4071

subx: conditional jump instructions

Lots of boilerplate here. This commit really strains my 'copyista'
ethic. But I think it's still clearer to see each instruction
implemented independently than to try to create a macro or something
like that.

3 files changed, 510 insertions, 46 deletions

diff --git a/subx/013immediate_addressing.cc b/subx/013immediate_addressing.cc
index e97b9f6c..dd1ce4c0 100644
--- a/subx/013immediate_addressing.cc
+++ b/subx/013immediate_addressing.cc
@@ -366,49 +366,3 @@ case 0xc7: {  // copy imm32 to r32
   *arg1 = arg2;
   break;
 }
-
-//:: jump
-
-:(scenario jump_rel8)
-# op  ModRM   SIB   displacement  immediate
-  eb                05                        # skip 1 instruction
-  05                              00 00 00 01
-  05                              00 00 00 02
-+run: inst: 0x00000001
-+run: jump 5
-+run: inst: 0x00000008
--run: inst: 0x00000003
-
-:(before "End Single-Byte Opcodes")
-case 0xeb: {  // jump rel8
-  int8_t offset = static_cast<int>(next());
-  trace(2, "run") << "jump " << NUM(offset) << end();
-  EIP += offset;
-  break;
-}
-
-//:
-
-:(scenario jump_rel16)
-# op  ModRM   SIB   displacement  immediate
-  e9                05 00                     # skip 1 instruction
-  05                              00 00 00 01
-  05                              00 00 00 02
-+run: inst: 0x00000001
-+run: jump 5
-+run: inst: 0x00000009
--run: inst: 0x00000003
-
-:(before "End Single-Byte Opcodes")
-case 0xe9: {  // jump rel8
-  int16_t offset = imm16();
-  trace(2, "run") << "jump " << offset << end();
-  EIP += offset;
-  break;
-}
-:(code)
-int16_t imm16() {
-  int16_t result = next();
-  result |= (next()<<8);
-  return result;
-}
diff --git a/subx/014jump_relative.cc b/subx/014jump_relative.cc
new file mode 100644
index 00000000..c9cdcd1b
--- /dev/null
+++ b/subx/014jump_relative.cc
@@ -0,0 +1,252 @@
+//: jump to 8-bit offset
+
+//:: jump
+
+:(scenario jump_rel8)
+# op  ModRM   SIB   displacement  immediate
+  eb                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0xeb: {  // jump rel8
+  int8_t offset = static_cast<int>(next());
+  trace(2, "run") << "jump " << NUM(offset) << end();
+  EIP += offset;
+  break;
+}
+
+//:: jump if equal/zero
+
+:(scenario je_rel8_success)
+% ZF = true;
+# op  ModRM   SIB   displacement  immediate
+  74                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0x74: {  // jump rel8 if ZF
+  int8_t offset = static_cast<int>(next());
+  if (ZF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario je_rel8_fail)
+% ZF = false;
+# op  ModRM   SIB   displacement  immediate
+  74                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000003
++run: inst: 0x00000008
+-run: jump 5
+
+//:: jump if not equal/not zero
+
+:(scenario jne_rel8_success)
+% ZF = false;
+# op  ModRM   SIB   displacement  immediate
+  75                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0x75: {  // jump rel8 unless ZF
+  int8_t offset = static_cast<int>(next());
+  if (!ZF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jne_rel8_fail)
+% ZF = true;
+# op  ModRM   SIB   displacement  immediate
+  75                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000003
++run: inst: 0x00000008
+-run: jump 5
+
+//:: jump if greater
+
+:(scenario jg_rel8_success)
+% ZF = false;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7f                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0x7f: {  // jump rel8 if !SF and !ZF
+  int8_t offset = static_cast<int>(next());
+  if (!ZF && SF == OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jg_rel8_fail)
+% ZF = false;
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7f                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000003
++run: inst: 0x00000008
+-run: jump 5
+
+//:: jump if greater or equal
+
+:(scenario jge_rel8_success)
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7d                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0x7d: {  // jump rel8 if !SF
+  int8_t offset = static_cast<int>(next());
+  if (SF == OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jge_rel8_fail)
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7d                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000003
++run: inst: 0x00000008
+-run: jump 5
+
+//:: jump if lesser
+
+:(scenario jl_rel8_success)
+% ZF = false;
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7c                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0x7c: {  // jump rel8 if SF and !ZF
+  int8_t offset = static_cast<int>(next());
+  if (SF != OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jl_rel8_fail)
+% ZF = false;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7c                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000003
++run: inst: 0x00000008
+-run: jump 5
+
+//:: jump if lesser or equal
+
+:(scenario jle_rel8_equal)
+% ZF = true;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7e                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(scenario jle_rel8_lesser)
+% ZF = false;
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7e                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000008
