target/arm: Implement MVE shifts by immediate

Implement the MVE shifts by immediate, which perform shifts
on a single general-purpose register.

These patterns overlap with the long-shift-by-immediates,
so we have to rearrange the grouping a little here.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210628135835.6690-18-peter.maydell@linaro.org

1 files changed, 66 insertions, 2 deletions

diff --git a/target/arm/translate.c b/target/arm/translate.c
index f123752431..e38619b571 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -3218,8 +3218,14 @@ static void gen_srshr16_i64(TCGv_i64 d, TCGv_i64 a, int64_t sh)
 
 static void gen_srshr32_i32(TCGv_i32 d, TCGv_i32 a, int32_t sh)
 {
-    TCGv_i32 t = tcg_temp_new_i32();
+    TCGv_i32 t;
 
+    /* Handle shift by the input size for the benefit of trans_SRSHR_ri */
+    if (sh == 32) {
+        tcg_gen_movi_i32(d, 0);
+        return;
+    }
+    t = tcg_temp_new_i32();
     tcg_gen_extract_i32(t, a, sh - 1, 1);
     tcg_gen_sari_i32(d, a, sh);
     tcg_gen_add_i32(d, d, t);
@@ -3419,8 +3425,14 @@ static void gen_urshr16_i64(TCGv_i64 d, TCGv_i64 a, int64_t sh)
 
 static void gen_urshr32_i32(TCGv_i32 d, TCGv_i32 a, int32_t sh)
 {
-    TCGv_i32 t = tcg_temp_new_i32();
+    TCGv_i32 t;
 
+    /* Handle shift by the input size for the benefit of trans_URSHR_ri */
+    if (sh == 32) {
+        tcg_gen_extract_i32(d, a, sh - 1, 1);
+        return;
+    }
+    t = tcg_temp_new_i32();
     tcg_gen_extract_i32(t, a, sh - 1, 1);
     tcg_gen_shri_i32(d, a, sh);
     tcg_gen_add_i32(d, d, t);
@@ -5861,6 +5873,58 @@ static bool trans_SQRSHRL48_rr(DisasContext *s, arg_mve_shl_rr *a)
     return do_mve_shl_rr(s, a, gen_helper_mve_sqrshrl48);
 }
 
+static bool do_mve_sh_ri(DisasContext *s, arg_mve_sh_ri *a, ShiftImmFn *fn)
+{
+    if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) {
+        /* Decode falls through to ORR/MOV UNPREDICTABLE handling */
+        return false;
+    }
+    if (!dc_isar_feature(aa32_mve, s) ||
+        !arm_dc_feature(s, ARM_FEATURE_M_MAIN) ||
+        a->rda == 13 || a->rda == 15) {
+        /* These rda cases are UNPREDICTABLE; we choose to UNDEF */
+        unallocated_encoding(s);
+        return true;
+    }
+
+    if (a->shim == 0) {
+        a->shim = 32;
+    }
+    fn(cpu_R[a->rda], cpu_R[a->rda], a->shim);
+
+    return true;
+}
+
+static bool trans_URSHR_ri(DisasContext *s, arg_mve_sh_ri *a)
+{
+    return do_mve_sh_ri(s, a, gen_urshr32_i32);
+}
+
+static bool trans_SRSHR_ri(DisasContext *s, arg_mve_sh_ri *a)
+{
+    return do_mve_sh_ri(s, a, gen_srshr32_i32);
+}
+
+static void gen_mve_sqshl(TCGv_i32 r, TCGv_i32 n, int32_t shift)
+{
+    gen_helper_mve_sqshl(r, cpu_env, n, tcg_constant_i32(shift));
+}
+
+static bool trans_SQSHL_ri(DisasContext *s, arg_mve_sh_ri *a)
+{
+    return do_mve_sh_ri(s, a, gen_mve_sqshl);
+}
+
+static void gen_mve_uqshl(TCGv_i32 r, TCGv_i32 n, int32_t shift)
+{
+    gen_helper_mve_uqshl(r, cpu_env, n, tcg_constant_i32(shift));
+}
+
+static bool trans_UQSHL_ri(DisasContext *s, arg_mve_sh_ri *a)
+{
+    return do_mve_sh_ri(s, a, gen_mve_uqshl);
+}
+
 /*
  * Multiply and multiply accumulate
  */