into Analysis as a standalone function, since there's no need for
it to be in VMCore. Also, update it to use isKnownNonZero and
other goodies available in Analysis, making it more precise,
enabling more aggressive optimization.
llvm-svn: 146610
This should always be done as a matter of principal. I don't have a
case that exposes the problem. I just noticed this recently while
scanning the code and realized I meant to fix it long ago.
llvm-svn: 146438
subdirectories to traverse into.
- Originally I wanted to avoid this and just autoscan, but this has one key
flaw in that new subdirectories can not automatically trigger a rerun of the
llvm-build tool. This is particularly a pain when switching back and forth
between trees where one has added a subdirectory, as the dependencies will
tend to be wrong. This will also eliminates FIXME implicitly.
llvm-svn: 146436
detected in the forward-CFG DFS. This prevents the reverse-CFG from
visiting blocks inside loops after blocks that dominate them in the
case where loops have multiple exits.
No testcase, because this fixes a bug which in practice only shows
up in a full optimizer run, due to the use-list order.
This fixes rdar://10422791 and others.
llvm-svn: 146408
indicates whether the intrinsic has a defined result for a first
argument equal to zero. This will eventually allow these intrinsics to
accurately model the semantics of GCC's __builtin_ctz and __builtin_clz
and the X86 instructions (prior to AVX) which implement them.
This patch merely sets the stage by extending the signature of these
intrinsics and establishing auto-upgrade logic so that the old spelling
still works both in IR and in bitcode. The upgrade logic preserves the
existing (inefficient) semantics. This patch should not change any
behavior. CodeGen isn't updated because it can use the existing
semantics regardless of the flag's value.
Note that this will be followed by API updates to Clang and DragonEgg.
Reviewed by Nick Lewycky!
llvm-svn: 146357
Since we're not rewriting IVs in other loops, there's not much reason
to consider their stride when generating formulae.
This should reduce the number of useless formulas considered by LSR.
llvm-svn: 146302
Patch by Brendon Cahoon!
This extends the existing LoopUnroll and LoopUnrollPass. Brendon
measured no regressions in the llvm test suite with -unroll-runtime
enabled. This implementation works by using the existing loop
unrolling code to unroll the loop by a power-of-two (default 8). It
generates an if-then-else sequence of code prior to the loop to
execute the extra iterations before entering the unrolled loop.
llvm-svn: 146245
- Walking over pred_begin/pred_end is an expensive operation.
- PHINodes contain a value for each predecessor anyway.
- While it may look like we used to save a few iterations with the set,
be aware that getIncomingValueForBlock does a linear search on
the values of the phi node.
- Another -5% on ARMDisassembler.cpp (Release build). This was the last
entry in the profile that was obviously wasting time.
llvm-svn: 145937
It's always good to prune early, but formulae that are unsatisfactory
in their own right need to be removed before running any other pruning
heuristics. We easily avoid generating such formulae, but we need them
as an intermediate basis for forming other good formulae.
llvm-svn: 145906
- Calling getUser in a loop is much more expensive than iterating over a few instructions.
- Use it instead of the open-coded loop in AddrModeMatcher.
- 5% speedup on ARMDisassembler.cpp Release builds.
llvm-svn: 145810
The callee is usually smaller than the caller, too. This reduces the compile
time of ARMDisassembler.cpp by 32% (Release build). It still takes ages to
compile though.
llvm-svn: 145690
