From: Richard Henderson <rth@twiddle.net>
To: Tom Musta <tommusta@gmail.com>, qemu-devel@nongnu.org
Cc: qemu-ppc@nongnu.org
Subject: Re: [Qemu-devel] [V3 PATCH 09/14] target-ppc: Add ISA 2.06 fcfid[u][s] Instructions
Date: Tue, 24 Dec 2013 07:41:14 -0800 [thread overview]
Message-ID: <52B9AB1A.2080403@twiddle.net> (raw)
In-Reply-To: <1387399747-4994-10-git-send-email-tommusta@gmail.com>
On 12/18/2013 12:49 PM, Tom Musta wrote:
> +#define FPU_FCFI(op, cvtr, is_single) \
> +uint64_t helper_##op(CPUPPCState *env, uint64_t arg) \
> +{ \
> + CPU_DoubleU farg; \
> + \
> + farg.d = cvtr(arg, &env->fp_status); \
> + \
> + if (is_single) { \
> + farg.d = helper_frsp(env, farg.d); \
> + } \
> + helper_float_check_status(env); \
> + return farg.ll; \
> +}
This formulation will lead to double-rounding errors for some int64 inputs.
You should convert to single-precision directly, then convert to double.
r~
next prev parent reply other threads:[~2013-12-24 15:41 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-18 20:48 [Qemu-devel] [V3 PATCH 00/14] target-ppc: Base ISA V2.06 for Power7/Power8 Tom Musta
2013-12-18 20:48 ` [Qemu-devel] [V3 PATCH 01/14] target-ppc: Add Flag for Power ISA V2.06 Tom Musta
2013-12-24 15:11 ` Richard Henderson
2013-12-18 20:48 ` [Qemu-devel] [V3 PATCH 02/14] target-ppc: Add ISA2.06 bpermd Instruction Tom Musta
2013-12-24 15:17 ` Richard Henderson
2013-12-28 0:23 ` Scott Wood
2013-12-30 14:48 ` Richard Henderson
2013-12-30 15:43 ` [Qemu-devel] [Qemu-ppc] " Alexander Graf
2013-12-30 16:23 ` Richard Henderson
2013-12-28 0:27 ` [Qemu-devel] " Scott Wood
2013-12-18 20:48 ` [Qemu-devel] [V3 PATCH 03/14] target-ppc: Add ISA2.06 divdeu[o] Instructions Tom Musta
2013-12-24 15:20 ` Richard Henderson
2013-12-28 0:30 ` [Qemu-devel] [Qemu-ppc] " Scott Wood
2014-01-03 19:24 ` Tom Musta
2014-01-03 19:43 ` Scott Wood
2013-12-18 20:48 ` [Qemu-devel] [V3 PATCH 04/14] target-ppc: Add ISA2.06 divde[o] Instructions Tom Musta
2013-12-24 15:22 ` Richard Henderson
2013-12-18 20:48 ` [Qemu-devel] [V3 PATCH 05/14] target-ppc: Add ISA 2.06 divwe[u][o] Instructions Tom Musta
2013-12-24 15:26 ` Richard Henderson
2013-12-18 20:48 ` [Qemu-devel] [V3 PATCH 06/14] target-ppc: Add ISA2.06 lbarx, lharx Instructions Tom Musta
2013-12-24 15:28 ` Richard Henderson
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 07/14] target-ppc: Add ISA 2.06 stbcx. and sthcx. Instructions Tom Musta
2013-12-24 15:31 ` Richard Henderson
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 08/14] target-ppc: Add ISA2.06 Float to Integer Instructions Tom Musta
2013-12-24 15:36 ` Richard Henderson
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 09/14] target-ppc: Add ISA 2.06 fcfid[u][s] Instructions Tom Musta
2013-12-24 15:41 ` Richard Henderson [this message]
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 10/14] target-ppc: Fix and enable fri[mnpz] Tom Musta
2013-12-24 16:02 ` Richard Henderson
2014-01-06 20:06 ` Tom Musta
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 11/14] target-ppc: Add ISA 2.06 ftdiv Instruction Tom Musta
2013-12-24 16:06 ` Richard Henderson
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 12/14] target-ppc: Add ISA 2.06 ftsqrt Tom Musta
2013-12-24 16:07 ` Richard Henderson
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 13/14] target-ppc: Enable frsqrtes on Power7 and Power8 Tom Musta
2013-12-24 16:07 ` Richard Henderson
2013-12-18 20:49 ` [Qemu-devel] [V3 PATCH 14/14] target-ppc: Add ISA2.06 lfiwzx Instruction Tom Musta
2013-12-24 16:09 ` Richard Henderson
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