44 lines · plain
1; RUN: opt < %s -passes=loop-vectorize,dce,instcombine -force-vector-interleave=1 -force-vector-width=4 -S | FileCheck %s2 3target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"4 5; PR15882: This test ensures that we do not produce wrapping arithmetic when6; creating constant reverse step vectors.7;8; int foo(int n, int *A) {9; int sum;10; for (int i=n; i > 0; i--)11; sum += A[i*2];12; return sum;13; }14;15 16;CHECK-LABEL: @foo(17;CHECK: <i32 0, i32 -1, i32 -2, i32 -3>18;CHECK: ret19define i32 @foo(i32 %n, ptr nocapture %A) {20 br label %.lr.ph21 22.lr.ph: ; preds = %023 %2 = sext i32 %n to i6424 br label %325 26; <label>:3 ; preds = %.lr.ph, %327 %indvars.iv = phi i64 [ %2, %.lr.ph ], [ %indvars.iv.next, %3 ]28 %sum.01 = phi i32 [ 0, %.lr.ph ], [ %9, %3 ]29 %4 = trunc i64 %indvars.iv to i3230 %5 = shl nsw i32 %4, 131 %6 = sext i32 %5 to i6432 %7 = getelementptr inbounds i32, ptr %A, i64 %633 %8 = load i32, ptr %7, align 434 %9 = add nsw i32 %8, %sum.0135 %indvars.iv.next = add i64 %indvars.iv, -136 %10 = trunc i64 %indvars.iv.next to i3237 %11 = icmp sgt i32 %10, 038 br i1 %11, label %3, label %._crit_edge39 40._crit_edge: ; preds = %341 ret i32 %942}43 44