RISC-V: Support LEN_FOLD_EXTRACT_LAST auto-vectorization
Consider this following case:
int __attribute__ ((noinline, noclone))
condition_reduction (int *a, int min_v)
{
int last = 66; /* High start value. */
for (int i = 0; i < 4; i++)
if (a[i] < min_v)
last = i;
return last;
}
--param=riscv-autovec-preference=fixed-vlmax --param=riscv-autovec-lmul=m8
condition_reduction:
vsetvli a4,zero,e32,m8,ta,ma
li a5,32
vmv.v.x v8,a1
vl8re32.v v0,0(a0)
vid.v v16
vmslt.vv v0,v0,v8
vsetvli zero,a5,e8,m2,ta,ma
vcpop.m a5,v0
beq a5,zero,.L2
addi a5,a5,-1
vsetvli a4,zero,e32,m8,ta,ma
vcompress.vm v8,v16,v0
vslidedown.vx v8,v8,a5
vmv.x.s a0,v8
ret
.L2:
li a0,66
ret
--param=riscv-autovec-preference=scalable
condition_reduction:
csrr a6,vlenb
mv a2,a0
li a3,32
li a0,66
srli a6,a6,2
vsetvli a4,zero,e32,m1,ta,ma
vmv.v.x v4,a1
vid.v v1
.L4:
vsetvli a5,a3,e8,mf4,tu,mu
vsetvli zero,a5,e32,m1,ta,ma ----> redundant vsetvl
vle32.v v0,0(a2)
vsetvli a4,zero,e32,m1,ta,ma
slli a1,a5,2
vmv.v.x v2,a6
vmslt.vv v0,v0,v4
sub a3,a3,a5
vmv1r.v v3,v1
vadd.vv v1,v1,v2
vsetvli zero,a5,e8,mf4,ta,ma
vcpop.m a5,v0
beq a5,zero,.L3
addi a5,a5,-1
vsetvli a4,zero,e32,m1,ta,ma
vcompress.vm v2,v3,v0
vslidedown.vx v2,v2,a5
vmv.x.s a0,v2
.L3:
sext.w a0,a0
add a2,a2,a1
bne a3,zero,.L4
ret
There is a redundant vsetvli instruction in VLA vectorized codes which is the VSETVL PASS issue.
vsetvl issue is not included in this patch but will be fixed soon.
gcc/ChangeLog:
* config/riscv/autovec.md (len_fold_extract_last_<mode>): New pattern.
* config/riscv/riscv-protos.h (enum insn_type): New enum.
(expand_fold_extract_last): New function.
* config/riscv/riscv-v.cc (emit_nonvlmax_slide_insn): Ditto.
(emit_cpop_insn): Ditto.
(emit_nonvlmax_compress_insn): Ditto.
(expand_fold_extract_last): Ditto.
* config/riscv/vector.md: Fix vcpop.m ratio demand.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/autovec/reduc/extract_last-1.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-10.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-11.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-12.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-13.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-14.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-2.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-3.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-4.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-5.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-6.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-7.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-8.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last-9.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-1.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-10.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-11.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-12.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-13.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-14.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-2.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-3.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-4.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-5.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-6.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-7.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-8.c: New test.
* gcc.target/riscv/rvv/autovec/reduc/extract_last_run-9.c: New test.
(cherry picked from commit
e7545cadbedfc167749d801bd574cf9fe22ed5c5)