[Qemu-devel] [PATCH v7 15/15] target-tricore: Add instructions of SR opcode format

[Bastian Koppelmann <kbastian@mail.uni-paderborn.de>]

Add instructions of SR opcode format.
Add micro-op generator functions for saturate.
Add helper return from exception (rfe).

Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
---
v6 -> v7:
    - CPUTRICOREState -> CPUTriCoreState.

 target-tricore/helper.h    |   1 +
 target-tricore/op_helper.c |  52 +++++++++++++++++++++
 target-tricore/translate.c | 111 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 164 insertions(+)

diff --git a/target-tricore/helper.h b/target-tricore/helper.h
index 3c73234..7b7d74b 100644
--- a/target-tricore/helper.h
+++ b/target-tricore/helper.h
@@ -22,3 +22,4 @@ DEF_HELPER_3(sub_ssov, i32, env, i32, i32)
 DEF_HELPER_2(call, void, env, i32)
 DEF_HELPER_1(ret, void, env)
 DEF_HELPER_2(bisr, void, env, i32)
+DEF_HELPER_1(rfe, void, env)
diff --git a/target-tricore/op_helper.c b/target-tricore/op_helper.c
index bb55a49..6376f07 100644
--- a/target-tricore/op_helper.c
+++ b/target-tricore/op_helper.c
@@ -99,6 +99,21 @@ static int cdc_decrement(target_ulong *psw)
     return 0;
 }
 
+static bool cdc_zero(target_ulong *psw)
+{
+    int cdc = *psw & MASK_PSW_CDC;
+    /* Returns TRUE if PSW.CDC.COUNT == 0 or if PSW.CDC ==
+       7'b1111111, otherwise returns FALSE. */
+    if (cdc == 0x7f) {
+        return true;
+    }
+    /* find CDC.COUNT */
+    int lo = clo32((*psw & MASK_PSW_CDC) << (32 - 7));
+    int mask = (1u << (7 - lo)) - 1;
+    int count = *psw & mask;
+    return count == 0;
+}
+
 static void save_context_upper(CPUTriCoreState *env, int ea,
                                target_ulong *new_FCX)
 {
@@ -302,6 +317,43 @@ void helper_bisr(CPUTriCoreState *env, uint32_t const9)
     }
 }
 
+void helper_rfe(CPUTriCoreState *env)
+{
+    target_ulong ea;
+    target_ulong new_PCXI;
+    target_ulong new_PSW;
+    /* if (PCXI[19: 0] == 0) then trap(CSU); */
+    if ((env->PCXI & 0xfffff) == 0) {
+        /* raise csu trap */
+    }
+    /* if (PCXI.UL == 0) then trap(CTYP); */
+    if ((env->PCXI & MASK_PCXI_UL) == 0) {
+        /* raise CTYP trap */
+    }
+    /* if (!cdc_zero() AND PSW.CDE) then trap(NEST); */
+    if (!cdc_zero(&(env->PSW)) && (env->PSW & MASK_PSW_CDE)) {
+        /* raise MNG trap */
+    }
+    /* ICR.IE = PCXI.PIE; */
+    env->ICR = (env->ICR & ~MASK_ICR_IE) + ((env->PCXI & MASK_PCXI_PIE) >> 15);
+    /* ICR.CCPN = PCXI.PCPN; */
+    env->ICR = (env->ICR & ~MASK_ICR_CCPN) +
+               ((env->PCXI & MASK_PCXI_PCPN) >> 24);
+    /*EA = {PCXI.PCXS, 6'b0, PCXI.PCXO, 6'b0};*/
+    ea = ((env->PCXI & MASK_PCXI_PCXS) << 12) +
+         ((env->PCXI & MASK_PCXI_PCXO) << 6);
+    /*{new_PCXI, PSW, A[10], A[11], D[8], D[9], D[10], D[11], A[12],
+      A[13], A[14], A[15], D[12], D[13], D[14], D[15]} = M(EA, 16 * word);
+      M(EA, word) = FCX;*/
+    restore_context_upper(env, ea, &new_PCXI, &new_PSW);
+    /* FCX[19: 0] = PCXI[19: 0]; */
+    env->FCX = (env->FCX & 0xfff00000) + (env->PCXI & 0x000fffff);
+    /* PCXI = new_PCXI; */
+    env->PCXI = new_PCXI;
+    /* write psw */
+    psw_write(env, new_PSW);
+}
+
 static inline void QEMU_NORETURN do_raise_exception_err(CPUTriCoreState *env,
                                                         uint32_t exception,
                                                         int error_code,
diff --git a/target-tricore/translate.c b/target-tricore/translate.c
index e24479d..4f654de 100644
--- a/target-tricore/translate.c
+++ b/target-tricore/translate.c
@@ -262,6 +262,29 @@ static inline void gen_mul_i32s(TCGv ret, TCGv r1, TCGv r2)
     tcg_temp_free(low);
 }
 
