llvm-opt-report - Man Page

generate optimization report from YAML

Synopsis

llvm-opt-report [options] [input]

Description

llvm-opt-report is a tool to generate an optimization report from YAML optimization record files.

You need to create an input YAML optimization record file before running llvm-opt-report.

$ clang -c foo.c -o foo.o -O3 -fsave-optimization-record

Then, you create a report using the llvm-opt-report command with the YAML optimization record file foo.opt.yaml as input.

$ llvm-opt-report foo.opt.yaml -o foo.lst

foo.lst is the generated optimization report.

< foo.c
 1          | void bar();
 2          | void foo() { bar(); }
 3          |
 4          | void Test(int *res, int *c, int *d, int *p, int n) {
 5          |   int i;
 6          |
 7          | #pragma clang loop vectorize(assume_safety)
 8     V4,1 |   for (i = 0; i < 1600; i++) {
 9          |     res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
10          |   }
11          |
12  U16     |   for (i = 0; i < 16; i++) {
13          |     res[i] = (p[i] == 0) ? res[i] : res[i] + d[i];
14          |   }
15          |
16 I        |   foo();
17          |
18          |   foo(); bar(); foo();
   I        |   ^
   I        |                 ^
19          | }
20          |

Symbols printed on the left side of the program indicate what kind of optimization was performed. The meanings of the symbols are as follows:

I: The function is inlined.
U: The loop is unrolled. The following number indicates the unroll factor.
V: The loop is vectorized. The following numbers indicate the vector length and the interleave factor.

Options

If input is "-" or omitted, llvm-opt-report reads from standard input. Otherwise, it will read from the specified filename.

If the -o option is omitted, then llvm-opt-report will send its output to standard output. If the -o option specifies "-", then the output will also be sent to standard output.

--help

Display available options.

--version

Display the version of this program.

--format=<string>

The format of the optimization record file. The Argument is one of the following: