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stage1: Unbreak build on FreeBSD

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It turns out that the endianness-detection header delivered with the
softfloat library is extremely brittle and gives wrong results when
targeting FreeBSD (long story short, _BIG_ENDIAN is always defined there
and that breaks the #if defined() chain).

Use our own endianness detection header to work around any potential
problem.
This commit is contained in:
LemonBoy
2021-04-21 18:43:22 +02:00
committed by Jakub Konka
parent c8753aceef
commit 6cd71931cb
1 changed files with 25 additions and 14 deletions
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39
src/stage1/softfloat_ext.cpp
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@@ -1,19 +1,21 @@
#include "softfloat_ext.hpp"
#include "zigendian.h"
extern "C" {
#include "platform.h"
#include "internals.h"
#include "softfloat.h"
}
void f128M_abs(const float128_t *aPtr, float128_t *zPtr) {
float128_t zero_float;
ui32_to_f128M(0, &zero_float);
if (f128M_lt(aPtr, &zero_float)) {
f128M_sub(&zero_float, aPtr, zPtr);
} else {
*zPtr = *aPtr;
}
// Clear the sign bit.
#if ZIG_BYTE_ORDER == ZIG_LITTLE_ENDIAN
zPtr->v[1] = aPtr->v[1] & ~(UINT64_C(1) << 63);
zPtr->v[0] = aPtr->v[0];
#elif ZIG_BYTE_ORDER == ZIG_BIG_ENDIAN
zPtr->v[0] = aPtr->v[0] & ~(UINT64_C(1) << 63);
zPtr->v[1] = aPtr->v[1];
#else
#error Unsupported endian
#endif
}
void f128M_trunc(const float128_t *aPtr, float128_t *zPtr) {
@@ -27,12 +29,21 @@ void f128M_trunc(const float128_t *aPtr, float128_t *zPtr) {
}
float16_t f16_neg(const float16_t a) {
union ui16_f16 uZ;
uZ.ui = a.v ^ (UINT16_C(1) << 15);
return uZ.f;
union { uint16_t ui; float16_t f; } uA;
// Toggle the sign bit.
uA.ui = a.v ^ (UINT16_C(1) << 15);
return uA.f;
}
void f128M_neg(const float128_t *aPtr, float128_t *zPtr) {
zPtr->v[indexWord(2,1)] = aPtr->v[indexWord(2,1)] ^ (UINT64_C(1) << 63);
zPtr->v[indexWord(2,0)] = aPtr->v[indexWord(2,0)];
// Toggle the sign bit.
#if ZIG_BYTE_ORDER == ZIG_LITTLE_ENDIAN
zPtr->v[1] = aPtr->v[1] ^ (UINT64_C(1) << 63);
zPtr->v[0] = aPtr->v[0];
#elif ZIG_BYTE_ORDER == ZIG_BIG_ENDIAN
zPtr->v[0] = aPtr->v[0] ^ (UINT64_C(1) << 63);
zPtr->v[1] = aPtr->v[1];
#else
#error Unsupported endian
#endif
}