diff options
| -rw-r--r-- | apps/desugar.subx | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/apps/desugar.subx b/apps/desugar.subx index 3559d1ef..db53139b 100644 --- a/apps/desugar.subx +++ b/apps/desugar.subx @@ -19,6 +19,16 @@ # 5. # $ echo "ab *(eax+ecx+4)" | ./subx run apps/desugar # ab 2/mod 4/rm32 0/base 1/index 0/scale 4/disp32 +# +# 6. +# $ echo "ab *(eax+ecx<<2+4)" | ./subx run apps/desugar +# ab 2/mod 4/rm32 0/base 1/index 2/scale 4/disp32 +# +# Addition isn't commutative here. Template must always be (base+index<<scale+disp), +# though some components are optional as described above. +# +# No metadata allowed inside '*(...)'. +# Whitespace inside '*(...)' is ok. == code # instruction effective address register displacement immediate @@ -1056,6 +1066,39 @@ test-next-word-or-expression-returns-whole-expression: # Default values: base: 0, index: 4 (none), scale: 0, disp: 0 # beware: modifies 'word' parse-effective-address: # word : (address slice) -> base/EAX, index/ECX, scale/EDX, disp/EBX + # pseudocode: + # ++word->start to skip '*' + # initialize defaults: base=0, index=4, scale=0, disp=0 + # if (*word->start != '(') { + # base = get-slice(Registers, word, row-size=8) + # return + # } + # # compound expressions + # skip whitespace + # read register into base + # skip whitespace + # if (*word->start == ')') goto end + # if (*word->start != '+') goto error2 + # ++word->start to skip '+' + # skip whitespace + # read register into index + # skip whitespace + # if (*word->start == ')') goto end + # if (*word->start == '<') { + # ++word->start to skip '<' + # if (*word->start != '<') goto error3 + # ++word->start to skip '<' + # skip whitespace + # read register into scale + # skip whitespace + # if (*word->start == ')') goto end + # } + # if (*word->start != '+') goto error4 + # ++word->start to skip '+' + # skip whitespace + # read register into disp + # skip whitespace + # if (*word->start != ')') goto error5 # . prolog 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP @@ -1097,6 +1140,31 @@ $parse-effective-address:simple-register: $parse-effective-address:compound-expression: # ++word->start to skip '(' ff 0/subop/increment 0/mod/indirect 6/rm32/ESI . . . . . . # increment *ESI + # skip whitespace + # read register into base + # skip whitespace + # if (*word->start == ')') goto end + # if (*word->start != '+') goto error2 + # ++word->start + # skip whitespace + # read register into index + # skip whitespace + # if (*word->start == ')') goto end + # if (*word->start == '<') { + # ++word->start to skip '<' + # if (*word->start != '<') goto error3 + # ++word->start to skip '<' + # skip whitespace + # read register into scale + # skip whitespace + # if (*word->start == ')') goto end + # } + # if (*word->start != '+') goto error4 + # ++word->start to skip '+' + # skip whitespace + # read register into disp + # skip whitespace + # if (*word->start != ')') goto error5 $parse-effective-address:end: # return base in EAX 89/copy 3/mod/direct 0/rm32/EAX . . . 7/r32/EDI . . # copy EDI to EAX |