RISC-V: Eliminate redundant vsetvli for duplicate AVL def
Commit Message
From: Juzhe-Zhong <juzhe.zhong@rivai.ai>
void f (int8_t* base1,int8_t* base2,int8_t* out,int n)
{
vint8mf4_t v = __riscv_vle8_v_i8mf4 (base1, 32);
for (int i = 0; i < n; i++){
v = __riscv_vor_vx_i8mf4 (v, 101, 32);
v = __riscv_vle8_v_i8mf4_tu (v, base2, 32);
}
__riscv_vse8_v_i8mf4 (out, v, 32);
}
before this patch:
f:
li a5,32
vsetvli zero,a5,e8,mf4,tu,ma
vle8.v v1,0(a0)
ble a3,zero,.L2
li t0,0
li a0,101
.L3:
addiw t0,t0,1
vor.vx v1,v1,a0
vle8.v v1,0(a1)
bne a3,t0,.L3
.L2:
vsetvli zero,zero,e8,mf4,tu,ma
vse8.v v1,0(a2)
ret
afther this patch:
f:
li a5,32
vsetvli zero,a5,e8,mf4,tu,ma
vle8.v v1,0(a0)
ble a3,zero,.L2
li t0,0
li a0,101
.L3:
addiw t0,t0,1
vor.vx v1,v1,a0
vle8.v v1,0(a1)
bne a3,t0,.L3
.L2:
vse8.v v1,0(a2)
ret
gcc/ChangeLog:
* config/riscv/riscv-vsetvl.cc (vector_infos_manager::all_avail_in_compatible_p): New function.
(pass_vsetvl::refine_vsetvls): Remove redundant vsetvli.
* config/riscv/riscv-vsetvl.h: New function declare.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/vsetvl/avl_single-102.c: New test.
---
gcc/config/riscv/riscv-vsetvl.cc | 67 ++++++++++++++++++-
gcc/config/riscv/riscv-vsetvl.h | 1 +
.../riscv/rvv/vsetvl/avl_single-102.c | 16 +++++
3 files changed, 81 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/vsetvl/avl_single-102.c
@@ -2376,6 +2376,23 @@ vector_infos_manager::all_empty_predecessor_p (const basic_block cfg_bb) const
return true;
}
+bool
+vector_infos_manager::all_avail_in_compatible_p (const basic_block cfg_bb) const
+{
+ const auto &info = vector_block_infos[cfg_bb->index].local_dem;
+ sbitmap avin = vector_avin[cfg_bb->index];
+ unsigned int bb_index;
+ sbitmap_iterator sbi;
+ EXECUTE_IF_SET_IN_BITMAP (avin, 0, bb_index, sbi)
+ {
+ const auto &avin_info
+ = static_cast<const vl_vtype_info &> (*vector_exprs[bb_index]);
+ if (!info.compatible_p (avin_info))
+ return false;
+ }
+ return true;
+}
+
bool
vector_infos_manager::all_same_avl_p (const basic_block cfg_bb,
sbitmap bitdata) const
@@ -3741,9 +3758,53 @@ pass_vsetvl::refine_vsetvls (void) const
m_vector_manager->to_refine_vsetvls.add (rinsn);
continue;
}
- rinsn = PREV_INSN (rinsn);
- rtx new_pat = gen_vsetvl_pat (VSETVL_VTYPE_CHANGE_ONLY, info, NULL_RTX);
- change_insn (rinsn, new_pat);
+
+ /* Optimize such case:
+ void f (int8_t* base1,int8_t* base2,int8_t* out,int n)
+ {
+ vint8mf4_t v = __riscv_vle8_v_i8mf4 (base1, 32);
+ for (int i = 0; i < n; i++){
+ v = __riscv_vor_vx_i8mf4 (v, 101, 32);
+ v = __riscv_vle8_v_i8mf4_tu (v, base2, 32);
+ }
+ __riscv_vse8_v_i8mf4 (out, v, 32);
+ }
+
+ f:
+ li a5,32
+ vsetvli zero,a5,e8,mf4,tu,ma
+ vle8.v v1,0(a0)
+ ble a3,zero,.L2
+ li t0,0
+ li a0,101
+ .L3:
+ addiw t0,t0,1
+ vor.vx v1,v1,a0
+ vle8.v v1,0(a1)
+ bne a3,t0,.L3
+ .L2:
+ vsetvli zero,zero,e8,mf4,tu,ma
+ vse8.v v1,0(a2)
+ ret
+
+ The second vsetvli is redundant. */
+
+ gcc_assert (has_vtype_op (insn->rtl ()));
+ rinsn = PREV_INSN (insn->rtl ());
+ gcc_assert (vector_config_insn_p (PREV_INSN (insn->rtl ())));
+ if (m_vector_manager->all_avail_in_compatible_p (cfg_bb))
+ {
+ size_t id = m_vector_manager->get_expr_id (info);
+ if (bitmap_bit_p (m_vector_manager->vector_del[cfg_bb->index], id))
+ continue;
+ eliminate_insn (rinsn);
+ }
+ else
+ {
+ rtx new_pat
+ = gen_vsetvl_pat (VSETVL_VTYPE_CHANGE_ONLY, info, NULL_RTX);
+ change_insn (rinsn, new_pat);
+ }
}
}
@@ -451,6 +451,7 @@ public:
bool all_same_ratio_p (sbitmap) const;
bool all_empty_predecessor_p (const basic_block) const;
+ bool all_avail_in_compatible_p (const basic_block) const;
void release (void);
void create_bitmap_vectors (void);
new file mode 100644
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv32gcv -mabi=ilp32 -fno-schedule-insns -fno-schedule-insns2 -fno-tree-vectorize -frename-registers" } */
+
+#include "riscv_vector.h"
+
+void f (int8_t* base1,int8_t* base2,int8_t* out,int n)
+{
+ vint8mf4_t v = __riscv_vle8_v_i8mf4 (base1, 32);
+ for (int i = 0; i < n; i++){
+ v = __riscv_vor_vx_i8mf4 (v, 101, 32);
+ v = __riscv_vle8_v_i8mf4_tu (v, base2, 32);
+ }
+ __riscv_vse8_v_i8mf4 (out, v, 32);
+}
+
+/* { dg-final { scan-assembler-times {vsetvli} 1 { target { no-opts "-O0" no-opts "-O1" no-opts "-Os" no-opts "-g" no-opts "-funroll-loops" } } } } */