diff options
| -rw-r--r-- | libacc/acc.cpp | 105 |
1 files changed, 65 insertions, 40 deletions
diff --git a/libacc/acc.cpp b/libacc/acc.cpp index b27fce4..c8c0826 100644 --- a/libacc/acc.cpp +++ b/libacc/acc.cpp @@ -248,49 +248,57 @@ class compiler { ARMCodeGenerator() {} virtual ~ARMCodeGenerator() {} - // The gnu ARM assembler prints the constants in little-endian, - // but C hexidecimal constants are big-endian. We trick the - // gnu assembler into putting out big-endian constants by - // using the -mbig-endian flag when assembling. - /* returns address to patch with local variable size */ virtual int functionEntry(int argCount) { fprintf(stderr, "functionEntry(%d);\n", argCount); - /* - 19 0000 E1A0C00D mov ip, sp - 20 0004 E92DD800 stmfd sp!, {fp, ip, lr, pc} - 21 0008 E24CB004 sub fp, ip, #4 - 22 000c E24DD008 sub sp, sp, #8 - */ - o4(0xE1A0C00D); - o4(0xE92DD800); - o4(0xE24CB004); - return o4(0xE24DD008); + // sp -> arg4 arg5 ... + // Push our register-based arguments back on the stack + if (argCount > 0) { + int regArgCount = argCount <= 4 ? argCount : 4; + o4(0xE92D0000 | ((1 << argCount) - 1)); // stmfd sp!, {} + } + // sp -> arg0 arg1 ... + o4(0xE92D4800); // stmfd sp!, {fp, lr} + // sp, fp -> oldfp, retadr, arg0 arg1 .... + o4(0xE1A0B00D); // mov fp, sp + return o4(0xE24DD000); // sub sp, sp, # <local variables> } virtual void functionExit(int argCount, int localVariableAddress, int localVariableSize) { fprintf(stderr, "functionExit(%d, %d, %d);\n", argCount, localVariableAddress, localVariableSize); - /* - 23 0010 E24BD00C sub sp, fp, #12 - 24 0014 E89DA800 ldmfd sp, {fp, sp, pc} - */ - o4(0xE24BD00C); - o4(0xE89DA800); - if (localVariableSize < 0 || localVariableSize > 255-8) { + // Patch local variable allocation code: + if (localVariableSize < 0 || localVariableSize > 255) { error("LocalVariableSize"); } - *(char*) (localVariableAddress) = localVariableSize + 8; + *(char*) (localVariableAddress) = localVariableSize; + + // sp -> locals .... fp -> oldfp, retadr, arg0, arg1, ... + o4(0xE1A0E00B); // mov lr, fp + o4(0xE59BB000); // ldr fp, [fp] + o4(0xE28ED004); // add sp, lr, #4 + // sp -> retadr, arg0, ... + o4(0xE8BD4000); // ldmfd sp!, {lr} + // sp -> arg0 .... + if (argCount > 0) { + // We store the PC into the lr so we can adjust the sp before + // returning. (We need to pull off the registers we pushed + // earlier. We don't need to actually store them anywhere, + // just adjust the stack. + int regArgCount = argCount <= 4 ? argCount : 4; + o4(0xE28DD000 | (regArgCount << 2)); // add sp, sp, #argCount << 2 + } + o4(0xE12FFF1E); // bx lr } /* load immediate value */ virtual void li(int t) { fprintf(stderr, "li(%d);\n", t); if (t >= 0 && t < 255) { - o4(0xE3A00000 + t); // E3A00000 mov r0, #0 + o4(0xE3A00000 + t); // mov r0, #0 } else if (t >= -256 && t < 0) { // mvn means move constant ^ ~0 - o4(0xE3E00001 - t); // E3E00000 mvn r0, #0 + o4(0xE3E00001 - t); // mvn r0, #0 } else { o4(0xE51F0000); // ldr r0, .L3 o4(0xEA000000); // b .L99 @@ -307,12 +315,14 @@ class compiler { /* l = 0: je, l == 1: jne */ virtual int gtst(bool l, int t) { fprintf(stderr, "gtst(%d, %d);\n", l, t); + error("Unimplemented"); o(0x0fc085); /* test %eax, %eax, je/jne xxx */ return psym(0x84 + l, t); } virtual void gcmp(int op) { fprintf(stderr, "gcmp(%d);\n", op); + error("Unimplemented"); #if 0 int t = decodeOp(op); o(0xc139); /* cmp %eax,%ecx */ @@ -354,7 +364,7 @@ class compiler { o4(0xE1E00000); // mvn r0, r0 break; default: - error("Unhandled op %d\n", op); + error("Unimplemented op %d\n", op); break; } #if 0 @@ -387,37 +397,52 @@ class compiler { virtual void loadEAXIndirect(bool isInt) { fprintf(stderr, "loadEAXIndirect(%d);\n", isInt); if (isInt) - o(0x8b); /* mov (%eax), %eax */ + o4(0xE5900000); // ldr r0, [r0] else - o(0xbe0f); /* movsbl (%eax), %eax */ - ob(0); /* add zero in code */ + o4(0xE5D00000); // ldrb r0, [r0] } virtual void leaEAX(int ea) { - fprintf(stderr, "leaEAX(%d);\n", ea); -#if 0 - gmov(10, ea); /* leal EA, %eax */ -#endif + fprintf(stderr, "[!!! fixme !!!] leaEAX(%d);\n", ea); + error("Unimplemented"); + if (ea < -4095 || ea > 4095) { + error("Offset out of range: %08x", ea); + } + o4(0xE59B0000 | (0x1fff & ea)); //ldr r0, [fp,#ea] } virtual void storeEAX(int ea) { fprintf(stderr, "storeEAX(%d);\n", ea); -#if 0 - gmov(6, ea); /* mov %eax, EA */ -#endif + int fpOffset = ea; + if (fpOffset < -4095 || fpOffset > 4095) { + error("Offset out of range: %08x", ea); + } + if (fpOffset < 0) { + o4(0xE50B0000 | (0xfff & (-fpOffset))); // str r0, [fp,#-ea] + } else { + o4(0xE58B0000 | (0xfff & fpOffset)); // str r0, [fp,#ea] + } } virtual void loadEAX(int ea) { fprintf(stderr, "loadEAX(%d);\n", ea); -#if 0 - gmov(8, ea); /* mov EA, %eax */ -#endif + int fpOffset = ea; + if (fpOffset < -4095 || fpOffset > 4095) { + error("Offset out of range: %08x", ea); + } + if (fpOffset < 0) { + o4(0xE51B0000 | (0xfff & (-fpOffset))); // ldr r0, [fp,#-ea] + } else { + o4(0xE59B0000 | (0xfff & fpOffset)); //ldr r0, [fp,#ea] + } } virtual void postIncrementOrDecrement(int n, int op) { fprintf(stderr, "postIncrementOrDecrement(%d, %d);\n", n, op); /* Implement post-increment or post decrement. */ + + error("Unimplemented"); #if 0 gmov(0, n); /* 83 ADD */ o(decodeOp(op)); @@ -459,7 +484,7 @@ class compiler { virtual void callRelative(int t) { fprintf(stderr, "callRelative(%d);\n", t); int abs = t + getPC() + jumpOffset(); - fprintf(stderr, "abs=%d\n", abs); + fprintf(stderr, "abs=%d (0x08%x)\n", abs, abs); if (t >= - (1 << 25) && t < (1 << 25)) { o4(0xEB000000 | encodeAddress(t)); } else { |