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Diffstat (limited to '')
-rw-r--r-- | arch/mips/math-emu/sp_tint.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_tint.c b/arch/mips/math-emu/sp_tint.c new file mode 100644 index 000000000..f7a5cf5e1 --- /dev/null +++ b/arch/mips/math-emu/sp_tint.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* IEEE754 floating point arithmetic + * single precision + */ +/* + * MIPS floating point support + * Copyright (C) 1994-2000 Algorithmics Ltd. + */ + +#include "ieee754sp.h" + +int ieee754sp_tint(union ieee754sp x) +{ + u32 residue; + int round; + int sticky; + int odd; + + COMPXSP; + + ieee754_clearcx(); + + EXPLODEXSP; + FLUSHXSP; + + switch (xc) { + case IEEE754_CLASS_SNAN: + case IEEE754_CLASS_QNAN: + ieee754_setcx(IEEE754_INVALID_OPERATION); + return ieee754si_indef(); + + case IEEE754_CLASS_INF: + ieee754_setcx(IEEE754_INVALID_OPERATION); + return ieee754si_overflow(xs); + + case IEEE754_CLASS_ZERO: + return 0; + + case IEEE754_CLASS_DNORM: + case IEEE754_CLASS_NORM: + break; + } + if (xe >= 31) { + /* look for valid corner case */ + if (xe == 31 && xs && xm == SP_HIDDEN_BIT) + return -0x80000000; + /* Set invalid. We will only use overflow for floating + point overflow */ + ieee754_setcx(IEEE754_INVALID_OPERATION); + return ieee754si_overflow(xs); + } + /* oh gawd */ + if (xe > SP_FBITS) { + xm <<= xe - SP_FBITS; + } else { + if (xe < -1) { + residue = xm; + round = 0; + sticky = residue != 0; + xm = 0; + } else { + /* Shifting a u32 32 times does not work, + * so we do it in two steps. Be aware that xe + * may be -1 */ + residue = xm << (xe + 1); + residue <<= 31 - SP_FBITS; + round = (residue >> 31) != 0; + sticky = (residue << 1) != 0; + xm >>= SP_FBITS - xe; + } + odd = (xm & 0x1) != 0x0; + switch (ieee754_csr.rm) { + case FPU_CSR_RN: + if (round && (sticky || odd)) + xm++; + break; + case FPU_CSR_RZ: + break; + case FPU_CSR_RU: /* toward +Infinity */ + if ((round || sticky) && !xs) + xm++; + break; + case FPU_CSR_RD: /* toward -Infinity */ + if ((round || sticky) && xs) + xm++; + break; + } + if ((xm >> 31) != 0) { + /* This can happen after rounding */ + ieee754_setcx(IEEE754_INVALID_OPERATION); + return ieee754si_overflow(xs); + } + if (round || sticky) + ieee754_setcx(IEEE754_INEXACT); + } + if (xs) + return -xm; + else + return xm; +} |