target-microblaze: Introduce a use-pcmp-instr property

Introduce a use-pcmp-instr property making pcmp instructions
optional.
Reviewed-by: NAlistair Francis <alistair.francis@xilinx.com>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>

target/microblaze/cpu.c

@@ -157,7 +157,6 @@ static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
                         | PVR2_D_LMB_MASK \
                         | PVR2_I_OPB_MASK \
                         | PVR2_I_LMB_MASK \
-                        | PVR2_USE_PCMP_INSTR \
                         | PVR2_FPU_EXC_MASK \
                         | 0;
 
@@ -188,7 +187,8 @@ static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
                         (cpu->cfg.use_hw_mul > 1 ? PVR2_USE_MUL64_MASK : 0) |
                         (cpu->cfg.use_barrel ? PVR2_USE_BARREL_MASK : 0) |
                         (cpu->cfg.use_div ? PVR2_USE_DIV_MASK : 0) |
-                        (cpu->cfg.use_msr_instr ? PVR2_USE_MSR_INSTR : 0);
+                        (cpu->cfg.use_msr_instr ? PVR2_USE_MSR_INSTR : 0) |
+                        (cpu->cfg.use_pcmp_instr ? PVR2_USE_PCMP_INSTR : 0);
 
     env->pvr.regs[5] |= cpu->cfg.dcache_writeback ?
                                         PVR5_DCACHE_WRITEBACK_MASK : 0;
@@ -242,6 +242,7 @@ static Property mb_properties[] = {
     DEFINE_PROP_BOOL("use-barrel", MicroBlazeCPU, cfg.use_barrel, true),
     DEFINE_PROP_BOOL("use-div", MicroBlazeCPU, cfg.use_div, true),
     DEFINE_PROP_BOOL("use-msr-instr", MicroBlazeCPU, cfg.use_msr_instr, true),
+    DEFINE_PROP_BOOL("use-pcmp-instr", MicroBlazeCPU, cfg.use_pcmp_instr, true),
     DEFINE_PROP_BOOL("use-mmu", MicroBlazeCPU, cfg.use_mmu, true),
     DEFINE_PROP_BOOL("dcache-writeback", MicroBlazeCPU, cfg.dcache_writeback,
                      false),

target/microblaze/cpu.h

@@ -302,6 +302,7 @@ struct MicroBlazeCPU {
         bool use_barrel;
         bool use_div;
         bool use_msr_instr;
+        bool use_pcmp_instr;
         bool use_mmu;
         bool dcache_writeback;
         bool endi;

target/microblaze/translate.c

@@ -326,7 +326,7 @@ static void dec_pattern(DisasContext *dc)
 
     if ((dc->tb_flags & MSR_EE_FLAG)
           && (dc->cpu->env.pvr.regs[2] & PVR2_ILL_OPCODE_EXC_MASK)
-          && !((dc->cpu->env.pvr.regs[2] & PVR2_USE_PCMP_INSTR))) {
+          && !dc->cpu->cfg.use_pcmp_instr) {
         tcg_gen_movi_tl(cpu_SR[SR_ESR], ESR_EC_ILLEGAL_OP);
         t_gen_raise_exception(dc, EXCP_HW_EXCP);
     }
@@ -762,11 +762,11 @@ static void dec_bit(DisasContext *dc)
         case 0xe0:
             if ((dc->tb_flags & MSR_EE_FLAG)
                 && (dc->cpu->env.pvr.regs[2] & PVR2_ILL_OPCODE_EXC_MASK)
-                && !((dc->cpu->env.pvr.regs[2] & PVR2_USE_PCMP_INSTR))) {
+                && !dc->cpu->cfg.use_pcmp_instr) {
                 tcg_gen_movi_tl(cpu_SR[SR_ESR], ESR_EC_ILLEGAL_OP);
                 t_gen_raise_exception(dc, EXCP_HW_EXCP);
             }
-            if (dc->cpu->env.pvr.regs[2] & PVR2_USE_PCMP_INSTR) {
+            if (dc->cpu->cfg.use_pcmp_instr) {
                 tcg_gen_clzi_i32(cpu_R[dc->rd], cpu_R[dc->ra], 32);
             }
             break;