+static void gen_saturate(TCGv ret, TCGv arg, int32_t up, int32_t low)
+{
+    TCGv sat_neg = tcg_const_i32(low);
+    TCGv temp = tcg_const_i32(up);
+
+    /* sat_neg = (arg < low ) ? low : arg; */
+    tcg_gen_movcond_tl(TCG_COND_LT, sat_neg, arg, sat_neg, sat_neg, arg);
+
+    /* ret = (sat_neg > up ) ? up  : sat_neg; */
+    tcg_gen_movcond_tl(TCG_COND_GT, ret, sat_neg, temp, temp, sat_neg);
+
+    tcg_temp_free(sat_neg);
+    tcg_temp_free(temp);
+}
+
+static void gen_saturate_u(TCGv ret, TCGv arg, int32_t up)
+{
+    TCGv temp = tcg_const_i32(up);
+    /* sat_neg = (arg > up ) ? up : arg; */
+    tcg_gen_movcond_tl(TCG_COND_GTU, ret, arg, temp, temp, arg);
+    tcg_temp_free(temp);
+}
+
 static void gen_shi(TCGv ret, TCGv r1, int32_t shift_count)
 {
     if (shift_count == -32) {
@@ -477,6 +500,15 @@ static void gen_compute_branch(DisasContext *ctx, uint32_t opc, int r1,
     case OPC1_16_SBR_LOOP:
         gen_loop(ctx, r1, offset * 2 - 32);
         break;
+/* SR-format jumps */
+    case OPC1_16_SR_JI:
+        tcg_gen_andi_tl(cpu_PC, cpu_gpr_a[r1], 0xfffffffe);
+        tcg_gen_exit_tb(0);
+        break;
+    case OPC2_16_SR_RET:
+        gen_helper_ret(cpu_env);
+        tcg_gen_exit_tb(0);
+        break;
     default:
         printf("Branch Error at %x\n", ctx->pc);
     }
@@ -794,6 +826,70 @@ static void decode_sro_opc(DisasContext *ctx, int op1)
     }
 }
 
+static void decode_sr_system(CPUTriCoreState *env, DisasContext *ctx)
+{
+    uint32_t op2;
+    op2 = MASK_OP_SR_OP2(ctx->opcode);
+
+    switch (op2) {
+    case OPC2_16_SR_NOP:
+        break;
+    case OPC2_16_SR_RET:
+        gen_compute_branch(ctx, op2, 0, 0, 0, 0);
+        break;
+    case OPC2_16_SR_RFE:
+        gen_helper_rfe(cpu_env);
+        tcg_gen_exit_tb(0);
+        ctx->bstate = BS_BRANCH;
+        break;
+    case OPC2_16_SR_DEBUG:
+        /* raise EXCP_DEBUG */
+        break;
+    }
+}
+
+static void decode_sr_accu(CPUTriCoreState *env, DisasContext *ctx)
+{
+    uint32_t op2;
+    uint32_t r1;
+    TCGv temp;
+
+    r1 = MASK_OP_SR_S1D(ctx->opcode);
+    op2 = MASK_OP_SR_OP2(ctx->opcode);
+
+    switch (op2) {
+    case OPC2_16_SR_RSUB:
+        /* overflow only if r1 = -0x80000000 */
+        temp = tcg_const_i32(-0x80000000);
+        /* calc V bit */
+        tcg_gen_setcond_tl(TCG_COND_EQ, cpu_PSW_V, cpu_gpr_d[r1], temp);
+        tcg_gen_shli_tl(cpu_PSW_V, cpu_PSW_V, 31);
+        /* calc SV bit */
+        tcg_gen_or_tl(cpu_PSW_SV, cpu_PSW_SV, cpu_PSW_V);
+        /* sub */
+        tcg_gen_neg_tl(cpu_gpr_d[r1], cpu_gpr_d[r1]);
+        /* calc av */
+        tcg_gen_add_tl(cpu_PSW_AV, cpu_gpr_d[r1], cpu_gpr_d[r1]);
+        tcg_gen_xor_tl(cpu_PSW_AV, cpu_gpr_d[r1], cpu_PSW_AV);
+        /* calc sav */
+        tcg_gen_or_tl(cpu_PSW_SAV, cpu_PSW_SAV, cpu_PSW_AV);
+        tcg_temp_free(temp);
+        break;
+    case OPC2_16_SR_SAT_B:
+        gen_saturate(cpu_gpr_d[r1], cpu_gpr_d[r1], 0x7f, -0x80);
+        break;
+    case OPC2_16_SR_SAT_BU:
+        gen_saturate_u(cpu_gpr_d[r1], cpu_gpr_d[r1], 0xff);
+        break;
+    case OPC2_16_SR_SAT_H:
+        gen_saturate(cpu_gpr_d[r1], cpu_gpr_d[r1], 0x7fff, -0x8000);
+        break;
+    case OPC2_16_SR_SAT_HU:
+        gen_saturate_u(cpu_gpr_d[r1], cpu_gpr_d[r1], 0xffff);
+        break;
+    }
+}
+
 static void decode_16Bit_opc(CPUTriCoreState *env, DisasContext *ctx)
 {
     int op1;
@@ -985,6 +1081,21 @@ static void decode_16Bit_opc(CPUTriCoreState *env, DisasContext *ctx)
         const16 = MASK_OP_SSRO_OFF4(ctx->opcode);
         gen_offset_st(ctx, cpu_gpr_d[r1], cpu_gpr_a[15], const16 * 4, MO_LESL);
         break;
+/* SR-format */
+    case OPCM_16_SR_SYSTEM:
+        decode_sr_system(env, ctx);
+        break;
+    case OPCM_16_SR_ACCU:
+        decode_sr_accu(env, ctx);
+        break;
+    case OPC1_16_SR_JI:
+        r1 = MASK_OP_SR_S1D(ctx->opcode);
+        gen_compute_branch(ctx, op1, r1, 0, 0, 0);
+        break;
+    case OPC1_16_SR_NOT:
+        r1 = MASK_OP_SR_S1D(ctx->opcode);
+        tcg_gen_not_tl(cpu_gpr_d[r1], cpu_gpr_d[r1]);
+        break;
     }
 }
 
-- 
2.1.0