target/arm: Convert T16, shift immediate

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-65-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target/arm/t16.decode b/target/arm/t16.decode
index f128110dee6ef3103998192fb17825b4fe94843a..79a1d66d6c19bbb52be438647bdca4c93505045a 100644 (file)
--- a/target/arm/t16.decode
+++ b/target/arm/t16.decode
@@ -126,6 +126,14 @@ ADD_rri         10101 rd:3 ........ \
 STM             11000 ... ........              @ldstm
 LDM_t16         11001 ... ........              @ldstm
 
+# Shift (immediate)
+
+@shift_i        ..... shim:5 rm:3 rd:3          &s_rrr_shi %s rn=%reg_0
+
+MOV_rxri        000 00 ..... ... ...            @shift_i shty=0  # LSL
+MOV_rxri        000 01 ..... ... ...            @shift_i shty=1  # LSR
+MOV_rxri        000 10 ..... ... ...            @shift_i shty=2  # ASR
+
 # Add/subtract (three low registers)
 
 @addsub_3       ....... rm:3 rn:3 rd:3 \

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 48ed6f6b5d51919a8d3329b63e0591a5fb2fe390..d409afd55ff136922f25b60edcfa1d5b386e226a 100644 (file)
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -10754,7 +10754,7 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
 
 static void disas_thumb_insn(DisasContext *s, uint32_t insn)
 {
-    uint32_t val, op, rm, rd, shift;
+    uint32_t val, rd;
     int32_t offset;
     TCGv_i32 tmp;
     TCGv_i32 tmp2;
@@ -10766,29 +10766,7 @@ static void disas_thumb_insn(DisasContext *s, uint32_t insn)
     /* fall back to legacy decoder */
 
     switch (insn >> 12) {
-    case 0: case 1:
-
-        rd = insn & 7;
-        op = (insn >> 11) & 3;
-        if (op == 3) {
-            /*
-             * 0b0001_1xxx_xxxx_xxxx
-             *  - Add, subtract (three low registers)
-             *  - Add, subtract (two low registers and immediate)
-             * In decodetree.
-             */
-            goto illegal_op;
-        } else {
-            /* shift immediate */
-            rm = (insn >> 3) & 7;
-            shift = (insn >> 6) & 0x1f;
-            tmp = load_reg(s, rm);
-            gen_arm_shift_im(tmp, op, shift, s->condexec_mask == 0);
-            if (!s->condexec_mask)
-                gen_logic_CC(tmp);
-            store_reg(s, rd, tmp);
-        }
-        break;
+    case 0: case 1: /* add/sub (3reg, 2reg imm), shift imm; in decodetree */
     case 2: case 3: /* add, sub, cmp, mov (reg, imm), in decodetree */
         goto illegal_op;
     case 4: