This patch will optimize the following cases:
sub r1, r3 | sub r1, imm
cmp r3, r1 or cmp r1, r3 | cmp r1, imm
bge L1
TO
subs r1, r3
bge L1 or ble L1
If the branch instruction can use flag from "sub", then we can replace
"sub" with "subs" and eliminate the "cmp" instruction.
rdar: 10734411
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156599 91177308-0d34-0410-b5e6-96231b3b80d8
This patch will optimize the following cases:
sub r1, r3 | sub r1, imm
cmp r3, r1 or cmp r1, r3 | cmp r1, imm
bge L1
TO
subs r1, r3
bge L1 or ble L1
If the branch instruction can use flag from "sub", then we can replace
"sub" with "subs" and eliminate the "cmp" instruction.
rdar: 10734411
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156550 91177308-0d34-0410-b5e6-96231b3b80d8
A MOVCCr instruction can be commuted by inverting the condition. This
can help reduce register pressure and remove unnecessary copies in some
cases.
<rdar://problem/11182914>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154033 91177308-0d34-0410-b5e6-96231b3b80d8
ARM recently gained DPair, DTriple, and DQuad register classes.
Update copyPhysReg() to handle copies in these register classes.
No test case, it is difficult to make the register allocator emit the
odd copies reliably. The missing DPair copy caused a failure on
partialsums in the nightly test suite.
<rdar://problem/11147997>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153686 91177308-0d34-0410-b5e6-96231b3b80d8
The arm_neon intrinsics can create virtual registers from the DPair
register class which allows both even-odd and odd-even D-register pairs.
This fixes PR12389.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153603 91177308-0d34-0410-b5e6-96231b3b80d8
produces a 32-bit immediate which is consumed by the use. It tries to
fold the immediate by breaking it into two parts and fold them into the
immmediate fields of two uses. e.g
movw r2, #40885
movt r3, #46540
add r0, r0, r3
=>
add.w r0, r0, #3019898880
add.w r0, r0, #30146560
;
However, this transformation is incorrect if the user produces a flag. e.g.
movw r2, #40885
movt r3, #46540
adds r0, r0, r3
=>
add.w r0, r0, #3019898880
adds.w r0, r0, #30146560
Note the adds.w may not set the carry flag even if the original sequence
would.
rdar://11116189
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153484 91177308-0d34-0410-b5e6-96231b3b80d8
When an instruction only writes sub-registers, it is still necessary to
add an <imp-def> operand for the super-register. When reloading into a
virtual register, rewriting will add the operand, but when loading
directly into a virtual register, the <imp-def> operand is still
necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152095 91177308-0d34-0410-b5e6-96231b3b80d8
With the new composite physical registers to represent arbitrary pairs
of DPR registers, we don't need the pseudo-registers anymore. Get rid of
a bunch of them that use DPR register pairs and just use the real
instructions directly instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152045 91177308-0d34-0410-b5e6-96231b3b80d8
MachineOperands that define part of a virtual register must have an
<undef> flag if they are not intended as read-modify-write operands.
The old trick of adding an <imp-def> operand doesn't work any longer.
Fixes PR12177.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152008 91177308-0d34-0410-b5e6-96231b3b80d8
Without this hook, functions w/ a completely empty body (including no
epilogue) will cause an MCEmitter assertion failure.
For example,
define internal fastcc void @empty_function() {
unreachable
}
rdar://10947471
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151673 91177308-0d34-0410-b5e6-96231b3b80d8
Even if a call instruction has %SP<imp-def> operands, it doesn't change
the value of the stack pointer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151104 91177308-0d34-0410-b5e6-96231b3b80d8
Now that canRealignStack() understands frozen reserved registers, it is
safe to use it for aligned spill instructions.
It will only return true if the registers reserved at the beginning of
register allocation allow for dynamic stack realignment.
<rdar://problem/10625436>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147579 91177308-0d34-0410-b5e6-96231b3b80d8
This patch caused a miscompilation of oggenc because a frame pointer was
suddenly needed halfway through register allocation.
