mov lr, pc
b.w _foo
The "mov" instruction doesn't set bit zero to one, it's putting incorrect
value in lr. It messes up backtraces.
rdar://12663632
llvm-svn: 167657
registers. Previously, the register we being marked as implicitly defined, but
not killed. In some cases this would cause the register scavenger to spill a
dead register.
Also, use an empty register mask to simplify the logic and to reduce the memory
footprint.
rdar://12592448
llvm-svn: 167499
Removed extra stack frame object for fixed byval arguments,
VarArgsStyleRegisters invocation was reworked due to some improper usage in
past. PR14099 also demonstrates it.
llvm-svn: 166273
Stack is formed improperly for long structures passed as byval arguments for
EABI mode.
If we took AAPCS reference, we can found the next statements:
A: "If the argument requires double-word alignment (8-byte), the NCRN (Next
Core Register Number) is rounded up to the next even register number." (5.5
Parameter Passing, Stage C, C.3).
B: "The alignment of an aggregate shall be the alignment of its most-aligned
component." (4.3 Composite Types, 4.3.1 Aggregates).
So if we have structure with doubles (9 double fields) and 3 Core unused
registers (r1, r2, r3): caller should use r2 and r3 registers only.
Currently r1,r2,r3 set is used, but it is invalid.
Callee VA routine should also use r2 and r3 regs only. All is ok here. This
behaviour is guessed by rounding up SP address with ADD+BFC operations.
Fix:
Main fix is in ARMTargetLowering::HandleByVal. If we detected AAPCS mode and
8 byte alignment, we waste odd registers then.
P.S.:
I also improved LDRB_POST_IMM regression test. Since ldrb instruction will
not generated by current regression test after this patch.
llvm-svn: 166018
local frame causes problem.
For example:
void f(StructToPass s) {
g(&s, sizeof(s));
}
will cause problem with tail-call since part of s is passed via registers and
saved in f's local frame. When g tries to access s, part of s may be corrupted
since f's local frame is popped out before the tail-call.
The current fix is to disable tail-call if getVarArgsRegSaveSize is not 0 for
the caller. This is a conservative approach, if we can prove the address of
s or part of s is not taken and passed to g, it should be okay to perform
tail-call.
rdar://12442472
llvm-svn: 165853
The backend already pattern matches to form VBSL when it can. We may want to
teach it to use the vbsl intrinsics at some point to prevent machine licm from
mucking with this, but using the Expand is completely correct.
http://llvm.org/bugs/show_bug.cgi?id=13831http://llvm.org/bugs/show_bug.cgi?id=13961
Patch by Peter Couperus <peter.couperus@st.com>.
llvm-svn: 165845
SDNode for LDRB_POST_IMM is invalid: number of registers added to SDNode fewer
that described in .td.
7 ops is needed, but SDNode with only 6 is created.
In more details:
In ARMInstrInfo.td, in multiclass AI2_ldridx, in definition _POST_IMM, offset
operand is defined as am2offset_imm. am2offset_imm is complex parameter type,
and actually it consists from dummy register and imm itself. As I understood
trick with dummy reg was made for AsmParser. In ARMISelLowering.cpp, this dummy
register was not added to SDNode, and it cause crash in Peephole Optimizer pass.
The problem fixed by setting up additional dummy reg when emitting
LDRB_POST_IMM instruction.
llvm-svn: 165617
SchedulerDAGInstrs::buildSchedGraph ignores dependencies between FixedStack
objects and byval parameters. So loading byval parameters from stack may be
inserted *before* it will be stored, since these operations are treated as
independent.
Fix:
Currently ARMTargetLowering::LowerFormalArguments saves byval registers with
FixedStack MachinePointerInfo. To fix the problem we need to store byval
registers with MachinePointerInfo referenced to first the "byval" parameter.
Also commit adds two new fields to the InputArg structure: Function's argument
index and InputArg's part offset in bytes relative to the start position of
Function's argument. E.g.: If function's argument is 128 bit width and it was
splitted onto 32 bit regs, then we got 4 InputArg structs with same arg index,
but different offset values.
llvm-svn: 165616
We use the enums to query whether an Attributes object has that attribute. The
opaque layer is responsible for knowing where that specific attribute is stored.
llvm-svn: 165488
aligned address. Based on patch by David Peixotto.
