[Qemu-devel] [PULL 01/12] target/arm: Use extract2 for EXTR

[Peter Maydell <peter.maydell@linaro.org>]

From: Richard Henderson <richard.henderson@linaro.org>

This is, after all, how we implement extract2 in tcg/aarch64.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190514011129.11330-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/translate-a64.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index b7c5a928b4a..2b135b938ce 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -4114,25 +4114,27 @@ static void disas_extract(DisasContext *s, uint32_t insn)
             } else {
                 tcg_gen_ext32u_i64(tcg_rd, cpu_reg(s, rm));
             }
-        } else if (rm == rn) { /* ROR */
-            tcg_rm = cpu_reg(s, rm);
-            if (sf) {
-                tcg_gen_rotri_i64(tcg_rd, tcg_rm, imm);
-            } else {
-                TCGv_i32 tmp = tcg_temp_new_i32();
-                tcg_gen_extrl_i64_i32(tmp, tcg_rm);
-                tcg_gen_rotri_i32(tmp, tmp, imm);
-                tcg_gen_extu_i32_i64(tcg_rd, tmp);
-                tcg_temp_free_i32(tmp);
-            }
         } else {
-            tcg_rm = read_cpu_reg(s, rm, sf);
-            tcg_rn = read_cpu_reg(s, rn, sf);
-            tcg_gen_shri_i64(tcg_rm, tcg_rm, imm);
-            tcg_gen_shli_i64(tcg_rn, tcg_rn, bitsize - imm);
-            tcg_gen_or_i64(tcg_rd, tcg_rm, tcg_rn);
-            if (!sf) {
-                tcg_gen_ext32u_i64(tcg_rd, tcg_rd);
+            tcg_rm = cpu_reg(s, rm);
+            tcg_rn = cpu_reg(s, rn);
+
+            if (sf) {
+                /* Specialization to ROR happens in EXTRACT2.  */
+                tcg_gen_extract2_i64(tcg_rd, tcg_rm, tcg_rn, imm);
+            } else {
+                TCGv_i32 t0 = tcg_temp_new_i32();
+
+                tcg_gen_extrl_i64_i32(t0, tcg_rm);
+                if (rm == rn) {
+                    tcg_gen_rotri_i32(t0, t0, imm);
+                } else {
+                    TCGv_i32 t1 = tcg_temp_new_i32();
+                    tcg_gen_extrl_i64_i32(t1, tcg_rn);
+                    tcg_gen_extract2_i32(t0, t0, t1, imm);
+                    tcg_temp_free_i32(t1);
+                }
+                tcg_gen_extu_i32_i64(tcg_rd, t0);
+                tcg_temp_free_i32(t0);
             }
         }
     }
-- 
2.20.1