https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70882
Bug ID: 70882
Summary: vectorized sincos trashes the stack
Product: gcc
Version: 5.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: blaffablaffa at gmail dot com
Target Milestone: ---
Created attachment 38381
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38381&action=edit
testcase
The double4 version of the vectorized sincos() in libmvec (glibc 2.22) causes
the stack to be corrupted, leading to assorted bugs such as crash, backtrace
corruption in gdb, etc. I am reporting a bug here because since it's the only
vectorized math function that uses pointers, so it might be an ABI problem. On
my CPU (ivybridge) I can only test the double4 version, not the wider ones.
Attached testcase, compile with
g++ -std=c++11 -O1 -fopenmp -ffast-math -march=ivybridge -mtune=ivybridge -o
double_sincos double_sincos.cpp
(interestingly, the vectorized call is not emitted with a c++ version lower
than 2011).
