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Match one function, update mips_to_c of 2 others (#164)

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There's a function that appears to use continued fractions
 to approximate the value of tanh(x/2), which is super weird.

Signed-off-by: Taggerung <tyler.taggerung@gmail.com>
This commit is contained in:
Tyler McGavran
2022-02-15 01:40:33 -05:00
committed by GitHub
parent 3403482de3
commit a4e6192030
3 changed files with 44 additions and 83 deletions
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src/code_80091750.c
+43 -56
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@@ -37,24 +37,21 @@ f64 exponent_by_squaring(f64 base, s32 exponent) {
}
#ifdef MIPS_TO_C
//generated by mips_to_c commit 3c3b0cede1a99430bfd3edf8d385802b94f91307
f64 exponent_by_squaring(s32); // extern
f64 func_8009186C(f64); // extern
f64 func_8009195C(f64, f64); // extern
extern f64 D_800F0CB0;
extern f64 D_800F0CB8;
//generated by mips_to_c commit 06ada559d7a32fdab49fa2d619cdfa027615bcda
f64 func_8009186C(); /* extern */
f64 func_8009195C(f64, f64); /* extern */
f64 func_800917B0(f64 arg0, f64 arg1, f64 arg2) {
f64 func_800917B0(f64 arg0, ? arg0_lo, f64 arg1, ? arg1_lo, ? arg2_unk0, ? arg2_unk4) {
s32 temp_f8;
f64 phi_a2;
phi_a2 = arg2;
if ((arg1 <= D_800F0CB0) && (D_800F0CB8 <= arg1) && (temp_f8 = arg1, phi_a2 = (bitwise f64) temp_f8, (arg1 == temp_f8))) {
return exponent_by_squaring(temp_f8);
if ((arg1 <= D_800F0CB0) && (arg1 >= D_800F0CB8)) {
temp_f8 = (s32) arg1;
if (arg1 == (f64) temp_f8) {
return exponent_by_squaring(arg0, temp_f8);
}
}
if (arg0 > 0.0) {
arg2 = arg1;
return func_8009195C(func_8009186C(phi_a2) * arg2, arg2);
return func_8009195C(func_8009186C() * arg1, arg1);
}
return 0.0;
}
@@ -107,70 +104,60 @@ GLOBAL_ASM("asm/non_matchings/code_80091750/func_8009186C.s")
#endif
#ifdef MIPS_TO_C
//generated by mips_to_c commit 3c3b0cede1a99430bfd3edf8d385802b94f91307
? func_80091A6C(f64, f64, s32); // extern
//generated by mips_to_c commit 06ada559d7a32fdab49fa2d619cdfa027615bcda
// This is an f64 approximation of ln(2)
extern f64 D_800F0CD0;
void func_8009195C(f64 arg0) {
f64 func_8009195C(f64 arg0) {
f64 temp_f14;
f64 temp_f18;
f64 temp_f2;
f64 temp_f2_2;
s32 temp_f10;
f64 thing;
if (arg0 >= 0.0) {
thing = 0.5
} else {
thing = -0.5
}
temp_f18 = D_800F0CD0;
temp_f10 = 0.0 + (arg0 / temp_f18);
temp_f14 = arg0 - (temp_f10 * temp_f18);
temp_f10 = (s32) (thing + (arg0 / D_800F0CD0));
temp_f14 = arg0 - ((f64) temp_f10 * D_800F0CD0);
temp_f2 = temp_f14 * temp_f14;
temp_f2_2 = 2.0 + (temp_f2 / (6 + (temp_f2 / (0xA + (temp_f2 / (0xE + (temp_f2 / (0x12 + (temp_f2 / 22.0)))))))));
func_80091A6C((temp_f2_2 + temp_f14) / (temp_f2_2 - temp_f14), temp_f14, temp_f10);
/**
* This is the denominator part a tanh(x/2) continued fraction, where temp_f14 is x
* The best reference to this I can find is: https://math.stackexchange.com/questions/3241906/continued-fraction-02-6-10-14-22n-1-frace-1e1
**/
temp_f2_2 = 2.0 + (temp_f2 / ((f64) 6 + (temp_f2 / ((f64) 0xA + (temp_f2 / ((f64) 0xE + (temp_f2 / ((f64) 0x12 + (temp_f2 / 22.0)))))))));
return func_80091A6C((temp_f2_2 + temp_f14) / (temp_f2_2 - temp_f14), temp_f10);
}
#else
GLOBAL_ASM("asm/non_matchings/code_80091750/func_8009195C.s")
#endif
#ifdef MIPS_TO_C
//generated by mips_to_c commit 3c3b0cede1a99430bfd3edf8d385802b94f91307
f64 func_80091A6C(f64 arg0, s32 arg2) {
s32 temp_t7;
s32 phi_a2;
s32 phi_a2_2;
f64 phi_f12;
f64 phi_f12_2;
f64 phi_f12_3;
f64 phi_f0;
phi_a2 = arg2;
phi_f12 = arg0;
phi_f12_3 = arg0;
if (arg2 >= 0) {
/**
* This function appears to multiply some `value`
* by 2 ^ `exponent`, even if that exponent is negative
**/
f64 func_80091A6C(f64 value, s32 exponent) {
f64 base;
if (exponent >= 0) {
base = 2.0;
} else {
phi_a2 = -arg2;
exponent = -exponent;
base = 0.5;
}
phi_a2_2 = phi_a2;
phi_f0 = 0.0;
if (phi_a2 != 0) {
if (exponent != 0) {
do {
temp_t7 = phi_a2_2 >> 1;
phi_f12_2 = phi_f12_3;
if ((phi_a2_2 & 1) != 0) {
phi_f12_2 = phi_f12_3 * phi_f0;
if ((exponent & 1) != 0) {
value *= base;
}
phi_a2_2 = temp_t7;
phi_f12 = phi_f12_2;
phi_f12_3 = phi_f12_2;
phi_f0 *= phi_f0;
} while (temp_t7 != 0);
exponent >>= 1;
base *= base;
} while (exponent != 0);
}
return phi_f12;
return value;
}
#else
GLOBAL_ASM("asm/non_matchings/code_80091750/func_80091A6C.s")
#endif
#ifdef MIPS_TO_C
//generated by mips_to_c commit 3c3b0cede1a99430bfd3edf8d385802b94f91307