- Rewrite/merge pseudo-atomic instruction emitters to address the
following issue:
* Reduce one unnecessary load in spin-loop
previously the spin-loop looks like
thisMBB:
newMBB:
ld t1 = [bitinstr.addr]
op t2 = t1, [bitinstr.val]
not t3 = t2 (if Invert)
mov EAX = t1
lcs dest = [bitinstr.addr], t3 [EAX is implicit]
bz newMBB
fallthrough -->nextMBB
the 'ld' at the beginning of newMBB should be lift out of the loop
as lcs (or CMPXCHG on x86) will load the current memory value into
EAX. This loop is refined as:
thisMBB:
EAX = LOAD [MI.addr]
mainMBB:
t1 = OP [MI.val], EAX
LCMPXCHG [MI.addr], t1, [EAX is implicitly used & defined]
JNE mainMBB
sinkMBB:
* Remove immopc as, so far, all pseudo-atomic instructions has
all-register form only, there is no immedidate operand.
* Remove unnecessary attributes/modifiers in pseudo-atomic instruction
td
* Fix issues in PR13458
- Add comprehensive tests on atomic ops on various data types.
NOTE: Some of them are turned off due to missing functionality.
- Revise tests due to the new spin-loop generated.
llvm-svn: 164281
We perform the following:
1> Use SUB instead of CMP for i8,i16,i32 and i64 in ISel lowering.
2> Modify MachineCSE to correctly handle implicit defs.
3> Convert SUB back to CMP if possible at peephole.
Removed pattern matching of (a>b) ? (a-b):0 and like, since they are handled
by peephole now.
rdar://11873276
llvm-svn: 161462
We can't rematerialize a PIC base after register allocation anyway, and
scanning physreg use-def chains is very expensive in a function with
many calls.
<rdar://problem/12047515>
llvm-svn: 161461
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
llvm-svn: 161152
Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.
rdar://10554090 and rdar://11873276
llvm-svn: 160919
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.
llvm-svn: 160912
Updated OptimizeCompare in peephole to remove redundant cmp against zero.
We only remove Compare if CF and OF are not used.
rdar://11855129
llvm-svn: 160454
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>
llvm-svn: 160260
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>
llvm-svn: 160230
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.
llvm-svn: 159955
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.
llvm-svn: 159888
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.
llvm-svn: 159838
Implement the TII hooks needed by EarlyIfConversion to create cmov
instructions and estimate their latency.
Early if-conversion is still not enabled by default.
llvm-svn: 159695
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.
llvm-svn: 158122
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.
llvm-svn: 158090
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.
llvm-svn: 157831
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.
llvm-svn: 157818
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
llvm-svn: 157755
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.
llvm-svn: 157737
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!
llvm-svn: 156328
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.
llvm-svn: 146542
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.
llvm-svn: 146026
Like V_SET0, these instructions are expanded by ExpandPostRA to xorps /
vxorps so they can participate in execution domain swizzling.
This also makes the AVX variants redundant.
llvm-svn: 145440
This was a bug in keeping track of the available domains when merging
domain values.
The wrong domain mask caused ExecutionDepsFix to try to move VANDPSYrr
to the integer domain which is only available in AVX2.
Also add an assertion to catch future attempts at emitting AVX2
instructions.
llvm-svn: 145096
Two new TargetInstrInfo hooks lets the target tell ExecutionDepsFix
about instructions with partial register updates causing false unwanted
dependencies.
The ExecutionDepsFix pass will break the false dependencies if the
updated register was written in the previoius N instructions.
The small loop added to sse-domains.ll runs twice as fast with
dependency-breaking instructions inserted.
llvm-svn: 144602
The xorps instruction is smaller than pxor, so prefer that encoding.
The ExecutionDepsFix pass will switch the encoding to pxor and xorpd
when appropriate.
llvm-svn: 143996
In 64-bit mode, sub_8bit_hi sub-registers can only be used by NOREX
instructions. The COPY created from the EXTRACT_SUBREG DAG node cannot
target all GR8 registers, only those in GR8_NOREX.
TO enforce this, we ensure that all instructions using the
EXTRACT_SUBREG are GR8_NOREX constrained.
This fixes PR11088.
llvm-svn: 141499
This instruction is explicitly encoded without an REX prefix, so both
operands but be *_NOREX.
Also add an assertion to copyPhysReg() that fires when the MOV8rr_NOREX
constraints are not satisfied.
This fixes a miscompilation in 20040709-2 in the gcc test suite.
llvm-svn: 141410
I am going to unify the SSEDomainFix and NEONMoveFix passes into a
single target independent pass. They are essentially doing the same
thing.
llvm-svn: 140652
We already support GR64 <-> VR128 copies. All of these copies break
partial register dependencies by zeroing the high part of the target
register.
llvm-svn: 140348
alignment check for 256-bit classes more strict. There're no testcases
but we catch more folding cases for AVX while running single and multi
sources in the llvm testsuite.
