This patch removes the PROC macro in favor of CPUKind enum and a
table that contains information about CPUs.
The current information in the table is the CPU name, CPUKind enum
value, key feature for target multiversioning, and Is64Bit capable.
For the strings that are aliases, I've duplicated the information
in the table. This means there are more rows in the table than
CPUKind enums.
This replaces multiple StringSwitch's with loops through the table.
They are linear searches due to the table being more logically
ordered than alphabetical. The StringSwitch's would have also been
linear. I've used StringLiteral on the strings in the table so we
can quickly check the length while searching.
I contemplated having a CPUKind for each string so there was a 1:1
mapping, but didn't want to spread more names to the places that
use the enum.
My ultimate goal here is to store the features for each CPU as a
bitset within the table. Hoping to use constexpr to make this
composable so we can group features and inherit them. After the
table lookup we can turn the bitset into a list of strings for the
frontend. The current switch we have for selecting features for
CPUs has become difficult to maintain while trying to express
inheritance relationships.
Differential Revision: https://reviews.llvm.org/D82414
Similar to what some other targets have done. This information
could be reused by other frontends so doesn't make sense to live
in clang.
-Rename CK_Generic to CK_None to better reflect its illegalness.
-Move function for translating from string to enum into llvm.
-Call checkCPUKind directly from the string to enum translation
and update CPU kind to CK_None accordinly. Caller will use CK_None
as sentinel for bad CPU.
I'm planning to move all the CPU to feature mapping out next. As
part of that I want to devise a better way to express CPUs inheriting
features from an earlier CPU. Allowing this to be expressed in a
less rigid way than just falling through a switch. Or using gotos
as we've had to do lately.
Differential Revision: https://reviews.llvm.org/D81439
Craig Topper