Add mips32 version for bf_dynasm.c

bf_mips.c

@@ -0,0 +1,241 @@
+// Compiled with `gcc -mabi=32 bf_mips.c` if your machine is mips64el.
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include "dasm_proto.h"
+#include "dasm_mips.h"
+#include <sys/mman.h>
+
+typedef struct bf_state
+{
+  unsigned char* tape;
+  unsigned char (*get_ch)(struct bf_state*);
+  void (*put_ch)(struct bf_state*, unsigned char);
+} bf_state_t;
+
+static void* link_and_encode(dasm_State** d)
+{
+  size_t sz;
+  void* buf = 0;
+  dasm_link(d, &sz);
+  buf = mmap(0, sz, PROT_READ | PROT_WRITE , MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (buf == (void*)-1) {
+    perror("link_and_encode mmap failed:");
+    return 0;
+  }
+  dasm_encode(d, buf);
+  mprotect(buf, sz, PROT_READ | PROT_EXEC);
+  return buf;
+}
+
+#define TAPE_SIZE 30000
+#define MAX_NESTING 100
+
+#define bad_program(s) exit(fprintf(stderr, "bad program near %.16s: %s\n", program, s))
+
+static void(* bf_compile(const char* program) )(bf_state_t*)
+{
+  |.arch mips
+  |.section code
+
+  unsigned loops[MAX_NESTING];
+  int nloops = 0;
+  int n;
+  dasm_State* d;
+  unsigned npc = 8;
+  unsigned nextpc = 0;
+  dasm_init(&d, DASM_MAXSECTION);
+
+  |.globals lbl_
+  void* labels[lbl__MAX];
+  dasm_setupglobal(&d, labels, lbl__MAX);
+
+  |.actionlist bf_actions
+  dasm_setup(&d, bf_actions);
+
+  dasm_growpc(&d, npc);
+
+  |.define ZERO, r0
+  |.define v0, r2
+  |.define aPtr, r16
+  |.define aState, r17
+  |.define aTapeBegin, r18
+  |.define aTapeEnd, r19
+  |.define aTMP, r20
+  |.define rArg1, r4
+  |.define rArg2, r5
+
+  |.macro prepcall1, arg1
+    | move rArg1, arg1
+  |.endmacro
+
+  |.macro prepcall2, arg1, arg2
+    | move rArg1, arg1
+    | move rArg2, arg2
+  |.endmacro
+
+  |.define postcall, .nop
+
+  |.macro prologue
+    | addiu sp, sp, -6*8
+    | sw aPtr, 0(sp)
+    | sw aState, 8(sp)
+    | sw aTapeBegin, 16(sp)
+    | sw aTapeEnd, 24(sp)
+    | sw v0, 32(sp)
+    | sw ra, 40(sp)
+    | move aState, rArg1
+  |.endmacro
+  |.macro epilogue
+    | lw aPtr, 0(sp)
+    | lw aState, 8(sp)
+    | lw aTapeBegin, 16(sp)
+    | lw aTapeEnd, 24(sp)
+    | lw v0, 32(sp)
+    | lw ra, 40(sp)
+    | addiu sp, sp, 6*8
+    | jr ra
+  |.endmacro
+
+  |.type STATE, bf_state_t, aState
+
+  dasm_State** Dst = &d;
+  |.code
+  |->bf_main:
+  | prologue
+  | lw aPtr, STATE->tape
+  | addi aTapeBegin, aPtr, -1
+  | addi aTapeEnd, aPtr, (TAPE_SIZE-1)
+
+  // Don't remove the `nop`s below.
+  // See also https://www.wikiwand.com/en/Delay_slot
+  for(;;) {
+    switch(*program++) {
+    case '<':
+      for(n = 1; *program == '<'; ++n, ++program);
+      | addi aPtr, aPtr, -n%TAPE_SIZE
+      | sub aTMP, aPtr, aTapeBegin
+      | bgtz aTMP, >1
+      | nop
+      | addi aPtr, aPtr, TAPE_SIZE
+      |1:
+      break;
+    case '>':
+      for(n = 1; *program == '>'; ++n, ++program);
+      | addi aPtr, aPtr, n%TAPE_SIZE
+      | sub aTMP, aPtr, aTapeEnd
+      | blez aTMP, >1
+      | nop
+      | addi aPtr, aPtr, -TAPE_SIZE
+      |1:
+      break;
+    case '+':
+      for(n = 1; *program == '+'; ++n, ++program);
+      | lb aTMP, 0(aPtr)
+      | addi aTMP, aTMP, n
+      | sb aTMP, 0(aPtr)
+      break;
+    case '-':
+      for(n = 1; *program == '-'; ++n, ++program);
+      | lb aTMP, 0(aPtr)
+      | addi aTMP, aTMP, -n
+      | sb aTMP, 0(aPtr)
+      break;
+    case ',':
+      | prepcall1 aState
+      | lw aTMP, STATE->get_ch
+      | jalr aTMP
+      | postcall 1
+      | sb v0, 0(aPtr)
+      break;
+    case '.':
+      | lb aTMP, 0(aPtr)
+      | prepcall2 aState, aTMP
+      | lw aTMP, STATE->put_ch
+      | jalr aTMP
+      | postcall 2
+      break;
+    case '[':
+      if(nloops == MAX_NESTING)
+        bad_program("Nesting too deep");
+      if(program[0] == '-' && program[1] == ']') {
+        program += 2;
+        | sb ZERO, 0(aPtr)
+      } else {
+        if(nextpc == npc) {
+          npc *= 2;
+          dasm_growpc(&d, npc);
+        }
+        | lb aTMP, 0(aPtr)
+        | beqz aTMP, =>nextpc+1
+        | nop
+        |=>nextpc:
+        loops[nloops++] = nextpc;
+        nextpc += 2;
+      }
+      break;
+    case ']':
+      if(nloops == 0)
+        bad_program("] without matching [");
+      --nloops;
+      | lb aTMP, 0(aPtr)
+      | bnez aTMP, =>loops[nloops]
+      | nop
+      |=>loops[nloops]+1:
+      break;
+    case 0:
+      if(nloops != 0)
+        program = "<EOF>", bad_program("[ without matching ]");
+      | epilogue
+
+      link_and_encode(&d);
+      dasm_free(&d);
+      return (void(*)(bf_state_t*))labels[lbl_bf_main];
+    }
+  }
+}
+
+static void bf_putchar(bf_state_t* s, unsigned char c)
+{
+  putchar((int)c);
+}
+
+static unsigned char bf_getchar(bf_state_t* s)
+{
+  return (unsigned char)getchar();
+}
+
+
+static void bf_run(const char* program)
+{
+  bf_state_t state;
+  unsigned char tape[TAPE_SIZE] = {0};
+  state.tape = tape;
+  state.get_ch = bf_getchar;
+  state.put_ch = bf_putchar;
+  bf_compile(program)(&state);
+}
+
+int main(int argc, char** argv)
+{
+  if(argc == 2) {
+    long sz;
+    char* program;
+    FILE* f = fopen(argv[1], "r");
+    if(!f) {
+      fprintf(stderr, "Cannot open %s\n", argv[1]);
+      return 1;
+    }
+    fseek(f, 0, SEEK_END);
+    sz = ftell(f);
+    program = (char*)malloc(sz + 1);
+    fseek(f, 0, SEEK_SET);
+    program[fread(program, 1, sz, f)] = 0;
+    fclose(f);
+    bf_run(program);
+    return 0;
+  } else {
+    fprintf(stderr, "Usage: %s INFILE.bf\n", argv[0]);
+    return 1;
+  }
+}