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| ; RUN: opt < %s -S -loop-unroll -unroll-threshold=30 | FileCheck %s
; RUN: opt < %s -S -loop-unroll -unroll-threshold=30 -unroll-allow-peeling=false | FileCheck %s --check-prefix=DISABLE
define i32 @invariant_backedge_1(i32 %a, i32 %b) {
; CHECK-LABEL: @invariant_backedge_1
; CHECK-NOT: %plus = phi
; CHECK: loop.peel:
; CHECK: loop:
; CHECK: %i = phi
; CHECK: %sum = phi
; DISABLE-LABEL: @invariant_backedge_1
; DISABLE-NOT: loop.peel:
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%sum = phi i32 [ 0, %entry ], [ %incsum, %loop ]
%plus = phi i32 [ %a, %entry ], [ %b, %loop ]
%incsum = add i32 %sum, %plus
%inc = add i32 %i, 1
%cmp = icmp slt i32 %i, 1000
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %sum
}
define i32 @invariant_backedge_2(i32 %a, i32 %b) {
; This loop should be peeled twice because it has a Phi which becomes invariant
; starting from 3rd iteration.
; CHECK-LABEL: @invariant_backedge_2
; CHECK: loop.peel{{.*}}:
; CHECK: loop.peel{{.*}}:
; CHECK: %i = phi
; CHECK: %sum = phi
; CHECK-NOT: %half.inv = phi
; CHECK-NOT: %plus = phi
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%sum = phi i32 [ 0, %entry ], [ %incsum, %loop ]
%half.inv = phi i32 [ %a, %entry ], [ %b, %loop ]
%plus = phi i32 [ %a, %entry ], [ %half.inv, %loop ]
%incsum = add i32 %sum, %plus
%inc = add i32 %i, 1
%cmp = icmp slt i32 %i, 1000
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %sum
}
define i32 @invariant_backedge_3(i32 %a, i32 %b) {
; This loop should be peeled thrice because it has a Phi which becomes invariant
; starting from 4th iteration.
; CHECK-LABEL: @invariant_backedge_3
; CHECK: loop.peel{{.*}}:
; CHECK: loop.peel{{.*}}:
; CHECK: loop.peel{{.*}}:
; CHECK: %i = phi
; CHECK: %sum = phi
; CHECK-NOT: %half.inv = phi
; CHECK-NOT: %half.inv.2 = phi
; CHECK-NOT: %plus = phi
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%sum = phi i32 [ 0, %entry ], [ %incsum, %loop ]
%half.inv = phi i32 [ %a, %entry ], [ %b, %loop ]
%half.inv.2 = phi i32 [ %a, %entry ], [ %half.inv, %loop ]
%plus = phi i32 [ %a, %entry ], [ %half.inv.2, %loop ]
%incsum = add i32 %sum, %plus
%inc = add i32 %i, 1
%cmp = icmp slt i32 %i, 1000
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %sum
}
define i32 @invariant_backedge_limited_by_size(i32 %a, i32 %b) {
; This loop should normally be peeled thrice because it has a Phi which becomes
; invariant starting from 4th iteration, but the size of the loop only allows
; us to peel twice because we are restricted to 30 instructions in resulting
; code. Thus, %plus Phi node should stay in loop even despite its backedge
; input is an invariant.
; CHECK-LABEL: @invariant_backedge_limited_by_size
; CHECK: loop.peel{{.*}}:
; CHECK: loop.peel{{.*}}:
; CHECK: %i = phi
; CHECK: %sum = phi
; CHECK: %plus = phi i32 [ %a, {{.*}} ], [ %b, %loop ]
; CHECK-NOT: %half.inv = phi
; CHECK-NOT: %half.inv.2 = phi
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%sum = phi i32 [ 0, %entry ], [ %incsum, %loop ]
%half.inv = phi i32 [ %a, %entry ], [ %b, %loop ]
%half.inv.2 = phi i32 [ %a, %entry ], [ %half.inv, %loop ]
%plus = phi i32 [ %a, %entry ], [ %half.inv.2, %loop ]
%incsum = add i32 %sum, %plus
%inc = add i32 %i, 1
%cmp = icmp slt i32 %i, 1000
%incsum2 = add i32 %incsum, %plus
%incsum3 = add i32 %incsum, %plus
%incsum4 = add i32 %incsum, %plus
%incsum5 = add i32 %incsum, %plus
%incsum6 = add i32 %incsum, %plus
%incsum7 = add i32 %incsum, %plus
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %sum
}
; Peeling should fail due to method size.
define i32 @invariant_backedge_negative(i32 %a, i32 %b) {
; CHECK-LABEL: @invariant_backedge_negative
; CHECK-NOT: loop.peel{{.*}}:
; CHECK: loop:
; CHECK: %i = phi
; CHECK: %sum = phi
; CHECK: %plus = phi
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%sum = phi i32 [ 0, %entry ], [ %incsum2, %loop ]
%plus = phi i32 [ %a, %entry ], [ %b, %loop ]
%incsum = add i32 %sum, %plus
%incsum2 = add i32 %incsum, %plus
%incsum3 = add i32 %incsum, %plus
%incsum4 = add i32 %incsum, %plus
%incsum5 = add i32 %incsum, %plus
%incsum6 = add i32 %incsum, %plus
%incsum7 = add i32 %incsum, %plus
%incsum8 = add i32 %incsum, %plus
%incsum9 = add i32 %incsum, %plus
%incsum10 = add i32 %incsum, %plus
%incsum11 = add i32 %incsum, %plus
%incsum12 = add i32 %incsum, %plus
%incsum13 = add i32 %incsum, %plus
%incsum14 = add i32 %incsum, %plus
%incsum15 = add i32 %incsum, %plus
%inc = add i32 %i, 1
%cmp = icmp slt i32 %i, 1000
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %sum
}
define i32 @cycled_phis(i32 %a, i32 %b) {
; Make sure that we do not crash working with cycled Phis and don't peel it.
; TODO: Actually this loop should be partially unrolled with factor 2.
; CHECK-LABEL: @cycled_phis
; CHECK-NOT: loop.peel{{.*}}:
; CHECK: loop:
; CHECK: %i = phi
; CHECK: %phi.a = phi
; CHECK: %phi.b = phi
; CHECK: %sum = phi
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%phi.a = phi i32 [ %a, %entry ], [ %phi.b, %loop ]
%phi.b = phi i32 [ %b, %entry ], [ %phi.a, %loop ]
%sum = phi i32 [ 0, %entry], [ %incsum, %loop ]
%incsum = add i32 %sum, %phi.a
%inc = add i32 %i, 1
%cmp = icmp slt i32 %i, 1000
br i1 %cmp, label %loop, label %exit
exit:
ret i32 %sum
}
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