Commit Graph

7 Commits

Author SHA1 Message Date
Bill Wendling
d64ba3ee62 It's an error to translate this:
%reg1025 = <sext> %reg1024
    ...
   %reg1026 = SUBREG_TO_REG 0, %reg1024, 4

into this:

   %reg1025 = <sext> %reg1024
    ...
   %reg1027 = EXTRACT_SUBREG %reg1025, 4
   %reg1026 = SUBREG_TO_REG 0, %reg1027, 4

The problem here is that SUBREG_TO_REG is there to assert that an implicit zext
occurs. It doesn't insert a zext instruction. If we allow the EXTRACT_SUBREG
here, it will give us the value after the <sext>, not the original value of
%reg1024 before <sext>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105741 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-09 19:00:55 +00:00
Dale Johannesen
1feeadac1b Handle DEBUG_VALUE in this pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99573 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-26 00:02:44 +00:00
Chris Lattner
518bb53485 move target-independent opcodes out of TargetInstrInfo
into TargetOpcodes.h.  #include the new TargetOpcodes.h
into MachineInstr.  Add new inline accessors (like isPHI())
to MachineInstr, and start using them throughout the 
codebase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95687 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 19:54:29 +00:00
Evan Cheng
590d16be6f Do not extend extension results beyond the use of a PHI instruction at the start of a use block. A PHI use is expected to kill its source values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93895 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-19 19:45:51 +00:00
Evan Cheng
eb18812f75 Commit some changes I had managed to lose last night while refactoring the code. Avoid change use of PHI instructions because it's not legal to insert any instructions before them.
This fixes PR6027.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93335 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-13 19:16:39 +00:00
Evan Cheng
d89d5180d1 Add comment; refactor; avoid pulling in DT if it's not used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93306 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-13 07:59:13 +00:00
Evan Cheng
7da9ecf967 Add a quick pass to optimize sign / zero extension instructions. For targets where the pre-extension values are available in the subreg of the result of the extension, replace the uses of the pre-extension value with the result + extract_subreg.
For now, this pass is fairly conservative. It only perform the replacement when both the pre- and post- extension values are used in the block. It will miss cases where the post-extension values are live, but not used.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93278 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-13 00:30:23 +00:00