riscv: Add evl argument to vext_ldst_elem_fn_host

Richard Henderson Sun, 16 Aug 2026 08:56:30 -0700

On 8/15/26 12:45, Richard Henderson wrote:

This merges vext_continuous_ldst_host into the ldst_host function.
We can then handle the byte little-endian optimization at compile-time.


Signed-off-by: Richard Henderson <[email protected]>
---
  target/riscv/tcg/vector_helper.c | 83 +++++++++++++++-----------------
  1 file changed, 40 insertions(+), 43 deletions(-)

In retrospect, this probably isn't a great idea. The load side is fine, but the storeside suffers from atomicity issues. I'll think of something else.

r~


diff --git a/target/riscv/tcg/vector_helper.c b/target/riscv/tcg/vector_helper.c
index 661f1ab2f6..3786a17231 100644
--- a/target/riscv/tcg/vector_helper.c
+++ b/target/riscv/tcg/vector_helper.c
@@ -214,7 +214,8 @@ static inline MemOpIdx vext_make_memop_idx(CPURISCVState 
*env, size_t size)
  /* elements operations for load and store */
  typedef void vext_ldst_elem_fn_tlb(CPURISCVState *env, abi_ptr addr,
                                     uint32_t idx, void *vd, uintptr_t retaddr);
-typedef void vext_ldst_elem_fn_host(void *vd, uint32_t idx, void *host);
+typedef void vext_ldst_elem_fn_host(void *vd, void *host,
+                                    uint32_t idx, uint32_t evl);

#define GEN_VEXT_TLB_LD_ELEM(NAME, ETYPE, H, LDSUF) \

  static inline QEMU_ALWAYS_INLINE                            \
@@ -226,12 +227,15 @@ void NAME##_tlb(CPURISCVState *env, abi_ptr addr,         
  \
      *cur = cpu_##LDSUF##_mmu(env, addr, oi, retaddr);       \
  }                                                           \

-#define GEN_VEXT_HOST_LD_ELEM(NAME, ETYPE, H, LDSUF) \

-static inline QEMU_ALWAYS_INLINE                            \
-void NAME##_host(void *vd, uint32_t idx, void *host)        \
-{                                                           \
-    ETYPE *cur = ((ETYPE *)vd + H(idx));                    \
-    *cur = (ETYPE)LDSUF##_p(host);                          \
+#define GEN_VEXT_HOST_LD_ELEM(NAME, ETYPE, H, LDSUF)                    \
+static inline QEMU_ALWAYS_INLINE                                        \
+void NAME##_host(void *vd, void *host, uint32_t idx, uint32_t evl)      \
+{                                                                       \
+    do {                                                                \
+        ETYPE *cur = (ETYPE *)vd + H(idx);                              \
+        *cur = LDSUF##_p(host);                                         \
+        host += sizeof(ETYPE);                                          \
+    } while (++idx < evl);                                              \
  }

GEN_VEXT_TLB_LD_ELEM(lde_b, uint8_t, H1, ldb)

@@ -239,7 +243,16 @@ GEN_VEXT_TLB_LD_ELEM(lde_h, uint16_t, H2, ldw)
  GEN_VEXT_TLB_LD_ELEM(lde_w, uint32_t, H4, ldl)
  GEN_VEXT_TLB_LD_ELEM(lde_d, uint64_t, H8, ldq)

+#if HOST_BIG_ENDIAN

  GEN_VEXT_HOST_LD_ELEM(lde_b, uint8_t,  H1, ldub)
+#else
+static inline QEMU_ALWAYS_INLINE
+void lde_b_host(void *vd, void *host, uint32_t idx, uint32_t evl)
+{
+    memcpy(vd + idx, host, evl - idx);
+}
+#endif
+
  GEN_VEXT_HOST_LD_ELEM(lde_h, uint16_t, H2, lduw_le)
  GEN_VEXT_HOST_LD_ELEM(lde_w, uint32_t, H4, ldl_le)
  GEN_VEXT_HOST_LD_ELEM(lde_d, uint64_t, H8, ldq_le)
@@ -254,12 +267,15 @@ void NAME##_tlb(CPURISCVState *env, abi_ptr addr,         
  \
      cpu_##STSUF##_mmu(env, addr, data, oi, retaddr);        \
  }                                                           \

