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LoopVersioningLICM: Respect convergent and noduplicate 

llvm-svn: 362031
This commit is contained in:
Matt Arsenault 2019-05-29 20:47:59 +00:00
parent 74c5fac3bb
commit 79b3ea701c
2 changed files with 106 additions and 1 deletions
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10
llvm/lib/Transforms/Scalar/LoopVersioningLICM.cpp
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@ -356,14 +356,22 @@ bool LoopVersioningLICM::legalLoopMemoryAccesses() {
/// 1) Check all load store in loop body are non atomic & non volatile.
/// 2) Check function call safety, by ensuring its not accessing memory.
/// 3) Loop body shouldn't have any may throw instruction.
/// 4) Loop body shouldn't have any convergent or noduplicate instructions.
bool LoopVersioningLICM::instructionSafeForVersioning(Instruction *I) {
assert(I != nullptr && "Null instruction found!");
// Check function call safety
if (auto *Call = dyn_cast<CallBase>(I))
if (auto *Call = dyn_cast<CallBase>(I)) {
if (Call->isConvergent() || Call->cannotDuplicate()) {
LLVM_DEBUG(dbgs() << " Convergent call site found.\n");
return false;
}
if (!AA->doesNotAccessMemory(Call)) {
LLVM_DEBUG(dbgs() << " Unsafe call site found.\n");
return false;
}
}
// Avoid loops with possiblity of throw
if (I->mayThrow()) {
LLVM_DEBUG(dbgs() << " May throw instruction found in loop body\n");

97
llvm/test/Transforms/LoopVersioningLICM/convergent.ll Normal file
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@ -0,0 +1,97 @@
; RUN: opt -S -loop-versioning-licm -licm-versioning-invariant-threshold=0 %s | FileCheck %s
; Make sure the convergent attribute is respected, and no condition is
; introduced
; CHECK-LABEL: @test_convergent(
; CHECK: call void @llvm.convergent()
; CHECK-NOT: call void @llvm.convergent()
define i32 @test_convergent(i32* nocapture %var1, i32* nocapture readnone %var2, i32* nocapture %var3, i32 %itr) #1 {
entry:
%cmp14 = icmp eq i32 %itr, 0
br i1 %cmp14, label %for.end13, label %for.cond1.preheader
for.cond1.preheader: ; preds = %entry, %for.inc11
%j.016 = phi i32 [ %j.1.lcssa, %for.inc11 ], [ 0, %entry ]
%i.015 = phi i32 [ %inc12, %for.inc11 ], [ 0, %entry ]
%cmp212 = icmp ult i32 %j.016, %itr
br i1 %cmp212, label %for.body3.lr.ph, label %for.inc11
for.body3.lr.ph: ; preds = %for.cond1.preheader
%add = add i32 %i.015, %itr
%idxprom6 = zext i32 %i.015 to i64
%arrayidx7 = getelementptr inbounds i32, i32* %var3, i64 %idxprom6
br label %for.body3
for.body3: ; preds = %for.body3, %for.body3.lr.ph
%j.113 = phi i32 [ %j.016, %for.body3.lr.ph ], [ %inc, %for.body3 ]
%idxprom = zext i32 %j.113 to i64
%arrayidx = getelementptr inbounds i32, i32* %var1, i64 %idxprom
store i32 %add, i32* %arrayidx, align 4
%load.arrayidx7 = load i32, i32* %arrayidx7, align 4
call void @llvm.convergent()
%add8 = add nsw i32 %load.arrayidx7, %add
store i32 %add8, i32* %arrayidx7, align 4
%inc = add nuw i32 %j.113, 1
%cmp2 = icmp ult i32 %inc, %itr
br i1 %cmp2, label %for.body3, label %for.inc11
for.inc11: ; preds = %for.body3, %for.cond1.preheader
%j.1.lcssa = phi i32 [ %j.016, %for.cond1.preheader ], [ %itr, %for.body3 ]
%inc12 = add nuw i32 %i.015, 1
%cmp = icmp ult i32 %inc12, %itr
br i1 %cmp, label %for.cond1.preheader, label %for.end13
for.end13: ; preds = %for.inc11, %entry
ret i32 0
}
; CHECK-LABEL: @test_noduplicate(
; CHECK: call void @llvm.noduplicate()
; CHECK-NOT: call void @llvm.noduplicate()
define i32 @test_noduplicate(i32* nocapture %var1, i32* nocapture readnone %var2, i32* nocapture %var3, i32 %itr) #2 {
entry:
%cmp14 = icmp eq i32 %itr, 0
br i1 %cmp14, label %for.end13, label %for.cond1.preheader
for.cond1.preheader: ; preds = %entry, %for.inc11
%j.016 = phi i32 [ %j.1.lcssa, %for.inc11 ], [ 0, %entry ]
%i.015 = phi i32 [ %inc12, %for.inc11 ], [ 0, %entry ]
%cmp212 = icmp ult i32 %j.016, %itr
br i1 %cmp212, label %for.body3.lr.ph, label %for.inc11
for.body3.lr.ph: ; preds = %for.cond1.preheader
%add = add i32 %i.015, %itr
%idxprom6 = zext i32 %i.015 to i64
%arrayidx7 = getelementptr inbounds i32, i32* %var3, i64 %idxprom6
br label %for.body3
for.body3: ; preds = %for.body3, %for.body3.lr.ph
%j.113 = phi i32 [ %j.016, %for.body3.lr.ph ], [ %inc, %for.body3 ]
%idxprom = zext i32 %j.113 to i64
%arrayidx = getelementptr inbounds i32, i32* %var1, i64 %idxprom
store i32 %add, i32* %arrayidx, align 4
%load.arrayidx7 = load i32, i32* %arrayidx7, align 4
call void @llvm.noduplicate()
%add8 = add nsw i32 %load.arrayidx7, %add
store i32 %add8, i32* %arrayidx7, align 4
%inc = add nuw i32 %j.113, 1
%cmp2 = icmp ult i32 %inc, %itr
br i1 %cmp2, label %for.body3, label %for.inc11
for.inc11: ; preds = %for.body3, %for.cond1.preheader
%j.1.lcssa = phi i32 [ %j.016, %for.cond1.preheader ], [ %itr, %for.body3 ]
%inc12 = add nuw i32 %i.015, 1
%cmp = icmp ult i32 %inc12, %itr
br i1 %cmp, label %for.cond1.preheader, label %for.end13
for.end13: ; preds = %for.inc11, %entry
ret i32 0
}
declare void @llvm.convergent() #1
declare void @llvm.noduplicate() #2
attributes #0 = { norecurse nounwind }
attributes #1 = { norecurse nounwind readnone convergent }
attributes #2 = { norecurse nounwind readnone noduplicate }