https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91913
--- Comment #13 from Martin Liška <marxin at gcc dot gnu.org> ---
commit r8-10119-g3d46f4875c6c50e8095294b6b700d6678a7e2f1e
Author: Richard Earnshaw <rearn...@arm.com>
Date: Fri Mar 6 10:04:51 2020 +0000
arm: correct constraints on movsi_compare0 [PR91913]
The peephole that detects a mov of one register to another followed by
a comparison of the original register against zero is only used in Arm
state; but the instruction that matches this is generic to all 32-bit
compilation states. That instruction lacks support for SP which is
permitted in Arm state, but has restrictions in Thumb2 code.
This patch fixes the problem by allowing SP when in ARM state for all
registers; in Thumb state it allows SP only as a source when the
register really is copied to another target.
gcc/ChangeLog:
PR target/91913
Backport from master
* config/arm/arm.md (movsi_compare0): Allow SP as a source register
in Thumb state and also as a destination in Arm state. Add T16
variants.
gcc/testsuite/ChangeLog:
2020-02-10 Jakub Jelinek <ja...@redhat.com>
PR target/91913
Backport from master
* gfortran.dg/pr91913.f90: New test.
