1; RUN: opt < %s -dfsan -S | FileCheck %s 2target 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" 3target triple = "x86_64-unknown-linux-gnu" 4 5@a = common global i32 0 6@b = common global i32 0 7 8; Check that we reuse unions where possible. 9 10; CHECK-LABEL: @"dfs$f" 11define void @f(i32 %x, i32 %y) { 12 ; CHECK: call{{.*}}__dfsan_union 13 %xay = add i32 %x, %y 14 store i32 %xay, i32* @a 15 ; CHECK-NOT: call{{.*}}__dfsan_union 16 %xmy = mul i32 %x, %y 17 store i32 %xmy, i32* @b 18 ret void 19} 20 21; In this case, we compute the unions on both sides because neither block 22; dominates the other. 23 24; CHECK-LABEL: @"dfs$g" 25define void @g(i1 %p, i32 %x, i32 %y) { 26 br i1 %p, label %l1, label %l2 27 28l1: 29 ; CHECK: call{{.*}}__dfsan_union 30 %xay = add i32 %x, %y 31 store i32 %xay, i32* @a 32 br label %l3 33 34l2: 35 ; CHECK: call{{.*}}__dfsan_union 36 %xmy = mul i32 %x, %y 37 store i32 %xmy, i32* @b 38 br label %l3 39 40l3: 41 ret void 42} 43 44; In this case, we know that the label for %xayax subsumes the label for %xay. 45 46; CHECK-LABEL: @"dfs$h" 47define i32 @h(i32 %x, i32 %y) { 48 ; CHECK: call{{.*}}__dfsan_union 49 %xay = add i32 %x, %y 50 ; CHECK-NOT: call{{.*}}__dfsan_union 51 %xayax = add i32 %xay, %x 52 ret i32 %xayax 53} 54