Implement the PowerPC floating point status and control register flag Fraction Rounded.
Signed-off-by: John Arbuckle <programmingk...@gmail.com> --- fpu/softfloat.c | 15 ++++++++++++--- include/fpu/softfloat-types.h | 1 + target/ppc/fpu_helper.c | 4 ++++ 3 files changed, 17 insertions(+), 3 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 2ba36ec370..ac34f6a2de 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -702,7 +702,7 @@ static FloatParts round_canonical(FloatParts p, float_status *s, const uint64_t roundeven_mask = parm->roundeven_mask; const int exp_max = parm->exp_max; const int frac_shift = parm->frac_shift; - uint64_t frac, inc; + uint64_t frac, inc, rounded; int exp, flags = 0; bool overflow_norm; @@ -744,7 +744,12 @@ static FloatParts round_canonical(FloatParts p, float_status *s, if (likely(exp > 0)) { if (frac & round_mask) { flags |= float_flag_inexact; - frac += inc; + rounded = frac + inc; + if ((rounded ^ frac) & frac_lsb) { + flags |= float_flag_rounded; + } + frac = rounded; + if (frac & DECOMPOSED_OVERFLOW_BIT) { frac >>= 1; exp++; @@ -793,7 +798,11 @@ static FloatParts round_canonical(FloatParts p, float_status *s, break; } flags |= float_flag_inexact; - frac += inc; + rounded = frac + inc; + if ((rounded ^ frac) & frac_lsb) { + flags |= float_flag_rounded; + } + frac = rounded; } exp = (frac & DECOMPOSED_IMPLICIT_BIT ? 1 : 0); diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h index 2aae6a89b1..bee576e0fd 100644 --- a/include/fpu/softfloat-types.h +++ b/include/fpu/softfloat-types.h @@ -147,6 +147,7 @@ enum { enum { float_flag_invalid = 1, + float_flag_rounded = 2, float_flag_divbyzero = 4, float_flag_overflow = 8, float_flag_underflow = 16, diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c index 0b7308f539..0baf1ce8e4 100644 --- a/target/ppc/fpu_helper.c +++ b/target/ppc/fpu_helper.c @@ -630,6 +630,10 @@ static void do_float_check_status(CPUPPCState *env, uintptr_t raddr) env->fpscr &= ~(1 << FPSCR_FI); /* clear the FPSCR[FI] bit */ } + /* Set or clear the Fraction Rounded bit */ + env->fpscr = deposit32(env->fpscr, FPSCR_FR, 1, + (status & float_flag_rounded) != 0); + if (cs->exception_index == POWERPC_EXCP_PROGRAM && (env->error_code & POWERPC_EXCP_FP)) { /* Differred floating-point exception after target FPR update */ -- 2.14.3 (Apple Git-98)