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Re: [Qemu-devel] [PATCH v3 19/22] fpu/softfloat: re-factor scalbn
From: |
Richard Henderson |
Subject: |
Re: [Qemu-devel] [PATCH v3 19/22] fpu/softfloat: re-factor scalbn |
Date: |
Mon, 29 Jan 2018 07:50:43 -0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 |
On 01/29/2018 03:59 AM, Alex Bennée wrote:
>
> Richard Henderson <address@hidden> writes:
>
>> On 01/24/2018 05:13 AM, Alex Bennée wrote:
>>> +/* Multiply A by 2 raised to the power N. */
>>> +static FloatParts scalbn_decomposed(FloatParts a, int n,
>>> + float_status *s)
>>> +{
>>> + if (a.cls == float_class_normal) {
>>> + a.exp += n;
>>> + }
>>> + return a;
>>> +}
>>
>> ...
>>
>>> - if ( aExp == 0x7FF ) {
>>> - if ( aSig ) {
>>> - return propagateFloat64NaN(a, a, status);
>>
>> This is where we used to raise inexact.
>> In the new function we need to handle this as in round_to_int.
>
> Why is the handling in round_canonical not good enough for this?
This is scalbn -- you don't call round_canonical.
r~
- [Qemu-devel] [PATCH v3 18/22] fpu/softfloat: re-factor int/uint to float, (continued)
- [Qemu-devel] [PATCH v3 18/22] fpu/softfloat: re-factor int/uint to float, Alex Bennée, 2018/01/24
- [Qemu-devel] [PATCH v3 20/22] fpu/softfloat: re-factor minmax, Alex Bennée, 2018/01/24
- [Qemu-devel] [PATCH v3 16/22] fpu/softfloat: re-factor round_to_int, Alex Bennée, 2018/01/24
- [Qemu-devel] [PATCH v3 21/22] fpu/softfloat: re-factor compare, Alex Bennée, 2018/01/24
- [Qemu-devel] [PATCH v3 19/22] fpu/softfloat: re-factor scalbn, Alex Bennée, 2018/01/24
[Qemu-devel] [PATCH v3 22/22] fpu/softfloat: re-factor sqrt, Alex Bennée, 2018/01/24
[Qemu-devel] [PATCH v3 15/22] fpu/softfloat: re-factor muladd, Alex Bennée, 2018/01/24
[Qemu-devel] [PATCH v3 17/22] fpu/softfloat: re-factor float to int/uint, Alex Bennée, 2018/01/24
Re: [Qemu-devel] [PATCH v3 00/22] re-factor softfloat and add fp16 functions, no-reply, 2018/01/24
Re: [Qemu-devel] [PATCH v3 00/22] re-factor softfloat and add fp16 functions, Howard Spoelstra, 2018/01/24