Also use vld1.64 / vst1.64 with 128-bit alignment to take advantage of alignment
hints. rdar://12090772, rdar://12238782
llvm-svn: 164089
If we have a BUILD_VECTOR that is mostly a constant splat, it is often better to splat that constant then insertelement the non-constant lanes instead of insertelementing every lane from an undef base.
llvm-svn: 163304
This patch corrects the definition of umlal/smlal instructions and adds support
for matching them to the ARM dag combiner.
Bug 12213
Patch by Yin Ma!
llvm-svn: 163136
Add these transformations to the existing add/sub ones:
(and (select cc, -1, c), x) -> (select cc, x, (and, x, c))
(or (select cc, 0, c), x) -> (select cc, x, (or, x, c))
(xor (select cc, 0, c), x) -> (select cc, x, (xor, x, c))
The selects can then be transformed to a single predicated instruction
by peephole.
This transformation will make it possible to eliminate the ISD::CAND,
COR, and CXOR custom DAG nodes.
llvm-svn: 162176
The ARM select instructions are just predicated moves. If the select is
the only use of an operand, the instruction defining the operand can be
predicated instead, saving one instruction and decreasing register
pressure.
This implementation can turn AND/ORR/EOR instructions into their
corresponding ANDCC/ORRCC/EORCC variants. Ideally, we should be able to
predicate any instruction, but we don't yet support predicated
instructions in SSA form.
llvm-svn: 161994
This patch corrects the definition of umlal/smlal instructions and adds support
for matching them to the ARM dag combiner.
Bug 12213
Patch by Yin Ma!
llvm-svn: 161581
Fast isel doesn't currently have support for translating builtin function
calls to target instructions. For embedded environments where the library
functions are not available, this is a matter of correctness and not
just optimization. Most of this patch is just arranging to make the
TargetLibraryInfo available in fast isel. <rdar://problem/12008746>
llvm-svn: 161232
This patch will optimize abs(x-y)
FROM
sub, movs, rsbmi
TO
subs, rsbmi
For abs, we will use cmp instead of movs. This is necessary because we already
have an existing peephole pass which optimizes away cmp following sub.
rdar: 11633193
llvm-svn: 158551
We turned off the CMN instruction because it had semantics which we weren't
getting correct. If we are comparing with an immediate, then it's okay to use
the CMN instruction.
<rdar://problem/7569620>
llvm-svn: 158302
We handle struct byval by inserting a pseudo op, which will be expanded to a
loop at ExpandISelPseudos.
A separate patch for clang will be submitted to enable struct byval.
rdar://9877866
llvm-svn: 157793
to pass around a struct instead of a large set of individual values. This
cleans up the interface and allows more information to be added to the struct
for future targets without requiring changes to each and every target.
NV_CONTRIB
llvm-svn: 157479
This will be used to determine whether it's profitable to turn a select into a
branch when the branch is likely to be predicted.
Currently enabled for everything but Atom on X86 and Cortex-A9 devices on ARM.
I'm not entirely happy with the name of this flag, suggestions welcome ;)
llvm-svn: 156233
This moves the logic for selecting a TLS model to a single place,
instead of the previous three (ARM, Mips, and X86 which already
uses this function).
llvm-svn: 156162
ARM BUILD_VECTORs created after type legalization cannot use i8 or i16
operands, since those types are not legal. Instead use i32 operands, which
will be implicitly truncated by the BUILD_VECTOR to match the element type.
llvm-svn: 155824
legalizer always use the DAG entry node. This is wrong when the libcall is
emitted as a tail call since it effectively folds the return node. If
the return node's input chain is not the entry (i.e. call, load, or store)
use that as the tail call input chain.
PR12419
rdar://9770785
rdar://11195178
llvm-svn: 154370
in-register, such that we can use a single vector store rather then a
series of scalar stores.
For func_4_8 the generated code
vldr d16, LCPI0_0
vmov d17, r0, r1
vadd.i16 d16, d17, d16
vmov.u16 r0, d16[3]
strb r0, [r2, #3]
vmov.u16 r0, d16[2]
strb r0, [r2, #2]
vmov.u16 r0, d16[1]
strb r0, [r2, #1]
vmov.u16 r0, d16[0]
strb r0, [r2]
bx lr
becomes
vldr d16, LCPI0_0
vmov d17, r0, r1
vadd.i16 d16, d17, d16
vuzp.8 d16, d17
vst1.32 {d16[0]}, [r2, :32]
bx lr
I'm not fond of how this combine pessimizes 2012-03-13-DAGCombineBug.ll,
but I couldn't think of a way to judiciously apply this combine.
