FWAIT

ergo720 · Jan 31, 2024 · 2372903 · 2372903
1 parent db47c90
commit 2372903
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Showing 3 changed files with 29 additions and 0 deletions.
diff --git a/lib86cpu/core/emitter/x64/jit.cpp b/lib86cpu/core/emitter/x64/jit.cpp
@@ -5213,6 +5213,30 @@ lc86_jit::fnstsw(decoded_instr *instr)
 	}
 }
 
+void
+lc86_jit::fwait(decoded_instr *instr)
+{
+	if ((m_cpu->cpu_ctx.hflags & (HFLG_CR0_MP | HFLG_CR0_TS)) == (HFLG_CR0_MP | HFLG_CR0_TS)) {
+		RAISEin0_t(EXP_NM);
+	}
+	else {
+		Label no_exp = m_a.newLabel();
+		LD_R16(AX, CPU_CTX_FSTATUS);
+		TEST(AX, FPU_EXP_ALL);
+		BR_EQ(no_exp);
+		LD_R16(AX, CPU_CTX_FCTRL);
+		AND(AX, FPU_EXP_ALL);
+		CMP(AX, FPU_EXP_ALL);
+		BR_EQ(no_exp);
+		static const char *abort_msg = "Unmasked fpu exceptions are not supported";
+		MOV(RCX, abort_msg);
+		MOV(RAX, &cpu_runtime_abort);
+		CALL(RAX); // won't return
+		INT3();
+		m_a.bind(no_exp);
+	}
+}
+
 void
 lc86_jit::fxrstor(decoded_instr *instr)
 {

diff --git a/lib86cpu/core/emitter/x64/jit.h b/lib86cpu/core/emitter/x64/jit.h
@@ -77,6 +77,7 @@ class lc86_jit : public Target {
 	void fld(decoded_instr *instr);
 	void fninit(decoded_instr *instr);
 	void fnstsw(decoded_instr *instr);
+	void fwait(decoded_instr *instr);
 	void fxrstor(decoded_instr *instr);
 	void fxsave(decoded_instr *instr);
 	void hlt(decoded_instr *instr);

diff --git a/lib86cpu/core/translate.cpp b/lib86cpu/core/translate.cpp
@@ -1162,6 +1162,10 @@ cpu_translate(cpu_t *cpu)
 			cpu->jit->fnstsw(&instr);
 			break;
 
+		case ZYDIS_MNEMONIC_FWAIT:
+			cpu->jit->fwait(&instr);
+			break;
+
 		case ZYDIS_MNEMONIC_FXRSTOR:
 			cpu->jit->fxrstor(&instr);
 			break;