Commit Graph

8 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen 00264624a9 Convert EXTRACT_SUBREG to COPY when emitting machine instrs.
EXTRACT_SUBREG no longer appears as a machine instruction. Use COPY instead.

Add isCopy() checks in many places using isMoveInstr() and isExtractSubreg().
The isMoveInstr hook will be removed later.

llvm-svn: 107879
2010-07-08 16:40:22 +00:00
Bill Wendling 5ac1d23d3d 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>.

llvm-svn: 105741
2010-06-09 19:00:55 +00:00
Dale Johannesen 5d99d7fe79 Handle DEBUG_VALUE in this pass.
llvm-svn: 99573
2010-03-26 00:02:44 +00:00
Chris Lattner b06015aa69 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.

llvm-svn: 95687
2010-02-09 19:54:29 +00:00
Evan Cheng bf43525a29 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.
llvm-svn: 93895
2010-01-19 19:45:51 +00:00
Evan Cheng af0ad65ff2 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.

llvm-svn: 93335
2010-01-13 19:16:39 +00:00
Evan Cheng 957b8beaaa Add comment; refactor; avoid pulling in DT if it's not used.
llvm-svn: 93306
2010-01-13 07:59:13 +00:00
Evan Cheng 30bebff456 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.

llvm-svn: 93278
2010-01-13 00:30:23 +00:00