https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112483
Xi Ruoyao <xry111 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |tamar.christina at arm dot com
Last reconfirmed| |2023-11-12
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #1 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
First bad commit is r14-5284:
middle-end: optimize fneg (fabs (x)) to copysign (x, -1) [PR109154]
This patch transforms fneg (fabs (x)) into copysign (x, -1) which is more
canonical and allows a target to expand this sequence efficiently. Such
sequences are common in scientific code working with gradients.
There is an existing canonicalization of copysign (x, -1) to fneg (fabs
(x))
which I remove since this is a less efficient form. The testsuite is also
updated in light of this.
gcc/ChangeLog:
PR tree-optimization/109154
* match.pd: Add new neg+abs rule, remove inverse copysign rule.
gcc/testsuite/ChangeLog:
PR tree-optimization/109154
* gcc.dg/fold-copysign-1.c: Updated.
* gcc.dg/pr55152-2.c: Updated.
* gcc.dg/tree-ssa/abs-4.c: Updated.
* gcc.dg/tree-ssa/backprop-6.c: Updated.
* gcc.dg/tree-ssa/copy-sign-2.c: Updated.
* gcc.dg/tree-ssa/mult-abs-2.c: Updated.
* gcc.target/aarch64/fneg-abs_1.c: New test.
* gcc.target/aarch64/fneg-abs_2.c: New test.
* gcc.target/aarch64/fneg-abs_3.c: New test.
* gcc.target/aarch64/fneg-abs_4.c: New test.
* gcc.target/aarch64/sve/fneg-abs_1.c: New test.
* gcc.target/aarch64/sve/fneg-abs_2.c: New test.
* gcc.target/aarch64/sve/fneg-abs_3.c: New test.
* gcc.target/aarch64/sve/fneg-abs_4.c: New test.
