test/Transforms/LoopUnroll/branch-weights-freq/peel.ll

; Test branch weight metadata, estimated trip count metadata, and block
; frequencies after loop peeling.

; ------------------------------------------------------------------------------
; RUN: opt < %s -S -passes='print<block-freq>' 2>&1 | \
; RUN:   FileCheck -check-prefix=CHECK %s
;
; Verify that the test code produces the original loop body frequency we expect.
; CHECK: - do.body: float = 10.0,

; ------------------------------------------------------------------------------
; RUN: opt < %s -S -passes='loop-unroll,print<block-freq>' \
; RUN:     -unroll-force-peel-count=2 2>&1 | \
; RUN:   FileCheck %s -check-prefix=CHECK-UR \
; RUN:       -implicit-check-not='llvm.loop.estimated_trip_count' \
; RUN:       -implicit-check-not='!prof' \
; RUN:       -implicit-check-not='branch_weights' \
; RUN:       -implicit-check-not='call void @f'
;
; The sum is the original loop body frequency, 10.
; CHECK-UR: block-frequency-info: test
; CHECK-UR: - do.body.peel: float = 1.0,
; CHECK-UR: - do.body.peel2: float = 0.9,
; CHECK-UR: - do.body: float = 8.1,
;
; The original branch weights are preserved across all peeled iterations and the
; remaining loop, and there is one original loop body (represented by a call to
; @f) within each peeled iteration.
; CHECK-UR: call void @f
; CHECK-UR: br i1 %{{.*}}, label %do.end, label %do.body.peel.next, !prof !0
; CHECK-UR: call void @f
; CHECK-UR: br i1 %{{.*}}, label %do.end, label %do.body.peel.next1, !prof !0
; CHECK-UR: call void @f
; CHECK-UR: br i1 %{{.*}}, label %do.end.loopexit, label %do.body, !prof !0, !llvm.loop !1
; CHECK-UR: !0 = !{!"branch_weights", i32 1, i32 9}
;
; llvm.loop.estimated_trip_count plus the number of peeled iterations, 2, equals
; the original estimated trip count, which is the original loop body frequency,
; 10, because there is no prior llvm.loop.estimated_trip_count.
; CHECK-UR: !1 = distinct !{!1, !2, !3, !4}
; CHECK-UR: !2 = !{!"llvm.loop.peeled.count", i32 2}
; CHECK-UR: !3 = !{!"llvm.loop.estimated_trip_count", i32 8}
; CHECK-UR: !4 = !{!"llvm.loop.unroll.disable"}

declare void @f(i32)

define void @test(i32 %n) {

entry:
  br label %do.body

do.body:
  %i = phi i32 [ 0, %entry ], [ %inc, %do.body ]
  %inc = add i32 %i, 1
  call void @f(i32 %i)
  %c = icmp sge i32 %inc, %n
  br i1 %c, label %do.end, label %do.body, !prof !0

do.end:
  ret void
}

!0 = !{!"branch_weights", i32 1, i32 9}