<rdar://problem/10625436>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147487 91177308-0d34-0410-b5e6-96231b3b80d8
Use the spill slot alignment as well as the local variable alignment to
determine when the stack needs to be realigned. This works now that the
ARM target can always realign the stack by using a base pointer.
Still respect the ARMBaseRegisterInfo::canRealignStack() function
vetoing a realigned stack. Don't use aligned spill code in that case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146997 91177308-0d34-0410-b5e6-96231b3b80d8
r0 = mov #0
r0 = moveq #1
Then the second instruction has an implicit data dependency on the first
instruction. Sadly I have yet to come up with a small test case that
demonstrate the post-ra scheduler taking advantage of this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146583 91177308-0d34-0410-b5e6-96231b3b80d8
to finalize MI bundles (i.e. add BUNDLE instruction and computing register def
and use lists of the BUNDLE instruction) and a pass to unpack bundles.
- Teach more of MachineBasic and MachineInstr methods to be bundle aware.
- Switch Thumb2 IT block to MI bundles and delete the hazard recognizer hack to
prevent IT blocks from being broken apart.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146542 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor the instructions into fixed writeback and register-stride
writeback variants to simplify the offset operand (no more optional
register operand using reg0). This is a simpler representation and allows
the assembly parser to more easily handle these instructions.
Add tests for the instruction variants now supported.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146278 91177308-0d34-0410-b5e6-96231b3b80d8
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.
For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146026 91177308-0d34-0410-b5e6-96231b3b80d8
1. Added opcode BUNDLE
2. Taught MachineInstr class to deal with bundled MIs
3. Changed MachineBasicBlock iterator to skip over bundled MIs; added an iterator to walk all the MIs
4. Taught MachineBasicBlock methods about bundled MIs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145975 91177308-0d34-0410-b5e6-96231b3b80d8
This pseudo-instruction contains a .align directive in its expansion, so
the total size may vary by 2 bytes.
It is too difficult to accurately keep track of this alignment
directive, just use the worst-case size instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145971 91177308-0d34-0410-b5e6-96231b3b80d8
This will widen 32-bit register vmov instructions to 64-bit when
possible. The 64-bit vmovd instructions can then be translated to NEON
vorr instructions by the execution dependency fix pass.
The copies are only widened if they are marked as clobbering the whole
D-register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144734 91177308-0d34-0410-b5e6-96231b3b80d8
Split am6offset into fixed and register offset variants so the instruction
encodings are explicit rather than relying an a magic reg0 marker.
Needed to being able to parse these.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142853 91177308-0d34-0410-b5e6-96231b3b80d8
Clean up the patterns, fix comments, and avoid confusing both tools
and coders. Note that the special adds/subs SelectionDAG nodes no
longer have the dummy cc_out operand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142397 91177308-0d34-0410-b5e6-96231b3b80d8
When widening a copy, we are reading a larger register that may not be
live. Use an <undef> flag to tell the register scavenger and machine
code verifier that we know the value isn't defined.
We now widen:
%S6<def> = COPY %S4<kill>, %D3<imp-def>
into:
%D3<def> = VMOVD %D2<undef>, pred:14, pred:%noreg, %S4<imp-use,kill>
This also keeps the <kill> flag on %S4 so we don't inadvertently kill a
live value in %S5.
Finally, ensure that ARMBaseInstrInfo::setExecutionDomain() preserves
the <undef> flag when converting VMOVD to VORR.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141746 91177308-0d34-0410-b5e6-96231b3b80d8
The VMOVS widening needs to look at the implicit COPY operands. Trying
to dig out the COPY instruction from an iterator in copyPhysReg() is the
wrong approach.
The expandPostRAPseudo() hook gets to look at COPY instructions before
they are converted to copyPhysReg() calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141619 91177308-0d34-0410-b5e6-96231b3b80d8
