1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
; RUN: opt -loop-accesses -analyze < %s | FileCheck %s
; In this loop just because we access A through different types (int, float)
; we still have a dependence cycle:
;
; for (i = 0; i < n; i++) {
; A_float = (float *) A;
; A_float[i + 1] = A[i] * B[i];
; }
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.10.0"
; CHECK: Report: unsafe dependent memory operations in loop
; CHECK-NOT: Memory dependences are safe
@B = common global i32* null, align 8
@A = common global i32* null, align 8
define void @f() {
entry:
%a = load i32*, i32** @A, align 8
%b = load i32*, i32** @B, align 8
br label %for.body
for.body: ; preds = %for.body, %entry
%storemerge3 = phi i64 [ 0, %entry ], [ %add, %for.body ]
%arrayidxA = getelementptr inbounds i32, i32* %a, i64 %storemerge3
%loadA = load i32, i32* %arrayidxA, align 2
%arrayidxB = getelementptr inbounds i32, i32* %b, i64 %storemerge3
%loadB = load i32, i32* %arrayidxB, align 2
%mul = mul i32 %loadB, %loadA
%add = add nuw nsw i64 %storemerge3, 1
%a_float = bitcast i32* %a to float*
%arrayidxA_plus_2 = getelementptr inbounds float, float* %a_float, i64 %add
%mul_float = sitofp i32 %mul to float
store float %mul_float, float* %arrayidxA_plus_2, align 2
%exitcond = icmp eq i64 %add, 20
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}
|
