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[PATCH] x86: Properly decode EVEX.W in vcvt[u]si2s[sd] in 32-bit

Jan Beulich JBeulich@suse.com
Mon Sep 17 12:46:00 GMT 2018 
>>> On 17.09.18 at 14:33, <hjl.tools@gmail.com> wrote:
> On Mon, Sep 17, 2018 at 5:18 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>> On 16.09.18 at 14:17, <hjl.tools@gmail.com> wrote:
>>> On Sun, Sep 16, 2018 at 1:57 AM, Jan Beulich <jbeulich@suse.com> wrote:
>>>>>>> "H.J. Lu" <hjl.tools@gmail.com> 09/14/18 7:47 PM >>>
>>>>>--- /dev/null
>>>>>+++ b/gas/testsuite/gas/i386/evex.d
>>>>>@@ -0,0 +1,16 @@
>>>>>+#objdump: -dw -Msuffix
>>>>>+#name: i386 EVX insns
>>>>>+
>>>>>+.*: +file format .*
>>>>>+
>>>>>+
>>>>>+Disassembly of section .text:
>>>>>+
>>>>>+0+ <_start>:
>>>>>+ +[a-f0-9]+:  62 f1 d6 38 2a f0       vcvtsi2ssl %eax,\{rd-sae\},%xmm5,%xmm6
>>>>>+ +[a-f0-9]+:  62 f1 d7 38 2a f0       vcvtsi2sdl %eax,\{rd-sae\},%xmm5,%xmm6
>>>>>+ +[a-f0-9]+:  62 f1 d6 08 7b f0       vcvtusi2ssl %eax,%xmm5,%xmm6
>>>>>+ +[a-f0-9]+:  62 f1 d7 08 7b f0       vcvtusi2sdl %eax,%xmm5,%xmm6
>>>>>+ +[a-f0-9]+:  62 f1 d6 38 7b f0       vcvtusi2ssl 
> %eax,\{rd-sae\},%xmm5,%xmm6
>>>>>+ +[a-f0-9]+:  62 f1 d7 38 7b f0       vcvtusi2sdl 
> %eax,\{rd-sae\},%xmm5,%xmm6
>>>>
>>>> Hmm, a new test demanding (according to what you've told me in earlier
>>>> discussions) bad behavior: You've said that you don't want suffixes on newer
>>>> insns when they're not needed. While these insns may indeed better have
>>>> suffixes in 64-bit mode (they strictly need them only with memory operands),
>>>> there's clearly nothing to disambiguate in 16- and 32-bit modes. May I ask
>>>> for consistency please between what you demand for patches I submit and
>>>> ones you commit, once again without even giving a little time for reviews?
>>>>
>>>
>>> I didn't add any new instructions.  These testcases are written in .byte.
>>> I just fixed the existing entries in disassembler.
>>
>> I didn't say "new instructions", but "new test": In a new test I don't think
>> it is appropriate to record expectations (here: all of the l suffixes above)
>> that are actually expected to not be there, but appear just because of
>> brokenness. Since you touch the respective disassembler patterns
>> anyway I don't really understand why you didn't make the bogus suffixes
>> go away in one go. These instructions usefully have suffixes only in
> 
> I am fixing a different issue.  Please feel free to submit a separate
> patch to address this particular issue.

I understand you're fixing a different issue, but while doing so you
introduce a testcase with bogus expected output. I don't think new
testcases should ever be added when their expectations don't
match "good" output.

Jan
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