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*From*: Gabriel Dos Reis <gdr at cs dot tamu dot edu>*To*: Fariborz Jahanian <fjahanian at apple dot com>*Cc*: Geoff Keating <geoffk at geoffk dot org>, gcc-patches at gcc dot gnu dot org*Date*: 05 Oct 2004 16:08:39 -0500*Subject*: Re: Patch gcc-4.0 should not apply mathematical associative rules for addition or multiplication*Organization*: Texas A&M University, Department of Computer Science*References*: <2B2F21A1-16FF-11D9-957B-000A95BA54A6@apple.com><m28yalosbv.fsf@greed.local><B5E42B5E-1709-11D9-957B-000A95BA54A6@apple.com><AE923EFA-1710-11D9-BB5A-000A95B1F520@geoffk.org><3D58A137-1712-11D9-957B-000A95BA54A6@apple.com>

Fariborz Jahanian <fjahanian@apple.com> writes: | On Oct 5, 2004, at 1:53 PM, Geoff Keating wrote: | | >> | >> Wording of ANSIC disallows such foldings even if it is safe sometimes. | > | > Could you explain why you think the standard says this? The quote | > you gave said "In the following fragment, rearrangements suggested | > by mathematical rules for real numbers are often not valid" but it | > did not say that they were *always* not valid. | | The section uses such words as 'often restricted', 'generally invalid' | 'cannot generally replace'. So, I posed this as | the question and consensus was that we should place this under | -funsafe-math-optimizations flag. Almost all | optimization placed under above flag is 'sometimes' valid and yet we | place them under this flag. Yes, and that is what we agreed on after repeated long debates. | I don't see a difference in this case. Right. -- Gaby

**References**:**Patch gcc-4.0 should not apply mathematical associative rules for addition or multiplication***From:*Fariborz Jahanian

**Re: Patch gcc-4.0 should not apply mathematical associative rules for addition or multiplication***From:*Geoffrey Keating

**Re: Patch gcc-4.0 should not apply mathematical associative rules for addition or multiplication***From:*Fariborz Jahanian

**Re: Patch gcc-4.0 should not apply mathematical associative rules for addition or multiplication***From:*Geoff Keating

**Re: Patch gcc-4.0 should not apply mathematical associative rules for addition or multiplication***From:*Fariborz Jahanian

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