third_party/llvm-7.0/llvm/test/Transforms/LoopDistribute/basic.ll

; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -verify-loop-info -verify-dom-info -S \
; RUN:   < %s | FileCheck %s

; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -verify-loop-info -verify-dom-info \
; RUN:   -loop-accesses -analyze < %s | FileCheck %s --check-prefix=ANALYSIS

; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -loop-vectorize -force-vector-width=4 -S \
; RUN:   < %s | FileCheck %s --check-prefix=VECTORIZE

; We should distribute this loop into a safe (2nd statement) and unsafe loop
; (1st statement):
;   for (i = 0; i < n; i++) {
;     A[i + 1] = A[i] * B[i];
;     =======================
;     C[i] = D[i] * E[i];
;   }

target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"

define void @f(i32* noalias %a,
               i32* noalias %b,
               i32* noalias %c,
               i32* noalias %d,
               i32* noalias %e) {
entry:
  br label %for.body

; Verify the two distributed loops.

; CHECK: entry.split.ldist1:
; CHECK:    br label %for.body.ldist1
; CHECK: for.body.ldist1:
; CHECK:    %mulA.ldist1 = mul i32 %loadB.ldist1, %loadA.ldist1
; CHECK:    br i1 %exitcond.ldist1, label %entry.split, label %for.body.ldist1

; CHECK: entry.split:
; CHECK:    br label %for.body
; CHECK: for.body:
; CHECK:    %mulC = mul i32 %loadD, %loadE
; CHECK: for.end:


; ANALYSIS: for.body:
; ANALYSIS-NEXT: Memory dependences are safe{{$}}
; ANALYSIS: for.body.ldist1:
; ANALYSIS-NEXT: Report: unsafe dependent memory operations in loop


; VECTORIZE: mul <4 x i32>

for.body:                                         ; preds = %for.body, %entry
  %ind = phi i64 [ 0, %entry ], [ %add, %for.body ]

  %arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
  %loadA = load i32, i32* %arrayidxA, align 4

  %arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind
  %loadB = load i32, i32* %arrayidxB, align 4

  %mulA = mul i32 %loadB, %loadA

  %add = add nuw nsw i64 %ind, 1
  %arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add
  store i32 %mulA, i32* %arrayidxA_plus_4, align 4

  %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
  %loadD = load i32, i32* %arrayidxD, align 4

  %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
  %loadE = load i32, i32* %arrayidxE, align 4

  %mulC = mul i32 %loadD, %loadE

  %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
  store i32 %mulC, i32* %arrayidxC, align 4

  %exitcond = icmp eq i64 %add, 20
  br i1 %exitcond, label %for.end, label %for.body

for.end:                                          ; preds = %for.body
  ret void
}