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terp.c
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// $Id: terp.c,v 1.42 2004/12/22 14:33:40 iain Exp $
// Interpreter engine.
#include "git.h"
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
// -------------------------------------------------------------
// Global variables
git_sint32* gStackPointer;
#ifdef USE_DIRECT_THREADING
Opcode* gOpcodeTable;
#endif
// -------------------------------------------------------------
// Useful macros for manipulating the stack
#define LOCAL(n) (locals[(n)])
#define PUSH(n) *sp++ = (n)
#define POP (*--sp)
#define READ_PC ((git_uint32)(*pc++))
#define CHECK_FREE(n) if ((top - sp) < (n)) goto stack_overflow
#define CHECK_USED(n) if ((sp - values) < (n)) goto stack_underflow
// -------------------------------------------------------------
// Floating point support
GIT_INLINE git_uint32 ENCODE_FLOAT(git_float f)
{
git_uint32 n;
memcpy(&n, &f, 4);
return n;
}
GIT_INLINE git_float DECODE_FLOAT(git_uint32 n) {
git_float f;
memcpy(&f, &n, 4);
return f;
}
int floatCompare(git_sint32 L1, git_sint32 L2, git_sint32 L3)
{
git_float F1, F2;
if (((L3 & 0x7F800000) == 0x7F800000) && ((L3 & 0x007FFFFF) != 0))
return 0;
if ((L1 == 0x7F800000 || L1 == 0xFF800000) && (L2 == 0x7F800000 || L2 == 0xFF800000))
return (L1 == L2);
F1 = DECODE_FLOAT(L2) - DECODE_FLOAT(L1);
F2 = fabs(DECODE_FLOAT(L3));
return ((F1 <= F2) && (F1 >= -F2));
}
#ifdef USE_OWN_POWF
float git_powf(float x, float y);
#endif
// -------------------------------------------------------------
// Functions
void startProgram (size_t cacheSize, enum IOMode ioMode)
{
Block pc; // Program counter (pointer into dynamically generated code)
git_sint32 L1=0, L2=0, L3=0, L4=0, L5=0, L6=0, L7=0;
#define S1 L1
#define S2 L2
git_float F1=0.0f, F2=0.0f, F3=0.0f, F4=0.0f;
git_sint32* base; // Bottom of the stack.
git_sint32* frame; // Bottom of the current stack frame.
git_sint32* locals; // Start of the locals section of the current frame.
git_sint32* values; // Start of the values section of the current frame.
git_sint32* sp; // Next free stack slot.
git_sint32* top; // The top of the stack -- that is, the first unusable slot.
git_sint32 args [64]; // Array of arguments. Count is stored in L2.
git_uint32 ioRock = 0;
git_uint32 stringTable = memRead32(28);
git_uint32 startPos = memRead32(24);
git_uint32 stackSize = memRead32(20);
git_uint32 protectPos = 0;
git_uint32 protectSize = 0;
git_uint32 maybe_unused glulxPC = 0;
git_uint32 maybe_unused glulxOpcode = 0;
acceleration_func accelfunc;
// Initialise the code cache.
#ifdef USE_DIRECT_THREADING
static Opcode opcodeTable [] = {
#define LABEL(label) &&do_ ## label,
#include "labels.inc"
NULL};
gOpcodeTable = opcodeTable;
#endif
initCompiler (cacheSize);
// Initialise the random number generator.
srand (time(NULL));
// Set up the stack.
base = malloc (stackSize);
if (base == NULL)
fatalError ("Couldn't allocate stack");
top = base + (stackSize / 4);
frame = locals = values = sp = base;
// Call the first function.
L1 = startPos; // Initial PC.
L2 = 0; // No arguments.
goto do_enter_function_L1;
#ifdef USE_DIRECT_THREADING
#define NEXT do { goto **(pc++); } while(0)
#else
#define NEXT goto next
//#define NEXT do { CHECK_USED(0); CHECK_FREE(0); goto next; } while (0)
next:
switch (*pc++)
{
#define LABEL(foo) case label_ ## foo: goto do_ ## foo;
#include "labels.inc"
default: fatalError("exec: bad opcode");
}
#endif
do_debug_step:
// This opcode lets us keep track of how the compiled
// code relates to the original glulx code.
glulxPC = READ_PC; // Glulx program counter.
glulxOpcode = READ_PC; // Glulx opcode number.
