On 6/13/24 10:51, Max Chou wrote:
The vector unmasked unit-stride and whole register load/store
instructions will load/store continuous memory. If the endian of both
the host and guest architecture are the same, then we can group the
element load/store to load/store more data at a time.
Signed-off-by: Max Chou <max.chou@sifive.com>
---
target/riscv/vector_helper.c | 160 +++++++++++++++++++++++++----------
1 file changed, 117 insertions(+), 43 deletions(-)
diff --git a/target/riscv/vector_helper.c b/target/riscv/vector_helper.c
index 793337a6f96..cba46ef16a5 100644
--- a/target/riscv/vector_helper.c
+++ b/target/riscv/vector_helper.c
@@ -457,6 +457,69 @@ GEN_VEXT_ST_ELEM(ste_h, uint16_t, H2, stw)
GEN_VEXT_ST_ELEM(ste_w, uint32_t, H4, stl)
GEN_VEXT_ST_ELEM(ste_d, uint64_t, H8, stq)
+static inline uint32_t
+vext_group_ldst_host(CPURISCVState *env, void *vd, uint32_t byte_end,
+ uint32_t byte_offset, void *host, uint32_t esz,
+ bool is_load)
+{
+ uint32_t group_size;
+ static vext_ldst_elem_fn_host * const fns[2][4] = {
+ /* Store */
+ { ste_b_host, ste_h_host, ste_w_host, ste_d_host },
+ /* Load */
+ { lde_b_host, lde_h_host, lde_w_host, lde_d_host }
+ };
+ vext_ldst_elem_fn_host *fn;
+
+ if (byte_offset + 8 < byte_end) {
+ group_size = MO_64;
+ } else if (byte_offset + 4 < byte_end) {
+ group_size = MO_32;
+ } else if (byte_offset + 2 < byte_end) {
+ group_size = MO_16;
+ } else {
+ group_size = MO_8;
+ }
+
+ fn = fns[is_load][group_size];
+ fn(vd, byte_offset, host + byte_offset);
This is a really bad idea. The table and indirect call means that
none of these will be properly inlined. Anyway...
+
+ return 1 << group_size;
+}
+
+static inline void
+vext_continus_ldst_tlb(CPURISCVState *env, vext_ldst_elem_fn_tlb
*ldst_tlb,
+ void *vd, uint32_t evl, target_ulong addr,
+ uint32_t reg_start, uintptr_t ra, uint32_t esz,
+ bool is_load)
+{
+ for (; reg_start < evl; reg_start++, addr += esz) {
+ ldst_tlb(env, adjust_addr(env, addr), reg_start * esz, vd, ra);
+ }
+}
+
+static inline void
+vext_continus_ldst_host(CPURISCVState *env, vext_ldst_elem_fn_host
*ldst_host,
+ void *vd, uint32_t evl, uint32_t reg_start,
void *host,
+ uint32_t esz, bool is_load)
+{
+#if TARGET_BIG_ENDIAN != HOST_BIG_ENDIAN
+ for (; reg_start < evl; reg_start++) {
+ uint32_t byte_off = reg_start * esz;
+ ldst_host(vd, byte_off, host + byte_off);
+ }
+#else
+ uint32_t group_byte;
+ uint32_t byte_start = reg_start * esz;
+ uint32_t byte_end = evl * esz;
+ while (byte_start < byte_end) {
+ group_byte = vext_group_ldst_host(env, vd, byte_end,
byte_start, host,
+ esz, is_load);
+ byte_start += group_byte;
+ }
... this is much better handled with memcpy, given that you know
endianness matches.