mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2025-01-17 00:57:54 +00:00
Evan Cheng
0a651c3314
Teach two-address pass to do some coalescing while eliminating REG_SEQUENCE
instructions. e.g. %reg1026<def> = VLDMQ %reg1025<kill>, 260, pred:14, pred:%reg0 %reg1027<def> = EXTRACT_SUBREG %reg1026, 6 %reg1028<def> = EXTRACT_SUBREG %reg1026<kill>, 5 ... %reg1029<def> = REG_SEQUENCE %reg1028<kill>, 5, %reg1027<kill>, 6, %reg1028, 7, %reg1027, 8, %reg1028, 9, %reg1027, 10, %reg1030<kill>, 11, %reg1032<kill>, 12 After REG_SEQUENCE is eliminated, we are left with: %reg1026<def> = VLDMQ %reg1025<kill>, 260, pred:14, pred:%reg0 %reg1029:6<def> = EXTRACT_SUBREG %reg1026, 6 %reg1029:5<def> = EXTRACT_SUBREG %reg1026<kill>, 5 The regular coalescer will not be able to coalesce reg1026 and reg1029 because it doesn't know how to combine sub-register indices 5 and 6. Now 2-address pass will consult the target whether sub-registers 5 and 6 of reg1026 can be combined to into a larger sub-register (or combined to be reg1026 itself as is the case here). If it is possible, it will be able to replace references of reg1026 with reg1029 + the larger sub-register index. llvm-svn: 103835
…
…
…
…
…
…
…
…
…
…
…
…
Low Level Virtual Machine (LLVM) ================================ This directory and its subdirectories contain source code for the Low Level Virtual Machine, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments. LLVM is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt. Please see the HTML documentation provided in docs/index.html for further assistance with LLVM. If you're writing a package for LLVM, see docs/Packaging.html for our suggestions.
Description
Languages
C++
96.9%
C
1%
Python
1%
CMake
0.6%
OCaml
0.2%
Other
0.1%