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Re: [Qemu-devel] [PATCH v4 5/7] target-m68k: use floatx80 internally
From: |
Laurent Vivier |
Subject: |
Re: [Qemu-devel] [PATCH v4 5/7] target-m68k: use floatx80 internally |
Date: |
Mon, 19 Jun 2017 23:42:07 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 |
Le 19/06/2017 à 23:03, Laurent Vivier a écrit :
> Le 19/06/2017 à 22:53, Richard Henderson a écrit :
>>
>> It would also make me happier if we were to adjust the definition of
>> fl0atx80 to more closely match m68k and those missing zeros. Shouldn't
>> real hardware move instructions propagate those middle 2 bytes
>> regardless of contents?
>>
>> Perhaps something like
>>
>> #ifdef TARGET_M68K
>> typedef struct {
>> uint64_t low;
>> union {
>> uin32_t high32;
>> struct {
>> #ifdef HOST_WORDS_BIGENDIAN
>> uint16_t high, zero;
>> #else
>> uint16_t zero, high;
>> #endif
>> };
>> };
>> } floatx80;
>> #else
>> ...
>> #endif
>>
>> (with a minor fix to make_floatx80 to use named initializers).
>>
>> Then you can use full 32-bit store insns when copying data here. Which
>> also allows you to drop some of the shifts you're needing to add.
>
> OK, I will.
The softfloat is in the target independent code, so we can't adjust the
size of floatx80 by target, TARGET_XXXX are poisoned when used in
softfloat.h.
Laurent
- [Qemu-devel] [PATCH v4 1/7] softfloat: define 680x0 specific values, (continued)
- [Qemu-devel] [PATCH v4 1/7] softfloat: define 680x0 specific values, Laurent Vivier, 2017/06/11
- [Qemu-devel] [PATCH v4 2/7] target-m68k: move FPU helpers to fpu_helper.c, Laurent Vivier, 2017/06/11
- [Qemu-devel] [PATCH v4 6/7] target-m68k: define 96bit FP registers for gdb on 680x0, Laurent Vivier, 2017/06/11
- [Qemu-devel] [PATCH v4 3/7] target-m68k: define ext_opsize, Laurent Vivier, 2017/06/11
- [Qemu-devel] [PATCH v4 7/7] target-m68k: add FPCR and FPSR, Laurent Vivier, 2017/06/11
- [Qemu-devel] [PATCH v4 5/7] target-m68k: use floatx80 internally, Laurent Vivier, 2017/06/11