-#define GEN_VEXT_HOST_ST_ELEM(NAME, ETYPE, H, STSUF) \

-static inline QEMU_ALWAYS_INLINE                            \
-void NAME##_host(void *vd, uint32_t idx, void *host)        \
-{                                                           \
-    ETYPE data = *((ETYPE *)vd + H(idx));                   \
-    STSUF##_p(host, data);                                  \
+#define GEN_VEXT_HOST_ST_ELEM(NAME, ETYPE, H, STSUF)                    \
+static inline QEMU_ALWAYS_INLINE                                        \
+void NAME##_host(void *vd, void *host, uint32_t idx, uint32_t evl)      \
+{                                                                       \
+    do {                                                                \
+        ETYPE data = *((ETYPE *)vd + H(idx));                           \
+        STSUF##_p(host, data);                                          \
+        host += sizeof(ETYPE);                                          \
+    } while (++idx < evl);                                              \
  }

GEN_VEXT_TLB_ST_ELEM(ste_b, uint8_t, H1, stb)

@@ -267,7 +283,16 @@ GEN_VEXT_TLB_ST_ELEM(ste_h, uint16_t, H2, stw)
  GEN_VEXT_TLB_ST_ELEM(ste_w, uint32_t, H4, stl)
  GEN_VEXT_TLB_ST_ELEM(ste_d, uint64_t, H8, stq)

+#if HOST_BIG_ENDIAN

  GEN_VEXT_HOST_ST_ELEM(ste_b, uint8_t,  H1, stb)
+#else
+static inline QEMU_ALWAYS_INLINE
+void ste_b_host(void *vd, void *host, uint32_t idx, uint32_t evl)
+{
+    memcpy(host, vd + idx, evl - idx);
+}
+#endif
+
  GEN_VEXT_HOST_ST_ELEM(ste_h, uint16_t, H2, stw_le)
  GEN_VEXT_HOST_ST_ELEM(ste_w, uint32_t, H4, stl_le)
  GEN_VEXT_HOST_ST_ELEM(ste_d, uint64_t, H8, stq_le)
@@ -284,33 +309,6 @@ vext_continuous_ldst_tlb(CPURISCVState *env, 
vext_ldst_elem_fn_tlb *ldst_tlb,
      }
  }

-static inline QEMU_ALWAYS_INLINE void

-vext_continuous_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 (HOST_BIG_ENDIAN) {
-        for (; reg_start < evl; reg_start++, host += esz) {
-            ldst_host(vd, reg_start, host);
-        }
-    } else {
-        if (esz == 1) {
-            uint32_t byte_offset = reg_start * esz;
-            uint32_t size = (evl - reg_start) * esz;
-
-            if (is_load) {
-                memcpy(vd + byte_offset, host, size);
-            } else {
-                memcpy(host, vd + byte_offset, size);
-            }
-        } else {
-            for (; reg_start < evl; reg_start++, host += esz) {
-                ldst_host(vd, reg_start, host);
-            }
-        }
-    }
-}
-
  static void vext_set_tail_elems_1s(uint32_t vl, void *vd, uint32_t nf,
                                     uint32_t esz, uint32_t max_elems)
  {
@@ -334,7 +332,7 @@ static void vext_ldst_nf_host(void *vd, void *host, 
uint32_t i, uint32_t nf,
                                vext_ldst_elem_fn_host *ldst_host)
  {
      for (uint32_t k = 0; k < nf; k++, host += esz) {
-        ldst_host(vd, i + k * max_elems, host);
+        ldst_host(vd + k * max_elems, host, i, i + 1);
      }
  }

@@ -450,8 +448,7 @@ vext_page_ldst_us(CPURISCVState *env, void *vd, target_ulong addr,

       */
      if (flags == 0 && (riscv_cpu_cfg(env)->ext_zicclsm || !misaligned)) {
          if (nf == 1) {
-            vext_continuous_ldst_host(env, ldst_host, vd, evl, env->vstart,
-                                      host, esz, is_load);
+            ldst_host(vd, host, env->vstart, evl);
          } else {
              for (uint32_t i = env->vstart; i < evl; ++i) {
                  vext_ldst_nf_host(vd, host, i, nf, esz, max_elems, ldst_host);

Re: [PATCH 05/23] target/riscv: Add evl argument to vext_ldst_elem_fn_host

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