Old recompiler improvements: limited in-block IRQ checking to floppy IRQ's only, rewrote the GPF handlers in ASM, and changed the recompiled INC and DEC instructions to actually use INC and DEC on host. Also removed the keyboard_at.c timer hack.

src/codegen/codegen_x86-64.c

@@ -294,6 +294,7 @@ void codegen_block_start_recompile(codeblock_t *block)
         block->status = cpu_cur_status;
         
         block_pos = BLOCK_GPF_OFFSET;
+#ifdef OLD_GPF
 #if WIN64
         addbyte(0x48); /*XOR RCX, RCX*/
         addbyte(0x31);
@@ -308,6 +309,17 @@ void codegen_block_start_recompile(codeblock_t *block)
         addbyte(0xf6);
 #endif
 	call(block, (uintptr_t)x86gpf);
+#else
+	addbyte(0xc6);	/* mov byte ptr[&(cpu_state.abrt)],ABRT_GPF */
+	addbyte(0x05);
+	addlong((uint32_t) (uintptr_t) &(cpu_state.abrt));
+	addbyte(ABRT_GPF);
+	addbyte(0x31);	/* xor eax,eax */
+	addbyte(0xc0);
+	addbyte(0x67);	/* mov [&(abrt_error)],eax */
+	addbyte(0xa3);
+	addlong((uint32_t) (uintptr_t) &(abrt_error));
+#endif
 	while (block_pos < BLOCK_EXIT_OFFSET)
 	       addbyte(0x90); /*NOP*/
         block_pos = BLOCK_EXIT_OFFSET; /*Exit code*/