[LLVMdev] [PATCH] fast-math patches!

Evan Cheng evan.cheng at apple.com
Thu Nov 15 10:51:49 PST 2012


On Nov 15, 2012, at 10:51 AM, Michael Ilseman <milseman at apple.com> wrote:

> 
> On Nov 15, 2012, at 10:38 AM, Evan Cheng <evan.cheng at apple.com> wrote:
> 
>> Hi Michael,
>> 
>> The patch looks good in general. But I'm a bit concerned about the textural representation about these flags. 'N', 'I', 'S', 'R', 'A' seem cryptic to me. Does it make sense to expand them a bit 'nnan', 'inf', etc.? They definitely need to be documented.
>> 
> 
> I think it does make sense to expand them to be more readable. Also, the textual representation doesn't have to precisely follow the internal names. What about:
> nnan : no nans
> ninf : no infs
> nsz : no signed zeros
> ar: allow reciprocal
> fast : unsafe algebra (and implicitly all the others)

These seem reasonable to me. Thanks!

Evan

> 
> I'll get started on documentation.
> 
>> Evan
>> 
>> On Nov 15, 2012, at 10:17 AM, Michael Ilseman <milseman at apple.com> wrote:
>> 
>>> Attached are some patches for adding in an IR-level mechanism for representing fast-math flags, as discussed in my prior RFC. Patches include infrastructure, API support, textual and bitcode reader/writer support, example optimization, and test cases.
>>> 
>>> <0002-Fast-math-flags-added-to-FPMathOperator.patch>
>>> <0003-Fast-math-interfaces-for-Instructions.patch>
>>> <0004-Fast-math-flags-for-LLVM-IR-parsing-and-printing.patch>
>>> <0005-Fast-math-flags-for-the-bitcode.patch>
>>> <0006-Fast-math-test-case-for-bitcode-and-textual-reading-.patch>
>>> <0007-Fast-math-optimization-fold-multiply-by-zero.patch>
>>> <0008-Fast-math-test-for-SimplifyInstruction-fold-multiply.patch>
>>> 
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>> 
> 




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