diff options
| -rw-r--r-- | compiler.scm | 19 | ||||
| -rw-r--r-- | test.c | 27 |
2 files changed, 44 insertions, 2 deletions
diff --git a/compiler.scm b/compiler.scm index 1285ac6..919be4c 100644 --- a/compiler.scm +++ b/compiler.scm @@ -5,6 +5,23 @@ (newline)) (define (compile-program x) + (define fixnum-shift 2) + (define fixnum-tag 0) + (define char-shift 8) + (define char-tag 15) + (define boolean-shift 7) + (define boolean-tag 31) + (define empty-list 47) ;; #b00101111 + (define (immediate-rep x) + (cond + ((integer? x) + (ash x fixnum-shift)) + ((char? x) + (logior (ash (char->integer x) char-shift) char-tag)) + ((boolean? x) + (logior (ash (if x 1 0) boolean-shift) boolean-tag)) + ((null? x) + empty-list))) (with-output-to-file "scheme_entry.S" (lambda () (display ".text @@ -13,5 +30,5 @@ .type scheme_entry, @function scheme_entry: ") - (emit "movl $~a, %eax" x) + (emit "movl $~a, %eax" (immediate-rep x)) (emit "ret")))) @@ -1,6 +1,31 @@ #include <stdio.h> +#define fixnum_mask 3 +#define fixnum_tag 0 +#define fixnum_shift 2 +#define char_mask 255 +#define char_shift 8 +#define char_tag 15 +#define boolean_mask 127 +#define boolean_shift 7 +#define boolean_tag 31 +#define empty_list 47 + int main(int argc, char** argv) { - printf("%d\n", scheme_entry()); + int val = scheme_entry(); + + if((val & fixnum_mask) == fixnum_tag) { + printf("%d\n", val >> fixnum_shift); + } else if((val & char_mask) == char_tag) { + printf("%c\n", val >> char_shift); + } else if((val & boolean_mask) == boolean_tag) { + if((val >> boolean_shift) == 1) { + printf("#t\n"); + } else { + printf("#f\n"); + } + } else if(val == empty_list) { + printf("()\n"); + } return 0; } |