Commit Graph

3 Commits

Author SHA1 Message Date
Fangrui Song 9ca1b94a6d [CodeGen] Add alias for cpu_dispatch function with IFunc & Fix resolver linkage type
Multi-versioned functions defined by cpu_dispatch and implemented with IFunc
can not be called outside the translation units where they are defined due to
lack of symbols. This patch add function aliases for these functions and thus
make them visible outside.

Differential Revision: https://reviews.llvm.org/D67058
Patch by Senran Zhang

llvm-svn: 371586
2019-09-11 01:54:48 +00:00
Tim Northover a009a60a91 IR: print value numbers for unnamed function arguments
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.

Also modifies the parser to accept IR in that form for obvious reasons.

llvm-svn: 367755
2019-08-03 14:28:34 +00:00
Erich Keane 19a8adc9bd Implement Function Multiversioning for Non-ELF Systems.
Similar to how ICC handles CPU-Dispatch on Windows, this patch uses the
resolver function directly to forward the call to the proper function.
This is not nearly as efficient as IFuncs of course, but is still quite
useful for large functions specifically developed for certain
processors.

This is unfortunately still limited to x86, since it depends on
__builtin_cpu_supports and __builtin_cpu_is, which are x86 builtins.

The naming for the resolver/forwarding function for cpu-dispatch was
taken from ICC's implementation, which uses the unmodified name for this
(no mangling additions).  This is possible, since cpu-dispatch uses '.A'
for the 'default' version.

In 'target' multiversioning, this function keeps the '.resolver'
extension in order to keep the default function keeping the default
mangling.

Change-Id: I4731555a39be26c7ad59a2d8fda6fa1a50f73284

Differential Revision: https://reviews.llvm.org/D53586

llvm-svn: 345298
2018-10-25 18:57:19 +00:00