about summary refs log tree commit diff stats
diff options
context:
space:
mode:
-rw-r--r--subx/010---vm.cc5
-rw-r--r--subx/011run.cc2
-rw-r--r--subx/013direct_addressing.cc89
-rw-r--r--subx/014indirect_addressing.cc18
-rw-r--r--subx/015immediate_addressing.cc32
-rw-r--r--subx/017jump_disp8.cc14
-rw-r--r--subx/018jump_disp16.cc14
-rw-r--r--subx/019functions.cc4
-rw-r--r--subx/020syscalls.cc2
9 files changed, 89 insertions, 91 deletions
diff --git a/subx/010---vm.cc b/subx/010---vm.cc
index cae54aec..41d98b82 100644
--- a/subx/010---vm.cc
+++ b/subx/010---vm.cc
@@ -373,7 +373,7 @@ map</*op*/string, string> name_f3_0f;
 init_op_names();
 :(code)
 void init_op_names() {
-  put(name, "f4", "halt");
+  put(name, "f4", "halt (hlt)");
   // End Initialize Op Names(name)
 }
 
@@ -390,7 +390,8 @@ if (key == "opcodes") {
     cerr << "  f3 0f " << p->first << ": " << p->second << '\n';
   cerr << "Run `subx help instructions` for details on words like 'r32' and 'disp8'.\n"
           "For complete details on these instructions, consult the IA-32 manual (volume 2).\n"
-          "There's various versions of it online, such as https://c9x.me/x86.\n";
+          "There's various versions of it online, such as https://c9x.me/x86.\n"
+          "The mnemonics in brackets will help you locate each instruction.\n";
   return 0;
 }
 :(before "End Help Contents")
diff --git a/subx/011run.cc b/subx/011run.cc
index d5d1c074..6dc1a09b 100644
--- a/subx/011run.cc
+++ b/subx/011run.cc
@@ -327,7 +327,7 @@ void parse_and_load(const string& text_bytes) {
 //:: run
 
 :(before "End Initialize Op Names(name)")
-put(name, "05", "add imm32 to EAX");
+put(name, "05", "add imm32 to EAX (add)");
 
 //: our first opcode
 :(before "End Single-Byte Opcodes")
diff --git a/subx/013direct_addressing.cc b/subx/013direct_addressing.cc
index 2767f32b..71b869d2 100644
--- a/subx/013direct_addressing.cc
+++ b/subx/013direct_addressing.cc
@@ -1,7 +1,7 @@
 //: operating directly on a register
 
 :(before "End Initialize Op Names(name)")
-put(name, "01", "add r32 to rm32");
+put(name, "01", "add r32 to rm32 (add)");
 
 :(scenario add_r32_to_r32)
 % Reg[EAX].i = 0x10;
@@ -76,7 +76,7 @@ string rname(uint8_t r) {
 //:: subtract
 
 :(before "End Initialize Op Names(name)")
-put(name, "29", "subtract r32 from rm32");
+put(name, "29", "subtract r32 from rm32 (sub)");
 
 :(scenario subtract_r32_from_r32)
 % Reg[EAX].i = 10;
@@ -102,7 +102,7 @@ case 0x29: {  // subtract r32 from r/m32
 //:: multiply
 
 :(before "End Initialize Op Names(name)")
-put(name, "f7", "test/negate/mul/div rm32 (with EAX if necessary) depending on subop");
+put(name, "f7", "negate/multiply rm32 (with EAX if necessary) depending on subop (neg/mul)");
 
 :(scenario multiply_eax_by_r32)
 % Reg[EAX].i = 4;
@@ -143,7 +143,7 @@ case 0xf7: {  // xor r32 with r/m32
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name_0f, "af", "multiply rm32 into r32");
+put(name_0f, "af", "multiply rm32 into r32 (imul)");
 