// fprintf (stdout, "\nPC: 0x%08x\nOpcode: 0x%04x\n", glulxPC, glulxOpcode);
// fprintf (stdout, "Stack:");
// for (L7 = 0 ; L7 < (sp - base) ; ++L7)
// fprintf (stdout," 0x%x", base[L7]);
// fprintf (stdout, "\n");
NEXT;
#define LOAD_INSTRUCTIONS(reg) \
do_ ## reg ## _const: reg = READ_PC; NEXT; \
do_ ## reg ## _stack: CHECK_USED(1); reg = POP; NEXT; \
do_ ## reg ## _addr: reg = memRead32 (READ_PC); NEXT; \
do_ ## reg ## _local: reg = LOCAL (READ_PC); NEXT
LOAD_INSTRUCTIONS(L1);
LOAD_INSTRUCTIONS(L2);
LOAD_INSTRUCTIONS(L3);
LOAD_INSTRUCTIONS(L4);
LOAD_INSTRUCTIONS(L5);
LOAD_INSTRUCTIONS(L6);
LOAD_INSTRUCTIONS(L7);
#define STORE_INSTRUCTIONS(reg) \
do_ ## reg ## _stack: CHECK_FREE(1); PUSH(reg); NEXT; \
do_ ## reg ## _addr: memWrite32 (READ_PC, reg); NEXT; \
do_ ## reg ## _local: LOCAL (READ_PC) = reg; NEXT
STORE_INSTRUCTIONS(S1);
STORE_INSTRUCTIONS(S2);
#define DOUBLE_LOAD(mode2) \
do_L1_const_L2_ ## mode2: L1 = READ_PC; goto do_L2_ ## mode2; \
do_L1_stack_L2_ ## mode2: CHECK_USED(1); L1 = POP; goto do_L2_ ## mode2; \
do_L1_local_L2_ ## mode2: L1 = LOCAL (READ_PC); goto do_L2_ ## mode2; \
do_L1_addr_L2_ ## mode2: L1 = memRead32 (READ_PC); goto do_L2_ ## mode2
DOUBLE_LOAD(const);
DOUBLE_LOAD(stack);
DOUBLE_LOAD(local);
DOUBLE_LOAD(addr);
#undef LOAD_INSTRUCTIONS
#undef STORE_INSTRUCTIONS
#undef DOUBLE_LOAD
do_L1_addr16: L1 = memRead16 (READ_PC); NEXT;
do_L1_addr8: L1 = memRead8 (READ_PC); NEXT;
do_S1_addr16: memWrite16 (READ_PC, S1); NEXT;
do_S1_addr8: memWrite8 (READ_PC, S1); NEXT;
#define UL7 ((git_uint32)L7)
do_recompile:
pc = compile (READ_PC);
NEXT;
do_jump_abs_L7:
pc = getCode (UL7);
NEXT;
do_enter_function_L1: // Arg count is in L2.
// Check for an accelerated function
accelfunc = accel_get_func(L1);
if (accelfunc) {
S1 = accelfunc(L2, (glui32 *) args);
goto do_pop_call_stub;
}
frame = sp;
// Read the function type.
L7 = memRead8(L1++);
// Parse the local variables descriptor.
L6 = L5 = L4 = 0;
do
{
L6 = memRead8(L1++); // LocalType
L5 = memRead8(L1++); // LocalCount
if (L6 != 4 && L6 != 0) // We only support 4-byte locals.
{
if (L6 == 1 || L6 == 2)
fatalError("Short local variables are not supported, use Glulxe");
else
fatalError("Local variable wasn't 4 bytes wide");
}
L4 += L5; // Cumulative local count.
}
while (L5 != 0);
// Write out the stack frame.
// Recall that the number of locals is stored in L4.
