long test(long x) { return (x & 123124) | 3; }
Currently compiles to:
_test:
orl $3, %edi
movq %rdi, %rax
andq $123127, %rax
ret
This is because instruction and DAG combiners canonicalize
(or (and x, C), D) -> (and (or, D), (C | D))
However, this is only profitable if (C & D) != 0. It gets in the way of the
3-addressification because the input bits are known to be zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97616 91177308-0d34-0410-b5e6-96231b3b80d8
and T->isPointerTy(). Convert most instances of the first form to the second form.
Requested by Chris.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96344 91177308-0d34-0410-b5e6-96231b3b80d8
odd offsets since the bitcasted pointer size and the offset pointer
size are going to be different types for the GEP vs base object.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96134 91177308-0d34-0410-b5e6-96231b3b80d8
what it does. Enhance it to return false to optimizing vector
sign extensions from vector comparisions, which is the idiom used
to get a splatted vector for a vector comparison.
Doing this breaks vector-casts.ll, add some compensating
transformations to handle the important case they cover without
depending on this canonicalization.
This fixes rdar://7434900 a serious pessimization of vector compares.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95855 91177308-0d34-0410-b5e6-96231b3b80d8
xform it is checking to actually pass. There is no need to match
m_SelectCst<0, -1> since instcombine canonicalizes that into not(sext).
Add matches for sext(not(x)) in addition to not(sext(x)).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95420 91177308-0d34-0410-b5e6-96231b3b80d8
Fix bugs where we would compute out of bounds as in bounds, and where
we couldn't know that the linker could override the size of an array.
Add a few new testcases, change existing testcase to use a private
global array instead of extern.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95283 91177308-0d34-0410-b5e6-96231b3b80d8
of objc message send was getting marked arm_apcscc, but the prototype
isn't. This is fine at runtime because objcmsgsend is implemented in
assembly. Only turn a mismatched caller and callee into 'unreachable'
if the callee is a definition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94986 91177308-0d34-0410-b5e6-96231b3b80d8
case, instcombine can't zap the invoke for fear of changing the CFG.
However, we have to do something to prevent the next iteration of
instcombine from inserting another store -> undef before the invoke
thereby getting into infinite iteration between dead store elim and
store insertion.
Just zap the callee to null, which will prevent the next iteration
from doing anything.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94985 91177308-0d34-0410-b5e6-96231b3b80d8
unconditionally. Besides checking the offset, also check that the underlying
object is aligned as much as the load itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94875 91177308-0d34-0410-b5e6-96231b3b80d8
create a testcase where this matters. The select+load transformation only
occurs when isSafeToLoadUnconditionally is true, and in those situations,
instcombine also changes the underlying objects to be aligned. This seems
like a good idea regardless, and I've verified that it doesn't pessimize
the subsequent realignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94850 91177308-0d34-0410-b5e6-96231b3b80d8
(via APInt &RHSKnownZero = KnownZero, etc) seems dangerous and confusing to me: it
is easy not to notice this, and then wonder why KnownZero/RHSKnownZero changed
underneath you when you modified RHSKnownZero/KnownZero etc. So get rid of this.
No intended functionality change (tested with "make check" + llvm-gcc bootstrap).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94802 91177308-0d34-0410-b5e6-96231b3b80d8
when it should have been and'd with LowBits. Fix that and while there beef
up the logic in the case of a negative LHS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94745 91177308-0d34-0410-b5e6-96231b3b80d8
"sext cond" instead of a select. This simplifies some instcombine
code, matches the policy for zext (cond ? 1 : 0 -> zext), and allows
us to generate better code for a testcase on ppc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94339 91177308-0d34-0410-b5e6-96231b3b80d8
missing ones are libsupport, libsystem and libvmcore. libvmcore is
currently blocked on bugpoint, which uses EH. Once it stops using
EH, we can switch it off.
This #if 0's out 3 unit tests, because gtest requires RTTI information.
Suggestions welcome on how to fix this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94164 91177308-0d34-0410-b5e6-96231b3b80d8
