Implement jcxz

mehfooz09 · May 25, 2018 · 2593132 · 2593132
1 parent 65d65a8
commit 2593132
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diff --git a/emu/gadgets-x86/control.S b/emu/gadgets-x86/control.S
@@ -31,6 +31,14 @@
 .gadget jmp
     movl (%_ip), %_eip
     jmp jit_ret
+.gadget jcxz
+    cmpl $0, %ecx
+    jne 1f
+    movl (%_ip), %_eip
+    jmp jit_ret
+1:
+    movl 8(%_ip), %_eip
+    jmp jit_ret
 
 #define COND_LIST o,c,z,cz,s,p,sxo,sxoz
 #define IMPLEMENTED_CONDS c,z,cz,s,p,sxo,sxoz

diff --git a/emu/gen.c b/emu/gen.c
@@ -156,7 +156,7 @@ static inline void gen_op(struct gen_state *state, gadget_t *gadgets, enum arg a
 
 #define JMP(loc) load(loc, OP_SIZE); g(jmp_indir)
 #define JMP_REL(off) gg(jmp, state->ip + off)
-#define JCXZ_REL(off) UNDEFINED
+#define JCXZ_REL(off) ggg(jcxz, state->ip + off, state->ip)
 #define J_REL(cc, off) gagg(jmp, cond_##cc, state->ip + off, state->ip)
 #define JN_REL(cc, off) gagg(jmp, cond_##cc, state->ip, state->ip + off)
 #define CALL(loc) load(loc, OP_SIZE); ggg(call_indir, saved_ip, state->ip)