CHECK_FREE(3 + L4);
PUSH (L4*4 + 12); // FrameLen
PUSH (12); // LocalsPos
if (L4 == 0)
L6 = 0;
else
L6 = (4 << 24) | (L4 << 16);
PUSH (L6); // format of locals
// This is where the local variables start, so:
locals = sp;
// Read the arguments, based on the function type.
switch (L7)
{
case 0xC0: // arguments should be placed on the stack.
// argc is in L2; we'll randomly use L5 as scratch.
CHECK_FREE(L5 + 1);
// Initialise the local variables.
for ( ; L4 > 0 ; --L4)
PUSH (0);
// This is where the temporary values start, so:
values = sp;
// Push the args onto the stack.
for (L5 = 0 ; L5 < L2 ; ++L5)
PUSH (args [L5]);
// Push the arg count.
PUSH (L2);
break;
case 0xC1: // arguments should be written into locals.
// argc is in L2, num locals is in L4.
// Stuff as many locals as possible with arguments.
for (L5 = 1 ; L5 <= L2 && L4 > 0 ; ++L5, --L4)
PUSH (args [L2 - L5]);
// Initialise any remaining locals.
for ( ; L4 > 0 ; --L4)
PUSH (0);
// This is where the temporary values start, so:
values = sp;
break;
default:
// This isn't a function!
fatalError("Not a function");
break;
}
// Start executing the function.
L7 = L1;
goto do_jump_abs_L7;
do_nop: NEXT;
#define PEEPHOLE_STORE(tag, code) \
do_ ## tag ## _discard: code; NEXT; \
do_ ## tag ## _S1_stack: code; goto do_S1_stack; \
do_ ## tag ## _S1_local: code; goto do_S1_local; \
do_ ## tag ## _S1_addr: code; goto do_S1_addr
PEEPHOLE_STORE(add, S1 = L1 + L2);
PEEPHOLE_STORE(sub, S1 = L1 - L2);
PEEPHOLE_STORE(mul, S1 = L1 * L2);
PEEPHOLE_STORE(div, if (L2 == 0) fatalError ("Divide by zero"); S1 = L1 / L2);
PEEPHOLE_STORE(mod, if (L2 == 0) fatalError ("Divide by zero"); S1 = L1 % L2);
PEEPHOLE_STORE(neg, S1 = -L1);
PEEPHOLE_STORE(bitnot, S1 = ~L1);
PEEPHOLE_STORE(bitand, S1 = L1 & L2);
PEEPHOLE_STORE(bitor, S1 = L1 | L2);
PEEPHOLE_STORE(bitxor, S1 = L1 ^ L2);
PEEPHOLE_STORE(shiftl, if (L2 > 31 || L2 < 0) S1 = 0; else S1 = L1 << ((git_uint32) L2));
PEEPHOLE_STORE(sshiftr, if (L2 > 31 || L2 < 0) L2 = 31; S1 = ((git_sint32) L1) >> ((git_uint32) L2));
PEEPHOLE_STORE(ushiftr, if (L2 > 31 || L2 < 0) S1 = 0; else S1 = ((git_uint32) L1) >> ((git_uint32) L2));
PEEPHOLE_STORE(aload, S1 = memRead32 (L1 + (L2<<2)));
PEEPHOLE_STORE(aloads, S1 = memRead16 (L1 + (L2<<1)));
PEEPHOLE_STORE(aloadb, S1 = memRead8 (L1 + L2));
PEEPHOLE_STORE(aloadbit,S1 = (memRead8 (L1 + (L2>>3)) >> (L2 & 7)) & 1);
PEEPHOLE_STORE(copys, S1 = L1 & 0xFFFF);
PEEPHOLE_STORE(copyb, S1 = L1 & 0x00FF);
PEEPHOLE_STORE(sexs, S1 = (git_sint32)((signed short)(L1 & 0xFFFF)));
PEEPHOLE_STORE(sexb, S1 = (git_sint32)((signed char)(L1 & 0x00FF)));
PEEPHOLE_STORE(fadd, F1 = DECODE_FLOAT(L1) + DECODE_FLOAT(L2); S1 = ENCODE_FLOAT(F1));
PEEPHOLE_STORE(fsub, F1 = DECODE_FLOAT(L1) - DECODE_FLOAT(L2); S1 = ENCODE_FLOAT(F1));
