relatively expensive comparison analyzer on each instruction. Also rename the
comparison analyzer method to something more in line with what it actually does.
This pass is will eventually be folded into the Machine CSE pass.
llvm-svn: 110539
necessary.
Sometimes, live range splitting doesn't shrink the current interval, but simply
changes some instructions to use a new interval. That makes the original more
suitable for spilling. In this case, we don't need to duplicate the original.
llvm-svn: 110481
implementation of the function is equivalent, so no need to provide
the target-specific version until/unless it needs to do something.
llvm-svn: 110465
After heavy editing of a live interval, it is much easier to simply renumber the
live values instead of trying to keep track of the unused ones.
llvm-svn: 110463
When a physical register is in use, some alias of that register has a live
interval with a relevant live range. That is the sad state of intervals after
physreg coalescing of subregs, and it is good enough for correct register
allocation.
llvm-svn: 110452
Without this what was happening was:
* R3 is not marked as "used"
* ARM backend thinks it has to save it to the stack because of vaarg
* Offset computation correctly ignores it
* Offsets are wrong
llvm-svn: 110446
Further clean up the comparison function by removing overly generalized
"domains".
Remove all understanding of ELF aliases and simplify folding code and comments.
llvm-svn: 110434
This pass tries to remove comparison instructions when possible. For instance,
if you have this code:
sub r1, 1
cmp r1, 0
bz L1
and "sub" either sets the same flag as the "cmp" instruction or could be
converted to set the same flag, then we can eliminate the "cmp" instruction all
together. This is a important for ARM where the ALU instructions could set the
CPSR flag, but need a special suffix ('s') to do so.
llvm-svn: 110423
AliasAnalysis base class and into BasicAliasAnalyais. This avoids confusion
about where such logic is happening when there are other AliasAnalysis
implementations present.
Move the logic for translating two-callsite getModRefInfo queries into
other AliasAnalysis queries out of BasicAliasAnalysis and into the
AliasAnalysis base class, as it is useful for other AliasAnalysis
implementations.
llvm-svn: 110421
LiveVariables becomes horribly wrong while the coalescer is running, but the
analysis is not zapped until after the coalescer pass has run. This causes tons
of false reports when calling verify form the coalescer.
llvm-svn: 110402
