[Qemu-devel] [RFC 12/28] target-xtensa: implement shifts (ST1 and RST1 groups)

[Max Filippov <jcmvbkbc@gmail.com>]

- ST1: SAR (shift amount special register) manipulation, NSA(U);
- RST1: shifts, 16-bit multiplication.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 target-xtensa/cpu.h       |    4 +
 target-xtensa/translate.c |  210 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 214 insertions(+), 0 deletions(-)

diff --git a/target-xtensa/cpu.h b/target-xtensa/cpu.h
index e99e3bb..a13a6cb 100644
--- a/target-xtensa/cpu.h
+++ b/target-xtensa/cpu.h
@@ -105,6 +105,10 @@ enum {
     FSR = 233,
 };
 
+enum {
+    SAR = 3,
+};
+
 typedef struct XtensaConfig {
     const char *name;
     uint64_t options;
diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index 031873e..a940417 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -57,6 +57,7 @@ static TCGv_i32 cpu_UR[256];
 #include "gen-icount.h"
 
 static const char * const sregnames[256] = {
+    [SAR] = "SAR",
 };
 
 static const char * const uregnames[256] = {
@@ -295,6 +296,101 @@ static void disas_xtensa_insn(DisasContext *dc)
                 break;
 
             case 4: /*ST1*/
+                switch (RRR_R) {
+                case 0: /*SSR*/
+                    tcg_gen_andi_i32(cpu_SR[SAR], cpu_R[RRR_S], 0x1f);
+                    break;
+
+                case 1: /*SSL*/
+                    {
+                        TCGv_i32 base = tcg_const_i32(32);
+                        TCGv_i32 tmp = tcg_temp_new_i32();
+                        tcg_gen_andi_i32(tmp, cpu_R[RRR_S], 0x1f);
+                        tcg_gen_sub_i32(cpu_SR[SAR], base, tmp);
+                        tcg_temp_free(tmp);
+                        tcg_temp_free(base);
+                    }
+                    break;
+
+                case 2: /*SSA8L*/
+                    {
+                        TCGv_i32 tmp = tcg_temp_new_i32();
+                        tcg_gen_andi_i32(tmp, cpu_R[RRR_S], 0x3);
+                        tcg_gen_shli_i32(cpu_SR[SAR], tmp, 3);
+                        tcg_temp_free(tmp);
+                    }
+                    break;
+
+                case 3: /*SSA8B*/
+                    {
+                        TCGv_i32 base = tcg_const_i32(32);
+                        TCGv_i32 tmp = tcg_temp_new_i32();
+                        tcg_gen_andi_i32(tmp, cpu_R[RRR_S], 0x3);
+                        tcg_gen_shli_i32(tmp, tmp, 3);
+                        tcg_gen_sub_i32(cpu_SR[SAR], base, tmp);
+                        tcg_temp_free(tmp);
+                        tcg_temp_free(base);
+                    }
+                    break;
+
+                case 4: /*SSAI*/
+                    tcg_gen_movi_i32(cpu_SR[SAR], RRR_S | ((RRR_T & 1) << 4));
+                    break;
+
+                case 6: /*RER*/
+                    break;
+
+                case 7: /*WER*/
+                    break;
+
+                case 8: /*ROTWw*/
+                    HAS_OPTION(XTENSA_OPTION_WINDOWED_REGISTER);
+                    break;
+
+                case 14: /*NSAu*/
+                    HAS_OPTION(XTENSA_OPTION_MISC_OP);
+                    break;
+
+                case 15: /*NSAUu*/
+                    HAS_OPTION(XTENSA_OPTION_MISC_OP);
+                    {
+#define gen_bit_bisect(w) do { \
+        int label = gen_new_label(); \
+        tcg_gen_brcondi_i32(TCG_COND_LTU, tmp, 1 << (w), label); \
+        tcg_gen_shri_i32(tmp, tmp, (w)); \
+        tcg_gen_subi_i32(res, res, (w)); \
+        gen_set_label(label); \
+    } while (0)
+
+                        int label = gen_new_label();
+                        TCGv_i32 res = tcg_temp_local_new_i32();
+
+                        tcg_gen_movi_i32(res, 32);
+                        tcg_gen_brcondi_i32(
+                                TCG_COND_EQ, cpu_R[RRR_S], 0, label);
+                        {
+                            TCGv_i32 tmp = tcg_temp_local_new_i32();
+                            tcg_gen_mov_i32(tmp, cpu_R[RRR_S]);
+                            tcg_gen_movi_i32(res, 31);
+
+                            gen_bit_bisect(16);
+                            gen_bit_bisect(8);
+                            gen_bit_bisect(4);
+                            gen_bit_bisect(2);
+                            gen_bit_bisect(1);
+
+                            tcg_temp_free(tmp);
+                        }
+                        gen_set_label(label);
+                        tcg_gen_mov_i32(cpu_R[RRR_T], res);
+                        tcg_temp_free(res);
+#undef gen_bit_bisect
+                    }
+                    break;
+
+                default: /*reserved*/
+                    break;
+                }
                 break;
 
             case 5: /*TLB*/
@@ -358,6 +454,111 @@ static void disas_xtensa_insn(DisasContext *dc)
             break;
 
