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make type punning of floating point/int in float_math and double_math use union to avoid warnings (#600)

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This commit is contained in:
Graham Sanderson
2021-10-12 09:07:36 -05:00
committed by GitHub
parent 30673fb6d0
commit d50e743e0e
2 changed files with 90 additions and 64 deletions
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77
src/rp2_common/pico_float/float_math.c
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@ -39,11 +39,25 @@ typedef int32_t i32;
#define FUNPACK(x,e,m) e=((x)>>23)&0xff,m=((x)&0x007fffff)|0x00800000
#define FUNPACKS(x,s,e,m) s=((x)>>31),FUNPACK((x),(e),(m))
_Pragma("GCC diagnostic push")
_Pragma("GCC diagnostic ignored \"-Wstrict-aliasing\"")
typedef union {
float f;
ui32 ix;
} float_ui32;
static inline float ui322float(ui32 ix) {
float_ui32 tmp;
tmp.ix = ix;
return tmp.f;
}
static inline ui32 float2ui32(float f) {
float_ui32 tmp;
tmp.f = f;
return tmp.ix;
}
static inline bool fisnan(float x) {
ui32 ix=*(ui32*)&x;
ui32 ix=float2ui32(x);
return ix * 2 > 0xff000000u;
}
@ -56,17 +70,17 @@ static inline bool fisnan(float x) {
#endif
static inline int fgetsignexp(float x) {
ui32 ix=*(ui32*)&x;
ui32 ix=float2ui32(x);
return (ix>>23)&0x1ff;
}
static inline int fgetexp(float x) {
ui32 ix=*(ui32*)&x;
ui32 ix=float2ui32(x);
return (ix>>23)&0xff;
}
static inline float fldexp(float x,int de) {
ui32 ix=*(ui32*)&x,iy;
ui32 ix=float2ui32(x),iy;
int e;
e=fgetexp(x);
if(e==0||e==0xff) return x;
@ -74,7 +88,7 @@ static inline float fldexp(float x,int de) {
if(e<=0) iy=ix&0x80000000; // signed zero for underflow
else if(e>=0xff) iy=(ix&0x80000000)|0x7f800000ULL; // signed infinity on overflow
else iy=ix+((ui32)de<<23);
return *(float*)&iy;
return ui322float(iy);
}
float WRAPPER_FUNC(ldexpf)(float x, int de) {
@ -83,9 +97,9 @@ float WRAPPER_FUNC(ldexpf)(float x, int de) {
}
static inline float fcopysign(float x,float y) {
ui32 ix=*(ui32*)&x,iy=*(ui32*)&y;
ui32 ix=float2ui32(x),iy=float2ui32(y);
ix=((ix&0x7fffffff)|(iy&0x80000000));
return *(float*)&ix;
return ui322float(ix);
}
float WRAPPER_FUNC(copysignf)(float x, float y) {
@ -101,7 +115,7 @@ static inline int fispinf(float x) { return fgetsignexp(x)==0xff; }
static inline int fisminf(float x) { return fgetsignexp(x)==0x1ff; }
static inline int fisint(float x) {
ui32 ix=*(ui32*)&x,m;
ui32 ix=float2ui32(x),m;
int e=fgetexp(x);
if(e==0) return 1; // 0 is an integer
e-=0x7f; // remove exponent bias
@ -114,7 +128,7 @@ static inline int fisint(float x) {
}
static inline int fisoddint(float x) {
ui32 ix=*(ui32*)&x,m;
ui32 ix=float2ui32(x),m;
int e=fgetexp(x);
e-=0x7f; // remove exponent bias
if(e<0) return 0; // |x|<1; 0 is not odd
@ -127,24 +141,24 @@ static inline int fisoddint(float x) {
}
static inline int fisstrictneg(float x) {
ui32 ix=*(ui32*)&x;
ui32 ix=float2ui32(x);
if(fiszero(x)) return 0;
return ix>>31;
}
static inline int fisneg(float x) {
ui32 ix=*(ui32*)&x;
ui32 ix=float2ui32(x);
return ix>>31;
}
static inline float fneg(float x) {
ui32 ix=*(ui32*)&x;
ui32 ix=float2ui32(x);
ix^=0x80000000;
