xref: /llvm-project/polly/test/CodeGen/exprModDiv.ll (revision e1f056f692d869708c1898d9d65a69ac5584a0ed)
1; RUN: opt %loadNPMPolly '-passes=polly-import-jscop,polly-codegen' \
2; RUN:     -S < %s | FileCheck %s
3; RUN: opt %loadNPMPolly '-passes=polly-import-jscop,polly-codegen' \
4; RUN:     -polly-import-jscop-postfix=pow2 \
5; RUN:     -S < %s | FileCheck %s -check-prefix=POW2
6;
7;    void exprModDiv(float *A, float *B, float *C, long N, long p) {
8;      for (long i = 0; i < N; i++)
9;        C[i] += A[i] + B[i] + A[i] + B[i + p];
10;    }
11;
12;
13; This test case changes the access functions such that the resulting index
14; expressions are modulo or division operations. We test that the code we
15; generate takes advantage of knowledge about unsigned numerators. This is
16; useful as LLVM will translate urem and udiv operations with power-of-two
17; denominators to fast bitwise and or shift operations.
18
19; A[i % 127]
20; CHECK:  %pexp.pdiv_r = urem i64 %polly.indvar, 127
21; CHECK:  %polly.access.A9 = getelementptr float, ptr %A, i64 %pexp.pdiv_r
22
23; A[floor(i / 127)]
24;
25; Note: without the floor, we would create a map i -> i/127, which only contains
26;       values of i that are divisible by 127. All other values of i would not
27;       be mapped to any value. However, to generate correct code we require
28;       each value of i to indeed be mapped to a value.
29;
30; CHECK:  %pexp.p_div_q = udiv i64 %polly.indvar, 127
31; CHECK:  %polly.access.B10 = getelementptr float, ptr %B, i64 %pexp.p_div_q
32
33; A[p % 128]
34
35; A[p / 127]
36; CHECK:  %pexp.div = sdiv exact i64 %p, 127
37; CHECK:  %polly.access.B12 = getelementptr float, ptr %B, i64 %pexp.div
38
39; A[i % 128]
40; POW2:  %pexp.pdiv_r = urem i64 %polly.indvar, 128
41; POW2:  %polly.access.A9 = getelementptr float, ptr %A, i64 %pexp.pdiv_r
42
43; A[floor(i / 128)]
44; POW2:  %pexp.p_div_q = udiv i64 %polly.indvar, 128
45; POW2:  %polly.access.B10 = getelementptr float, ptr %B, i64 %pexp.p_div_q
46
47; A[p % 128]
48
49; A[p / 128]
50; POW2:  %pexp.div = sdiv exact i64 %p, 128
51; POW2:  %polly.access.B12 = getelementptr float, ptr %B, i64 %pexp.div
52
53target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
54
55define void @exprModDiv(ptr %A, ptr %B, ptr %C, i64 %N, i64 %p) {
56entry:
57  br label %for.cond
58
59for.cond:                                         ; preds = %for.inc, %entry
60  %i.0 = phi i64 [ 0, %entry ], [ %inc, %for.inc ]
61  %cmp = icmp slt i64 %i.0, %N
62  br i1 %cmp, label %for.body, label %for.end
63
64for.body:                                         ; preds = %for.cond
65  %arrayidx = getelementptr inbounds float, ptr %A, i64 %i.0
66  %tmp = load float, ptr %arrayidx, align 4
67  %arrayidx1 = getelementptr inbounds float, ptr %B, i64 %i.0
68  %tmp1 = load float, ptr %arrayidx1, align 4
69  %add = fadd float %tmp, %tmp1
70  %arrayidx2 = getelementptr inbounds float, ptr %A, i64 %i.0
71  %tmp2 = load float, ptr %arrayidx2, align 4
72  %add3 = fadd float %add, %tmp2
73  %padd = add nsw i64 %p, %i.0
74  %arrayidx4 = getelementptr inbounds float, ptr %B, i64 %padd
75  %tmp3 = load float, ptr %arrayidx4, align 4
76  %add5 = fadd float %add3, %tmp3
77  %arrayidx6 = getelementptr inbounds float, ptr %C, i64 %i.0
78  %tmp4 = load float, ptr %arrayidx6, align 4
79  %add7 = fadd float %tmp4, %add5
80  store float %add7, ptr %arrayidx6, align 4
81  br label %for.inc
82
83for.inc:                                          ; preds = %for.body
84  %inc = add nuw nsw i64 %i.0, 1
85  br label %for.cond
86
87for.end:                                          ; preds = %for.cond
88  ret void
89}
90