         case 1: /*RST1*/
+            switch (_OP2) {
+            case 0: /*SLLI*/
+            case 1:
+                tcg_gen_shli_i32(cpu_R[RRR_R], cpu_R[RRR_S],
+                        32 - (RRR_T | ((_OP2 & 1) << 4)));
+                break;
+
+            case 2: /*SRAI*/
+            case 3:
+                tcg_gen_sari_i32(cpu_R[RRR_R], cpu_R[RRR_T],
+                        RRR_S | ((_OP2 & 1) << 4));
+                break;
+
+            case 4: /*SRLI*/
+                tcg_gen_shri_i32(cpu_R[RRR_R], cpu_R[RRR_T], RRR_S);
+                break;
+
+            case 6: /*XSR*/
+                {
+                    TCGv_i32 tmp = tcg_temp_new_i32();
+                    tcg_gen_mov_i32(tmp, cpu_R[RRR_T]);
+                    gen_rsr(cpu_R[RRR_T], RSR_SR);
+                    gen_wsr(dc, RSR_SR, tmp);
+                    tcg_temp_free(tmp);
+                }
+                break;
+
+#define gen_shift_reg(cmd, reg) do { \
+                    TCGv_i64 tmp = tcg_temp_new_i64(); \
+                    tcg_gen_extu_i32_i64(tmp, reg); \
+                    tcg_gen_andi_i64(tmp, tmp, 63); \
+                    tcg_gen_##cmd##_i64(v, v, tmp); \
+                    tcg_gen_trunc_i64_i32(cpu_R[RRR_R], v); \
+                    tcg_temp_free_i64(v); \
+                    tcg_temp_free_i64(tmp); \
+                } while (0)
+
+#define gen_shift(cmd) gen_shift_reg(cmd, cpu_SR[SAR])
+
+            case 8: /*SRC*/
+                {
+                    TCGv_i64 v = tcg_temp_new_i64();
+                    tcg_gen_concat_i32_i64(v, cpu_R[RRR_T], cpu_R[RRR_S]);
+                    gen_shift(shr);
+                }
+                break;
+
+            case 9: /*SRL*/
+                {
+                    TCGv_i64 v = tcg_temp_new_i64();
+                    tcg_gen_extu_i32_i64(v, cpu_R[RRR_T]);
+                    gen_shift(shr);
+                }
+                break;
+
+            case 10: /*SLL*/
+                {
+                    TCGv_i64 v = tcg_temp_new_i64();
+                    TCGv_i32 s = tcg_const_i32(32);
+                    tcg_gen_sub_i32(s, s, cpu_SR[SAR]);
+                    tcg_gen_extu_i32_i64(v, cpu_R[RRR_S]);
+                    gen_shift_reg(shl, s);
+                    tcg_temp_free(s);
+                }
+                break;
+
+            case 11: /*SRA*/
+                {
+                    TCGv_i64 v = tcg_temp_new_i64();
+                    tcg_gen_ext_i32_i64(v, cpu_R[RRR_T]);
+                    gen_shift(sar);
+                }
+                break;
+#undef gen_shift
+#undef gen_shift_reg
+
+            case 12: /*MUL16U*/
+                HAS_OPTION(XTENSA_OPTION_16_BIT_IMUL);
+                {
+                    TCGv_i32 v1 = tcg_temp_new_i32();
+                    TCGv_i32 v2 = tcg_temp_new_i32();
+                    tcg_gen_ext16u_i32(v1, cpu_R[RRR_S]);
+                    tcg_gen_ext16u_i32(v2, cpu_R[RRR_T]);
+                    tcg_gen_mul_i32(cpu_R[RRR_R], v1, v2);
+                    tcg_temp_free(v2);
+                    tcg_temp_free(v1);
+                }
+                break;
+
+            case 13: /*MUL16S*/
+                HAS_OPTION(XTENSA_OPTION_16_BIT_IMUL);
+                {
+                    TCGv_i32 v1 = tcg_temp_new_i32();
+                    TCGv_i32 v2 = tcg_temp_new_i32();
+                    tcg_gen_ext16s_i32(v1, cpu_R[RRR_S]);
+                    tcg_gen_ext16s_i32(v2, cpu_R[RRR_T]);
+                    tcg_gen_mul_i32(cpu_R[RRR_R], v1, v2);
+                    tcg_temp_free(v2);
+                    tcg_temp_free(v1);
+                }
+                break;
+
+            default: /*reserved*/
+                break;
+            }
             break;
 
         case 2: /*RST2*/
@@ -487,6 +688,15 @@ static void disas_xtensa_insn(DisasContext *dc)
 
         case 4: /*EXTUI*/
         case 5:
+            {
+                int shiftimm = RRR_S | (_OP1 << 4);
+                int maskimm = (1 << (_OP2 + 1)) - 1;
+
+                TCGv_i32 tmp = tcg_temp_new_i32();
+                tcg_gen_shri_i32(tmp, cpu_R[RRR_T], shiftimm);
+                tcg_gen_andi_i32(cpu_R[RRR_R], tmp, maskimm);
+                tcg_temp_free(tmp);
+            }
             break;
 
         case 6: /*CUST0*/
-- 
1.7.3.4