Displaying 2 results from an estimated 2 matches for "41a00000".
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41a00001
2019 Aug 06
3
[RFC] Improve iteration of estimating divisions
...t division transformation (turn `a / b` into `a * (1/b)`) is worse in precision compared with GCC. Like this case in ppc64le:
float fdiv(unsigned int a, unsigned int b) {
return (float)a / (float)b;
}
Result of Clang -Ofast is 41A00001 (in Hex), while GCC produces 41A00000 which is the same as no optimizations opened.
Currently, DAGCombiner uses `BuildReciprocalEstimate` to calculate the reciprocal (`1/b`) first and multiply it with `a`. But if we put the operand `a` into iterations in the estimate function, the result would be better.
Patching such a change may b...
2019 Aug 08
2
回复: [RFC] Improve iteration of estimating divisions
...`a / b` into `a * (1/b)`) is worse in precision compared with GCC. Like this case in ppc64le:
>
> float fdiv(unsigned int a, unsigned int b) {
> return (float)a / (float)b;
> }
>
> Result of Clang -Ofast is 41A00001 (in Hex), while GCC produces 41A00000 which is the same as no optimizations opened.
>
> Currently, DAGCombiner uses `BuildReciprocalEstimate` to calculate the reciprocal (`1/b`) first and multiply it with `a`. But if we put the operand `a` into iterations in the estimate function, the result would be better.
>
> Patching s...