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| author | Evan Cheng <evan.cheng@apple.com> | 2009-01-25 03:53:59 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2009-01-25 03:53:59 +0000 |
| commit | d498c8f2c8eb5598bf2e0c3ab30016734e490c6b (patch) | |
| tree | 33b7931d23d322b8f809c568f5600f31f6009117 /test/CodeGen/X86/2008-02-22-ReMatBug.ll | |
| parent | 9b9948507474acd3c5941ad7d33a37cb066803ad (diff) | |
| download | external_llvm-d498c8f2c8eb5598bf2e0c3ab30016734e490c6b.zip external_llvm-d498c8f2c8eb5598bf2e0c3ab30016734e490c6b.tar.gz external_llvm-d498c8f2c8eb5598bf2e0c3ab30016734e490c6b.tar.bz2 | |
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
Diffstat (limited to 'test/CodeGen/X86/2008-02-22-ReMatBug.ll')
| -rw-r--r-- | test/CodeGen/X86/2008-02-22-ReMatBug.ll | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/test/CodeGen/X86/2008-02-22-ReMatBug.ll b/test/CodeGen/X86/2008-02-22-ReMatBug.ll index f78d526..539fc15 100644 --- a/test/CodeGen/X86/2008-02-22-ReMatBug.ll +++ b/test/CodeGen/X86/2008-02-22-ReMatBug.ll @@ -1,4 +1,4 @@ -; RUN: llvm-as < %s | llc -march=x86 -stats |& grep {Number of re-materialization} | grep 3 +; RUN: llvm-as < %s | llc -march=x86 -stats |& grep {Number of re-materialization} | grep 4 ; RUN: llvm-as < %s | llc -march=x86 -stats |& grep {Number of dead spill slots removed} ; rdar://5761454 |