PEEPHOLE_STORE(fmul, F1 = DECODE_FLOAT(L1) * DECODE_FLOAT(L2); S1 = ENCODE_FLOAT(F1));
PEEPHOLE_STORE(fdiv, F1 = DECODE_FLOAT(L1) / DECODE_FLOAT(L2); S1 = ENCODE_FLOAT(F1));
#define PEEPHOLE_LOAD(tag,reg) \
do_ ## tag ## _ ## reg ## _const: reg = READ_PC; goto do_ ## tag; \
do_ ## tag ## _ ## reg ## _stack: CHECK_USED(1); reg = POP; goto do_ ## tag; \
do_ ## tag ## _ ## reg ## _local: reg = LOCAL(READ_PC); goto do_ ## tag; \
do_ ## tag ## _ ## reg ## _addr: reg = memRead32(READ_PC); goto do_ ## tag
PEEPHOLE_LOAD (return, L1);
PEEPHOLE_LOAD (astore, L3);
PEEPHOLE_LOAD (astores, L3);
PEEPHOLE_LOAD (astoreb, L3);
PEEPHOLE_LOAD (astorebit, L3);
#undef PEEPHOLE_STORE
do_astore: memWrite32 (L1 + (L2<<2), L3); NEXT;
do_astores: memWrite16 (L1 + (L2<<1), L3); NEXT;
do_astoreb: memWrite8 (L1 + L2, L3); NEXT;
do_astorebit:
L4 = memRead8(L1 + (L2>>3));
if (L3 == 0)
L4 &= ~(1 << (L2 & 7));
else
L4 |= (1 << (L2 & 7));
memWrite8(L1 + (L2>>3), L4);
NEXT;
#define DO_JUMP(tag, reg, cond) \
do_ ## tag ## _var: L7 = READ_PC; if (cond) goto do_goto_ ## reg ## _from_L7; NEXT; \
do_ ## tag ## _const: L7 = READ_PC; if (cond) goto do_jump_abs_L7; NEXT; \
do_ ## tag ## _by: L7 = READ_PC; if (cond) pc += L7; NEXT; \
do_ ## tag ## _return0: if (cond) { L1 = 0; goto do_return; } NEXT; \
do_ ## tag ## _return1: if (cond) { L1 = 1; goto do_return; } NEXT
DO_JUMP(jump, L1, 1 == 1);
DO_JUMP(jz, L2, L1 == 0);
DO_JUMP(jnz, L2, L1 != 0);
DO_JUMP(jeq, L3, L1 == L2);
DO_JUMP(jne, L3, L1 != L2);
DO_JUMP(jlt, L3, L1 < L2);
DO_JUMP(jge, L3, L1 >= L2);
DO_JUMP(jgt, L3, L1 > L2);
DO_JUMP(jle, L3, L1 <= L2);
DO_JUMP(jltu, L3, ((git_uint32)L1 < (git_uint32)L2));
DO_JUMP(jgeu, L3, ((git_uint32)L1 >= (git_uint32)L2));
DO_JUMP(jgtu, L3, ((git_uint32)L1 > (git_uint32)L2));
DO_JUMP(jleu, L3, ((git_uint32)L1 <= (git_uint32)L2));
DO_JUMP(jisnan, L2, (((L1 & 0x7F800000) == 0x7F800000) && ((L1 & 0x007FFFFF) != 0)));
DO_JUMP(jisinf, L2, ((L1 == 0x7F800000) || (L1 == 0xFF800000)));
DO_JUMP(jflt, L3, DECODE_FLOAT(L1) < DECODE_FLOAT(L2));
DO_JUMP(jfge, L3, DECODE_FLOAT(L1) >= DECODE_FLOAT(L2));
DO_JUMP(jfgt, L3, DECODE_FLOAT(L1) > DECODE_FLOAT(L2));
DO_JUMP(jfle, L3, DECODE_FLOAT(L1) <= DECODE_FLOAT(L2));
DO_JUMP(jfeq, L4, floatCompare(L1, L2, L3) != 0);
DO_JUMP(jfne, L4, floatCompare(L1, L2, L3) == 0);
#undef DO_JUMP
do_jumpabs: L7 = L1; goto do_jump_abs_L7; NEXT;
do_goto_L4_from_L7: L1 = L4; goto do_goto_L1_from_L7;
do_goto_L3_from_L7: L1 = L3; goto do_goto_L1_from_L7;
do_goto_L2_from_L7: L1 = L2; goto do_goto_L1_from_L7;
do_goto_L1_from_L7:
if (L1 == 0 || L1 == 1) goto do_return;
L7 = L7 + L1 - 2; goto do_jump_abs_L7;
do_args_stack:
// The first argument is topmost in the stack; the count is in L2.
