4920

10 files changed, 467 insertions, 183 deletions

diff --git a/subx/010---vm.cc b/subx/010---vm.cc
index 3744d721..3af4a579 100644
--- a/subx/010---vm.cc
+++ b/subx/010---vm.cc
@@ -296,14 +296,14 @@ inline bool already_allocated(uint32_t addr) {
 void run_one_instruction() {
   uint8_t op=0, op2=0, op3=0;
   // Run One Instruction
-  trace(90, "run") << "inst: 0x" << HEXWORD << EIP << end();
-  op = next();
   if (Dump_trace) {
-    cerr << "opcode: " << HEXBYTE << NUM(op) << '\n';
-    cerr << "registers at start: ";
+    cerr << "registers: ";
     dump_registers();
 //?     dump_stack();  // for debugging; not defined until later layer
   }
+  trace(90, "run") << "inst: 0x" << HEXWORD << EIP << end();
+  op = next();
+  if (Dump_trace) cerr << "opcode: " << HEXBYTE << NUM(op) << '\n';
   switch (op) {
   case 0xf4:  // hlt
     EIP = End_of_program;
diff --git a/subx/069slice.subx b/subx/069slice.subx
index ef45e508..d813c3e8 100644
--- a/subx/069slice.subx
+++ b/subx/069slice.subx
@@ -26,7 +26,7 @@ slice-empty?:  # s : (address slice) -> bool/EAX
     8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy *ECX to EAX
     # . compare EAX with s->end
     39/compare                      1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # compare EAX and *(ECX+4)
-    b8/copy-to-EAX  1/imm32/false
+    b8/copy-to-EAX  1/imm32/true
     74/jump-if-equal  $slice-empty?:end/disp8
     b8/copy-to-EAX  0/imm32/false
 $slice-empty?:end:
diff --git a/subx/071hex.subx b/subx/071hex.subx
new file mode 100644
index 00000000..22864d53
--- /dev/null
+++ b/subx/071hex.subx
@@ -0,0 +1,458 @@
+# some utilities for converting numbers to/from hex
+# lowercase letters only
+
+== code
+#   instruction                     effective address                                                   register    displacement    immediate
+# . op          subop               mod             rm32          base        index         scale       r32
+# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
+
+# main:
+#? e8/call test-is-hex-int-handles-0x-prefix/disp32
+    e8/call  run-tests/disp32  # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
+    # syscall(exit, Num-test-failures)
+    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/EBX   Num-test-failures/disp32          # copy *Num-test-failures to EBX
+    b8/copy-to-EAX  1/imm32/exit
+    cd/syscall  0x80/imm8
+
+is-hex-int?:  # in : (address slice) -> bool/EAX
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    51/push-ECX
+    52/push-EDX
+    53/push-EBX
+    # ECX = s
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
+    # EDX = s->end
+    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           2/r32/EDX   4/disp8         .                 # copy *(ECX+4) to EDX
+    # curr/ECX = s->start
+    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           1/r32/ECX   .               .                 # copy *ECX to ECX
+    # if s is empty return false
+    b8/copy-to-EAX  0/imm32/false
+    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
+    7d/jump-if-greater-or-equal  $is-hex-int?:end/disp8
+    # skip past leading '0x'
+$is-hex-int?:initial-0:
+    # . if (*curr != '0') jump to loop
+    31/xor                          3/mod/direct    3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # clear EBX
+    8a/copy-byte                    0/mod/indirect  1/rm32/ECX    .           .             .           3/r32/BL    .               .                 # copy byte at *ECX to BL
+    81          7/subop/compare     3/mod/direct    3/rm32/EBX    .           .             .           .           .               0x30/imm32/0      # compare EBX
+    75/jump-if-not-equal  $is-hex-int?:loop/disp8
+    # . ++curr
+    41/increment-ECX
+$is-hex-int?:initial-0x:
+    # . if (curr >= in->end) return true
+    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
+    7d/jump-if-greater-or-equal  $is-hex-int?:true/disp8
