llvm/test/Analysis/Delinearization/divide_by_one.ll

; RUN: opt < %s -passes='print<delinearization>' -disable-output 2>&1 | FileCheck %s

target datalayout = "e-m:e-p:32:32-i1:32-i64:64-a:0-n32"

; Check that division by 1 can be delinearized.
;
; void test1(unsigned char *dst, int stride, int bs) {
;   for (int r = bs; r >= 0; --r)
;     for (int c = 0; c < bs; ++c)
;       dst[r * stride + c] = dst[(r + 1) * stride + c - 1];
; }

; AddRec: {{(-1 + ((1 + %bs) * %stride)),+,(-1 * %stride)}<%for.cond1.preheader>,+,1}<nw><%for.body3>
; CHECK: Inst:  %0 = load i8, i8* %arrayidx, align 1
; CHECK: Base offset: %dst
; CHECK: ArrayDecl[UnknownSize][%stride] with elements of 1 bytes.
; CHECK: ArrayRef[{(1 + %bs),+,-1}<nw><%for.cond1.preheader>][{-1,+,1}<nw><%for.body3>]

; AddRec: {{(%stride * %bs),+,(-1 * %stride)}<%for.cond1.preheader>,+,1}<nw><%for.body3>
; CHECK: Inst:  store i8 %0, i8* %arrayidx7, align 1
; CHECK: Base offset: %dst
; CHECK: ArrayDecl[UnknownSize][%stride] with elements of 1 bytes.
; CHECK: ArrayRef[{%bs,+,-1}<nsw><%for.cond1.preheader>][{0,+,1}<nuw><nsw><%for.body3>]

define void @test(i8* nocapture %dst, i32 %stride, i32 %bs) {
entry:
  %cmp20 = icmp sgt i32 %bs, -1
  br i1 %cmp20, label %for.cond1.preheader.lr.ph, label %for.end9

for.cond1.preheader.lr.ph:
  %cmp218 = icmp slt i32 0, %bs
  br label %for.cond1.preheader

for.cond1.preheader:
  %r.021 = phi i32 [ %bs, %for.cond1.preheader.lr.ph ], [ %dec, %for.inc8 ]
  br i1 %cmp218, label %for.body3.lr.ph, label %for.inc8

for.body3.lr.ph:
  %add = add nsw i32 %r.021, 1
  %mul = mul nsw i32 %add, %stride
  %add4 = add i32 %mul, -1
  %mul5 = mul nsw i32 %r.021, %stride
  br label %for.body3

for.body3:
  %c.019 = phi i32 [ 0, %for.body3.lr.ph ], [ %inc, %for.body3 ]
  %sub = add i32 %add4, %c.019
  %arrayidx = getelementptr inbounds i8, i8* %dst, i32 %sub
  %0 = load i8, i8* %arrayidx, align 1
  %add6 = add nsw i32 %c.019, %mul5
  %arrayidx7 = getelementptr inbounds i8, i8* %dst, i32 %add6
  store i8 %0, i8* %arrayidx7, align 1
  %inc = add nsw i32 %c.019, 1
  %cmp2 = icmp slt i32 %inc, %bs
  br i1 %cmp2, label %for.body3, label %for.cond1.for.inc8_crit_edge

for.cond1.for.inc8_crit_edge:
  br label %for.inc8

for.inc8:
  %dec = add nsw i32 %r.021, -1
  %cmp = icmp sgt i32 %dec, -1
  br i1 %cmp, label %for.cond1.preheader, label %for.cond.for.end9_crit_edge

for.cond.for.end9_crit_edge:
  br label %for.end9

for.end9:
  ret void
}