1 ; RUN: opt -analyze -scalar-evolution < %s | FileCheck %s 2 3 ; The initial SCEV for the backedge count is 4 ; (zext i2 {(trunc i32 (1 + %a1) to i2),+,1}<%b2> to i32). 5 ; In howFarToZero, this was further converted to an add-rec, the complexity 6 ; of which defeated the calculation of the backedge taken count. 7 ; Since such zero-extensions preserve the values being extended, strip 8 ; them in howFarToZero to simplify the input SCEV. 9 10 ; Check that the backedge taken count was actually computed: 11 ; CHECK: Determining loop execution counts for: @f0 12 ; CHECK-NEXT: Loop %b2: backedge-taken count is (-1 + (-1 * (trunc i32 %a1 to i2))) 13 14 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" 15 16 define i32 @f0(i32 %a0, i32 %a1, i32* nocapture %a2) #0 { 17 b0: 18 %v0 = and i32 %a1, 3 19 %v1 = icmp eq i32 %v0, 0 20 br i1 %v1, label %b4, label %b1 21 22 b1: ; preds = %b0 23 %v2 = shl i32 %a0, 7 24 %v3 = add i32 %v2, -128 25 br label %b2 26 27 b2: ; preds = %b2, %b1 28 %v4 = phi i32 [ %a1, %b1 ], [ %v9, %b2 ] 29 %v5 = phi i32* [ %a2, %b1 ], [ %v8, %b2 ] 30 %v6 = getelementptr inbounds i32, i32* %v5, i32 0 31 store i32 %v3, i32* %v6, align 4 32 %v8 = getelementptr inbounds i32, i32* %v5, i32 1 33 %v9 = add nsw i32 %v4, 1 34 %v10 = and i32 %v9, 3 35 %v11 = icmp eq i32 %v10, 0 36 br i1 %v11, label %b3, label %b2 37 38 b3: ; preds = %b2 39 br label %b4 40 41 b4: ; preds = %b3, %b0 42 ret i32 0 43 } 44 45 attributes #0 = { norecurse nounwind } 46