 :(scenario multiply_r32_into_r32)
 % Reg[EAX].i = 4;
@@ -169,7 +169,7 @@ case 0xaf: {  // multiply r32 into r/m32
 //:: and
 
 :(before "End Initialize Op Names(name)")
-put(name, "21", "rm32 = bitwise AND of r32 with rm32");
+put(name, "21", "rm32 = bitwise AND of r32 with rm32 (and)");
 
 :(scenario and_r32_with_r32)
 % Reg[EAX].i = 0x0a0b0c0d;
@@ -195,7 +195,7 @@ case 0x21: {  // and r32 with r/m32
 //:: or
 
 :(before "End Initialize Op Names(name)")
-put(name, "09", "rm32 = bitwise OR of r32 with rm32");
+put(name, "09", "rm32 = bitwise OR of r32 with rm32 (or)");
 
 :(scenario or_r32_with_r32)
 % Reg[EAX].i = 0x0a0b0c0d;
@@ -221,7 +221,7 @@ case 0x09: {  // or r32 with r/m32
 //:: xor
 
 :(before "End Initialize Op Names(name)")
-put(name, "31", "rm32 = bitwise XOR of r32 with rm32");
+put(name, "31", "rm32 = bitwise XOR of r32 with rm32 (xor)");
 
 :(scenario xor_r32_with_r32)
 % Reg[EAX].i = 0x0a0b0c0d;
@@ -246,9 +246,6 @@ case 0x31: {  // xor r32 with r/m32
 
 //:: not
 
-:(before "End Initialize Op Names(name)")
-put(name, "f7", "bitwise complement of rm32");
-
 :(scenario not_r32)
 % Reg[EBX].i = 0x0f0f00ff;
 == 0x1
@@ -274,7 +271,7 @@ case 2: {  // not r/m32
 //:: compare (cmp)
 
 :(before "End Initialize Op Names(name)")
-put(name, "39", "compare: set SF if rm32 < r32");
+put(name, "39", "compare: set SF if rm32 < r32 (cmp)");
 
 :(scenario compare_r32_with_r32_greater)
 % Reg[EAX].i = 0x0a0b0c0d;
@@ -328,7 +325,7 @@ case 0x39: {  // set SF if r/m32 < r32
 //:: copy (mov)
 
 :(before "End Initialize Op Names(name)")
-put(name, "89", "copy r32 to rm32");
+put(name, "89", "copy r32 to rm32 (mov)");
 
 :(scenario copy_r32_to_r32)
 % Reg[EBX].i = 0xaf;
@@ -354,7 +351,7 @@ case 0x89: {  // copy r32 to r/m32
 //:: xchg
 
 :(before "End Initialize Op Names(name)")
-put(name, "87", "swap the contents of r32 and rm32");
+put(name, "87", "swap the contents of r32 and rm32 (xchg)");
 
 :(scenario xchg_r32_with_r32)
 % Reg[EBX].i = 0xaf;
@@ -385,14 +382,14 @@ case 0x87: {  // exchange r32 with r/m32
 //:: increment
 
 :(before "End Initialize Op Names(name)")
-put(name, "40", "increment EAX");
-put(name, "41", "increment ECX");
-put(name, "42", "increment EDX");
-put(name, "43", "increment EBX");
-put(name, "44", "increment ESP");
-put(name, "45", "increment EBP");
-put(name, "46", "increment ESI");
-put(name, "47", "increment EDI");
+put(name, "40", "increment EAX (inc)");
+put(name, "41", "increment ECX (inc)");
+put(name, "42", "increment EDX (inc)");
+put(name, "43", "increment EBX (inc)");
+put(name, "44", "increment ESP (inc)");
+put(name, "45", "increment EBP (inc)");
+put(name, "46", "increment ESI (inc)");
+put(name, "47", "increment EDI (inc)");
 
 :(scenario increment_r32)
 % Reg[ECX].u = 0x1f;
@@ -419,7 +416,7 @@ case 0x47: {  // increment r32
 }
 
