[libc][math] Improve fmul performance by using double-double arithmetic. (#107517)

2024-09-14T21:32:22+00:00

```
 Performance tests with inputs in denormal range:
-- My function --
     Total time      : 2731072304 ns 
     Average runtime : 68.2767 ns/op 
     Ops per second  : 14646276 op/s 
-- Other function --
     Total time      : 3259744268 ns 
     Average runtime : 81.4935 ns/op 
     Ops per second  : 12270913 op/s 
-- Average runtime ratio --
     Mine / Other's  : 0.837818 

 Performance tests with inputs in normal range:
-- My function --
     Total time      : 93467258 ns 
     Average runtime : 2.33668 ns/op 
     Ops per second  : 427957777 op/s 
-- Other function --
     Total time      : 637295452 ns 
     Average runtime : 15.9324 ns/op 
     Ops per second  : 62765299 op/s 
-- Average runtime ratio --
     Mine / Other's  : 0.146662 

 Performance tests with inputs in normal range with exponents close to each other:
-- My function --
     Total time      : 95764894 ns 
     Average runtime : 2.39412 ns/op 
     Ops per second  : 417690014 op/s 
-- Other function --
     Total time      : 639866770 ns 
     Average runtime : 15.9967 ns/op 
     Ops per second  : 62513075 op/s 
-- Average runtime ratio --
     Mine / Other's  : 0.149664 
```

---------

Co-authored-by: Tue Ly

[libc][math][c23] Add {f,d}mul{l,f128} and f16mul{,f,l,f128} C23 math functions (#98972)

2024-07-18T17:50:49+00:00

Part of #93566.
                
Fixes #94833.

[libc] Add mpfr tests for fmul. (#97376)

2024-07-02T04:38:15+00:00

Fixes https://github.com/llvm/llvm-project/issues/94834

llvm-project.git/libc/test/src/math/fmul_test.cpp, branch users/nico/python-2

[libc][math] Improve fmul performance by using double-double arithmetic. (#107517)

[libc][math][c23] Add {f,d}mul{l,f128} and f16mul{,f,l,f128} C23 math functions (#98972)

[libc] Add mpfr tests for fmul. (#97376)