diff options
Diffstat (limited to 'target/arm/vfp_helper.c')
-rw-r--r-- | target/arm/vfp_helper.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/target/arm/vfp_helper.c b/target/arm/vfp_helper.c index 74d3030..cc7f9f5 100644 --- a/target/arm/vfp_helper.c +++ b/target/arm/vfp_helper.c @@ -1086,3 +1086,91 @@ int arm_rmode_to_sf(int rmode) } return rmode; } + +/* + * Implement float64 to int32_t conversion without saturation; + * the result is supplied modulo 2^32. + */ +uint64_t HELPER(fjcvtzs)(float64 value, void *vstatus) +{ + float_status *status = vstatus; + uint32_t exp, sign; + uint64_t frac; + uint32_t inexact = 1; /* !Z */ + + sign = extract64(value, 63, 1); + exp = extract64(value, 52, 11); + frac = extract64(value, 0, 52); + + if (exp == 0) { + /* While not inexact for IEEE FP, -0.0 is inexact for JavaScript. */ + inexact = sign; + if (frac != 0) { + if (status->flush_inputs_to_zero) { + float_raise(float_flag_input_denormal, status); + } else { + float_raise(float_flag_inexact, status); + inexact = 1; + } + } + frac = 0; + } else if (exp == 0x7ff) { + /* This operation raises Invalid for both NaN and overflow (Inf). */ + float_raise(float_flag_invalid, status); + frac = 0; + } else { + int true_exp = exp - 1023; + int shift = true_exp - 52; + + /* Restore implicit bit. */ + frac |= 1ull << 52; + + /* Shift the fraction into place. */ + if (shift >= 0) { + /* The number is so large we must shift the fraction left. */ + if (shift >= 64) { + /* The fraction is shifted out entirely. */ + frac = 0; + } else { + frac <<= shift; + } + } else if (shift > -64) { + /* Normal case -- shift right and notice if bits shift out. */ + inexact = (frac << (64 + shift)) != 0; + frac >>= -shift; + } else { + /* The fraction is shifted out entirely. */ + frac = 0; + } + + /* Notice overflow or inexact exceptions. */ + if (true_exp > 31 || frac > (sign ? 0x80000000ull : 0x7fffffff)) { + /* Overflow, for which this operation raises invalid. */ + float_raise(float_flag_invalid, status); + inexact = 1; + } else if (inexact) { + float_raise(float_flag_inexact, status); + } + + /* Honor the sign. */ + if (sign) { + frac = -frac; + } + } + + /* Pack the result and the env->ZF representation of Z together. */ + return deposit64(frac, 32, 32, inexact); +} + +uint32_t HELPER(vjcvt)(float64 value, CPUARMState *env) +{ + uint64_t pair = HELPER(fjcvtzs)(value, &env->vfp.fp_status); + uint32_t result = pair; + uint32_t z = (pair >> 32) == 0; + + /* Store Z, clear NCV, in FPSCR.NZCV. */ + env->vfp.xregs[ARM_VFP_FPSCR] + = (env->vfp.xregs[ARM_VFP_FPSCR] & ~CPSR_NZCV) | (z * CPSR_Z); + + return result; +} |