Since some 128-bit AVX instructions have different number of operands
than their SSE counterparts, they are placed in different tables.
256-bit AVX instructions should also be added in the table soon. And
there a few more 128-bit versions to handled, which should come in
the following commits.
llvm-svn: 139687
single field (Flags), which is a bitwise OR of items from the TB_*
enum. This makes it easier to add new information in the future.
* Gives every static array an equivalent layout: { RegOp, MemOp, Flags }
* Adds a helper function, AddTableEntry, to avoid duplication of the
insertion code.
* Renames TB_NOT_REVERSABLE to TB_NO_REVERSE.
* Adds TB_NO_FORWARD, which is analogous to TB_NO_REVERSE, except that
it prevents addition of the Reg->Mem entry. (This is going to be used
by Native Client, in the next CL).
Patch by David Meyer
llvm-svn: 139311
sink them into MC layer.
- Added MCInstrInfo, which captures the tablegen generated static data. Chang
TargetInstrInfo so it's based off MCInstrInfo.
llvm-svn: 134021
we try to branch to them.
Before we were creating successor lists with duplicated entries. Fixing that
found a bug in isBlockOnlyReachableByFallthrough that would causes it to
return the wrong answer for
-----------
...
jne foo
jmp bar
foo:
----------
llvm-svn: 132882
Add TargetRegisterInfo::hasSubClassEq and use it to check for compatible
register classes instead of trying to list all register classes in
X86's getLoadStoreRegOpcode.
llvm-svn: 132398
after folding ADD32ri to ADD32mi, so don't do that.
This only happens when the greedy register allocator gets itself in trouble and
spills %vreg9 here:
16L %vreg9<def> = MOVPC32r 0, %ESP<imp-use>; GR32:%vreg9
48L %vreg9<def> = ADD32ri %vreg9, <es:_GLOBAL_OFFSET_TABLE_>[TF=1], %EFLAGS<imp-def,dead>; GR32:%vreg9
That should never happen, the live range should be split instead.
llvm-svn: 130625
Now that we have a first-class way to represent unaligned loads, the unaligned
load intrinsics are superfluous.
First part of <rdar://problem/8460511>.
llvm-svn: 129401
regs. This is the only change in this checkin that may affects the
default scheduler. With better register tracking and heuristics, it
doesn't make sense to artificially lower the register limit so much.
Added -sched-high-latency-cycles and X86InstrInfo::isHighLatencyDef to
give the scheduler a way to account for div and sqrt on targets that
don't have an itinerary. It is currently defaults to 10 (the actual
number doesn't matter much), but only takes effect on non-default
schedulers: list-hybrid and list-ilp.
Added several heuristics that can be individually disabled for the
non-default sched=list-ilp mode. This helps us determine how much
better we can do on a given benchmark than the default
scheduler. Certain compute intensive loops run much faster in this
mode with the right set of heuristics, and it doesn't seem to have
much negative impact elsewhere. Not all of the heuristics are needed,
but we still need to experiment to decide which should be disabled by
default for sched=list-ilp.
llvm-svn: 127067
"long latency" enough to hoist even if it may increase spilling. Reloading
a value from spill slot is often cheaper than performing an expensive
computation in the loop. For X86, that means machine LICM will hoist
SQRT, DIV, etc. ARM will be somewhat aggressive with VFP and NEON
instructions.
- Enable register pressure aware machine LICM by default.
llvm-svn: 116781
The reg-reg copies were no longer being generated since copyPhysReg copies
physical registers only.
The loads and stores are not necessary - The TC constraint is imposed by the
TAILJMP and TCRETURN instructions, there should be no need for constrained loads
and stores.
llvm-svn: 116314
reapply: reimplement the second half of the or/add optimization. We should now
with no changes. Turns out that one missing "Defs = [EFLAGS]" can upset things
a bit.
llvm-svn: 116040
only end up emitting LEA instead of OR. If we aren't able to promote
something into an LEA, we should never be emitting it as an ADD.
Add some testcases that we emit "or" in cases where we used to produce
an "add".
llvm-svn: 116026
is general goodness because it allows ORs to be converted to LEA to avoid
inserting copies. However, this is bad because it makes the generated .s
file less obvious and gives valgrind heartburn (tons of false positives in
bitfield code).
While the general fix should be in valgrind, we can at least try to avoid
emitting ADD instructions that *don't* get promoted to LEA. This is more
work because it requires introducing pseudo instructions to represents
"add that knows the bits are disjoint", but hey, people really love valgrind.
This fixes this testcase:
https://bugs.kde.org/show_bug.cgi?id=242137#c20
the add r/i cases are coming next.
llvm-svn: 116007
operands.
With this done, we can remove the _Int suffixes from the round instructions
without the disassembler blowing up. This allows the assembler to support
them, implementing rdar://8456376 - llvm-mc rejects 'roundss'
llvm-svn: 115019
Michael Liao