static bool inSubLoop(BasicBlock *BB, Loop *CurLoop, LoopInfo *LI);
static bool isNotUsedInLoop(const Instruction &I, const Loop *CurLoop,
const LICMSafetyInfo *SafetyInfo);
-static bool hoist(Instruction &I, BasicBlock *Preheader);
+static bool hoist(Instruction &I, const DominatorTree *DT, const Loop *CurLoop,
+ const LICMSafetyInfo *SafetyInfo);
static bool sink(Instruction &I, const LoopInfo *LI, const DominatorTree *DT,
const Loop *CurLoop, AliasSetTracker *CurAST,
const LICMSafetyInfo *SafetyInfo);
canSinkOrHoistInst(I, AA, DT, TLI, CurLoop, CurAST, SafetyInfo) &&
isSafeToExecuteUnconditionally(I, DT, TLI, CurLoop, SafetyInfo,
CurLoop->getLoopPreheader()->getTerminator()))
- Changed |= hoist(I, CurLoop->getLoopPreheader());
+ Changed |= hoist(I, DT, CurLoop, SafetyInfo);
}
const std::vector<DomTreeNode*> &Children = N->getChildren();
/// When an instruction is found to only use loop invariant operands that
/// is safe to hoist, this instruction is called to do the dirty work.
///
-static bool hoist(Instruction &I, BasicBlock *Preheader) {
+static bool hoist(Instruction &I, const DominatorTree *DT, const Loop *CurLoop,
+ const LICMSafetyInfo *SafetyInfo) {
+ auto *Preheader = CurLoop->getLoopPreheader();
DEBUG(dbgs() << "LICM hoisting to " << Preheader->getName() << ": "
<< I << "\n");
+
+ // Metadata can be dependent on conditions we are hoisting above.
+ // Conservatively strip all metadata on the instruction unless we were
+ // guaranteed to execute I if we entered the loop, in which case the metadata
+ // is valid in the loop preheader.
+ if (I.hasMetadataOtherThanDebugLoc() &&
+ // The check on hasMetadataOtherThanDebugLoc is to prevent us from burning
+ // time in isGuaranteedToExecute if we don't actually have anything to
+ // drop. It is a compile time optimization, not required for correctness.
+ !isGuaranteedToExecute(I, DT, CurLoop, SafetyInfo))
+ I.dropUnknownNonDebugMetadata();
+
// Move the new node to the Preheader, before its terminator.
I.moveBefore(Preheader->getTerminator());
- // Metadata can be dependent on the condition we are hoisting above.
- // Conservatively strip all metadata on the instruction.
- I.dropUnknownNonDebugMetadata();
-
if (isa<LoadInst>(I)) ++NumMovedLoads;
else if (isa<CallInst>(I)) ++NumMovedCalls;
++NumHoisted;
ret void
}
+define void @test11(i32* noalias %a, i32* %b, i32** dereferenceable(8) %cptr, i32 %n) #0 {
+; CHECK-LABEL: @test11(
+entry:
+ %cmp11 = icmp sgt i32 %n, 0
+ br i1 %cmp11, label %for.body, label %for.end
+
+; CHECK: for.body.preheader:
+; CHECK: %c = load i32*, i32** %cptr, !dereferenceable !0
+; CHECK: %d = load i32, i32* %c, align 4
+
+
+for.body: ; preds = %entry, %for.inc
+ %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
+ %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
+ %0 = load i32, i32* %arrayidx, align 4
+ %cmp1 = icmp sgt i32 %0, 0
+ %c = load i32*, i32** %cptr, !dereferenceable !0
+ br i1 %cmp1, label %if.then, label %for.inc
+
+if.then: ; preds = %for.body
+ %d = load i32, i32* %c, align 4
+ %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv
+ %e = load i32, i32* %arrayidx3, align 4
+ %mul = mul nsw i32 %e, %d
+ store i32 %mul, i32* %arrayidx, align 4
+ br label %for.inc
+
+for.inc: ; preds = %for.body, %if.then
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+ %exitcond = icmp eq i32 %lftr.wideiv, %n
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end: ; preds = %for.inc, %entry
+ ret void
+}
+
attributes #0 = { nounwind uwtable }
!0 = !{i64 4}