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; RUN: opt -analyze -scalar-evolution < %s | FileCheck %s
; The initial SCEV for the backedge count is
; (zext i2 {(trunc i32 (1 + %a1) to i2),+,1}<%b2> to i32).
; In howFarToZero, this was further converted to an add-rec, the complexity
; of which defeated the calculation of the backedge taken count.
; Since such zero-extensions preserve the values being extended, strip
; them in howFarToZero to simplify the input SCEV.
; Check that the backedge taken count was actually computed:
; CHECK: Determining loop execution counts for: @f0
; CHECK-NEXT: Loop %b2: backedge-taken count is (-1 + (-1 * (trunc i32 %a1 to i2)))
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64"
define i32 @f0(i32 %a0, i32 %a1, i32* nocapture %a2) #0 {
b0:
%v0 = and i32 %a1, 3
%v1 = icmp eq i32 %v0, 0
br i1 %v1, label %b4, label %b1
b1: ; preds = %b0
%v2 = shl i32 %a0, 7
%v3 = add i32 %v2, -128
br label %b2
b2: ; preds = %b2, %b1
%v4 = phi i32 [ %a1, %b1 ], [ %v9, %b2 ]
%v5 = phi i32* [ %a2, %b1 ], [ %v8, %b2 ]
%v6 = getelementptr inbounds i32, i32* %v5, i32 0
store i32 %v3, i32* %v6, align 4
%v8 = getelementptr inbounds i32, i32* %v5, i32 1
%v9 = add nsw i32 %v4, 1
%v10 = and i32 %v9, 3
%v11 = icmp eq i32 %v10, 0
br i1 %v11, label %b3, label %b2
b3: ; preds = %b2
br label %b4
b4: ; preds = %b3, %b0
ret i32 0
}
attributes #0 = { norecurse nounwind }
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