xref: /llvm-project/llvm/test/Transforms/IRCE/single-access-with-preloop.ll (revision 0ec421d024fe47fb43afdaa625309b0f799e9a59)
1; RUN: opt -verify-loop-info -passes=irce -S < %s | FileCheck %s
2; RUN: opt -verify-loop-info -passes='require<branch-prob>,irce' -S < %s | FileCheck %s
3
4define void @single_access_with_preloop(ptr %arr, ptr %a_len_ptr, i32 %n, i32 %offset) {
5 entry:
6  %len = load i32, ptr %a_len_ptr, !range !0
7  %first.itr.check = icmp sgt i32 %n, 0
8  br i1 %first.itr.check, label %loop, label %exit
9
10 loop:
11  %idx = phi i32 [ 0, %entry ] , [ %idx.next, %in.bounds ]
12  %idx.next = add i32 %idx, 1
13  %array.idx = add i32 %idx, %offset
14  %abc.high = icmp slt i32 %array.idx, %len
15  %abc.low = icmp sge i32 %array.idx, 0
16  %abc = and i1 %abc.low, %abc.high
17  br i1 %abc, label %in.bounds, label %out.of.bounds, !prof !1
18
19 in.bounds:
20  %addr = getelementptr i32, ptr %arr, i32 %array.idx
21  store i32 0, ptr %addr
22  %next = icmp slt i32 %idx.next, %n
23  br i1 %next, label %loop, label %exit
24
25 out.of.bounds:
26  ret void
27
28 exit:
29  ret void
30}
31
32; CHECK-LABEL: @single_access_with_preloop(
33; CHECK: loop.preheader:
34; CHECK: [[safe_offset_preloop:[^ ]+]] = call i32 @llvm.smax.i32(i32 %offset, i32 -2147483647)
35; If Offset was a SINT_MIN, we could have an overflow here. That is why we calculated its safe version.
36; CHECK: [[safe_start:[^ ]+]] = sub i32 0, [[safe_offset_preloop]]
37; CHECK: [[exit_preloop_at_loclamp:[^ ]+]] = call i32 @llvm.smin.i32(i32 %n, i32 [[safe_start]])
38; CHECK: [[exit_preloop_at:[^ ]+]] = call i32 @llvm.smax.i32(i32 [[exit_preloop_at_loclamp]], i32 0)
39
40
41; CHECK: [[len_minus_sint_max:[^ ]+]] = add nuw nsw i32 %len, -2147483647
42; CHECK: [[safe_offset_mainloop:[^ ]+]] = call i32 @llvm.smax.i32(i32 %offset, i32 [[len_minus_sint_max]])
43; If Offset was a SINT_MIN, we could have an overflow here. That is why we calculated its safe version.
44; CHECK: [[safe_upper_end:[^ ]+]] = sub i32 %len, [[safe_offset_mainloop]]
45; CHECK: [[exit_mainloop_at_loclamp:[^ ]+]] = call i32 @llvm.smin.i32(i32 %n, i32 [[safe_upper_end]])
46; CHECK: [[safe_offset_mainloop_2:[^ ]+]] = call i32 @llvm.smax.i32(i32 %offset, i32 0)
47; CHECK: [[safe_lower_end:[^ ]+]] = sub i32 2147483647, [[safe_offset_mainloop_2]]
48; CHECK: [[exit_mainloop_at_hiclamp:[^ ]+]] = call i32 @llvm.smin.i32(i32 [[exit_mainloop_at_loclamp]], i32 [[safe_lower_end]])
49; CHECK: [[exit_mainloop_at:[^ ]+]] = call i32 @llvm.smax.i32(i32 [[exit_mainloop_at_hiclamp]], i32 0)
50
51; CHECK: mainloop:
52; CHECK: br label %loop
53
54; CHECK: loop:
55; CHECK: %abc.high = icmp slt i32 %array.idx, %len
56; CHECK: %abc.low = icmp sge i32 %array.idx, 0
57; CHECK: %abc = and i1 true, true
58; CHECK: br i1 %abc, label %in.bounds, label %[[loopexit:[^ ,]+]]
59
60; CHECK: in.bounds:
61; CHECK: [[continue_mainloop_cond:[^ ]+]] = icmp slt i32 %idx.next, [[exit_mainloop_at]]
62; CHECK: br i1 [[continue_mainloop_cond]], label %loop, label %main.exit.selector
63
64; CHECK: main.exit.selector:
65; CHECK: [[mainloop_its_left:[^ ]+]] = icmp slt i32 %idx.next.lcssa, %n
66; CHECK: br i1 [[mainloop_its_left]], label %main.pseudo.exit, label %exit.loopexit
67
68; CHECK: in.bounds.preloop:
69; CHECK: [[continue_preloop_cond:[^ ]+]] = icmp slt i32 %idx.next.preloop, [[exit_preloop_at]]
70; CHECK: br i1 [[continue_preloop_cond]], label %loop.preloop, label %preloop.exit.selector
71
72; CHECK: preloop.exit.selector:
73; CHECK: [[preloop_its_left:[^ ]+]] = icmp slt i32 %idx.next.preloop.lcssa, %n
74; CHECK: br i1 [[preloop_its_left]], label %preloop.pseudo.exit, label %exit.loopexit
75
76; CHECK: in.bounds.postloop:
77; CHECK: %next.postloop = icmp slt i32 %idx.next.postloop, %n
78; CHECK: br i1 %next.postloop, label %loop.postloop, label %exit.loopexit
79
80!0 = !{i32 0, i32 2147483647}
81!1 = !{!"branch_weights", i32 64, i32 4}
82