Displaying 4 results from an estimated 4 matches for "consantfold".
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constantfold
2010 Mar 03
5
[LLVMdev] folding x * 0 = 0
...=1]
%mul2 = fmul float %mul, 0.000000e+000 ; <float> [#uses=1]
%mul6 = fmul float 0x3FDAED54A0000000, %mul2 ; <float> [#uses=1]
ret float %mul6
}
the sin and cos calls are folded, but not the mul by zero.
May be this is missing in llvm::ConstantFoldInstOperands in
ConsantFolding.cpp?
I would expect the following optimizations, but didn't find them in the
code:
x + 0 = x
x * 0 = 0
x * 1 = 1
x * -1 = -x
-Jochen
2010 Mar 01
2
[LLVMdev] constant folding for standard math functions
Hi!
I'd like to replace all calls to standard math functions (e.g. sin(0.5)) by
their result.
What strategy do you recommend?
Should I write a pass that does only this or should I copy and
modify the SCCP pass?
A problem with an extra pass could be that that I need to alternate
my pass and SCCP several times since the results of the math functions
could be folded again.
-Jochen
2010 Mar 01
0
[LLVMdev] constant folding for standard math functions
On Mar 1, 2010, at 9:44 AM, Jochen Wilhelmy wrote:
> Hi!
>
> I'd like to replace all calls to standard math functions (e.g. sin(0.5)) by
> their result.
> What strategy do you recommend?
> Should I write a pass that does only this or should I copy and
> modify the SCCP pass?
>
> A problem with an extra pass could be that that I need to alternate
> my pass and
2010 Mar 05
0
[LLVMdev] folding x * 0 = 0
...00000e+000 ;<float> [#uses=1]
> %mul6 = fmul float 0x3FDAED54A0000000, %mul2 ;<float> [#uses=1]
> ret float %mul6
> }
>
> the sin and cos calls are folded, but not the mul by zero.
> May be this is missing in llvm::ConstantFoldInstOperands in
> ConsantFolding.cpp?
>
> I would expect the following optimizations, but didn't find them in the
> code:
> x + 0 = x
> x * 0 = 0
> x * 1 = 1
> x * -1 = -x
>
> -Jochen
>
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