return *(float*)&ix;
return ui322float(ix);
}
static inline int fispo2(float x) {
ui32 ix=*(ui32*)&x;
ui32 ix=float2ui32(x);
if(fiszero(x)) return 0;
if(fisinf(x)) return 0;
ix&=0x007fffff;
@ -161,33 +175,33 @@ static inline float fnan_or(float x) {
float WRAPPER_FUNC(truncf)(float x) {
check_nan_f1(x);
ui32 ix=*(ui32*)&x,m;
ui32 ix=float2ui32(x),m;
int e=fgetexp(x);
e-=0x7f; // remove exponent bias
if(e<0) { // |x|<1
ix&=0x80000000;
return *(float*)&ix;
return ui322float(ix);
}
e=23-e; // bit position in mantissa with significance 1
if(e<=0) return x; // |x| large, so must be an integer
m=(1<<e)-1; // mask for bits of significance <1
ix&=~m;
return *(float*)&ix;
return ui322float(ix);
}
float WRAPPER_FUNC(roundf)(float x) {
check_nan_f1(x);
ui32 ix=*(ui32*)&x,m;
ui32 ix=float2ui32(x),m;
int e=fgetexp(x);
e-=0x7f; // remove exponent bias
if(e<-1) { // |x|<0.5
ix&=0x80000000;
return *(float*)&ix;
return ui322float(ix);
}
if(e==-1) { // 0.5<=|x|<1
ix&=0x80000000;
ix|=0x3f800000; // ±1
return *(float*)&ix;
return ui322float(ix);
}
e=23-e; // bit position in mantissa with significance 1, <=23
if(e<=0) return x; // |x| large, so must be an integer
@ -195,16 +209,16 @@ float WRAPPER_FUNC(roundf)(float x) {
ix+=m;
m=m+m-1; // mask for bits of significance <1
ix&=~m;
return *(float*)&ix;
return ui322float(ix);
}
float WRAPPER_FUNC(floorf)(float x) {
check_nan_f1(x);
ui32 ix=*(ui32*)&x,m;
ui32 ix=float2ui32(x),m;
int e=fgetexp(x);
if(e==0) { // x==0
ix&=0x80000000;
return *(float*)&ix;
return ui322float(ix);
}
e-=0x7f; // remove exponent bias
if(e<0) { // |x|<1, not zero
@ -216,16 +230,16 @@ float WRAPPER_FUNC(floorf)(float x) {
m=(1<<e)-1; // mask for bit of significance <1
if(fisneg(x)) ix+=m; // add 1-ε to magnitude if negative
ix&=~m; // truncate
return *(float*)&ix;
return ui322float(ix);
}
float WRAPPER_FUNC(ceilf)(float x) {
check_nan_f1(x);
ui32 ix=*(ui32*)&x,m;
ui32 ix=float2ui32(x),m;
int e=fgetexp(x);
if(e==0) { // x==0
ix&=0x80000000;
return *(float*)&ix;
return ui322float(ix);
}
e-=0x7f; // remove exponent bias
if(e<0) { // |x|<1, not zero
@ -237,7 +251,7 @@ float WRAPPER_FUNC(ceilf)(float x) {
m=(1<<e)-1; // mask for bit of significance <1
if(!fisneg(x)) ix+=m; // add 1-ε to magnitude if positive
ix&=~m; // truncate
return *(float*)&ix;
return ui322float(ix);
}
float WRAPPER_FUNC(asinf)(float x) {
@ -505,7 +519,7 @@ static i32 frem_0(i32 mx,i32 my,int e,int*pquo) {
float WRAPPER_FUNC(fmodf)(float x,float y) {
check_nan_f2(x,y);
ui32 ix=*(ui32*)&x,iy=*(ui32*)&y;
ui32 ix=float2ui32(x),iy=float2ui32(y);
int sx,ex,ey;
i32 mx,my;
FUNPACKS(ix,sx,ex,mx);
@ -526,7 +540,7 @@ float WRAPPER_FUNC(fmodf)(float x,float y) {
float WRAPPER_FUNC(remquof)(float x,float y,int*quo) {
check_nan_f2(x,y);
ui32 ix=*(ui32*)&x,iy=*(ui32*)&y;
ui32 ix=float2ui32(x),iy=float2ui32(y);
int sx,sy,ex,ey,q;
i32 mx,my;
FUNPACKS(ix,sx,ex,mx);
@ -567,5 +581,4 @@ float WRAPPER_FUNC(dremf)(float x,float y) { check_nan_f2(x,y); return remquof(x
float WRAPPER_FUNC(remainderf)(float x,float y) { check_nan_f2(x,y); return remquof(x,y,0); }
_Pragma("GCC diagnostic pop") // strict-aliasing
_Pragma("GCC diagnostic pop") // conversion