 :(before "End Initialize Op Names(name)")
-put(name, "ff", "inc/dec/jump/push/call rm32 based on subop");
+put(name, "ff", "increment/decrement/jump/push/call rm32 based on subop (inc/dec/jmp/push/call)");
 
 :(scenario increment_rm32)
 % Reg[EAX].u = 0x20;
@@ -451,14 +448,14 @@ case 0xff: {
 //:: decrement
 
 :(before "End Initialize Op Names(name)")
-put(name, "48", "decrement EAX");
-put(name, "49", "decrement ECX");
-put(name, "4a", "decrement EDX");
-put(name, "4b", "decrement EBX");
-put(name, "4c", "decrement ESP");
-put(name, "4d", "decrement EBP");
-put(name, "4e", "decrement ESI");
-put(name, "4f", "decrement EDI");
+put(name, "48", "decrement EAX (dec)");
+put(name, "49", "decrement ECX (dec)");
+put(name, "4a", "decrement EDX (dec)");
+put(name, "4b", "decrement EBX (dec)");
+put(name, "4c", "decrement ESP (dec)");
+put(name, "4d", "decrement EBP (dec)");
+put(name, "4e", "decrement ESI (dec)");
+put(name, "4f", "decrement EDI (dec)");
 
 :(scenario decrement_r32)
 % Reg[ECX].u = 0x1f;
@@ -506,14 +503,14 @@ case 1: {  // decrement r/m32
 //:: push
 
 :(before "End Initialize Op Names(name)")
-put(name, "50", "push EAX to stack");
-put(name, "51", "push ECX to stack");
-put(name, "52", "push EDX to stack");
-put(name, "53", "push EBX to stack");
-put(name, "54", "push ESP to stack");
-put(name, "55", "push EBP to stack");
-put(name, "56", "push ESI to stack");
-put(name, "57", "push EDI to stack");
+put(name, "50", "push EAX to stack (push)");
+put(name, "51", "push ECX to stack (push)");
+put(name, "52", "push EDX to stack (push)");
+put(name, "53", "push EBX to stack (push)");
+put(name, "54", "push ESP to stack (push)");
+put(name, "55", "push EBP to stack (push)");
+put(name, "56", "push ESI to stack (push)");
+put(name, "57", "push EDI to stack (push)");
 
 :(scenario push_r32)
 % Reg[ESP].u = 0x64;
@@ -544,14 +541,14 @@ case 0x57: {  // push r32 to stack
 //:: pop
 
 :(before "End Initialize Op Names(name)")
-put(name, "58", "pop top of stack to EAX");
-put(name, "59", "pop top of stack to ECX");
-put(name, "5a", "pop top of stack to EDX");
-put(name, "5b", "pop top of stack to EBX");
-put(name, "5c", "pop top of stack to ESP");
-put(name, "5d", "pop top of stack to EBP");
-put(name, "5e", "pop top of stack to ESI");
-put(name, "5f", "pop top of stack to EDI");
+put(name, "58", "pop top of stack to EAX (pop)");
+put(name, "59", "pop top of stack to ECX (pop)");
+put(name, "5a", "pop top of stack to EDX (pop)");
+put(name, "5b", "pop top of stack to EBX (pop)");
+put(name, "5c", "pop top of stack to ESP (pop)");
+put(name, "5d", "pop top of stack to EBP (pop)");
+put(name, "5e", "pop top of stack to ESI (pop)");
+put(name, "5f", "pop top of stack to EDI (pop)");
 
 :(scenario pop_r32)
 % Reg[ESP].u = 0x2000;
diff --git a/subx/014indirect_addressing.cc b/subx/014indirect_addressing.cc
index 1e20cff5..8bcedbd3 100644
--- a/subx/014indirect_addressing.cc
+++ b/subx/014indirect_addressing.cc
@@ -28,7 +28,7 @@ case 0:  // indirect addressing
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "03", "add rm32 to r32");
+put(name, "03", "add rm32 to r32 (add)");
 
