explanation from IRC:
|sabre| I think it's an order of evaluation thing
|sabre| for me, the RHS of the assignment is evaluated first
|sabre| getTypeDescription checks to see if ConcreteTypeDescription[Ty] contains anything
|sabre| since it doesn't, it computes and returns the value
|sabre| this gets put into the map.
|sabre| For you, the LHS is evaluated first.
|sabre| Map[Ty] (aka ConcreteTypeDescriptions[Ty]) inserts an empty string into the map, returning a reference
|sabre| getTypeDesc then sees the empty string in the map
|sabre| and returns it
|sabre| bork :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20394 91177308-0d34-0410-b5e6-96231b3b80d8
* Loop invariant code does not dominate the loop header, but rather
the end of the loop preheader.
* The base for a reduced GEP isn't a constant unless all of its
operands (preceding the induction variable) are constant.
* Allow induction variable elimination for the simple case after all.
Also made changes recommended by Chris for properly deleting
instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20383 91177308-0d34-0410-b5e6-96231b3b80d8
If we fold three constants together (c1+c2+c3), make sure to keep
LHSC updated, instead of reusing (in this case), the 1 instead of the
partial sum.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20337 91177308-0d34-0410-b5e6-96231b3b80d8
Actually teach dsa about select instructions. This doesn't affect the
graph in any way other than not setting a spurious U marker on pointer
nodes that are selected.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20324 91177308-0d34-0410-b5e6-96231b3b80d8
X = gep null, ...
Used to not create a scalar map entry for X, which caused clients to barf.
This is bad.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20316 91177308-0d34-0410-b5e6-96231b3b80d8
This does a simple form of "jump threading", which eliminates CFG edges that
are provably dead. This triggers 90 times in the external tests, and
eliminating CFG edges is always always a good thing! :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20300 91177308-0d34-0410-b5e6-96231b3b80d8
Changing 'op' here caused us to not enter the store into a map, causing
reemission of the code!! In practice, a simple loop like this:
no_exit: ; preds = %no_exit, %entry
%indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ] ; <uint> [#uses=3]
%tmp.4 = getelementptr "complex long double"* %P, uint %indvar, uint 0 ; <double*> [#uses=1]
store double 0.000000e+00, double* %tmp.4
%indvar.next = add uint %indvar, 1 ; <uint> [#uses=2]
%exitcond = seteq uint %indvar.next, %N ; <bool> [#uses=1]
br bool %exitcond, label %return, label %no_exit
was being code gen'd to:
.LBBtest_1: # no_exit
movl %edx, %esi
shll $4, %esi
movl $0, 4(%eax,%esi)
movl $0, (%eax,%esi)
incl %edx
movl $0, (%eax,%esi)
movl $0, 4(%eax,%esi)
cmpl %ecx, %edx
jne .LBBtest_1 # no_exit
Note that we are doing 4 32-bit stores instead of 2. Now we generate:
.LBBtest_1: # no_exit
movl %edx, %esi
incl %esi
shll $4, %edx
movl $0, (%eax,%edx)
movl $0, 4(%eax,%edx)
cmpl %ecx, %esi
movl %esi, %edx
jne .LBBtest_1 # no_exit
This is much happier, though it would be even better if the increment of ESI
was scheduled after the compare :-/
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20265 91177308-0d34-0410-b5e6-96231b3b80d8