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0x7e: {  // jump rel8 if SF or ZF
+  int8_t offset = static_cast<int>(next());
+  if (ZF || SF != OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jle_rel8_greater)
+% ZF = false;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  7e                05                        # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000003
++run: inst: 0x00000008
+-run: jump 5
diff --git a/subx/015jump_relative.cc b/subx/015jump_relative.cc
new file mode 100644
index 00000000..b48b2072
--- /dev/null
+++ b/subx/015jump_relative.cc
@@ -0,0 +1,258 @@
+//: jump to 16-bit offset
+
+//:: jump
+
+:(scenario jump_rel16)
+# op  ModRM   SIB   displacement  immediate
+  e9                05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x00000009
+-run: inst: 0x00000003
+
+:(before "End Single-Byte Opcodes")
+case 0xe9: {  // jump rel8
+  int16_t offset = imm16();
+  trace(2, "run") << "jump " << offset << end();
+  EIP += offset;
+  break;
+}
+:(code)
+int16_t imm16() {
+  int16_t result = next();
+  result |= (next()<<8);
+  return result;
+}
+
+//:: jump if equal/zero
+
+:(scenario je_rel16_success)
+% ZF = true;
+# op  ModRM   SIB   displacement  immediate
+  0f 84             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x0000000a
+-run: inst: 0x00000005
+
+:(before "End Two-Byte Opcodes Starting With 0f")
+case 0x84: {  // jump rel16 if ZF
+  int8_t offset = imm16();
+  if (ZF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario je_rel16_fail)
+% ZF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 84             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000005
++run: inst: 0x0000000a
+-run: jump 5
+
+//:: jump if not equal/not zero
+
+:(scenario jne_rel16_success)
+% ZF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 85             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x0000000a
+-run: inst: 0x00000005
+
+:(before "End Two-Byte Opcodes Starting With 0f")
+case 0x85: {  // jump rel16 unless ZF
+  int8_t offset = imm16();
+  if (!ZF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jne_rel16_fail)
+% ZF = true;
+# op  ModRM   SIB   displacement  immediate
+  0f 85             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000005
++run: inst: 0x0000000a
+-run: jump 5
+
+//:: jump if greater
+
+:(scenario jg_rel16_success)
+% ZF = false;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8f             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x0000000a
+-run: inst: 0x00000005
+
+:(before "End Two-Byte Opcodes Starting With 0f")
+case 0x8f: {  // jump rel16 if !SF and !ZF
+  int8_t offset = imm16();
+  if (!ZF && SF == OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jg_rel16_fail)
+% ZF = false;
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8f             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000005
++run: inst: 0x0000000a
+-run: jump 5
+
+//:: jump if greater or equal
+
+:(scenario jge_rel16_success)
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8d             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x0000000a
+-run: inst: 0x00000005
+
+:(before "End Two-Byte Opcodes Starting With 0f")
+case 0x8d: {  // jump rel16 if !SF
+  int8_t offset = imm16();
+  if (SF == OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jge_rel16_fail)
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8d             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000005
++run: inst: 0x0000000a
+-run: jump 5
+
+//:: jump if lesser
+
+:(scenario jl_rel16_success)
+% ZF = false;
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8c             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x0000000a
+-run: inst: 0x00000005
+
+:(before "End Two-Byte Opcodes Starting With 0f")
+case 0x8c: {  // jump rel16 if SF and !ZF
+  int8_t offset = imm16();
+  if (SF != OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jl_rel16_fail)
+% ZF = false;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8c             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000005
++run: inst: 0x0000000a
+-run: jump 5
+
+//:: jump if lesser or equal
+
+:(scenario jle_rel16_equal)
+% ZF = true;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8e             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x0000000a
+-run: inst: 0x00000005
+
+:(scenario jle_rel16_lesser)
+% ZF = false;
+% SF = true;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8e             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: jump 5
++run: inst: 0x0000000a
+-run: inst: 0x00000005
+
+:(before "End Two-Byte Opcodes Starting With 0f")
+case 0x8e: {  // jump rel16 if SF or ZF
+  int8_t offset = imm16();
+  if (ZF || SF != OF) {
+    trace(2, "run") << "jump " << NUM(offset) << end();
+    EIP += offset;
+  }
+  break;
+}
+
+:(scenario jle_rel16_greater)
+% ZF = false;
+% SF = false;
+% OF = false;
+# op  ModRM   SIB   displacement  immediate
+  0f 8e             05 00                     # skip 1 instruction
+  05                              00 00 00 01
+  05                              00 00 00 02
++run: inst: 0x00000001
++run: inst: 0x00000005
++run: inst: 0x0000000a
+-run: jump 5