CHECK_USED(L2);
// We want to store the arguments in 'args' in the same order.
for (L3 = L2 - 1 ; L3 >= 0 ; --L3)
args [L3] = POP;
NEXT;
// Specialised versions of above:
do_args_stack_call_stub_discard:
CHECK_USED(L2);
for (L3 = L2 - 1 ; L3 >= 0 ; --L3)
args [L3] = POP;
goto do_call_stub_discard;
do_args_stack_call_stub_addr:
CHECK_USED(L2);
for (L3 = L2 - 1 ; L3 >= 0 ; --L3)
args [L3] = POP;
goto do_call_stub_addr;
do_args_stack_call_stub_local:
CHECK_USED(L2);
for (L3 = L2 - 1 ; L3 >= 0 ; --L3)
args [L3] = POP;
goto do_call_stub_local;
do_args_stack_call_stub_stack:
CHECK_USED(L2);
for (L3 = L2 - 1 ; L3 >= 0 ; --L3)
args [L3] = POP;
goto do_call_stub_stack;
do_args_3:
args [0] = L4;
args [1] = L3;
args [2] = L2;
L2 = 3;
NEXT;
do_args_2:
args [0] = L3;
args [1] = L2;
L2 = 2;
NEXT;
do_args_1:
args [0] = L2;
L2 = 1;
NEXT;
do_args_0:
L2 = 0;
NEXT;
do_undo_stub_discard:
CHECK_FREE(4);
PUSH (0); // DestType
PUSH (0); // DestAddr
goto finish_undo_stub;
do_undo_stub_addr:
CHECK_FREE(4);
PUSH (1); // DestType
PUSH (READ_PC); // DestAddr
goto finish_undo_stub;
do_undo_stub_local:
CHECK_FREE(4);
PUSH (2); // DestType
PUSH (READ_PC); // DestAddr
goto finish_undo_stub;
do_undo_stub_stack:
CHECK_FREE(4);
PUSH (3); // DestType
PUSH (0); // DestAddr
goto finish_undo_stub;
finish_undo_stub:
PUSH (READ_PC); // PC
PUSH ((frame - base) * 4); // FramePtr
saveUndo (base, sp);
S1 = 0;
goto do_pop_call_stub;
do_restoreundo:
if (restoreUndo (base, protectPos, protectSize) == 0)
{
sp = gStackPointer;
S1 = -1;
goto do_pop_call_stub;
}
S1 = 1;
NEXT;
do_save_stub_discard:
CHECK_FREE(4);
PUSH (0); // DestType
PUSH (0); // DestAddr
goto finish_save_stub;
do_save_stub_addr:
CHECK_FREE(4);
PUSH (1); // DestType
PUSH (READ_PC); // DestAddr
goto finish_save_stub;
do_save_stub_local:
CHECK_FREE(4);
PUSH (2); // DestType
PUSH (READ_PC); // DestAddr
goto finish_save_stub;
do_save_stub_stack:
CHECK_FREE(4);
PUSH (3); // DestType
PUSH (0); // DestAddr
goto finish_save_stub;
finish_save_stub:
PUSH (READ_PC); // PC
PUSH ((frame - base) * 4); // FramePtr
if (ioMode == IO_GLK)
S1 = saveToFile (base, sp, L1);
else
S1 = 1;
goto do_pop_call_stub;
do_restore:
if (ioMode == IO_GLK
&& restoreFromFile (base, L1, protectPos, protectSize) == 0)
{
sp = gStackPointer;
S1 = -1;
goto do_pop_call_stub;
}
S1 = 1;
NEXT;
do_catch_stub_discard:
CHECK_FREE(4);
L7 = 0;
PUSH (0); // DestType
goto finish_catch_stub_addr_L7;
do_catch_stub_addr:
CHECK_FREE(4);
L7 = READ_PC;
memWrite32(L7, (sp-base+4)*4);
PUSH (1); // DestType
goto finish_catch_stub_addr_L7;
do_catch_stub_local:
CHECK_FREE(4);
L7 = READ_PC;
LOCAL(L7 / 4) = (sp-base+4)*4;
PUSH (2); // DestType
goto finish_catch_stub_addr_L7;
do_catch_stub_stack:
CHECK_FREE(5);
PUSH (3); // DestType
PUSH (0); // DestAddr
PUSH (READ_PC); // PC
PUSH ((frame - base) * 4); // FramePtr
L7 = (sp - base)*4; // Catch token.
