[Bug tree-optimization/92645] Hand written vector code is 450 times slower when compiled with GCC compared to Clang

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92645

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Nov 26 08:32:38 2019
New Revision: 278719

URL: https://gcc.gnu.org/viewcvs?rev=278719&root=gcc&view=rev
Log:
2019-11-26  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/92645
        * tree-vect-slp.c (vect_build_slp_tree_2): For unary ops
        do not build the operation from scalars if the operand is.

        * gcc.target/i386/pr92645.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr92645.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-slp.c