Add PC-relative branch support to moxie sim.

diff --git a/sim/moxie/ChangeLog b/sim/moxie/ChangeLog
index c528de3..eacfeb9 100644 (file)
--- a/sim/moxie/ChangeLog
+++ b/sim/moxie/ChangeLog
@@ -1,3 +1,8 @@
+2009-06-11  Anthony Green  <green@moxielogic.com>
+
+       * interp.c (INST2OFFSET): Define.
+       (sim_resume): Support new PC relative branch instructions.
+
 2009-05-09  Anthony Green  <green@moxielogic.com>
 
        * interp.c (sim_resume): Add missing breaks in switch.

diff --git a/sim/moxie/interp.c b/sim/moxie/interp.c
index dd87648..4980ff1 100644 (file)
--- a/sim/moxie/interp.c
+++ b/sim/moxie/interp.c
@@ -35,6 +35,10 @@ host_callback *       callback;
 
 FILE *tracefile;
 
+/* Extract the signed 10-bit offset from a 16-bit branch
+   instruction.  */
+#define INST2OFFSET(o) ((((signed short)((o & ((1<<10)-1))<<6))>>6)<<1)
+
 #define EXTRACT_WORD(addr) (((addr)[0] << 24) \
                            + ((addr)[1] << 16) \
                            + ((addr)[2] << 8) \
@@ -424,10 +428,86 @@ sim_resume (sd, step, siggnal)
          if (inst & (1 << 14))
            {
              /* This is a Form 3 instruction.  */
-             /* We haven't implemented any yet, so just SIGILL for now.  */
-             TRACE("SIGILL3");
-             cpu.asregs.exception = SIGILL;
-             break;
+             int opcode = (inst >> 10 & 0xf);
+
+             switch (opcode)
+               {
+               case 0x00: /* beq */
+                 {
+                   TRACE("beq");
+                   if (cpu.asregs.cc & CC_EQ)
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x01: /* bne */
+                 {
+                   TRACE("bne");
+                   if (! (cpu.asregs.cc & CC_EQ))
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x02: /* blt */
+                 {
+                   TRACE("blt");
+                   if (cpu.asregs.cc & CC_LT)
+                     pc += INST2OFFSET(inst) - 2;
+                 }               break;
+               case 0x03: /* bgt */
+                 {
+                   TRACE("bgt");
+                   if (cpu.asregs.cc & CC_GT)
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x04: /* bltu */
+                 {
+                   TRACE("bltu");
+                   if (cpu.asregs.cc & CC_LTU)
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x05: /* bgtu */
+                 {
+                   TRACE("bgtu");
+                   if (cpu.asregs.cc & CC_GTU)
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x06: /* bge */
+                 {
+                   TRACE("bge");
+                   if (cpu.asregs.cc & (CC_GT | CC_EQ))
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x07: /* ble */
+                 {
+                   TRACE("ble");
+                   if (cpu.asregs.cc & (CC_LT | CC_EQ))
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x08: /* bgeu */
+                 {
+                   TRACE("bgeu");
+                   if (cpu.asregs.cc & (CC_GTU | CC_EQ))
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               case 0x09: /* bleu */
+                 {
+                   TRACE("bleu");
+                   if (cpu.asregs.cc & (CC_LTU | CC_EQ))
+                     pc += INST2OFFSET(inst) - 2;
+                 }
+                 break;
+               default:
+                 {
+                   TRACE("SIGILL3");
+                   cpu.asregs.exception = SIGILL;
+                   break;
+                 }
+               }
            }
          else
            {
@@ -655,126 +735,22 @@ sim_resume (sd, step, siggnal)
                cpu.asregs.cc = cc;
              }
              break;
-           case 0x0f: /* beq */
+           case 0x0f:
+           case 0x10:
+           case 0x11:
+           case 0x12:
+           case 0x13:
+           case 0x14:
+           case 0x15:
+           case 0x16:
+           case 0x17:
+           case 0x18:
              {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("beq");
-               if (cpu.asregs.cc & CC_EQ)
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
+               opc = opcode;
+               TRACE("SIGILL0");
+               cpu.asregs.exception = SIGILL;
+               break;
              }
-             break;
-           case 0x10: /* bne */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("bne");
-               if (! (cpu.asregs.cc & CC_EQ))
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x11: /* blt */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("blt");
-               if (cpu.asregs.cc & CC_LT)
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x12: /* bgt */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("bgt");
-               if (cpu.asregs.cc & CC_GT)
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x13: /* bltu */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("bltu");
-               if (cpu.asregs.cc & CC_LTU)
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x14: /* bgtu */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("bgtu");
-               if (cpu.asregs.cc & CC_GTU)
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x15: /* bge */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("bge");
-               if ((cpu.asregs.cc & CC_GT) || (cpu.asregs.cc & CC_EQ))            
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x16: /* ble */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("ble");
-               if ((cpu.asregs.cc & CC_LT) || (cpu.asregs.cc & CC_EQ))
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x17: /* bgeu */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("bgeu");
-               if ((cpu.asregs.cc & CC_GTU) || (cpu.asregs.cc & CC_EQ))
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
-           case 0x18: /* bleu */
-             {
-               unsigned int tgt = EXTRACT_WORD(&memory[pc+2]);
-               TRACE("bleu");
-               if ((cpu.asregs.cc & CC_LTU) || (cpu.asregs.cc & CC_EQ))
-                 {
-                   pc = tgt - 2;
-                 }
-               else
-                 pc += 4;
-             }
-             break;
            case 0x19: /* jsr */
              {
                unsigned int fn = cpu.asregs.regs[(inst >> 4) & 0xf];