vec-report can't report all

[xiaoming_l_]

I use -vec-report=3  it can't report whether line 22 is vectored.

I don't know why , can you help me ?

$ icpc -vec-report=3 -o element element.c
element.c(26): (col. 2) remark: LOOP WAS VECTORIZED.
element.c(18): (col. 2) remark: LOOP WAS VECTORIZED.
element.c(9): (col. 1) remark: FUNCTION WAS VECTORIZED.
element.c(9): (col. 1) remark: FUNCTION WAS VECTORIZED.

code:

1 #include <stdio.h>
2 #include <stdlib.h>
3 int a[1000];
4 int N = 1000;
5 __declspec(noinline)
6 int checksum()
7 {
8 int i;
9 int sum = 0;
10 for(i =0; i < N; i++)
11 sum += a;
12
13 return sum;
14 }
15
16 int main()
17 {
18 for(int i =0; i < 1000; i++)
19 a = i;
20 int sum[100];
21 #pragma simd
22 for(int i =0; i< 100; i++)
23 sum = checksum();
24
25 return 0;
26 }

[Jianbin_F_]

Have you ever tried the code without 'noinline' declearation?

[TimP]

2 (or more) reasons:

Inner loop vectorization at line 10 should be preferred (as you have implied -fp-model=fast).

In-lining, required to vectorize a function, should lead to dead code elimination.

I think they told us customers who were consulted disliked reports of dead code elimination.  opt-report would be the way to see it if it were available.  As it is, absence of a report is likely to indicate that.

This is the MIC forum; you didn't set any MIC compile option.  Even if you did, eliminated dead code shouldn't show any value for MIC.