Marking implicit CC defs as dead everywhere except when CC is actually
defined and used explicitly, is important since the post-ra scheduler
will otherwise insert edges between instructions unnecessarily.
Also temporarily disable LA(Y)-> AGSI optimization in
foldMemoryOperandImpl(), since this inroduces a def of the CC reg,
which is illegal unless it is known to be dead.
Reviewed by Ulrich Weigand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268215 91177308-0d34-0410-b5e6-96231b3b80d8
This adds a conditional variant of CallBR instruction, CallBCR. Also,
it can be fused with integer comparisons, resulting in one of the new
C*BCall instructions.
In addition to CallBRCL limitations, this has another one: it won't
trigger if the function to call isn't already in %r1 - see f22 in the
test for an example (it's also why the loads in tests are volatile).
Author: koriakin
Differential Revision: http://reviews.llvm.org/D18928
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265933 91177308-0d34-0410-b5e6-96231b3b80d8
Return is now considered a predicable instruction, and is converted
to a newly-added CondReturn (which maps to BCR to %r14) instruction by
the if conversion pass.
Also, fused compare-and-branch transform knows about conditional
returns, emitting the proper fused instructions for them.
This transform triggers on a *lot* of tests, hence the huge diffstat.
The changes are mostly jX to br %r14 -> bXr %r14.
Author: koriakin
Differential Revision: http://reviews.llvm.org/D17339
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265689 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This adds the same checks that were added in r264593 to all
target-specific passes that run after register allocation.
Reviewers: qcolombet
Subscribers: jyknight, dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D18525
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265313 91177308-0d34-0410-b5e6-96231b3b80d8
expandPostRAPseudo():
STX -> 2 * STD: The first STD should not have the kill flag set for the address.
SystemZElimCompare:
BRC -> BRCT conversion: Don't forget to remove the CC<use,kill> operand.
Needed to make SystemZ/asm-17.ll pass with -verify-machineinstrs, which
now runs with this flag.
Reviewed by Ulrich Weigand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249945 91177308-0d34-0410-b5e6-96231b3b80d8
Compare elimination extended to recognize load-and-test instructions used
for comparison and eliminate them the same way as with compare instructions.
Test case fp-cmp-05.ll updated to expect optimized results now also for z13.
The order of instruction shortening and compare elimination passes have been
changed so that opcodes do not have to be handled in both passes.
Reviewed by Ulrich Weigand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249666 91177308-0d34-0410-b5e6-96231b3b80d8
shorter/easier and have the DAG use that to do the same lookup. This
can be used in the future for TargetMachine based caching lookups from
the MachineFunction easily.
Update the MIPS subtarget switching machinery to update this pointer
at the same time it runs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214838 91177308-0d34-0410-b5e6-96231b3b80d8
Just the simple cases for now. There were a few knock-on changes of
MachineBasicBlock *s to MachineBasicBlock &s. No functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203105 91177308-0d34-0410-b5e6-96231b3b80d8
This follows the same lines as the integer code. In the end it seemed
easier to have a second 4-bit mask in TSFlags to specify the compare-like
CC values. That eats one more TSFlags bit than adding a CCHasUnordered
would have done, but it feels more concise.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187883 91177308-0d34-0410-b5e6-96231b3b80d8
This patch just uses a peephole test for "add; compare; branch" sequences
within a single block. The IR optimizers already convert loops to
decrement-and-branch-on-nonzero form in some cases, so even this
simplistic test triggers many times during a clang bootstrap and
projects/test-suite run. It looks like there are still cases where we
need to more strongly prefer branches on nonzero though. E.g. I saw a
case where a loop that started out with a check for 0 ended up with a
check for -1. I'll try to look at that sometime.
I ended up adding the Reference class because MachineInstr::readsRegister()
doesn't check for subregisters (by design, as far as I could tell).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187723 91177308-0d34-0410-b5e6-96231b3b80d8
Perhaps predictably, doing comparison elimination on the fly during
SystemZLongBranch turned out to be a bad idea. The next patches make
use of LOAD AND TEST and BRANCH ON COUNT, both of which require
changes to earlier instructions.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187718 91177308-0d34-0410-b5e6-96231b3b80d8
