xref: /llvm-project/llvm/test/Analysis/BasicAA/phi-loop.ll (revision 05ff7606c9d47135ecf5b69e25b1327634f6fa27)
1; RUN: opt < %s -aa-pipeline=basic-aa -passes=gvn -S | FileCheck %s
2;
3; Check that section->word_ofs doesn't get reloaded in every iteration of the
4; for loop.
5;
6; Code:
7;
8; typedef struct {
9;   unsigned num_words;
10;   unsigned word_ofs;
11;   const unsigned *data;
12; } section_t;
13;
14;
15; void test2(const section_t * restrict section, unsigned * restrict dst) {;
16;   while (section->data != NULL) {
17;     const unsigned *src = section->data;
18;     for (unsigned i=0; i < section->num_words; ++i) {
19;       dst[section->word_ofs + i] = src[i];
20;     }
21;
22;     ++section;
23;   }
24; }
25;
26
27; CHECK-LABEL: for.body:
28; CHECK-NOT: load i32, i32* %word_ofs
29
30%struct.section_t = type { i32, i32, ptr }
31
32define void @test2(ptr noalias nocapture readonly %section, ptr noalias nocapture %dst) {
33entry:
34  %data13 = getelementptr inbounds %struct.section_t, ptr %section, i32 0, i32 2
35  %0 = load ptr, ptr %data13, align 4
36  %cmp14 = icmp eq ptr %0, null
37  br i1 %cmp14, label %while.end, label %for.cond.preheader
38
39for.cond.preheader:                               ; preds = %entry, %for.end
40  %1 = phi ptr [ %6, %for.end ], [ %0, %entry ]
41  %section.addr.015 = phi ptr [ %incdec.ptr, %for.end ], [ %section, %entry ]
42  %2 = load i32, ptr %section.addr.015, align 4
43  %cmp211 = icmp eq i32 %2, 0
44  br i1 %cmp211, label %for.end, label %for.body.lr.ph
45
46for.body.lr.ph:                                   ; preds = %for.cond.preheader
47  %word_ofs = getelementptr inbounds %struct.section_t, ptr %section.addr.015, i32 0, i32 1
48  br label %for.body
49
50for.body:                                         ; preds = %for.body.lr.ph, %for.body
51  %arrayidx.phi = phi ptr [ %1, %for.body.lr.ph ], [ %arrayidx.inc, %for.body ]
52  %i.012 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
53  %3 = load i32, ptr %arrayidx.phi, align 4
54  %4 = load i32, ptr %word_ofs, align 4
55  %add = add i32 %4, %i.012
56  %arrayidx3 = getelementptr inbounds i32, ptr %dst, i32 %add
57  store i32 %3, ptr %arrayidx3, align 4
58  %inc = add i32 %i.012, 1
59  %5 = load i32, ptr %section.addr.015, align 4
60  %cmp2 = icmp ult i32 %inc, %5
61  %arrayidx.inc = getelementptr i32, ptr %arrayidx.phi, i32 1
62  br i1 %cmp2, label %for.body, label %for.end
63
64for.end:                                          ; preds = %for.body, %for.cond.preheader
65  %incdec.ptr = getelementptr inbounds %struct.section_t, ptr %section.addr.015, i32 1
66  %data = getelementptr inbounds %struct.section_t, ptr %section.addr.015, i32 1, i32 2
67  %6 = load ptr, ptr %data, align 4
68  %cmp = icmp eq ptr %6, null
69  br i1 %cmp, label %while.end, label %for.cond.preheader
70
71while.end:                                        ; preds = %for.end, %entry
72  ret void
73}
74
75