mirror of
https://github.com/ZDoom/qzdoom-gpl.git
synced 2024-12-03 08:52:59 +00:00
7d4a5898ac
That only leaves the Scale function which is still being used in a few places and which would create considerably worse code without assembly on 32 bit platforms. This is also far too primitive (2 or 3 assembly instructions) to claim any copyright on it, so I think m_fixed.h can now be considered free of Build-related issues. The deficated inline headers have been removed because that sole remaining function could be easily moved into m_fixed.h.
128 lines
4 KiB
C
128 lines
4 KiB
C
#ifndef __M_FIXED__
|
|
#define __M_FIXED__
|
|
|
|
#include <stdlib.h>
|
|
#include "doomtype.h"
|
|
|
|
// Unfortunately, the Scale function still gets badly handled on 32 bit x86 platforms so it's the last remaining piece of inline assembly
|
|
|
|
// GCC inlines
|
|
#if defined(__GNUC__) && defined(__i386__) && !defined(__clang__)
|
|
#ifndef alloca
|
|
// MinGW does not seem to come with alloca defined.
|
|
#define alloca __builtin_alloca
|
|
#endif
|
|
|
|
static inline int32_t Scale(int32_t a, int32_t b, int32_t c)
|
|
{
|
|
int32_t result, dummy;
|
|
|
|
asm volatile
|
|
("imull %3\n\t"
|
|
"idivl %4"
|
|
: "=a,a,a,a,a,a" (result),
|
|
"=&d,&d,&d,&d,d,d" (dummy)
|
|
: "a,a,a,a,a,a" (a),
|
|
"m,r,m,r,d,d" (b),
|
|
"r,r,m,m,r,m" (c)
|
|
: "cc"
|
|
);
|
|
|
|
return result;
|
|
}
|
|
|
|
// MSVC inlines
|
|
#elif defined(_MSC_VER) && defined(_M_IX86)
|
|
#pragma warning (disable: 4035)
|
|
|
|
__forceinline int32_t Scale(int32_t a, int32_t b, int32_t c)
|
|
{
|
|
__asm mov eax, a
|
|
__asm imul b
|
|
__asm idiv c
|
|
}
|
|
|
|
#pragma warning (default: 4035)
|
|
#else
|
|
|
|
static __forceinline int32_t Scale(int32_t a, int32_t b, int32_t c)
|
|
{
|
|
return (int32_t)(((int64_t)a*b) / c);
|
|
}
|
|
|
|
#endif
|
|
|
|
// Modern compilers are smart enough to do these multiplications intelligently.
|
|
__forceinline int32_t MulScale14(int32_t a, int32_t b) { return (int32_t)(((int64_t)a * b) >> 14); } // only used by R_DrawVoxel
|
|
__forceinline int32_t MulScale30(int32_t a, int32_t b) { return (int32_t)(((int64_t)a * b) >> 30); } // only used once in the node builder
|
|
__forceinline int32_t MulScale32(int32_t a, int32_t b) { return (int32_t)(((int64_t)a * b) >> 32); } // only used by R_DrawVoxel
|
|
|
|
__forceinline uint32_t UMulScale16(uint32_t a, uint32_t b) { return (uint32_t)(((uint64_t)a * b) >> 16); } // used for sky drawing
|
|
|
|
__forceinline int32_t DMulScale3(int32_t a, int32_t b, int32_t c, int32_t d) { return (int32_t)(((int64_t)a*b + (int64_t)c*d) >> 3); } // used for setting up slopes for Build maps
|
|
__forceinline int32_t DMulScale6(int32_t a, int32_t b, int32_t c, int32_t d) { return (int32_t)(((int64_t)a*b + (int64_t)c*d) >> 6); } // only used by R_DrawVoxel
|
|
__forceinline int32_t DMulScale10(int32_t a, int32_t b, int32_t c, int32_t d) { return (int32_t)(((int64_t)a*b + (int64_t)c*d) >> 10); } // only used by R_DrawVoxel
|
|
__forceinline int32_t DMulScale18(int32_t a, int32_t b, int32_t c, int32_t d) { return (int32_t)(((int64_t)a*b + (int64_t)c*d) >> 18); } // only used by R_DrawVoxel
|
|
__forceinline int32_t DMulScale32(int32_t a, int32_t b, int32_t c, int32_t d) { return (int32_t)(((int64_t)a*b + (int64_t)c*d) >> 32); } // used by R_PointOnSide.
|
|
|
|
// Sadly, for divisions this is not true but these are so infrequently used that the C versions are just fine, despite not being fully optimal.
|
|
__forceinline int32_t DivScale6(int32_t a, int32_t b) { return (int32_t)(((int64_t)a << 6) / b); } // only used by R_DrawVoxel
|
|
__forceinline int32_t DivScale21(int32_t a, int32_t b) { return (int32_t)(((int64_t)a << 21) / b); } // only used by R_DrawVoxel
|
|
__forceinline int32_t DivScale30(int32_t a, int32_t b) { return (int32_t)(((int64_t)a << 30) / b); } // only used once in the node builder
|
|
|
|
__forceinline void fillshort(void *buff, unsigned int count, WORD clear)
|
|
{
|
|
SWORD *b2 = (SWORD *)buff;
|
|
for (unsigned int i = 0; i != count; ++i)
|
|
{
|
|
b2[i] = clear;
|
|
}
|
|
}
|
|
|
|
#include "xs_Float.h"
|
|
|
|
inline int32_t FixedDiv (int32_t a, int32_t b)
|
|
{
|
|
if ((uint32_t)abs(a) >> (31-16) >= (uint32_t)abs (b))
|
|
return (a^b)<0 ? FIXED_MIN : FIXED_MAX;
|
|
|
|
return (int32_t)(((int64_t)a << 16) / b);
|
|
}
|
|
|
|
__forceinline int32_t FixedMul(int32_t a, int32_t b)
|
|
{
|
|
return (int32_t)(((int64_t)a * b) >> 16);
|
|
}
|
|
|
|
inline fixed_t FloatToFixed(double f)
|
|
{
|
|
return xs_Fix<16>::ToFix(f);
|
|
}
|
|
|
|
inline double FixedToFloat(fixed_t f)
|
|
{
|
|
return f / 65536.;
|
|
}
|
|
|
|
inline unsigned FloatToAngle(double f)
|
|
{
|
|
return xs_CRoundToInt((f)* (0x40000000 / 90.));
|
|
}
|
|
|
|
inline double AngleToFloat(unsigned f)
|
|
{
|
|
return f * (90. / 0x40000000);
|
|
}
|
|
|
|
inline double AngleToFloat(int f)
|
|
{
|
|
return f * (90. / 0x40000000);
|
|
}
|
|
|
|
#define FLOAT2FIXED(f) FloatToFixed(f)
|
|
#define FIXED2FLOAT(f) float(FixedToFloat(f))
|
|
#define FIXED2DBL(f) FixedToFloat(f)
|
|
|
|
#define ANGLE2DBL(f) AngleToFloat(f)
|
|
|
|
#endif
|