| commit | 8dfec7ce7a6b6fa6f7c366f0b68b3adf194ad121 | [log] [tgz] |
|---|---|---|
| author | Sean Fertile <sfertile@ca.ibm.com> | Thu Sep 20 00:26:44 2018 +0000 |
| committer | Sean Fertile <sfertile@ca.ibm.com> | Thu Sep 20 00:26:44 2018 +0000 |
| tree | cdd5b68de0ad8dc4b11e1f3c02d45cf145014bc2 | |
| parent | 9b7710b45abec273f5e66515f2dafeadeee444fd [diff] |
[PPC64] Optimize redundant instructions in global access sequences. The access sequence for global variables in the medium and large code models use 2 instructions to add an offset to the toc-pointer. If the offset fits whithin 16-bits then the instruction that sets the high 16 bits is redundant. This patch adds the --toc-optimize option, (on by default) and enables rewriting of 2 instruction global variable accesses into 1 when the offset from the TOC-pointer to the variable (or .got entry) fits in 16 signed bits. eg addis %r3, %r2, 0 --> nop addi %r3, %r3, -0x8000 --> addi %r3, %r2, -0x8000 This rewriting can be disabled with the --no-toc-optimize flag Differential Revision: https://reviews.llvm.org/D49237 git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@342602 91177308-0d34-0410-b5e6-96231b3b80d8
This directory and its subdirectories contain source code for the LLVM Linker, a modular cross platform linker which is built as part of the LLVM compiler infrastructure project.
lld is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt.
In order to make sure various developers can evaluate patches over the same tests, we create a collection of self contained programs.
It is hosted at https://s3-us-west-2.amazonaws.com/linker-tests/lld-speed-test.tar.xz
The current sha256 is 10eec685463d5a8bbf08d77f4ca96282161d396c65bd97dc99dbde644a31610f.