xref: /aosp_15_r20/external/llvm/test/Transforms/LoopStrengthReduce/ephemeral.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker; RUN: opt < %s -loop-reduce -S | FileCheck %s
2*9880d681SAndroid Build Coastguard Worker
3*9880d681SAndroid Build Coastguard Workertarget datalayout = "e-i64:64-v16:16-v32:32-n16:32:64"
4*9880d681SAndroid Build Coastguard Worker
5*9880d681SAndroid Build Coastguard Worker; for (int i = 0; i < n; ++i) {
6*9880d681SAndroid Build Coastguard Worker;   use(i * 5 + 3);
7*9880d681SAndroid Build Coastguard Worker;   // i * a + b is ephemeral and shouldn't be promoted by LSR
8*9880d681SAndroid Build Coastguard Worker;   __builtin_assume(i * a + b >= 0);
9*9880d681SAndroid Build Coastguard Worker; }
10*9880d681SAndroid Build Coastguard Workerdefine void @ephemeral(i32 %a, i32 %b, i32 %n) {
11*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @ephemeral(
12*9880d681SAndroid Build Coastguard Workerentry:
13*9880d681SAndroid Build Coastguard Worker  br label %loop
14*9880d681SAndroid Build Coastguard Worker
15*9880d681SAndroid Build Coastguard Workerloop:
16*9880d681SAndroid Build Coastguard Worker  %i = phi i32 [ 0, %entry ], [ %inc, %loop ]
17*9880d681SAndroid Build Coastguard Worker  ; Only i and i * 5 + 3 should be indvars, not i * a + b.
18*9880d681SAndroid Build Coastguard Worker; CHECK: phi i32
19*9880d681SAndroid Build Coastguard Worker; CHECK: phi i32
20*9880d681SAndroid Build Coastguard Worker; CHECK-NOT: phi i32
21*9880d681SAndroid Build Coastguard Worker  %inc = add nsw i32 %i, 1
22*9880d681SAndroid Build Coastguard Worker  %exitcond = icmp eq i32 %inc, %n
23*9880d681SAndroid Build Coastguard Worker
24*9880d681SAndroid Build Coastguard Worker  %0 = mul nsw i32 %i, 5
25*9880d681SAndroid Build Coastguard Worker  %1 = add nsw i32 %0, 3
26*9880d681SAndroid Build Coastguard Worker  call void @use(i32 %1)
27*9880d681SAndroid Build Coastguard Worker
28*9880d681SAndroid Build Coastguard Worker  %2 = mul nsw i32 %i, %a
29*9880d681SAndroid Build Coastguard Worker  %3 = add nsw i32 %2, %b
30*9880d681SAndroid Build Coastguard Worker  %4 = icmp sgt i32 %3, -1
31*9880d681SAndroid Build Coastguard Worker  call void @llvm.assume(i1 %4)
32*9880d681SAndroid Build Coastguard Worker
33*9880d681SAndroid Build Coastguard Worker  br i1 %exitcond, label %exit, label %loop
34*9880d681SAndroid Build Coastguard Worker
35*9880d681SAndroid Build Coastguard Workerexit:
36*9880d681SAndroid Build Coastguard Worker  ret void
37*9880d681SAndroid Build Coastguard Worker}
38*9880d681SAndroid Build Coastguard Worker
39*9880d681SAndroid Build Coastguard Workerdeclare void @use(i32)
40*9880d681SAndroid Build Coastguard Worker
41*9880d681SAndroid Build Coastguard Workerdeclare void @llvm.assume(i1)
42