+    # . if (*curr != 'x') jump to loop  # the previous '0' is still valid so doesn't need to be checked again
+    31/xor                          3/mod/direct    3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # clear EBX
+    8a/copy-byte                    0/mod/indirect  1/rm32/ECX    .           .             .           3/r32/BL    .               .                 # copy byte at *ECX to BL
+    81          7/subop/compare     3/mod/direct    3/rm32/EBX    .           .             .           .           .               0x78/imm32/x      # compare EBX
+    75/jump-if-not-equal  $is-hex-int?:loop/disp8
+    # . ++curr
+    41/increment-ECX
+$is-hex-int?:loop:
+    # if (curr >= in->end) return true
+    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
+    7d/jump-if-greater-or-equal  $is-hex-int?:true/disp8
+    # EAX = is-hex-byte?(*curr)
+    # . . push args
+    8a/copy-byte                    0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/AL    .               .                 # copy byte at *ECX to AL
+    50/push-EAX
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # if EAX == false return false
+    3d/compare-with-EAX  0/imm32
+    74/jump-if-equal  $is-hex-int?:end/disp8
+    # ++curr
+    41/increment-ECX
+    # loop
+    eb/jump  $is-hex-int?:loop/disp8
+$is-hex-int?:true:
+    # return true
+    b8/copy-to-EAX  1/imm32/true
+$is-hex-int?:end:
+    # . restore registers
+    5b/pop-to-EBX
+    5a/pop-to-EDX
+    59/pop-to-ECX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-is-hex-int:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # var slice/ECX = "34"
+    68/push  _test-slice-hex-int-end/imm32
+    68/push  _test-slice-hex-int/imm32
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # EAX = is-hex-int?(slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  is-hex-int?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 1, msg)
+    # . . push args
+    68/push  "F - test-is-hex-int"/imm32
+    68/push  1/imm32/true
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-is-hex-int-handles-letters:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # var slice/ECX = "34a"
+    68/push  _test-slice-hex-int-letters-end/imm32
+    68/push  _test-slice-hex-int-letters/imm32
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # EAX = is-hex-int?(slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  is-hex-int?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 1, msg)
+    # . . push args
+    68/push  "F - test-is-hex-int-handles-letters"/imm32
+    68/push  1/imm32/true
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-is-hex-int-with-trailing-char:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # var slice/ECX = "34q"
+    68/push  _test-slice-digits-and-char-end/imm32
+    68/push  _test-slice-digits-and-char/imm32
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # EAX = is-hex-int?(slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  is-hex-int?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 0, msg)
+    # . . push args
+    68/push  "F - test-is-hex-int-with-trailing-char"/imm32
+    68/push  0/imm32/false
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-is-hex-int-with-leading-char:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # var slice/ECX = "q34"
+    68/push  _test-slice-char-and-digits-end/imm32
+    68/push  _test-slice-char-and-digits/imm32
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # EAX = is-hex-int?(slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  is-hex-int?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 0, msg)
+    # . . push args
+    68/push  "F - test-is-hex-int-with-leading-char"/imm32
+    68/push  0/imm32/false
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-is-hex-int-empty:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # var slice/ECX = ""
+    68/push  _test-slice-empty-end/imm32
