Displaying 5 results from an estimated 5 matches for "simplifyfadd".
2015 Jan 08
3
[LLVMdev] Floating-point range checks
...InstCombine and ValueTracking.
Take a look at ComputeSignBit in ValueTracking.cpp. This doesn't apply (?) to floating point numbers, but we'd need something equivalent for them. It looks like there may already be a start in the form of:
CannotBeNegativeZero
Other places to look would be SimplifyFAdd and InstCombine::visitFAdd.
For this particular example, you're probably going to want a pattern in SimplifyFCmp of the form:
matcher: sqrt_call( fadd(Value(X), SpecificValue(X)), fadd(Value(Y), SpecificValue(Y)))
&& CannotBeNegativeZero(X) && CannotBeNegativeZero(Y)
You might...
2015 Jan 07
2
[LLVMdev] Floating-point range checks
The Julia language implements sqrt(x) with conditional branch taken if x<0. Alas this prevents vectorization of loops with sqrt. Often the argument can be proven to be non-negative. E.g., sqrt(x*x+y*y). Is there an existing LLVM pass or analysis that does floating-point range propagation to eliminate such unnecessary checks?
Arch D. Robison
Intel Corporation
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2015 Jan 08
2
[LLVMdev] Floating-point range checks
...> Take a look at ComputeSignBit in ValueTracking.cpp. This doesn't apply
> (?) to floating point numbers, but we'd need something equivalent for
> them. It looks like there may already be a start in the form of:
> CannotBeNegativeZero
>
> Other places to look would be SimplifyFAdd and InstCombine::visitFAdd.
>
> For this particular example, you're probably going to want a pattern
> in SimplifyFCmp of the form:
> matcher: sqrt_call( fadd(Value(X), SpecificValue(X)), fadd(Value(Y),
> SpecificValue(Y)))
> && CannotBeNegativeZero(X) && Can...
2015 Jan 08
2
[LLVMdev] Floating-point range checks
...doesn't
>>> apply
>>> (?) to floating point numbers, but we'd need something equivalent
>>> for
>>> them. It looks like there may already be a start in the form of:
>>> CannotBeNegativeZero
>>>
>>> Other places to look would be SimplifyFAdd and
>>> InstCombine::visitFAdd.
>>>
>>> For this particular example, you're probably going to want a
>>> pattern
>>> in SimplifyFCmp of the form:
>>> matcher: sqrt_call( fadd(Value(X), SpecificValue(X)),
>>> fadd(Value(Y),
>>&...
2015 Jan 08
2
[LLVMdev] Floating-point range checks
...> >>> (?) to floating point numbers, but we'd need something equivalent
> >>> for them. It looks like there may already be a start in the form
> >>> of:
> >>> CannotBeNegativeZero
> >>>
> >>> Other places to look would be SimplifyFAdd and
> >>> InstCombine::visitFAdd.
> >>>
> >>> For this particular example, you're probably going to want a
> >>> pattern in SimplifyFCmp of the form:
> >>> matcher: sqrt_call( fadd(Value(X), SpecificValue(X)),
> >>> fadd...