Re: [PATCH 01/05] Math optimizations for POWER8

[Andreas Schwab <schwab at linux-m68k dot org>]

Adhemerval Zanella <azanella@linux.vnet.ibm.com> writes:

> POWER8 follows ISA 2.07 and it adds the mfvsrd/mtvsrd instruction class to
> transfer data between GRP register to/from FPR register without the need of
> memory access. These instructions shows a better latency than the sequence
> std,...,ld which may create load-hit-stores and stalls in some CPUs. 
>
> These patches add a slight more optimized implementations of
> isnan/isinf/finite/llround/llrint using these instruction to gains some
> cycles by avoiding the possible load-hit-store of FP<->INT conversion.
>
> Tested on powerpc64 and powerpc64le.

Failure: float isinf (inf) == 1
Failure: float isinf (-inf) == -1
Failure: float isnan (qNaN)
Failure: float isnan (sNaN)
Failure: float isnan (-qNaN)
Failure: float isnan (-sNaN)
Failure: float isnan (NAN)
Failure: float isnan (-NAN)
Failure: float isnan (nan (""))
Failure: float isnan (-nan (""))
Failure: float isinf (HUGE_VALx) == +1
Failure: float isinf (-HUGE_VALx) == -1
Failure: double isinf (inf) == 1
Failure: double isinf (-inf) == -1
Failure: double isnan (qNaN)
Failure: double isnan (sNaN)
Failure: double isnan (-qNaN)
Failure: double isnan (-sNaN)
Failure: double isnan (NAN)
Failure: double isnan (-NAN)
Failure: double isnan (nan (""))
Failure: double isnan (-nan (""))
Failure: double isinf (HUGE_VALx) == +1
Failure: double isinf (-HUGE_VALx) == -1
Failure:  float x = (float) (double) qNaN, isnan
Failure:  float x = (float) (double) sNaN, isnan
Failure:  float x = (float) (double) Inf
Failure:  double x = (double) (float) qNaN, isnan
Failure:  double x = (double) (float) sNaN, isnan
Failure:  double x = (double) (float) Inf
Failure: long double isnan (NAN)
Failure: long double isnan (-NAN)
Failure:  float x = (float) (long double) sNaN, isnan
Failure:  float x = (float) (long double) Inf
Failure:  double x = (double) (long double) qNaN, isnan
Failure:  double x = (double) (long double) sNaN, isnan
Failure:  double x = (double) (long double) Inf

Failure: float isnan (qNaN)
Failure: float isnan (-qNaN)
Failure: float isnan (sNaN)
Failure: float isnan (-sNaN)
Failure: float isfinite (qNaN)
Failure: float isfinite (-qNaN)
Failure: float isfinite (sNaN)
Failure: float isfinite (-sNaN)
Failure: double isnan (qNaN)
Failure: double isnan (-qNaN)
Failure: double isnan (sNaN)
Failure: double isnan (-sNaN)
Failure: double isfinite (qNaN)
Failure: double isfinite (-qNaN)
Failure: double isfinite (sNaN)
Failure: double isfinite (-sNaN)

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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