First stage of dynamic recompiler rewrite.

Basic IR generation calls C implementation of all instructions.
Backend generation implemented for x86, x86-64, ARM and ARM64.

src/codegen_backend_x86.c

@@ -0,0 +1,121 @@
+#if defined i386 || defined __i386 || defined __i386__ || defined _X86_ || defined WIN32 || defined _WIN32 || defined _WIN32
+
+#include "ibm.h"
+#include "codegen.h"
+#include "codegen_backend.h"
+#include "x86.h"
+
+#if defined(__linux__) || defined(__APPLE__)
+#include <sys/mman.h>
+#include <unistd.h>
+#endif
+#if defined WIN32 || defined _WIN32 || defined _WIN32
+#include <windows.h>
+#endif
+
+static void *mem_abrt_rout;
+
+void codegen_backend_init()
+{
+        int c;
+#if defined(__linux__) || defined(__APPLE__)
+	void *start;
+	size_t len;
+	long pagesize = sysconf(_SC_PAGESIZE);
+	long pagemask = ~(pagesize - 1);
+#endif
+
+#if defined WIN32 || defined _WIN32 || defined _WIN32
+        codeblock = VirtualAlloc(NULL, (BLOCK_SIZE+1) * sizeof(codeblock_t), MEM_COMMIT, PAGE_EXECUTE_READWRITE);
+#else
+        codeblock = malloc((BLOCK_SIZE+1) * sizeof(codeblock_t));
+#endif
+        codeblock_hash = malloc(HASH_SIZE * sizeof(codeblock_t *));
+
+        memset(codeblock, 0, (BLOCK_SIZE+1) * sizeof(codeblock_t));
+        memset(codeblock_hash, 0, HASH_SIZE * sizeof(codeblock_t *));
+
+        for (c = 0; c < BLOCK_SIZE; c++)
+                codeblock[c].pc = BLOCK_PC_INVALID;
+
+#if defined(__linux__) || defined(__APPLE__)
+	start = (void *)((long)codeblock & pagemask);
+	len = (((BLOCK_SIZE+1) * sizeof(codeblock_t)) + pagesize) & pagemask;
+	if (mprotect(start, len, PROT_READ | PROT_WRITE | PROT_EXEC) != 0)
+	{
+		perror("mprotect");
+		exit(-1);
+	}
+#endif
+//        pclog("Codegen is %p\n", (void *)pages[0xfab12 >> 12].block);
+
+        block_current = BLOCK_SIZE;
+        block_pos = 0;
+        mem_abrt_rout = &codeblock[block_current].data[block_pos];
+        addbyte(0x83); /*ADDL $16+4,%esp*/
+        addbyte(0xC4);
+        addbyte(0x10+4);
+        addbyte(0x5f); /*POP EDI*/
+        addbyte(0x5e); /*POP ESI*/
+        addbyte(0x5d); /*POP EBP*/
+        addbyte(0x5b); /*POP EDX*/
+        addbyte(0xC3); /*RET*/
+
+        asm(
+                "fstcw %0\n"
+                : "=m" (cpu_state.old_npxc)
+        );
+}
+
+void codegen_backend_prologue(codeblock_t *block)
+{
+        block_pos = 0; /*Entry code*/
+        addbyte(0x53); /*PUSH EBX*/
+        addbyte(0x55); /*PUSH EBP*/
+        addbyte(0x56); /*PUSH ESI*/
+        addbyte(0x57); /*PUSH EDI*/
+        addbyte(0x83); /*SUBL $16,%esp*/
+        addbyte(0xEC);
+        addbyte(0x10);
+        addbyte(0xBD); /*MOVL EBP, &cpu_state*/
+        addlong(((uintptr_t)&cpu_state) + 128);
+}
+
+void codegen_backend_epilogue(codeblock_t *block)
+{
+        addbyte(0x83); /*ADDL $16,%esp*/
+        addbyte(0xC4);
+        addbyte(0x10);
+        addbyte(0x5f); /*POP EDI*/
+        addbyte(0x5e); /*POP ESI*/
+        addbyte(0x5d); /*POP EBP*/
+        addbyte(0x5b); /*POP EDX*/
+        addbyte(0xC3); /*RET*/
+
+        if (block_pos > BLOCK_GPF_OFFSET)
+                fatal("Over limit!\n");
+
+        block_pos = BLOCK_GPF_OFFSET;
+        addbyte(0xc7); /*MOV [ESP],0*/
+        addbyte(0x04);
+        addbyte(0x24);
+        addlong(0);
+        addbyte(0xc7); /*MOV [ESP+4],0*/
+        addbyte(0x44);
+        addbyte(0x24);
+        addbyte(0x04);
+        addlong(0);
+        addbyte(0xe8); /*CALL x86gpf*/
+        addlong((uint32_t)x86gpf - (uint32_t)(&codeblock[block_current].data[block_pos + 4]));
+        block_pos = BLOCK_EXIT_OFFSET; /*Exit code*/
+        addbyte(0x83); /*ADDL $16,%esp*/
+        addbyte(0xC4);
+        addbyte(0x10);
+        addbyte(0x5f); /*POP EDI*/
+        addbyte(0x5e); /*POP ESI*/
+        addbyte(0x5d); /*POP EBP*/
+        addbyte(0x5b); /*POP EDX*/
+        addbyte(0xC3); /*RET*/
+}
+
+#endif