PUSH (L7);
NEXT;
finish_catch_stub_addr_L7:
PUSH (L7); // DestAddr
PUSH (READ_PC); // PC
PUSH ((frame - base) * 4); // FramePtr
NEXT;
do_throw:
if (L2 < 16 || L2 > ((sp-base)*4))
fatalError ("Invalid catch token in throw");
sp = base + L2 / 4;
goto do_pop_call_stub;
do_call_stub_discard:
CHECK_FREE(4);
PUSH (0); // DestType
PUSH (0); // DestAddr
goto finish_call_stub;
do_call_stub_addr:
CHECK_FREE(4);
PUSH (1); // DestType
PUSH (READ_PC); // DestAddr
goto finish_call_stub;
do_call_stub_local:
CHECK_FREE(4);
PUSH (2); // DestType
PUSH (READ_PC); // DestAddr
goto finish_call_stub;
do_call_stub_stack:
CHECK_FREE(4);
PUSH (3); // DestType
PUSH (0); // DestAddr
goto finish_call_stub;
finish_call_stub:
PUSH (READ_PC); // PC
PUSH ((frame - base) * 4); // FramePtr
goto do_enter_function_L1;
do_tailcall:
// Zap the current stack frame, down to its call stub.
sp = frame;
// Call the function!
goto do_enter_function_L1;
do_return:
sp = frame;
// ...
// fall through
// ...
do_pop_call_stub:// L1 holds the return value.
if (sp - base < 4)
{
if (sp == base)
// We just exited the top-level function.
goto finished;
else
// Something nasty happened.
goto stack_underflow;
}
L2 = POP; // FramePtr
L7 = POP; // PC
L6 = POP; // DestAddr
switch (POP) // DestType
{
case 0: // Do not store.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
break;
case 1: // Store in main memory.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
memWrite32 (L6, L1);
break;
case 2: // Store in local variable.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
LOCAL(L6/4) = L1;
break;
case 3: // Push on stack.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
PUSH (L1);
break;
case 10: // Resume printing a compressed (E1) string.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
goto resume_compressed_string_L7_bit_L6;
case 11: // Resume executing function code after a string completes.
// Don't restore the frame pointer.
break;
case 12: // Resume printing a signed decimal integer.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
goto resume_number_L7_digit_L6;
case 13: // Resume printing a C-style (E0) string.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
goto resume_c_string_L7;
case 14: // Resume printing a Unicode (E2) string.
frame = base + L2 / 4;
locals = frame + frame[1]/4;
values = frame + frame[0]/4;
goto resume_uni_string_L7;
default:
fatalError("Bad call stub");
}
// Restore the PC.
goto do_jump_abs_L7;
do_stkcount:
S1 = sp - values; NEXT;
do_stkpeek:
if (L1 < 0 || L1 > (sp - values))
fatalError("Out of bounds in stkpeek");
S1 = sp[-1 - L1]; NEXT;
do_stkswap:
CHECK_USED(2);
L1 = POP; L2 = POP; PUSH(L1); PUSH(L2); NEXT;
do_stkcopy:
CHECK_USED(L1);
for (L2 = L1 ; L2 > 0 ; --L2)
{
L3 = sp[-L1];
PUSH (L3);
}
NEXT;
resume_number_L7_digit_L6:
{
char buffer [16];
git_uint32 absn;
// If the IO mode is 'null', do nothing.
if (ioMode == IO_NULL)
goto do_pop_call_stub;
// Write the number into the buffer.
absn = (L7 < 0) ? -L7 : L7; // Absolute value of number.
