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| author | Hal Finkel <hfinkel@anl.gov> | 2014-07-25 21:13:35 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2014-07-25 21:13:35 +0000 |
| commit | 930469107d34d66b015f6e48b3f05554819216d8 (patch) | |
| tree | 3d23c9a2e9b5241703cbcfcc6040619ea65894d1 /clang/lib/CodeGen/CodeGenFunction.cpp | |
| parent | c888757a2dcaf365a115cd250da045e12af013c1 (diff) | |
| download | llvm-930469107d34d66b015f6e48b3f05554819216d8.zip llvm-930469107d34d66b015f6e48b3f05554819216d8.tar.gz llvm-930469107d34d66b015f6e48b3f05554819216d8.tar.bz2 | |
Add @llvm.assume, lowering, and some basic properties
This is the first commit in a series that add an @llvm.assume intrinsic which
can be used to provide the optimizer with a condition it may assume to be true
(when the control flow would hit the intrinsic call). Some basic properties are added here:
- llvm.invariant(true) is dead.
- llvm.invariant(false) is unreachable (this directly corresponds to the
documented behavior of MSVC's __assume(0)), so is llvm.invariant(undef).
The intrinsic is tagged as writing arbitrarily, in order to maintain control
dependencies. BasicAA has been updated, however, to return NoModRef for any
particular location-based query so that we don't unnecessarily block code
motion.
llvm-svn: 213973
Diffstat (limited to 'clang/lib/CodeGen/CodeGenFunction.cpp')
0 files changed, 0 insertions, 0 deletions