+    68/push  _test-slice-empty/imm32
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # EAX = is-hex-int?(slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  is-hex-int?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 0, msg)
+    # . . push args
+    68/push  "F - test-is-hex-int-empty"/imm32
+    68/push  0/imm32/false
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-is-hex-int-handles-0x-prefix:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # var slice/ECX = "0x3a"
+    68/push  _test-slice-hex-int-with-0x-prefix-end/imm32
+    68/push  _test-slice-hex-int-with-0x-prefix/imm32
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # EAX = is-hex-int?(slice)
+    # . . push args
+    51/push-ECX
+    # . . call
+    e8/call  is-hex-int?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 1, msg)
+    # . . push args
+    68/push  "F - test-is-hex-int-handles-0x-prefix"/imm32
+    68/push  1/imm32/true
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+is-hex-byte?:  # c : byte -> bool/EAX
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    51/push-ECX
+    # ECX = c
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
+    # return false if c < '0'
+    b8/copy-to-EAX  0/imm32/false
+    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x30/imm32        # compare ECX
+    7c/jump-if-lesser  $is-hex-byte?:end/disp8
+    # return false if c > 'f'
+    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x66/imm32        # compare ECX
+    7f/jump-if-greater  $is-hex-byte?:end/disp8
+    # return true if c <= '9'
+    b8/copy-to-EAX  1/imm32/true
+    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x39/imm32        # compare ECX
+    7e/jump-if-lesser-or-equal  $is-hex-byte?:end/disp8
+    # return true if c >= 'a'
+    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x61/imm32        # compare ECX
+    7d/jump-if-greater-or-equal  $is-hex-byte?:end/disp8
+    # otherwise return false
+    b8/copy-to-EAX  0/imm32/false
+$is-hex-byte?:end:
+    # . restore registers
+    59/pop-to-ECX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-hex-below-0:
+    # EAX = is-hex-byte?(0x2f)
+    # . . push args
+    68/push  0x2f/imm32
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 0, msg)
+    # . . push args
+    68/push  "F - test-hex-below-0"/imm32
+    68/push  0/imm32/false
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    c3/return
+
+test-hex-0-to-9:
+    # EAX = is-hex-byte?(0x30)
+    # . . push args
+    68/push  0x30/imm32
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 1, msg)
+    # . . push args
+    68/push  "F - test-hex-at-0"/imm32
+    68/push  1/imm32/true
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # EAX = is-hex-byte?(0x39)
+    # . . push args
+    68/push  0x39/imm32
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 1, msg)
+    # . . push args
+    68/push  "F - test-hex-at-9"/imm32
+    68/push  1/imm32/true
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    c3/return
+
+test-hex-above-9-to-a:
+    # EAX = is-hex-byte?(0x3a)
+    # . . push args
+    68/push  0x3a/imm32
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 0, msg)
+    # . . push args
+    68/push  "F - test-hex-above-9-to-a"/imm32
+    68/push  0/imm32/false
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    c3/return
+
+test-hex-a-to-f:
+    # EAX = is-hex-byte?(0x61)
+    # . . push args
+    68/push  0x61/imm32
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 1, msg)
+    # . . push args
+    68/push  "F - test-hex-at-a"/imm32
+    68/push  1/imm32/true
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # EAX = is-hex-byte?(0x66)
+    # . . push args
+    68/push  0x66/imm32
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 1, msg)
+    # . . push args
+    68/push  "F - test-hex-at-f"/imm32
+    68/push  1/imm32/true
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    c3/return
+
+test-hex-above-f:
