Commit e223bcad authored by Tristan Gingold's avatar Tristan Gingold Committed by Alexander Graf
Browse files

powerpc: use float64 for frsqrte 



Remove the code that reduce the result to float32 as the frsqrte
instruction is defined to return a double-precision estimate of
the reciprocal square root.

Although reducing the fractional part is harmless (as the estimation
must have at least 12 bits of precision according to the old PEM),
reducing the exponent range is not correct.

Signed-off-by: default avatarTristan Gingold <gingold@adacore.com>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent 23825581

target-ppc/fpu_helper.c

+0 −3
Original line number Diff line number Diff line
@@ -977,7 +977,6 @@ uint64_t helper_fres(CPUPPCState *env, uint64_t arg) 
uint64_t helper_frsqrte(CPUPPCState *env, uint64_t arg)

{

    CPU_DoubleU farg;

    float32 f32;



    farg.ll = arg;
@@ -991,8 +990,6 @@ uint64_t helper_frsqrte(CPUPPCState *env, uint64_t arg) 
        }

        farg.d = float64_sqrt(farg.d, &env->fp_status);

        farg.d = float64_div(float64_one, farg.d, &env->fp_status);

        f32 = float64_to_float32(farg.d, &env->fp_status);

        farg.d = float32_to_float64(f32, &env->fp_status);

    }

    return farg.ll;

}