Displaying 3 results from an estimated 3 matches for "vcomiss".
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ucomiss
2013 May 20
2
[LLVMdev] VCOMISS instruction in X86
Hi,
I'm looking at scalar and packed instructions in X86.
The instruction VCOMISS is scalar. May I remove SSEPackedSingle/SSEPackedDouble domain from it?
defm VUCOMISS : sse12_ord_cmp<0x2E, FR32, X86cmp, f32, f32mem, loadf32,
"ucomiss", SSEPackedSingle>, TB, VEX, VEX_LIG;
defm VUCOMISD : sse12_ord_cmp<0x2E, FR64, X86cmp,...
2013 Aug 29
0
[LLVMdev] Ordered / Unordered FP compare are not handled properly on X86
But this is another case. LLVM IR distinguishes between ordered and unordered compare and X86 backend has appropriate instructions.
But during DAG selection we just lose this information and always generate unordered fcmp.
I.e. in case of ordered fcmp the vcomiss should be generated, and in case of unordered - vucomiss.
- Elena
-----Original Message-----
From: Dr D. Chisnall [mailto:dc552 at hermes.cam.ac.uk] On Behalf Of David Chisnall
Sent: Thursday, August 29, 2013 10:50
To: Tim Northover
Cc: Demikhovsky, Elena; llvmdev at cs.uiuc.edu
Subject: Re: [...
2013 Aug 29
2
[LLVMdev] Ordered / Unordered FP compare are not handled properly on X86
On 29 Aug 2013, at 08:19, Tim Northover <t.p.northover at gmail.com> wrote:
> If so, a compare that used that instruction would have to become more
> like an "invoke" with a landingpad for the exception and so on,
> wouldn't it? The current fcmp can already distinguish between ordered
> and unordered, because ucomiss provides that information.
There are currently