exact backedge taken count, when checking for infinite loops. This allows
it to delete loops with multiple exit conditions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84952 91177308-0d34-0410-b5e6-96231b3b80d8
non-type-safe constant initializers. This sort of thing happens
quite a bit for 4-byte loads out of string constants, unions,
bitfields, and an interesting endianness check from sqlite, which
is something like this:
const int sqlite3one = 1;
# define SQLITE_BIGENDIAN (*(char *)(&sqlite3one)==0)
# define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)
# define SQLITE_UTF16NATIVE (SQLITE_BIGENDIAN?SQLITE_UTF16BE:SQLITE_UTF16LE)
all of these macros now constant fold away.
This implements PR3152 and is based on a patch started by Eli, but heavily
modified and extended.
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to break up CFG diamonds by banishing one of the blocks to the end of
the function, which is bad for code density and branch size.
This does pessimize MultiSource/Benchmarks/Ptrdist/yacr2, the
benchmark cited as the reason for the change, however I've examined
the code and it looks more like a case of gaming a particular
branch than of being generally applicable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84803 91177308-0d34-0410-b5e6-96231b3b80d8
Most changes are cleanup, but there is 1 correctness fix:
I fixed InstCombine so that the icmp is removed only if the malloc call is removed (which requires explicit removal because the Worklist won't DCE any calls since they can have side-effects).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84772 91177308-0d34-0410-b5e6-96231b3b80d8
in the PHI's Basic Block. This uses a conservative approach, because we don't
have dominator info in instcombine.
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encounters an OEQ or UNE comparison, and update its callers to check
for this return status and recover. This fixes a problem resulting from
the LowerOperation hooks being called from LegalizeVectorOps, because
LegalizeVectorOps only lowers vectors, so OEQ and UNE comparisons may
still be at large. This fixes PR5092.
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When an incoming value for a PHI is updated, we must also updated all other
incoming values for the same BB to match, otherwise we create invalid PHIs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84638 91177308-0d34-0410-b5e6-96231b3b80d8
when the invoke had multiple return values: it set the lattice value only on the
extractvalue.
This caused the invoke's lattice value to remain the default (undefined), and
later propagated to extractvalue's operand, which incorrectly introduces
undefined behavior.
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tracked. Instead of trying to manually keep track of these locations
while doing complex modifications, just recompute them when they're needed.
This fixes a bug in which the TopMBB and BotMBB were not correctly updated,
leading to invalid transformations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84598 91177308-0d34-0410-b5e6-96231b3b80d8
where a loop's header is being split and it has predecessors which are not
contained by the most-nested loop which contains the loop.
This fixes PR5235.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84505 91177308-0d34-0410-b5e6-96231b3b80d8
LLC was scheduling compares before the adds causing wrong branches to be taken
in programs, resulting in misoptimized code wherever atomic adds where used.
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