L2 = 0; // Current buffer position.
do
{
buffer [L2++] = '0' + (absn % 10);
absn /= 10;
}
while (absn > 0);
if (L7 < 0)
buffer [L2++] = '-';
if (L6 >= L2)
goto do_pop_call_stub; // We printed the whole number already.
// If we're in filter mode, push a call stub
// and filter the next character.
if (ioMode == IO_FILTER)
{
// Store the next character in the args array.
args[0] = buffer [L2 - L6 - 1];
++L6;
// Push a call stub to print the next character.
CHECK_FREE(4);
PUSH(12); // DestType
PUSH(L6); // DestAddr (next digit)
PUSH(L7); // PC (number to print)
PUSH ((frame - base) * 4); // FramePtr
// Call the filter function.
L1 = ioRock;
L2 = 1;
goto do_enter_function_L1;
}
else
{
// We're in Glk mode. Just print all the characters.
for ( ; L6 < L2 ; ++L6)
glk_put_char (buffer [L2 - L6 - 1]);
}
}
goto do_pop_call_stub;
resume_c_string_L7:
// If the IO mode is 'null', or if we've reached the
// end of the string, do nothing.
L2 = memRead8(L7++);
if (L2 == 0 || ioMode == IO_NULL)
goto do_pop_call_stub;
// Otherwise we're going to have to print something,
// If the IO mode is 'filter', filter the next char.
if (ioMode == IO_FILTER)
{
// Store this character in the args array.
args [0] = L2;
// Push a call stub.
CHECK_FREE(4);
PUSH(13); // DestType (resume C string)
PUSH(L6); // DestAddr (ignored)
PUSH(L7); // PC (next char to print)
PUSH ((frame - base) * 4); // FramePtr
// Call the filter function.
L1 = ioRock;
L2 = 1;
goto do_enter_function_L1;
}
// We're in Glk mode. Just print all the characters.
while (L2 != 0)
{
glk_put_char ((unsigned char) L2);
L2 = memRead8(L7++);
}
goto do_pop_call_stub;
resume_uni_string_L7:
// If the IO mode is 'null', or if we've reached the
// end of the string, do nothing.
L2 = memRead32(L7);
L7 += 4;
if (L2 == 0 || ioMode == IO_NULL)
goto do_pop_call_stub;
// Otherwise we're going to have to print something,
// If the IO mode is 'filter', filter the next char.
if (ioMode == IO_FILTER)
{
// Store this character in the args array.
args [0] = L2;
// Push a call stub.
CHECK_FREE(4);
PUSH(14); // DestType (resume Unicode string)
PUSH(L6); // DestAddr (ignored)
PUSH(L7); // PC (next char to print)
PUSH ((frame - base) * 4); // FramePtr
// Call the filter function.
L1 = ioRock;
L2 = 1;
goto do_enter_function_L1;
}
// We're in Glk mode. Just print all the characters.
while (L2 != 0)
{
#ifdef GLK_MODULE_UNICODE
glk_put_char_uni ((glui32) L2);
#else
unsigned char c = (L2 > 0 && L2 < 256) ? L2 : '?';
glk_put_char (c);
#endif // GLK_MODULE_UNICODE
L2 = memRead32(L7);
L7 += 4;
}
goto do_pop_call_stub;
resume_compressed_string_L7_bit_L6:
// Load the first string table node into L1.
// Its address is stored at stringTable + 8.
L1 = memRead32 (stringTable + 8);
// Load the node's type byte.
L2 = memRead8 (L1++);
// Is the root node a branch?
if (L2 == 0)
{
// We'll keep a reservoir of input bits in L5.
L5 = memRead8(L7);
// Keep following branch nodes until we hit a leaf node.
while (L2 == 0)
{
// Read the next bit.
L4 = (L5 >> L6) & 1;
// If we're finished reading this byte,
// move on to the next one.
if (++L6 > 7)
{
L6 -= 8;
L5 = memRead8(++L7);
}
// Follow the branch.
