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| ; RUN: opt -verify-loop-info -irce-print-changed-loops -irce -S
; RUN: opt -verify-loop-info -irce-print-changed-loops -passes='require<branch-prob>,loop(irce)' -S
; Make sure that IRCE doesn't apply in case of empty ranges.
; (i + 30 < 40) if i in [-30, 10).
; Intersected with iteration space, it is [0, 10).
; (i - 60 < 40) if i in [60 , 100).
; The intersection with safe iteration space is the empty range [60, 10).
; It is better to eliminate one range check than attempt to eliminate both given
; that we will never go to the main loop in the latter case and basically
; only duplicate code with no benefits.
define void @test_01(i32* %arr, i32* %a_len_ptr) #0 {
; CHECK-LABEL: test_01(
; CHECK-NOT: preloop
; CHECK: entry:
; CHECK-NEXT: br i1 true, label %loop.preheader, label %main.pseudo.exit
; CHECK: in.bounds.1:
; CHECK-NEXT: %addr = getelementptr i32, i32* %arr, i32 %idx
; CHECK-NEXT: store i32 0, i32* %addr
; CHECK-NEXT: %off1 = add i32 %idx, 30
; CHECK-NEXT: %c2 = icmp slt i32 %off1, 40
; CHECK-NEXT: br i1 true, label %in.bounds.2, label %exit.loopexit2
; CHECK: in.bounds.2:
; CHECK-NEXT: %off2 = add i32 %idx, -60
; CHECK-NEXT: %c3 = icmp slt i32 %off2, 40
; CHECK-NEXT: br i1 %c3, label %in.bounds.3, label %exit.loopexit2
; CHECK: in.bounds.3:
; CHECK-NEXT: %next = icmp ult i32 %idx.next, 100
; CHECK-NEXT: [[COND1:%[^ ]+]] = icmp ult i32 %idx.next, 10
; CHECK-NEXT: br i1 [[COND1]], label %loop, label %main.exit.selector
; CHECK: main.exit.selector:
; CHECK-NEXT: %idx.next.lcssa = phi i32 [ %idx.next, %in.bounds.3 ]
; CHECK-NEXT: [[COND2:%[^ ]+]] = icmp ult i32 %idx.next.lcssa, 100
; CHECK-NEXT: br i1 [[COND2]], label %main.pseudo.exit, label %exit
; CHECK: postloop:
entry:
br label %loop
loop:
%idx = phi i32 [ 0, %entry ], [ %idx.next, %in.bounds.3 ]
%idx.next = add nsw nuw i32 %idx, 1
%c1 = icmp slt i32 %idx, 20
br i1 %c1, label %in.bounds.1, label %out.of.bounds
in.bounds.1:
%addr = getelementptr i32, i32* %arr, i32 %idx
store i32 0, i32* %addr
%off1 = add i32 %idx, 30
%c2 = icmp slt i32 %off1, 40
br i1 %c2, label %in.bounds.2, label %exit
in.bounds.2:
%off2 = add i32 %idx, -60
%c3 = icmp slt i32 %off2, 40
br i1 %c3, label %in.bounds.3, label %exit
in.bounds.3:
%next = icmp ult i32 %idx.next, 100
br i1 %next, label %loop, label %exit
out.of.bounds:
ret void
exit:
ret void
}
|