xref: /aosp_15_r20/external/llvm/test/Transforms/GVN/pre-no-cost-phi.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; RUN: opt < %s -gvn -S | FileCheck %s
2*9880d681SAndroid Build Coastguard Worker; This testcase tests insertion of no-cost phis.  That is,
3*9880d681SAndroid Build Coastguard Worker; when the value is already available in every predecessor,
4*9880d681SAndroid Build Coastguard Worker; and we just need to insert a phi node to merge the available values.
5*9880d681SAndroid Build Coastguard Worker
6*9880d681SAndroid Build Coastguard Worker@c = global i32 0, align 4
7*9880d681SAndroid Build Coastguard Worker@d = global i32 0, align 4
8*9880d681SAndroid Build Coastguard Worker
9*9880d681SAndroid Build Coastguard Worker
10*9880d681SAndroid Build Coastguard Workerdefine i32 @mai(i32 %foo, i32 %a, i32 %b) {
11*9880d681SAndroid Build Coastguard Worker  %1 = icmp ne i32 %foo, 0
12*9880d681SAndroid Build Coastguard Worker  br i1 %1, label %bb1, label %bb2
13*9880d681SAndroid Build Coastguard Worker
14*9880d681SAndroid Build Coastguard Workerbb1:
15*9880d681SAndroid Build Coastguard Worker  %2 = add nsw i32 %a, %b
16*9880d681SAndroid Build Coastguard Worker  store i32 %2, i32* @c, align 4
17*9880d681SAndroid Build Coastguard Worker  br label %mergeblock
18*9880d681SAndroid Build Coastguard Worker
19*9880d681SAndroid Build Coastguard Workerbb2:
20*9880d681SAndroid Build Coastguard Worker  %3 = add nsw i32 %a, %b
21*9880d681SAndroid Build Coastguard Worker  store i32 %3, i32* @d, align 4
22*9880d681SAndroid Build Coastguard Worker  br label %mergeblock
23*9880d681SAndroid Build Coastguard Worker
24*9880d681SAndroid Build Coastguard Workermergeblock:
25*9880d681SAndroid Build Coastguard Worker; CHECK: pre-phi = phi i32 [ %3, %bb2 ], [ %2, %bb1 ]
26*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT: ret i32 %.pre-phi
27*9880d681SAndroid Build Coastguard Worker  %4 = add nsw i32 %a, %b
28*9880d681SAndroid Build Coastguard Worker  ret i32 %4
29*9880d681SAndroid Build Coastguard Worker}
30*9880d681SAndroid Build Coastguard Worker
31*9880d681SAndroid Build Coastguard Worker
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