llvm-6502/test/CodeGen
Evan Cheng d498c8f2c8 Teach 2addr pass to be do more commuting. If both uses of a two-address instruction are killed, but the first operand has a use before and after the def, commute if the second operand does not suffer from the same issue.
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1                                                                                                                                     
%reg1029<def> = MOV8rr %reg1028                                                                                                                                                      
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>                                                                                                                            
insert => %reg1030<def> = MOV8rr %reg1028                                                                                                                                            
%reg1030<def> = ADD8rr %reg1028<kill>, %reg1029<kill>, %EFLAGS<imp-def,dead>                                                                                                         

In this case, it might not be possible to coalesce the second MOV8rr                                                                                                                 
instruction if the first one is coalesced. So it would be profitable to                                                                                                              
commute it:                                                                                                                                                                          
%reg1028<def> = EXTRACT_SUBREG %reg1027<kill>, 1                                                                                                                                     
%reg1029<def> = MOV8rr %reg1028                                                                                                                                                      
%reg1029<def> = SHR8ri %reg1029, 7, %EFLAGS<imp-def,dead>                                                                                                                            
insert => %reg1030<def> = MOV8rr %reg1029                                                                                                                                            
%reg1030<def> = ADD8rr %reg1029<kill>, %reg1028<kill>, %EFLAGS<imp-def,dead>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62954 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-25 03:53:59 +00:00
..
Alpha Fix Alpha test and support for private linkage. 2009-01-15 21:51:46 +00:00
ARM Add the private linkage. 2009-01-15 20:18:42 +00:00
CBackend
CellSPU Don't rely on grep -w working. 2009-01-21 09:41:42 +00:00
CPP
Generic Let's try to have our cake and eat it to: move 2009-01-21 11:37:31 +00:00
IA64 Add the private linkage. 2009-01-15 20:18:42 +00:00
Mips Add the private linkage. 2009-01-15 20:18:42 +00:00
PowerPC Fix PPC ISD::Declare isel and eliminate the need for PPCTargetLowering::LowerGlobalAddress to check if isVerifiedDebugInfoDesc() is true. Given the recent changes, it would falsely return true for a lot of GlobalAddressSDNode's. 2009-01-16 22:57:32 +00:00
SPARC Add the private linkage. 2009-01-15 20:18:42 +00:00
X86 Teach 2addr pass to be do more commuting. If both uses of a two-address instruction are killed, but the first operand has a use before and after the def, commute if the second operand does not suffer from the same issue. 2009-01-25 03:53:59 +00:00
XCore Add the private linkage. 2009-01-15 20:18:42 +00:00