+    # EAX = is-hex-byte?(0x67)
+    # . . push args
+    68/push  0x67/imm32
+    # . . call
+    e8/call  is-hex-byte?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(EAX, 0, msg)
+    # . . push args
+    68/push  "F - test-hex-above-f"/imm32
+    68/push  0/imm32/false
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    c3/return
+
+parse-hex-digit:  # in/EAX : byte -> out/EAX : num
+    # no error checking; accepts argument in EAX
+    # if EAX <= '9' return EAX - '0'
+    3d/compare-EAX  0x39/imm32/9
+    7f/jump-if-greater  $parse-hex-digit:else/disp8
+    2d/subtract-from-EAX  0x30/imm32/0
+    c3/return
+$parse-hex-digit:else:
+    # otherwise return EAX - 'a' + 10
+    2d/subtract-from-EAX  0x57/imm32/a-10
+    c3/return
+
+== data
+
+_test-slice-empty:
+  # nothing
+_test-slice-empty-end:
+
+_test-slice-hex-int:
+  33/3 34/4
+_test-slice-hex-int-end:
+
+_test-slice-hex-int-with-0x-prefix:
+  30/0 78/x 33/3 34/4
+_test-slice-hex-int-with-0x-prefix-end:
+
+_test-slice-hex-int-letters:
+  33/3 34/4 61/a
+_test-slice-hex-int-letters-end:
+
+_test-slice-char-and-digits:
+  71/q 33/3 34/4
+_test-slice-char-and-digits-end:
+
+_test-slice-digits-and-char:
+  33/3 34/4 71/q
+_test-slice-digits-and-char-end:
+
+# . . vim:nowrap:textwidth=0
diff --git a/subx/apps/crenshaw2-1 b/subx/apps/crenshaw2-1
index 5d45b5fa..e2d5636f 100755
--- a/subx/apps/crenshaw2-1
+++ b/subx/apps/crenshaw2-1
Binary files differdiff --git a/subx/apps/crenshaw2-1b b/subx/apps/crenshaw2-1b
index b462d387..aba0f893 100755
--- a/subx/apps/crenshaw2-1b
+++ b/subx/apps/crenshaw2-1b
Binary files differdiff --git a/subx/apps/factorial b/subx/apps/factorial
index f5c91de1..97116bad 100755
--- a/subx/apps/factorial
+++ b/subx/apps/factorial
Binary files differdiff --git a/subx/apps/handle b/subx/apps/handle
index 61f3e1dd..35633c17 100755
--- a/subx/apps/handle
+++ b/subx/apps/handle
Binary files differdiff --git a/subx/apps/hex b/subx/apps/hex
index b51a79be..4d5a737f 100755
--- a/subx/apps/hex
+++ b/subx/apps/hex
Binary files differdiff --git a/subx/apps/hex.subx b/subx/apps/hex.subx
index 1d306782..8f6e1575 100644
--- a/subx/apps/hex.subx
+++ b/subx/apps/hex.subx
@@ -490,7 +490,7 @@ scan-next-byte:  # in : (address buffered-file), err : (address buffered-file),
     #   repeatedly
     #     EAX = read-byte(in)
     #     if EAX == 0xffffffff return EAX
-    #     if is-hex-lowercase-byte?(EAX) return EAX
+    #     if is-hex-byte?(EAX) return EAX
     #     if EAX == ' ' or '\t' or '\n' continue
     #     if EAX == '#' skip-until-newline(in)
     #     else error-byte(ed, err, "invalid byte: " EAX)
@@ -510,14 +510,14 @@ $scan-next-byte:loop:
     # if (EAX == 0xffffffff) return EAX
     3d/compare-with-EAX  0xffffffff/imm32
     74/jump-if-equal  $scan-next-byte:end/disp8
-    # if is-hex-lowercase-byte?(EAX) return EAX
+    # if is-hex-byte?(EAX) return EAX
     # . save EAX for now
     50/push-EAX
-    # . is-hex-lowercase-byte?(EAX)
+    # . is-hex-byte?(EAX)
     # . . push args
     50/push-EAX
     # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
+    e8/call  is-hex-byte?/disp32
     # . . discard args
     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
     # . compare with 'false'
@@ -1408,177 +1408,6 @@ $test-scan-next-byte-aborts-on-invalid-byte:end:
     5d/pop-to-EBP
     c3/return
 
-is-hex-lowercase-byte?:  # c : byte -> bool/EAX
-    # . prolog
-    55/push-EBP
-    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
-    # . save registers
-    51/push-ECX
-    # ECX = c
-    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
-    # return false if c < '0'
-    b8/copy-to-EAX  0/imm32/false
-    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x30/imm32        # compare ECX
-    7c/jump-if-lesser  $is-hex-lowercase-byte?:end/disp8
-    # return false if c > 'f'
-    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x66/imm32        # compare ECX