L1 = memRead32(L1 + 4 * L4);
L2 = memRead8 (L1++);
}
}
else if (L2 == 2 || L2 == 3)
{
// The root node prints a single character or a string.
// This will produce infinite output in the Null or Glk
// I/O modes, so we'll catch that here.
if (ioMode != IO_FILTER)
fatalError ("String table prints infinite strings!");
// In Filter mode, the output will be sent to the current
// filter function, which can change the string table
// before returning, so we'll continue and see what happens.
}
// We're at a leaf node.
switch (L2)
{
case 1: // Terminator.
goto do_pop_call_stub;
case 2: // Single char.
if (ioMode == IO_NULL)
{ /* Do nothing */ }
else if (ioMode == IO_GLK)
glk_put_char ((unsigned char) memRead8(L1));
else
{
// Store this character in the args array.
args [0] = memRead8(L1);
// Push a call stub.
CHECK_FREE(4);
PUSH(10); // DestType
PUSH(L6); // DestAddr (bit number in string)
PUSH(L7); // PC (byte address in string)
PUSH ((frame - base) * 4); // FramePtr
// Call the filter function.
L1 = ioRock;
L2 = 1;
goto do_enter_function_L1;
}
break;
case 3: // C string.
// Push a 'resume compressed string' call stub.
CHECK_FREE(4);
PUSH (10); // DestType
PUSH (L6); // DestAddr (bit number in string)
PUSH (L7); // PC (byte address in string)
PUSH ((frame - base) * 4); // FramePtr
// Print the C string.
L7 = L1;
goto resume_c_string_L7;
case 4: // Unicode char
if (ioMode == IO_NULL)
{ /* Do nothing */ }
else if (ioMode == IO_GLK)
{
#ifdef GLK_MODULE_UNICODE
glk_put_char_uni (memRead32(L1));
#else
git_uint32 c = memRead32(L1);
if (c > 255) c = '?';
glk_put_char ((unsigned char) c);
#endif // GLK_MODULE_UNICODE
}
else
{
// Store this character in the args array.
args [0] = memRead32(L1);
// Push a call stub.
CHECK_FREE(4);
PUSH(10); // DestType
PUSH(L6); // DestAddr (bit number in string)
PUSH(L7); // PC (byte address in string)
PUSH ((frame - base) * 4); // FramePtr
// Call the filter function.
L1 = ioRock;
L2 = 1;
goto do_enter_function_L1;
}
break;
case 5: // Unicode string.
// Push a 'resume compressed string' call stub.
CHECK_FREE(4);
PUSH (10); // DestType
PUSH (L6); // DestAddr (bit number in string)
PUSH (L7); // PC (byte address in string)
PUSH ((frame - base) * 4); // FramePtr
// Print the Unicode string.
L7 = L1;
goto resume_uni_string_L7;
case 8: // Indirect reference.
L3 = memRead32(L1);
L2 = 0; goto indirect_L3_args_L2;
case 9: // Double-indirect reference.
L3 = memRead32(L1); L3 = memRead32(L3);
L2 = 0; goto indirect_L3_args_L2;
case 10: // Indirect reference with args.
L3 = memRead32(L1);
L2 = memRead32(L1 + 4); goto indirect_L3_args_L2;
case 11: // Double-indirect reference with args.
L3 = memRead32(L1); L3 = memRead32(L3);
L2 = memRead32(L1 + 4); goto indirect_L3_args_L2;
indirect_L3_args_L2:
// Push a 'resume compressed string' call stub.
CHECK_FREE(4);
PUSH (10); // DestType
PUSH (L6); // DestAddr (bit number in string)
PUSH (L7); // PC (byte address in string)
PUSH ((frame - base) * 4); // FramePtr
// Check the type of the embedded object.
switch (memRead8(L3))
{
case 0xE0: // C string.
L7 = L3 + 1;
goto resume_c_string_L7;
case 0xE1: // Compressed string.
L7 = L3 + 1;
L6 = 0;
goto resume_compressed_string_L7_bit_L6;
case 0xE2: // Unicode string.
L7 = L3 + 4; // Skip extra three padding bytes.