* %tmp1, i32* %tmp3) nounwind {
+; CHECK-LABEL: for.body.lr.ph:
+; CHECK: store float 1.000000e+00, float* %tmp1
+; CHECK-LABEL: for.cond.for.end_crit_edge:
+; CHECK: store i32 1, i32* %tmp3
+
entry:
%cmp1 = icmp slt i32 0, %n
br i1 %cmp1, label %for.body.lr.ph, label %for.end
@@ -25,9 +30,6 @@ for.body: ; preds = %for.body, %for.body
%cmp = icmp slt i32 %inc, %n
br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge
-; CHECK: for.cond.for.end_crit_edge:
-; CHECK: store float 1.000000e+00, float* %tmp1
-; CHECK: store i32 1, i32* %tmp3
for.cond.for.end_crit_edge: ; preds = %for.body
%split = phi i32* [ %tmp3, %for.body ]
br label %for.end
diff --git a/llvm/test/Transforms/LICM/store-hoisting.ll b/llvm/test/Transforms/LICM/store-hoisting.ll
index 651fd9b2a71..11922fa77ee 100644
--- a/llvm/test/Transforms/LICM/store-hoisting.ll
+++ b/llvm/test/Transforms/LICM/store-hoisting.ll
@@ -3,8 +3,9 @@
define void @test(i32* %loc) {
; CHECK-LABEL: @test
-; CHECK-LABEL: exit:
+; CHECK-LABEL: entry:
; CHECK: store i32 0, i32* %loc
+; CHECK-LABEL: loop:
entry:
br label %loop
@@ -21,10 +22,9 @@ exit:
define void @test_multiexit(i32* %loc, i1 %earlycnd) {
; CHECK-LABEL: @test_multiexit
-; CHECK-LABEL: exit1:
-; CHECK: store i32 0, i32* %loc
-; CHECK-LABEL: exit2:
+; CHECK-LABEL: entry:
; CHECK: store i32 0, i32* %loc
+; CHECK-LABEL: loop:
entry:
br label %loop
@@ -44,6 +44,24 @@ exit2:
ret void
}
+define i32* @false_negative_2use(i32* %loc) {
+; CHECK-LABEL: @false_negative_2use
+; CHECK-LABEL: exit:
+; CHECK: store i32 0, i32* %loc
+entry:
+ br label %loop
+
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %loop]
+ store i32 0, i32* %loc
+ %iv.next = add i32 %iv, 1
+ %cmp = icmp slt i32 %iv, 200
+ br i1 %cmp, label %loop, label %exit
+
+exit:
+ ret i32* %loc
+}
+
define void @neg_lv_value(i32* %loc) {
; CHECK-LABEL: @neg_lv_value
; CHECK-LABEL: exit:
@@ -227,4 +245,67 @@ exit:
ret void
}
+declare void @maythrow() inaccessiblememonly
+
+define void @neg_early_exit(i32* %loc) {
+; CHECK-LABEL: @neg_early_exit
+; CHECK-LABEL: body:
+; CHECK: store i32 0, i32* %loc
+; CHECK-LABEL: exit:
+entry:
+ br label %loop
+
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %body]
+ %is_null = icmp eq i32* %loc, null
+ br i1 %is_null, label %exit, label %body
+body:
+ call void @maythrow()
+ store i32 0, i32* %loc
+ %iv.next = add i32 %iv, 1
+ %cmp = icmp slt i32 %iv, 200
+ br i1 %cmp, label %loop, label %exit
+
+exit:
+ ret void
+}
+
+define void @neg_early_throw(i32* %loc) {
+; CHECK-LABEL: @neg_early_throw
+; CHECK-LABEL: loop:
+; CHECK: store i32 0, i32* %loc
+; CHECK-LABEL: exit:
+entry:
+ br label %loop
+
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %loop]
+ call void @maythrow()
+ store i32 0, i32* %loc
+ %iv.next = add i32 %iv, 1
+ %cmp = icmp slt i32 %iv, 200
+ br i1 %cmp, label %loop, label %exit
+
+exit:
+ ret void
+}
+
+define void @test_late_throw(i32* %loc) {
+; CHECK-LABEL: @test_late_throw
+; CHECK-LABEL: entry:
+; CHECK: store i32 0, i32* %loc
+; CHECK-LABEL: loop:
+entry:
+ br label %loop
+loop:
+ %iv = phi i32 [0, %entry], [%iv.next, %loop]
+ store i32 0, i32* %loc
+ call void @maythrow()
+ %iv.next = add i32 %iv, 1
+ %cmp = icmp slt i32 %iv, 200
+ br i1 %cmp, label %loop, label %exit
+
+exit:
+ ret void
+}
OpenPOWER on IntegriCloud