-    7f/jump-if-greater  $is-hex-lowercase-byte?:end/disp8
-    # return true if c <= '9'
-    b8/copy-to-EAX  1/imm32/true
-    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x39/imm32        # compare ECX
-    7e/jump-if-lesser-or-equal  $is-hex-lowercase-byte?:end/disp8
-    # return true if c >= 'a'
-    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0x61/imm32        # compare ECX
-    7d/jump-if-greater-or-equal  $is-hex-lowercase-byte?:end/disp8
-    # otherwise return false
-    b8/copy-to-EAX  0/imm32/false
-$is-hex-lowercase-byte?:end:
-    # . restore registers
-    59/pop-to-ECX
-    # . epilog
-    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
-    5d/pop-to-EBP
-    c3/return
-
-test-hex-below-0:
-    # is-hex-lowercase-byte?(0x2f)
-    # . . push args
-    68/push  0x2f/imm32
-    # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-hex-below-0"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-hex-0-to-9:
-    # is-hex-lowercase-byte?(0x30)
-    # . . push args
-    68/push  0x30/imm32
-    # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # check-ints-equal(EAX, 1, msg)
-    # . . push args
-    68/push  "F - test-hex-at-0"/imm32
-    68/push  1/imm32/true
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    # is-hex-lowercase-byte?(0x39)
-    # . . push args
-    68/push  0x39/imm32
-    # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # check-ints-equal(EAX, 1, msg)
-    # . . push args
-    68/push  "F - test-hex-at-9"/imm32
-    68/push  1/imm32/true
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-hex-above-9-to-a:
-    # is-hex-lowercase-byte?(0x3a)
-    # . . push args
-    68/push  0x3a/imm32
-    # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-hex-above-9-to-a"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-hex-a-to-f:
-    # is-hex-lowercase-byte?(0x61)
-    # . . push args
-    68/push  0x61/imm32
-    # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # check-ints-equal(EAX, 1, msg)
-    # . . push args
-    68/push  "F - test-hex-at-a"/imm32
-    68/push  1/imm32/true
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    # is-hex-lowercase-byte?(0x66)
-    # . . push args
-    68/push  0x66/imm32
-    # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # check-ints-equal(EAX, 1, msg)
-    # . . push args
-    68/push  "F - test-hex-at-f"/imm32
-    68/push  1/imm32/true
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-test-hex-above-f:
-    # is-hex-lowercase-byte?(0x67)
-    # . . push args
-    68/push  0x67/imm32
-    # . . call
-    e8/call  is-hex-lowercase-byte?/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # check-ints-equal(EAX, 0, msg)
-    # . . push args
-    68/push  "F - test-hex-above-f"/imm32
-    68/push  0/imm32/false
-    50/push-EAX
-    # . . call
-    e8/call  check-ints-equal/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-    c3/return
-
-parse-hex-digit:  # in/EAX : byte -> out/EAX : num
-    # no error checking; accepts argument in EAX
-    # if EAX <= '9' return EAX - '0'
-    3d/compare-EAX  0x39/imm32/9
-    7f/jump-if-greater  $parse-hex-digit:else/disp8
-    2d/subtract-from-EAX  0x30/imm32/0
-    c3/return
-$parse-hex-digit:else:
-    # otherwise return EAX - 'a' + 10
-    2d/subtract-from-EAX  0x57/imm32/a-10
-    c3/return
-
 skip-until-newline:  # in : (address buffered-file) -> <void>
     # pseudocode:
     #   push EAX
diff --git a/subx/apps/pack.subx b/subx/apps/pack.subx
index d83a5398..b2b7a32a 100644
--- a/subx/apps/pack.subx
+++ b/subx/apps/pack.subx
@@ -121,10 +121,7 @@ $main:end:
 #   slice-equal?(slice, kernel string)
 
 # helpers:
-#   is-hex-int(in : &slice)
-#   parse-hex-int(in : &slice) -> int
 #   emit-maybe(out : &buffered-file, n : int, width : int)
-#   emit-hex-int(out : &buffered-file, n : int)
 #   emit(out : &buffered-file, word : &slice)
 #   has-metadata?(word : &slice, s : &kernel-string) -> bool