 :(scenario add_mem_at_r32_to_r32)
 % Reg[EAX].i = 0x2000;
@@ -71,7 +71,7 @@ case 0x03: {  // add r/m32 to r32
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "2b", "subtract rm32 from r32");
+put(name, "2b", "subtract rm32 from r32 (sub)");
 
 :(scenario subtract_mem_at_r32_from_r32)
 % Reg[EAX].i = 0x2000;
@@ -114,7 +114,7 @@ case 0x2b: {  // subtract r/m32 from r32
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "23", "r32 = bitwise AND of r32 with rm32");
+put(name, "23", "r32 = bitwise AND of r32 with rm32 (and)");
 
 :(scenario and_mem_at_r32_with_r32)
 % Reg[EAX].i = 0x2000;
@@ -157,7 +157,7 @@ case 0x23: {  // and r/m32 with r32
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "0b", "r32 = bitwise OR of r32 with rm32");
+put(name, "0b", "r32 = bitwise OR of r32 with rm32 (or)");
 
 :(scenario or_mem_at_r32_with_r32)
 % Reg[EAX].i = 0x2000;
@@ -200,7 +200,7 @@ case 0x0b: {  // or r/m32 with r32
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "33", "r32 = bitwise XOR of r32 with rm32");
+put(name, "33", "r32 = bitwise XOR of r32 with rm32 (xor)");
 
 :(scenario xor_mem_at_r32_with_r32)
 % Reg[EAX].i = 0x2000;
@@ -284,7 +284,7 @@ ff 00 0f 0f  # 0x0f0f00ff
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "3b", "compare: set SF if r32 < rm32");
+put(name, "3b", "compare: set SF if r32 < rm32 (cmp)");
 
 :(scenario compare_r32_with_mem_at_r32_greater)
 % Reg[EAX].i = 0x2000;
@@ -357,7 +357,7 @@ case 0x3b: {  // set SF if r32 < r/m32
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "8b", "copy rm32 to r32");
+put(name, "8b", "copy rm32 to r32 (mov)");
 
 :(scenario copy_mem_at_r32_to_r32)
 % Reg[EAX].i = 0x2000;
@@ -437,7 +437,7 @@ case 6: {  // push r/m32 to stack
 //:: pop
 
 :(before "End Initialize Op Names(name)")
-put(name, "8f", "pop top of stack to rm32");
+put(name, "8f", "pop top of stack to rm32 (pop)");
 
 :(scenario pop_mem_at_r32)
 % Reg[EAX].i = 0x60;
@@ -581,7 +581,7 @@ case 2:  // indirect + disp32 addressing
 //:: lea
 
 :(before "End Initialize Op Names(name)")
-put(name, "8d", "load effective address of memory in rm32 into r32");
+put(name, "8d", "copy address in rm32 into r32 (lea)");
 
 :(scenario lea)
 % Reg[EAX].u = 0x2000;
diff --git a/subx/015immediate_addressing.cc b/subx/015immediate_addressing.cc
index 7f1f1a7e..7e6c6e28 100644
--- a/subx/015immediate_addressing.cc
+++ b/subx/015immediate_addressing.cc
@@ -1,7 +1,7 @@
 //: instructions that (immediately) contain an argument to act with
 
 :(before "End Initialize Op Names(name)")
-put(name, "81", "combine rm32 with imm32 based on subop");
+put(name, "81", "combine rm32 with imm32 based on subop (add/sub/and/or/xor/cmp)");
 
 :(scenario add_imm32_to_r32)
 % Reg[EBX].i = 1;
@@ -55,7 +55,7 @@ case 0x81: {  // combine imm32 with r/m32
 //:: subtract
 
