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[PowerPC] Make sure that we remove dead PHI nodes after the PPCCTRLoops pass
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Authored by stefanp on Jun 29 2017, 12:23 PM.

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LGTM

This revision is now accepted and ready to land.Jul 3 2017, 8:11 PM

This revision was automatically updated to reflect the committed changes.

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test/

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Show First 20 Lines • Show All 601 Lines • ▼ Show 20 Lines	#endif

// The false branch must exit the loop.		// The false branch must exit the loop.
if (!L->contains(CountedExitBranch->getSuccessor(0)))		if (!L->contains(CountedExitBranch->getSuccessor(0)))
CountedExitBranch->swapSuccessors();		CountedExitBranch->swapSuccessors();

// The old condition may be dead now, and may have even created a dead PHI		// The old condition may be dead now, and may have even created a dead PHI
// (the original induction variable).		// (the original induction variable).
RecursivelyDeleteTriviallyDeadInstructions(OldCond);		RecursivelyDeleteTriviallyDeadInstructions(OldCond);
DeleteDeadPHIs(CountedExitBlock);		// Run through the basic blocks of the loop and see if any of them have dead
		// PHIs that can be removed.
		for (auto I : L->blocks())
		DeleteDeadPHIs(I);

++NumCTRLoops;		++NumCTRLoops;
return MadeChange;		return MadeChange;
}		}

#ifndef NDEBUG		#ifndef NDEBUG
static bool clobbersCTR(const MachineInstr &MI) {		static bool clobbersCTR(const MachineInstr &MI) {
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {		for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
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				; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs \| FileCheck %s
				; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs \| FileCheck %s
				; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 -verify-machineinstrs \| FileCheck %s
				; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr8 -verify-machineinstrs \| FileCheck %s

				; Function Attrs: norecurse nounwind readonly
				define signext i32 @limit_loop(i32 signext %iters, i32* nocapture readonly %vec, i32 signext %limit) local_unnamed_addr {
				entry:
				%cmp5 = icmp sgt i32 %iters, 0
				br i1 %cmp5, label %for.body.preheader, label %cleanup

				for.body.preheader: ; preds = %entry
				%0 = sext i32 %iters to i64
				br label %for.body

				for.cond: ; preds = %for.body
				%cmp = icmp slt i64 %indvars.iv.next, %0
				br i1 %cmp, label %for.body, label %cleanup

				for.body: ; preds = %for.body.preheader, %for.cond
				%indvars.iv = phi i64 [ 0, %for.body.preheader ], [ %indvars.iv.next, %for.cond ]
				%arrayidx = getelementptr inbounds i32, i32* %vec, i64 %indvars.iv
				%1 = load i32, i32* %arrayidx, align 4
				%cmp1 = icmp slt i32 %1, %limit
				%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
				br i1 %cmp1, label %for.cond, label %cleanup

				cleanup: ; preds = %for.body, %for.cond, %entry
				%2 = phi i32 [ 0, %entry ], [ 0, %for.cond ], [ 1, %for.body ]
				ret i32 %2
				; CHECK-LABEL: limit_loop
				; CHECK: mtctr
				; CHECK-NOT: addi {{[0-9]+}}, {{[0-9]+}}, 1
				; CHECK: bdnz
				; CHECK: blr
				}