Both Eisel-Lemire and Ryu depend on a table of
truncated 128-bit mantissas of powers of 10,
and so will Dragonbox.
This CL:
- Moves the table to a separate file, so it doesn't look tied to Eisel-Lemire.
- Introduces a uint128 type in math.go for the table values,
since .Hi and .Lo are clearer than [1] and [0].
- Generates the table from a standalone generator pow10gen.go.
- Adds a new pow10 function in math.go to handle table access details.
- Factors a 64x128->192-bit multiply into umul192 in math.go.
- Moves multiplication by log₁₀ 2 and log₂ 10 into math.go.
- Introduces an import_test.go to avoid having to type differently
cased names in test code versus regular code.
- Introduces named constants for the floating-point size parameters.
Previously these were only in the floatInfo global variables.
- Changes the BenchmarkAppendUintVarlen subtest names
to be more useful.
Change-Id: I9826ee5f41c5c19be3b6a7c3c5f277ec6c23b39a
Reviewed-on: https://go-review.googlesource.com/c/go/+/712661
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