 :(before "End Initialize Op Names(name)")
-put(name, "2d", "subtract imm32 from EAX");
+put(name, "2d", "subtract imm32 from EAX (sub)");
 
 :(scenario subtract_imm32_from_eax)
 % Reg[EAX].i = 0x0d0c0baa;
@@ -113,7 +113,7 @@ case 5: {
 //:: and
 
 :(before "End Initialize Op Names(name)")
-put(name, "25", "EAX = bitwise AND of imm32 with EAX");
+put(name, "25", "EAX = bitwise AND of imm32 with EAX (and)");
 
 :(scenario and_imm32_with_eax)
 % Reg[EAX].i = 0xff;
@@ -171,7 +171,7 @@ case 4: {
 //:: or
 
 :(before "End Initialize Op Names(name)")
-put(name, "0d", "EAX = bitwise OR of imm32 with EAX");
+put(name, "0d", "EAX = bitwise OR of imm32 with EAX (or)");
 
 :(scenario or_imm32_with_eax)
 % Reg[EAX].i = 0xd0c0b0a0;
@@ -227,7 +227,7 @@ case 1: {
 //:: xor
 
 :(before "End Initialize Op Names(name)")
-put(name, "35", "EAX = bitwise XOR of imm32 with EAX");
+put(name, "35", "EAX = bitwise XOR of imm32 with EAX (xor)");
 
 :(scenario xor_imm32_with_eax)
 % Reg[EAX].i = 0xddccb0a0;
@@ -283,7 +283,7 @@ case 6: {
 //:: compare (cmp)
 
 :(before "End Initialize Op Names(name)")
-put(name, "3d", "compare: set SF if EAX < imm32");
+put(name, "3d", "compare: set SF if EAX < imm32 (cmp)");
 
 :(scenario compare_imm32_with_eax_greater)
 % Reg[EAX].i = 0x0d0c0b0a;
@@ -413,14 +413,14 @@ case 7: {
 //:: copy (mov)
 
 :(before "End Initialize Op Names(name)")
-put(name, "b8", "copy imm32 to EAX");
-put(name, "b9", "copy imm32 to ECX");
-put(name, "ba", "copy imm32 to EDX");
-put(name, "bb", "copy imm32 to EBX");
-put(name, "bc", "copy imm32 to ESP");
-put(name, "bd", "copy imm32 to EBP");
-put(name, "be", "copy imm32 to ESI");
-put(name, "bf", "copy imm32 to EDI");
+put(name, "b8", "copy imm32 to EAX (mov)");
+put(name, "b9", "copy imm32 to ECX (mov)");
+put(name, "ba", "copy imm32 to EDX (mov)");
+put(name, "bb", "copy imm32 to EBX (mov)");
+put(name, "bc", "copy imm32 to ESP (mov)");
+put(name, "bd", "copy imm32 to EBP (mov)");
+put(name, "be", "copy imm32 to ESI (mov)");
+put(name, "bf", "copy imm32 to EDI (mov)");
 
 :(scenario copy_imm32_to_r32)
 == 0x1
@@ -447,7 +447,7 @@ case 0xbf: {  // copy imm32 to r32
 //:
 
 :(before "End Initialize Op Names(name)")
-put(name, "c7", "copy imm32 to rm32");
+put(name, "c7", "copy imm32 to rm32 (mov)");
 
 :(scenario copy_imm32_to_mem_at_r32)
 % Reg[EBX].i = 0x60;
@@ -473,7 +473,7 @@ case 0xc7: {  // copy imm32 to r32
 //:: push
 
 :(before "End Initialize Op Names(name)")
-put(name, "68", "push imm32 to stack");
+put(name, "68", "push imm32 to stack (push)");
 
 :(scenario push_imm32)
 % Reg[ESP].u = 0x14;
diff --git a/subx/017jump_disp8.cc b/subx/017jump_disp8.cc
index b60d69b6..67dc6656 100644
--- a/subx/017jump_disp8.cc
+++ b/subx/017jump_disp8.cc
@@ -3,7 +3,7 @@
 //:: jump
 
