tcg: Implement gvec support for rotate by immediate

No host backend support yet, but the interfaces for rotli
are in place.  Canonicalize immediate rotate to the left,
based on a survey of architectures, but provide both left
and right shift interfaces to the translators.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/tcg/tcg-op-gvec.c b/tcg/tcg-op-gvec.c
index 049a55e700..25300b1577 100644
--- a/tcg/tcg-op-gvec.c
+++ b/tcg/tcg-op-gvec.c
@@ -2694,6 +2694,74 @@ void tcg_gen_gvec_sari(unsigned vece, uint32_t dofs, uint32_t aofs,
     }
 }
 
+void tcg_gen_vec_rotl8i_i64(TCGv_i64 d, TCGv_i64 a, int64_t c)
+{
+    uint64_t mask = dup_const(MO_8, 0xff << c);
+
+    tcg_gen_shli_i64(d, a, c);
+    tcg_gen_shri_i64(a, a, 8 - c);
+    tcg_gen_andi_i64(d, d, mask);
+    tcg_gen_andi_i64(a, a, ~mask);
+    tcg_gen_or_i64(d, d, a);
+}
+
+void tcg_gen_vec_rotl16i_i64(TCGv_i64 d, TCGv_i64 a, int64_t c)
+{
+    uint64_t mask = dup_const(MO_16, 0xffff << c);
+
+    tcg_gen_shli_i64(d, a, c);
+    tcg_gen_shri_i64(a, a, 16 - c);
+    tcg_gen_andi_i64(d, d, mask);
+    tcg_gen_andi_i64(a, a, ~mask);
+    tcg_gen_or_i64(d, d, a);
+}
+
+void tcg_gen_gvec_rotli(unsigned vece, uint32_t dofs, uint32_t aofs,
+                        int64_t shift, uint32_t oprsz, uint32_t maxsz)
+{
+    static const TCGOpcode vecop_list[] = { INDEX_op_rotli_vec, 0 };
+    static const GVecGen2i g[4] = {
+        { .fni8 = tcg_gen_vec_rotl8i_i64,
+          .fniv = tcg_gen_rotli_vec,
+          .fno = gen_helper_gvec_rotl8i,
+          .opt_opc = vecop_list,
+          .vece = MO_8 },
+        { .fni8 = tcg_gen_vec_rotl16i_i64,
+          .fniv = tcg_gen_rotli_vec,
+          .fno = gen_helper_gvec_rotl16i,
+          .opt_opc = vecop_list,
+          .vece = MO_16 },
+        { .fni4 = tcg_gen_rotli_i32,
+          .fniv = tcg_gen_rotli_vec,
+          .fno = gen_helper_gvec_rotl32i,
+          .opt_opc = vecop_list,
+          .vece = MO_32 },
+        { .fni8 = tcg_gen_rotli_i64,
+          .fniv = tcg_gen_rotli_vec,
+          .fno = gen_helper_gvec_rotl64i,
+          .opt_opc = vecop_list,
+          .prefer_i64 = TCG_TARGET_REG_BITS == 64,
+          .vece = MO_64 },
+    };
+
+    tcg_debug_assert(vece <= MO_64);
+    tcg_debug_assert(shift >= 0 && shift < (8 << vece));
+    if (shift == 0) {
+        tcg_gen_gvec_mov(vece, dofs, aofs, oprsz, maxsz);
+    } else {
+        tcg_gen_gvec_2i(dofs, aofs, oprsz, maxsz, shift, &g[vece]);
+    }
+}
+
+void tcg_gen_gvec_rotri(unsigned vece, uint32_t dofs, uint32_t aofs,
+                        int64_t shift, uint32_t oprsz, uint32_t maxsz)
+{
+    tcg_debug_assert(vece <= MO_64);
+    tcg_debug_assert(shift >= 0 && shift < (8 << vece));
+    tcg_gen_gvec_rotli(vece, dofs, aofs, -shift & ((8 << vece) - 1),
+                       oprsz, maxsz);
+}
+
 /*
  * Specialized generation vector shifts by a non-constant scalar.
  */