1; RUN: opt < %s -reassociate -dce -S | FileCheck %s
2; PR12985
3
4; Verify the nsw flags are preserved when converting shl to mul.
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6; CHECK-LABEL: @shl_to_mul_nsw(
7; CHECK: %mul = mul i32 %i, -2147483648
8; CHECK: add i32 %mul, 1
9define i32 @shl_to_mul_nsw(i32 %i) {
10entry:
11  %mul = shl nsw i32 %i, 31
12  %mul2 = add i32 %mul, 1
13  ret i32 %mul2
14}
15
16; CHECK-LABEL: @shl_to_mul_nuw(
17; CHECK: %mul = mul nuw i32 %i, 4
18; CHECK: add i32 %mul, 1
19define i32 @shl_to_mul_nuw(i32 %i) {
20entry:
21  %mul = shl nuw i32 %i, 2
22  %mul2 = add i32 %mul, 1
23  ret i32 %mul2
24}
25
26; CHECK-LABEL: @shl_to_mul_nuw_nsw(
27; CHECK: %mul = mul nuw nsw i32 %i, 4
28; CHECK: add i32 %mul, 1
29define i32 @shl_to_mul_nuw_nsw(i32 %i) {
30entry:
31  %mul = shl nuw nsw i32 %i, 2
32  %mul2 = add i32 %mul, 1
33  ret i32 %mul2
34}
35