target/arm: Split out get_zarray

Prepare for MOVA array to/from vector with multiple registers
by adding a div_len parameter, herein always 1, and a vec_mod
parameter, herein always 0.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250704142112.1018902-24-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target/arm/tcg/translate-sme.c b/target/arm/tcg/translate-sme.c
index 2c8cb24b7cd8e5285a73e7705655bae800709251..ea0e5a7cb5bb2340fc67ab0813a4452e0347a059 100644 (file)
--- a/target/arm/tcg/translate-sme.c
+++ b/target/arm/tcg/translate-sme.c
@@ -43,7 +43,8 @@ static bool sme2_zt0_enabled_check(DisasContext *s)
 
 /* Resolve tile.size[rs+imm] to a host pointer. */
 static TCGv_ptr get_tile_rowcol(DisasContext *s, int esz, int rs,
-                                int tile, int imm, bool vertical)
+                                int tile, int imm, int div_len,
+                                int vec_mod, bool vertical)
 {
     int pos, len, offset;
     TCGv_i32 tmp;
@@ -52,10 +53,23 @@ static TCGv_ptr get_tile_rowcol(DisasContext *s, int esz, int rs,
     /* Compute the final index, which is Rs+imm. */
     tmp = tcg_temp_new_i32();
     tcg_gen_trunc_tl_i32(tmp, cpu_reg(s, rs));
+    /*
+     * Round the vector index down to a multiple of vec_mod if necessary.
+     * We do this before adding the offset, to handle cases like
+     * MOVA (tile to vector, 2 registers) where we want to call this
+     * several times in a loop with an increasing offset. We rely on
+     * the instruction encodings always forcing the initial offset in
+     * [rs + offset] to be a multiple of vec_mod. The pseudocode usually
+     * does the round-down after adding the offset rather than before,
+     * but MOVA is an exception.
+     */
+    if (vec_mod > 1) {
+        tcg_gen_andc_i32(tmp, tmp, tcg_constant_i32(vec_mod - 1));
+    }
     tcg_gen_addi_i32(tmp, tmp, imm);
 
     /* Prepare a power-of-two modulo via extraction of @len bits. */
-    len = ctz32(streaming_vec_reg_size(s)) - esz;
+    len = ctz32(streaming_vec_reg_size(s) / div_len) - esz;
 
     if (!len) {
         /*
@@ -111,6 +125,14 @@ static TCGv_ptr get_tile_rowcol(DisasContext *s, int esz, int rs,
     return addr;
 }
 
+/* Resolve ZArray[rs+imm] to a host pointer. */
+static TCGv_ptr get_zarray(DisasContext *s, int rs, int imm,
+                           int div_len, int vec_mod)
+{
+    /* ZA[n] equates to ZA0H.B[n]. */
+    return get_tile_rowcol(s, MO_8, rs, 0, imm, div_len, vec_mod, false);
+}
+
 /*
  * Resolve tile.size[0] to a host pointer.
  * Used by e.g. outer product insns where we require the entire tile.
@@ -177,7 +199,7 @@ static bool do_mova_tile(DisasContext *s, arg_mova_p *a, bool to_vec)
         return true;
     }
 
-    t_za = get_tile_rowcol(s, a->esz, a->rs, a->za, a->off, a->v);
+    t_za = get_tile_rowcol(s, a->esz, a->rs, a->za, a->off, 1, 0, a->v);
     t_zr = vec_full_reg_ptr(s, a->zr);
     t_pg = pred_full_reg_ptr(s, a->pg);
 
@@ -259,7 +281,7 @@ static bool trans_LDST1(DisasContext *s, arg_LDST1 *a)
         return true;
     }
 
-    t_za = get_tile_rowcol(s, a->esz, a->rs, a->za, a->off, a->v);
+    t_za = get_tile_rowcol(s, a->esz, a->rs, a->za, a->off, 1, 0, a->v);
     t_pg = pred_full_reg_ptr(s, a->pg);
     addr = tcg_temp_new_i64();
 
@@ -281,19 +303,14 @@ typedef void GenLdStR(DisasContext *, TCGv_ptr, int, int, int, int, MemOp);
 
 static bool do_ldst_r(DisasContext *s, arg_ldstr *a, GenLdStR *fn)
 {
-    int svl = streaming_vec_reg_size(s);
-    int imm = a->imm;
-    TCGv_ptr base;
+    if (sme_za_enabled_check(s)) {
+        int svl = streaming_vec_reg_size(s);
+        int imm = a->imm;
+        TCGv_ptr base = get_zarray(s, a->rv, imm, 1, 0);
 
-    if (!sme_za_enabled_check(s)) {
-        return true;
+        fn(s, base, 0, svl, a->rn, imm * svl,
+           s->align_mem ? MO_ALIGN_16 : MO_UNALN);
     }
-
-    /* ZA[n] equates to ZA0H.B[n]. */
-    base = get_tile_rowcol(s, MO_8, a->rv, 0, imm, false);
-
-    fn(s, base, 0, svl, a->rn, imm * svl,
-       s->align_mem ? MO_ALIGN_16 : MO_UNALN);
     return true;
 }