diff --git a/emu/decode.h b/emu/decode.h
index be96d2c705..270d827519 100644
--- a/emu/decode.h
+++ b/emu/decode.h
@@ -571,6 +571,8 @@ __no_instrument DECODER_RET glue(DECODER_NAME, OP_SIZE)(DECODER_ARGS) {
                 switch (insn << 4 | modrm.opcode) {
                     case 0xd80: TRACE("fadd mem32"); FADDM(mem_addr_real,32); break;
                     case 0xd81: TRACE("fmul mem32"); FMULM(mem_addr_real,32); break;
+                    case 0xd82: TRACE("fcom mem32"); FCOMM(mem_addr_real,32); break;
+                    case 0xd83: TRACE("fcomp mem32"); FCOMM(mem_addr_real,32); FPOP; break;
                     case 0xd84: TRACE("fsub mem32"); FSUBM(mem_addr_real,32); break;
                     case 0xd85: TRACE("fsubr mem32"); FSUBRM(mem_addr_real,32); break;
                     case 0xd86: TRACE("fdiv mem32"); FDIVM(mem_addr_real,32); break;
@@ -612,6 +614,8 @@ __no_instrument DECODER_RET glue(DECODER_NAME, OP_SIZE)(DECODER_ARGS) {
                 switch (insn << 4 | modrm.opcode) {
                     case 0xd80: TRACE("fadd st(i), st"); FADD(st_i, st_0); break;
                     case 0xd81: TRACE("fmul st(i), st"); FMUL(st_i, st_0); break;
+                    case 0xd82: TRACE("fcom st"); FCOM(); break;
+                    case 0xd83: TRACE("fcomp st"); FCOM(); FPOP; break;
                     case 0xd84: TRACE("fsub st(i), st"); FSUB(st_i, st_0); break;
                     case 0xd85: TRACE("fsubr st(i), st"); FSUBR(st_i, st_0); break;
                     case 0xd86: TRACE("fdiv st(i), st"); FDIV(st_i, st_0); break;
@@ -640,6 +644,7 @@ __no_instrument DECODER_RET glue(DECODER_NAME, OP_SIZE)(DECODER_ARGS) {
                     default: switch (insn << 8 | modrm.opcode << 4 | modrm.rm_opcode) {
                     case 0xd940: TRACE("fchs"); FCHS(); break;
                     case 0xd941: TRACE("fabs"); FABS(); break;
+                    case 0xd944: TRACE("fchs"); FCHS(); break;
                     case 0xd945: TRACE("fxam"); FXAM(); break;
                     case 0xd950: TRACE("fld1"); FLDC(one); break;
                     case 0xd951: TRACE("fldl2t"); FLDC(log2t); break;
@@ -654,6 +659,7 @@ __no_instrument DECODER_RET glue(DECODER_NAME, OP_SIZE)(DECODER_ARGS) {
                     case 0xd970: TRACE("fprem"); FPREM(); break;
                     case 0xd972: TRACE("fsqrt"); FSQRT(); break;
                     case 0xd974: TRACE("frndint"); FRNDINT(); break;
+                    case 0xde31: TRACE("fcompp"); FCOM(); FPOP; FPOP; break;
                     case 0xdf40: TRACE("fnstsw ax"); FSTSW(reg_a); break;
                     default: TRACE("undefined"); UNDEFINED;
                 }}
diff --git a/emu/float80.c b/emu/float80.c
index cf9892753d..6fa067c5a4 100644
--- a/emu/float80.c
+++ b/emu/float80.c
@@ -452,6 +452,8 @@ float80 f80_log2(float80 x) {
     float80 zero = f80_from_int(0);
     float80 one = f80_from_int(1);
     float80 two = f80_from_int(2);
+    if (f80_isnan(x) || f80_lte(x, zero))
+        return F80_NAN;
 
     int ipart = 0;
     while (f80_lt(x, one)) {
diff --git a/emu/fpu.c b/emu/fpu.c
index 24b8bdc6b7..046690c86b 100644
--- a/emu/fpu.c
+++ b/emu/fpu.c
@@ -125,9 +125,15 @@ void fpu_com(struct cpu_state *cpu, int i) {
 void fpu_comi(struct cpu_state *cpu, int i) {
     fpu_comparei(cpu, ST(i));
 }
+void fpu_comm32(struct cpu_state *cpu, float *f) {
+    fpu_compare(cpu, f80_from_double(*f));
+}
 void fpu_comm64(struct cpu_state *cpu, double *f) {
     fpu_compare(cpu, f80_from_double(*f));
 }
+void fpu_tst(struct cpu_state *cpu) {
+    fpu_compare(cpu, fpu_consts[fconst_zero]);
+}
 
 void fpu_abs(struct cpu_state *cpu) {
     ST(0) = f80_abs(ST(0));
diff --git a/emu/fpu.h b/emu/fpu.h
index d6b15d6363..036f8808a6 100644
--- a/emu/fpu.h
+++ b/emu/fpu.h
@@ -54,8 +54,10 @@ void fpu_yl2x(struct cpu_state *cpu);
 void fpu_2xm1(struct cpu_state *cpu);
 
 void fpu_com(struct cpu_state *cpu, int i);
+void fpu_comm32(struct cpu_state *cpu, float *f);
 void fpu_comm64(struct cpu_state *cpu, double *f);
 void fpu_comi(struct cpu_state *cpu, int i);
+void fpu_tst(struct cpu_state *cpu);
 #define fpu_ucom fpu_com
 #define fpu_ucomi fpu_comi
 
diff --git a/emu/interp/fpu.h b/emu/interp/fpu.h
index 8095323d14..5c7ed683e2 100644
--- a/emu/interp/fpu.h
+++ b/emu/interp/fpu.h
@@ -101,6 +101,7 @@
 #define FCOM() F_COMPARE(ST_i)
 #define FUCOM FCOM
 #define FCOMM(val,z) F_COMPARE(f80_from_float(get(val,z),z))
+#define FTST() F_COMPARE(fpu_consts[fconst_zero])
 
 #define FILD(val,z) \
     FPUSH(f80_from_int((sint(z)) get(val,z)))
diff --git a/jit/gen.c b/jit/gen.c
index 0ff1a24a57..c6062e2ca1 100644
--- a/jit/gen.c
+++ b/jit/gen.c
@@ -356,6 +356,8 @@ void helper_rdtsc(struct cpu_state *cpu);
 #define FUCOM() hh(fpu_ucom, st_i)
 #define FUCOMI() hh(fpu_ucomi, st_i)
 #define FCOMI() hh(fpu_comi, st_i)
+#define FTST() h(fpu_tst)
+#define FXAM() h(fpu_xam)
 #define FST() hh(fpu_st, st_i)
 #define FCHS() h(fpu_chs)
 #define FABS() h(fpu_abs)
@@ -388,7 +390,6 @@ void helper_rdtsc(struct cpu_state *cpu);
 #define FIDIVR(val,z) h_read(fpu_idivr, z)
 #define FDIVRM(val,z) h_read(fpu_divrm, z)
 #define FPATAN() h(fpu_patan)
-#define FXAM() h(fpu_xam)
 
 #define DECODER_RET int
 #define DECODER_NAME gen_step