File: sve-tail-folding-cost.ll

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llvm-toolchain-16 1%3A16.0.6-15~deb12u1
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; RUN: opt -S -passes=loop-vectorize -prefer-predicate-over-epilogue=predicate-else-scalar-epilogue <%s | FileCheck %s

target triple = "aarch64-unknown-linux-gnu"

; The uniform load of %d in the following loop triggers the special
; branch costing code in LoopVectorizationCostModel::getInstructionCost.
; However, this should only affect the fixed-width cost because for
; NEON it needs to scalarize the load, whereas for SVE it can use a predicated load.
; Because of how the LoopVectorizer annotates the load to need scalarization with
; predicated blocks, this leads to different costs for the branch instruction.
;
; NOTE: This test assumes we will never use a fixed-width VF due to
; the high cost of scalarizing the masked store, however this assumption may
; break in future if we permit the use of SVE loads and stores to perform the
; fixed-width operations.
define i32 @uniform_load(i64 %n, ptr readnone %c, ptr %d) #0 {
; CHECK-LABEL: @uniform_load(
; CHECK: call void @llvm.masked.store.nxv4f32.p0(<vscale x 4 x float>
entry:
  br label %for.body

for.body:                                         ; preds = %entry, %for.body
  %indvars.iv = phi i64 [ 1, %entry ], [ %indvars.iv.next, %for.body ]
  %load2 = load float, ptr %d, align 4
  %arrayidx2 = getelementptr inbounds float, ptr %c, i64 %indvars.iv
  store float %load2, ptr %arrayidx2, align 4
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %n
  br i1 %exitcond.not, label %for.end, label %for.body

for.end:                                          ; preds = %for.body
  ret i32 0
}

attributes #0 = { vscale_range(1,16) "target-features"="+sve" }