it can check whether the visible direct callers are passing in parameters to
dead arguments and replace those with undef.
This reinstates r94322 with bugs fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101213 91177308-0d34-0410-b5e6-96231b3b80d8
numerator is an induction variable. For example, with code like this:
for (i=0;i<n;++i)
x[i%n] = 0;
IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the remainder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101113 91177308-0d34-0410-b5e6-96231b3b80d8
expression is a UDiv and it doesn't appear that the UDiv came from
the user's source.
ScalarEvolution has recently figured out how to compute a tripcount
expression for the inner loop in
SingleSource/Benchmarks/Shootout/sieve.c, using a udiv. Emitting a
udiv instruction dramatically slows down the enclosing loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101068 91177308-0d34-0410-b5e6-96231b3b80d8
a ScalarEvolution bug with overflow handling is fixed, the normal analysis
code will automatically decline to operate on the icmp instructions which
are responsible for the loop exit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101032 91177308-0d34-0410-b5e6-96231b3b80d8
instead of deleting just the user. This makes it more consistent with
other code in IndVarSimplify, and theoretically can eliminate more users
earlier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101027 91177308-0d34-0410-b5e6-96231b3b80d8
the loop exit test. This usually doesn't come up for a variety of
reasons, but it isn't impossible, so make IndVarSimplify handle it
conservatively.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101008 91177308-0d34-0410-b5e6-96231b3b80d8
variables. For example, with code like this:
for (i=0;i<n;++i)
if (i<n)
x[i] = 0;
IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the if.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101000 91177308-0d34-0410-b5e6-96231b3b80d8
parameters in the CBE by implicitly adding a fixed argument.
This allows eliminating a work-around from DAE. Patch by
Sylvere Teissier!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100944 91177308-0d34-0410-b5e6-96231b3b80d8
into adjacent loops. Also, ensure that the insert position is
dominated by the loop latch of any loop in the post-inc set which
has a latch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100906 91177308-0d34-0410-b5e6-96231b3b80d8
forced constant is changed to a constant, we would end
up adding the instruction to the wrong worklist,
preventing it from being properly revisited. This fixes
rdar://7832370
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100837 91177308-0d34-0410-b5e6-96231b3b80d8
explicitly split into stride-and-offset pairs. Also, add the
ability to track multiple post-increment loops on the same expression.
This refines the concept of "normalizing" SCEV expressions used for
to post-increment uses, and introduces a dedicated utility routine for
normalizing and denormalizing expressions.
This fixes the expansion of expressions which are post-increment users
of more than one loop at a time. More broadly, this takes LSR another
step closer to being able to reason about more than one loop at a time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100699 91177308-0d34-0410-b5e6-96231b3b80d8
undefs in branches/switches, we have two cases: a branch on a literal
undef or a branch on a symbolic value which is undef. If we have a
literal undef, the code was correct: forcing it to a constant is the
right thing to do.
If we have a branch on a symbolic value that is undef, we should force
the symbolic value to a constant, which then makes the successor block
live. Forcing the condition of the branch to being a constant isn't
safe if later paths become live and the value becomes overdefined. This
is the case that 'forcedconstant' is designed to handle, so just use it.
This fixes rdar://7765019 but there is no good testcase for this, the
one I have is too insane to be useful in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100478 91177308-0d34-0410-b5e6-96231b3b80d8
Added support for address spaces and added a isVolatile field to memcpy, memmove, and memset,
e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100304 91177308-0d34-0410-b5e6-96231b3b80d8
exits the loop. With this information we can guarantee
the iteration count of the loop is bounded by the
compare. I think this xforms is finally safe now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100285 91177308-0d34-0410-b5e6-96231b3b80d8