gnu /
gcc /
77ef91d7159613c0cfc2920ddd5a32952c61ff5b RISC-V: Do not delete fused vsetvl if it has uses [PR119115].
In PR119115 we end up with an orphaned
vsetvli zero,t1,e16,m1,ta,ma.
t1 originally came from another vsetvl that was fused from
vsetvli a4,a3,e8,mf2,ta,ma
vsetvli t1,a3,e8,mf2,ta,ma (1)
to
vsetvli zero,a3,e16,m1,ta,ma.
This patch checks if t1, the VL operand of (1), has AVL uses and does
not delete the vsetvl if so. While doing so, it also wraps the search
for VL uses into two new functions reg_used and reg_single_use_in_avl.
PR target/119115
gcc/ChangeLog:
* config/riscv/riscv-vsetvl.cc (reg_used): New function.
(reg_single_use_in_avl): Ditto.
(pre_vsetvl::fuse_local_vsetvl_info): Use reg_single_use_in_avl
when checking if vsetvl can be deleted.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/base/pr119115.c: New test.
2 files changed