 :(before "End Initialize Op Names(name)")
-put(name, "eb", "jump disp8 bytes away");
+put(name, "eb", "jump disp8 bytes away (jmp)");
 
 :(scenario jump_rel8)
 == 0x1
@@ -27,7 +27,7 @@ case 0xeb: {  // jump rel8
 //:: jump if equal/zero
 
 :(before "End Initialize Op Names(name)")
-put(name, "74", "jump disp8 bytes away if ZF is set");
+put(name, "74", "jump disp8 bytes away if equal, if ZF is set. (jcc/jz/je)");
 
 :(scenario je_rel8_success)
 % ZF = true;
@@ -66,7 +66,7 @@ case 0x74: {  // jump rel8 if ZF
 //:: jump if not equal/not zero
 
 :(before "End Initialize Op Names(name)")
-put(name, "75", "jump disp8 bytes away if ZF is not set");
+put(name, "75", "jump disp8 bytes away if not equal, if ZF is not set. (jcc/jnz/jne)");
 
 :(scenario jne_rel8_success)
 % ZF = false;
@@ -105,7 +105,7 @@ case 0x75: {  // jump rel8 unless ZF
 //:: jump if greater
 
 :(before "End Initialize Op Names(name)")
-put(name, "7f", "jump disp8 bytes away if greater (ZF is unset, SF == OF)");
+put(name, "7f", "jump disp8 bytes away if greater, if ZF is unset and SF == OF. (jcc/jg/jnle)");
 
 :(scenario jg_rel8_success)
 % ZF = false;
@@ -148,7 +148,7 @@ case 0x7f: {  // jump rel8 if !SF and !ZF
 //:: jump if greater or equal
 
 :(before "End Initialize Op Names(name)")
-put(name, "7d", "jump disp8 bytes away if greater or equal (SF == OF)");
+put(name, "7d", "jump disp8 bytes away if greater or equal, if SF == OF. (jcc/jge/jnl)");
 
 :(scenario jge_rel8_success)
 % SF = false;
@@ -189,7 +189,7 @@ case 0x7d: {  // jump rel8 if !SF
 //:: jump if lesser
 
 :(before "End Initialize Op Names(name)")
-put(name, "7c", "jump disp8 bytes away if lesser (SF != OF)");
+put(name, "7c", "jump disp8 bytes away if lesser, if SF != OF. (jcc/jl/jnge)");
 
 :(scenario jl_rel8_success)
 % ZF = false;
@@ -232,7 +232,7 @@ case 0x7c: {  // jump rel8 if SF and !ZF
 //:: jump if lesser or equal
 
 :(before "End Initialize Op Names(name)")
-put(name, "7e", "jump disp8 bytes away if lesser or equal (ZF is set or SF != OF)");
+put(name, "7e", "jump disp8 bytes away if lesser or equal, if ZF is set or SF != OF. (jcc/jle/jng)");
 
 :(scenario jle_rel8_equal)
 % ZF = true;
diff --git a/subx/018jump_disp16.cc b/subx/018jump_disp16.cc
index 7adb2321..b09c26b5 100644
--- a/subx/018jump_disp16.cc
+++ b/subx/018jump_disp16.cc
@@ -3,7 +3,7 @@
 //:: jump
 
 :(before "End Initialize Op Names(name)")
-put(name, "e9", "jump disp16 bytes away");
+put(name, "e9", "jump disp16 bytes away (jmp)");
 
 :(scenario jump_rel16)
 == 0x1
@@ -33,7 +33,7 @@ int16_t imm16() {
 //:: jump if equal/zero
 
 :(before "End Initialize Op Names(name)")
-put(name_0f, "84", "jump disp16 bytes away if ZF is set");
+put(name_0f, "84", "jump disp16 bytes away if equal, if ZF is set. (jcc/jz/je)");
 
