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Differential D36104 Diff 109257 test/CodeGen/AArch64/copy-zero-reg.ll

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test/CodeGen/AArch64/copy-zero-reg.ll

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; RUN: llc < %s -verify-machineinstrs -mtriple=aarch64-none-linux-gnu | FileCheck %s
; Verify no tiny block has only one mov wzr instruction
define void @unroll_by_2(i32 %trip_count, i32* %p) {
gberryUnsubmitted
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This description seems a little vague. Can you spell out which block you don't want the mov to appear in? Also, it seems like you might want a negative CHECK-NOT below to make sure there isn't another mov?

gberry: This description seems a little vague. Can you spell out which block you don't want the mov to…
; CHECK-LABEL: unroll_by_2
; CHECK: // %for.body.lr.ph
; CHECK: mov w{{[0-9]+}}, wzr
; CHECK: // %for.body.lr.ph.new
; CHECK: // %for.body
; CHECK: // %sw.epilog.loopexit
; CHECK: // %for.body.epil
; CHECK: // %exit
; CHECK-NEXT: ret
for.body.lr.ph:
%xtraiter = and i32 %trip_count, 1
%cmp = icmp eq i32 %trip_count, 1
br i1 %cmp, label %sw.epilog.loopexit, label %for.body.lr.ph.new
for.body.lr.ph.new:
%unroll_iter = sub nsw i32 %trip_count, %xtraiter
br label %for.body
for.body:
%indvars = phi i32 [ 0, %for.body.lr.ph.new ], [ %indvars.next, %for.body ]
%niter = phi i32 [ %unroll_iter, %for.body.lr.ph.new ], [ %niter.nsub, %for.body ]
%array = getelementptr inbounds i32, i32 * %p, i32 %indvars
store i32 %niter, i32* %array
%indvars.next = add i32 %indvars, 2
%niter.nsub = add i32 %niter, -2
%niter.ncmp = icmp eq i32 %niter.nsub, 0
br i1 %niter.ncmp, label %sw.epilog.loopexit, label %for.body
sw.epilog.loopexit:
%indvars.unr = phi i32 [ 0, %for.body.lr.ph ], [ %indvars.next, %for.body ]
%lcmp.mod = icmp eq i32 %xtraiter, 0
br i1 %lcmp.mod, label %exit, label %for.body.epil
for.body.epil:
%array.epil = getelementptr inbounds i32, i32* %p, i32 %indvars.unr
store i32 %indvars.unr, i32* %array.epil
br label %exit
exit:
ret void
}