Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.
This patch is a rework of r160919 and was tested on clang self-host on my local
machine.
rdar://10554090 and rdar://11873276
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161152 91177308-0d34-0410-b5e6-96231b3b80d8
Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.
rdar://10554090 and rdar://11873276
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160919 91177308-0d34-0410-b5e6-96231b3b80d8
It is possible that an instruction can use and update EFLAGS.
When checking the safety, we should check the usage of EFLAGS first before
declaring it is safe to optimize due to the update.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160912 91177308-0d34-0410-b5e6-96231b3b80d8
Updated OptimizeCompare in peephole to remove redundant cmp against zero.
We only remove Compare if CF and OF are not used.
rdar://11855129
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160454 91177308-0d34-0410-b5e6-96231b3b80d8
undef virtual register. The problem is that ProcessImplicitDefs removes the
definition of the register and marks all uses as undef. If we lose the undef
marker then we get a register which has no def, is not marked as undef. The
live interval analysis does not collect information for these virtual
registers and we crash in later passes.
Together with Michael Kuperstein <michael.m.kuperstein@intel.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160260 91177308-0d34-0410-b5e6-96231b3b80d8
Allow the folding of vbroadcastRR to vbroadcastRM, where the memory operand is a spill slot.
PR12782.
Together with Michael Kuperstein <michael.m.kuperstein@intel.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160230 91177308-0d34-0410-b5e6-96231b3b80d8
getCondFromSETOpc, getCondFromCMovOpc, getSETFromCond, getCMovFromCond
No functional change intended.
If we want to update the condition code of CMOV|SET|Jcc, we first analyze the
opcode to get the condition code, then update the condition code, finally
synthesize the new opcode form the new condition code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159955 91177308-0d34-0410-b5e6-96231b3b80d8
It is safe if EFLAGS is killed or re-defined.
When we are done with the basic block, check whether EFLAGS is live-out.
Do not optimize away cmp if EFLAGS is live-out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159888 91177308-0d34-0410-b5e6-96231b3b80d8
For each Cmp, we check whether there is an earlier Sub which make Cmp
redundant. We handle the case where SUB operates on the same source operands as
Cmp, including the case where the two source operands are swapped.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159838 91177308-0d34-0410-b5e6-96231b3b80d8
Implement the TII hooks needed by EarlyIfConversion to create cmov
instructions and estimate their latency.
Early if-conversion is still not enabled by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159695 91177308-0d34-0410-b5e6-96231b3b80d8
The commit is intended to fix rdar://11540023.
It is implemented as part of peephole optimization. We can actually implement
this in the SelectionDAG lowering phase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158122 91177308-0d34-0410-b5e6-96231b3b80d8
There are some that I didn't remove this round because they looked like
obvious stubs. There are dead variables in gtest too, they should be
fixed upstream.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158090 91177308-0d34-0410-b5e6-96231b3b80d8
This patch will optimize the following:
sub r1, r3
cmp r3, r1 or cmp r1, r3
bge L1
TO
sub r1, r3
bge L1 or ble L1
If the branch instruction can use flag from "sub", then we can eliminate
the "cmp" instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157831 91177308-0d34-0410-b5e6-96231b3b80d8
This implements codegen support for accesses to thread-local variables
using the local-dynamic model, and adds a clean-up pass so that the base
address for the TLS block can be re-used between local-dynamic access on
an execution path.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157818 91177308-0d34-0410-b5e6-96231b3b80d8
This patch will optimize the following
movq %rdi, %rax
subq %rsi, %rax
cmovsq %rsi, %rdi
movq %rdi, %rax
to
cmpq %rsi, %rdi
cmovsq %rsi, %rdi
movq %rdi, %rax
Perform this optimization if the actual result of SUB is not used.
rdar: 11540023
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157755 91177308-0d34-0410-b5e6-96231b3b80d8
I disabled FMA3 autodetection, since the result may differ from expected for some benchmarks.
I added tests for GodeGen and intrinsics.
I did not change llvm.fma.f32/64 - it may be done later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157737 91177308-0d34-0410-b5e6-96231b3b80d8
The getPointerRegClass() hook can return register classes that depend on
the calling convention of the current function (ptr_rc_tailcall).
So far, we have been able to infer the calling convention from the
subtarget alone, but as we add support for multiple calling conventions
per target, that no longer works.
Patch by Yiannis Tsiouris!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156328 91177308-0d34-0410-b5e6-96231b3b80d8
The different calling conventions and call-preserved registers are
represented with regmask operands that are added dynamically.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150708 91177308-0d34-0410-b5e6-96231b3b80d8
