Implement fxtract

Go's math/big has an initializer that creates a singleton 3, and doing so involves fxtract For ish-app#57
saiminhtet · May 4, 2020 · d73ca72 · d73ca72
1 parent 7b90fb1
commit d73ca72
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diff --git a/emu/decode.h b/emu/decode.h
@@ -725,6 +725,7 @@ __no_instrument DECODER_RET glue(DECODER_NAME, OP_SIZE)(DECODER_ARGS) {
                     case 0xd960: TRACE("f2xm1"); F2XM1(); break;
                     case 0xd961: TRACE("fyl2x"); FYL2X(); break;
                     case 0xd963: TRACE("fpatan"); FPATAN(); break;
+                    case 0xd964: TRACE("fxtract"); FXTRACT(); break;
                     case 0xd967: TRACE("fincstp"); FINCSTP(); break;
                     case 0xd970: TRACE("fprem"); FPREM(); break;
                     case 0xd972: TRACE("fsqrt"); FSQRT(); break;

diff --git a/emu/float80.c b/emu/float80.c
@@ -515,3 +515,9 @@ float80 f80_scale(float80 x, int scale) {
         return F80_NAN;
     return u128_normalize_round((uint128_t) x.signif << 64, unbias(x.exp) + scale, x.sign);
 }
+
+void f80_xtract(float80 f, int *exp, float80 *signif) {
+    *exp = unbias(f.exp);
+    *signif = f;
+    signif->exp = bias(0);
+}
diff --git a/emu/float80.h b/emu/float80.h
@@ -45,6 +45,9 @@ float80 f80_sqrt(float80 x);
 
 float80 f80_scale(float80 x, int scale);
 
+// Used to implement fxtract
+void f80_xtract(float80 f, int *exp, float80 *signif);
+
 enum f80_rounding_mode {
     round_to_nearest = 0,
     round_down = 1,

diff --git a/emu/fpu.c b/emu/fpu.c
@@ -274,6 +274,14 @@ void fpu_cos(struct cpu_state *cpu) {
     ST(0) = f80_from_double(cos(f80_to_double(ST(0))));
 }
 
+void fpu_xtract(struct cpu_state *cpu) {
+    int exp;
+    float80 signif;
+    f80_xtract(ST(0), &exp, &signif);
+    ST(0) = f80_from_int(exp);
+    fpush(signif);
+}
+
 void fpu_xam(struct cpu_state *cpu) {
     float80 f = ST(0);
     int outflags = 0;

diff --git a/emu/fpu.h b/emu/fpu.h
@@ -102,6 +102,7 @@ void fpu_patan(struct cpu_state *cpu);
 void fpu_sin(struct cpu_state *cpu);
 void fpu_cos(struct cpu_state *cpu);
 void fpu_xam(struct cpu_state *cpu);
+void fpu_xtract(struct cpu_state *cpu);
 
 void fpu_stcw16(struct cpu_state *cpu, uint16_t *i);
 void fpu_ldcw16(struct cpu_state *cpu, uint16_t *i);

diff --git a/jit/gen.c b/jit/gen.c
@@ -423,6 +423,7 @@ void helper_rdtsc(struct cpu_state *cpu);
 #define FPATAN() h(fpu_patan)
 #define FSIN() h(fpu_sin)
 #define FCOS() h(fpu_cos)
+#define FXTRACT() h(fpu_xtract)
 
 // vector