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Re: [Qemu-ppc] [Qemu-devel] [V4 PATCH 04/22] softfloat: Fix float64_to_u
From: |
Peter Maydell |
Subject: |
Re: [Qemu-ppc] [Qemu-devel] [V4 PATCH 04/22] softfloat: Fix float64_to_uint32 |
Date: |
Thu, 19 Dec 2013 21:48:27 +0000 |
On 18 December 2013 20:19, Tom Musta <address@hidden> wrote:
> The float64_to_uint32 has several flaws:
>
> - for numbers between 2**32 and 2**64, the inexact exception flag
> may get incorrectly set. In this case, only the invalid flag
> should be set.
>
> test pattern: 425F81378DC0CD1F / 0x1.f81378dc0cd1fp+38
>
> - for numbers between 2**63 and 2**64, incorrect results may
> be produced:
>
> test pattern: 43EAAF73F1F0B8BD / 0x1.aaf73f1f0b8bdp+63
>
> This patch re-implements float64_to_uint32 to re-use the
> float64_to_uint64 routine (instead of float64_to_int64). For the
> saturation case, the inexact bit is explicitly cleared before raising
> the invalid flag, provided that it was not previously set.
>
> V4: Fixed handling of stickiness of the inexact bit per comments from
> Peter Maydell.
>
> This contribution can be licensed under either the softfloat-2a or -2b
> license.
>
> Signed-off-by: Tom Musta <address@hidden>
Reviewed-by: Peter Maydell <address@hidden>
(though you might tidy up the commit message as per other
email).
I have a patch which fixes the remaining float-to-int conversion
functions (ie the ones you didn't deal with in this series) to not
raise Inexact when they raise Invalid for out of range, and one
which fixes a bug in scalbn. I'll send those out shortly.
thanks
-- PMM
- [Qemu-ppc] [V4 PATCH 00/22] PowerPC VSX Stage 3, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 01/22] softfloat: Fix float64_to_uint64, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 02/22] softfloat: Add float32_to_uint64(), Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 03/22] softfloat: Fix float64_to_uint64_round_to_zero, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 04/22] softfloat: Fix float64_to_uint32, Tom Musta, 2013/12/18
- Re: [Qemu-ppc] [Qemu-devel] [V4 PATCH 04/22] softfloat: Fix float64_to_uint32,
Peter Maydell <=
- [Qemu-ppc] [V4 PATCH 05/22] softfloat: Fix float64_to_uint32_round_to_zero, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 06/22] target-ppc: Add set_fprf Argument to fload_invalid_op_excp(), Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 07/22] target-ppc: General Support for VSX Helpers, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 08/22] target-ppc: Add VSX ISA2.06 xadd/xsub Instructions, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 10/22] target-ppc: Add VSX ISA2.06 xdiv Instructions, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 09/22] target-ppc: Add VSX ISA2.06 xmul Instructions, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 12/22] target-ppc: Add VSX ISA2.06 xsqrt Instructions, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 11/22] target-ppc: Add VSX ISA2.06 xre Instructions, Tom Musta, 2013/12/18
- [Qemu-ppc] [V4 PATCH 16/22] target-ppc: Add VSX ISA2.06 Multiply Add Instructions, Tom Musta, 2013/12/18