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[Bug tree-optimization/71060] New: Compiler reports "loop vectorized" but actually it was not
- From: "niva at niisi dot msk.ru" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 11 May 2016 09:20:04 +0000
- Subject: [Bug tree-optimization/71060] New: Compiler reports "loop vectorized" but actually it was not
- Auto-submitted: auto-generated
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71060
Bug ID: 71060
Summary: Compiler reports "loop vectorized" but actually it
was not
Product: gcc
Version: 5.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: niva at niisi dot msk.ru
Target Milestone: ---
Created attachment 38467
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38467&action=edit
The test case to reproduce the problem
I compile the attached test8.c as follows:
/usr/local/bin/gcc -O3 -S -mavx -fopt-info-vec-optimized -DSCOUT -Wall
-Wextra -Werror -Wno-unknown-pragmas test8.c -o test8.s3
The output is:
test8.c:24:2: note: loop vectorized
test8.c:24:2: note: loop versioned for vectorization because of possible
aliasing
But the resulting assembler code contains no vector instructions.
Other problems related to this test are:
1. The pointers in this function has the restrict specifier, so there should be
no loop versioning.
2. I tried to use -ftree-loop-if-convert-stores but it did not help.
Possibly this bug is the same as 65206.