 :(scenario je_rel16_success)
 % ZF = true;
@@ -72,7 +72,7 @@ case 0x84: {  // jump rel16 if ZF
 //:: jump if not equal/not zero
 
 :(before "End Initialize Op Names(name)")
-put(name_0f, "85", "jump disp16 bytes away if ZF is not set");
+put(name_0f, "85", "jump disp16 bytes away if not equal, if ZF is not set. (jcc/jnz/jne)");
 
 :(scenario jne_rel16_success)
 % ZF = false;
@@ -111,7 +111,7 @@ case 0x85: {  // jump rel16 unless ZF
 //:: jump if greater
 
 :(before "End Initialize Op Names(name)")
-put(name_0f, "8f", "jump disp16 bytes away if greater (ZF is unset, SF == OF)");
+put(name_0f, "8f", "jump disp16 bytes away if greater, if ZF is unset and SF == OF. (jcc/jg/jnle)");
 
 :(scenario jg_rel16_success)
 % ZF = false;
@@ -154,7 +154,7 @@ case 0x8f: {  // jump rel16 if !SF and !ZF
 //:: jump if greater or equal
 
 :(before "End Initialize Op Names(name)")
-put(name_0f, "8d", "jump disp16 bytes away if greater or equal (SF == OF)");
+put(name_0f, "8d", "jump disp16 bytes away if greater or equal, if SF == OF. (jcc/jge/jnl)");
 
 :(scenario jge_rel16_success)
 % SF = false;
@@ -195,7 +195,7 @@ case 0x8d: {  // jump rel16 if !SF
 //:: jump if lesser
 
 :(before "End Initialize Op Names(name)")
-put(name_0f, "8c", "jump disp16 bytes away if lesser (SF != OF)");
+put(name_0f, "8c", "jump disp16 bytes away if lesser, if SF != OF. (jcc/jl/jnge)");
 
 :(scenario jl_rel16_success)
 % ZF = false;
@@ -238,7 +238,7 @@ case 0x8c: {  // jump rel16 if SF and !ZF
 //:: jump if lesser or equal
 
 :(before "End Initialize Op Names(name)")
-put(name_0f, "8e", "jump disp16 bytes away if lesser or equal (ZF is set or SF != OF)");
+put(name_0f, "8e", "jump disp16 bytes away if lesser or equal, if ZF is set or SF != OF. (jcc/jle/jng)");
 
 :(scenario jle_rel16_equal)
 % ZF = true;
diff --git a/subx/019functions.cc b/subx/019functions.cc
index 09f4d690..a672dcfe 100644
--- a/subx/019functions.cc
+++ b/subx/019functions.cc
@@ -1,7 +1,7 @@
 //:: call
 
 :(before "End Initialize Op Names(name)")
-put(name, "e8", "call disp32");
+put(name, "e8", "call disp32 (call)");
 
 :(scenario call_disp32)
 % Reg[ESP].u = 0x64;
@@ -68,7 +68,7 @@ a0 00 00 00  # 0xa0
 //:: ret
 
 :(before "End Initialize Op Names(name)")
-put(name, "c3", "return from most recent unfinished call");
+put(name, "c3", "return from most recent unfinished call (ret)");
 
 :(scenario ret)
 % Reg[ESP].u = 0x2000;
diff --git a/subx/020syscalls.cc b/subx/020syscalls.cc
index d61693ca..673e38a3 100644
--- a/subx/020syscalls.cc
+++ b/subx/020syscalls.cc
@@ -1,5 +1,5 @@
 :(before "End Initialize Op Names(name)")
-put(name, "cd", "software interrupt");
+put(name, "cd", "software interrupt (int)");
 
 :(before "End Single-Byte Opcodes")
 case 0xcd: {  // int imm8 (software interrupt)