This
ldrh r0, [r0, #4]
strh r0, [r1]
becomes
vldr d16, [r0]
vmov.u16 r0, d16[2]
vmov.32 d16[0], r0
vuzp.16 d16, d17
vst1.32 {d16[0]}, [r1, :32]
PR11158
rdar://10703339
llvm-svn: 154340
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.
llvm-svn: 154011
floating point equality comparisons into integer ones with -ffast-math. The
issue is the optimization causes +0.0 != -0.0.
Now the optimization is only done when one side is known to be 0.0. The other
side's sign bit is masked off for the comparison.
rdar://10964603
llvm-svn: 151861
the processor keeps a return addresses stack (RAS) which stores the address
and the instruction execution state of the instruction after a function-call
type branch instruction.
Calling a "noreturn" function with normal call instructions (e.g. bl) can
corrupt RAS and causes 100% return misprediction so LLVM should use a
unconditional branch instead. i.e.
mov lr, pc
b _foo
The "mov lr, pc" is issued in order to get proper backtrace.
rdar://8979299
llvm-svn: 151623
I'll let the buildbots determine the compile time improvements from this
change, but 464.h264ref has 5% faster codegen at -O2.
This patch does cause some assembly changes. Branch folding can make
different decisions about calls with dead return values.
CriticalAntiDepBreaker may choose different registers because its
liveness tracking is affected. MachineCopyPropagation may sometimes
leave a dead copy behind.
llvm-svn: 151331
value is zero. Instead of a cmov + op, issue an conditional op instead. e.g.
cmp r9, r4
mov r4, #0
moveq r4, #1
orr lr, lr, r4
should be:
cmp r9, r4
orreq lr, lr, #1
That is, optimize (or x, (cmov 0, y, cond)) to (or.cond x, y). Similarly extend
this to xor as well as (and x, (cmov -1, y, cond)) => (and.cond x, y).
It's possible to extend this to ADD and SUB but I don't think they are common.
rdar://8659097
llvm-svn: 151224
My change r146949 added register clobbers to the eh_sjlj_dispatchsetup pseudo
instruction, but on Thumb1 some of those registers cannot be used. This
caused massive failures on the testsuite when compiling for Thumb1. While
fixing that, I noticed that the eh_sjlj_setjmp instruction has a "nofp"
variant, and I realized that dispatchsetup needs the same thing, so I have
added that as well.
llvm-svn: 147204
undefined result. This adds new ISD nodes for the new semantics,
selecting them when the LLVM intrinsic indicates that the undef behavior
is desired. The new nodes expand trivially to the old nodes, so targets
don't actually need to do anything to support these new nodes besides
indicating that they should be expanded. I've done this for all the
operand types that I could figure out for all the targets. Owners of
various targets, please review and let me know if any of these are
incorrect.
Note that the expand behavior is *conservatively correct*, and exactly
matches LLVM's current behavior with these operations. Ideally this
patch will not change behavior in any way. For example the regtest suite
finds the exact same instruction sequences coming out of the code
generator. That's why there are no new tests here -- all of this is
being exercised by the existing test suite.
Thanks to Duncan Sands for reviewing the various bits of this patch and
helping me get the wrinkles ironed out with expanding for each target.
Also thanks to Chris for clarifying through all the discussions that
this is indeed the approach he was looking for. That said, there are
likely still rough spots. Further review much appreciated.
llvm-svn: 146466
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
change, now you need a TargetOptions object to create a TargetMachine. Clang
patch to follow.
One small functionality change in PTX. PTX had commented out the machine
verifier parts in their copy of printAndVerify. That now calls the version in
LLVMTargetMachine. Users of PTX who need verification disabled should rely on
not passing the command-line flag to enable it.
llvm-svn: 145714
The EmitBasePointerRecalculation function has 2 problems, one minor and one
fatal. The minor problem is that it inserts the code at the setjmp
instead of in the dispatch block. The fatal problem is that at the point
where this code runs, we don't know whether there will be a base pointer,
so the entire function is a no-op. The base pointer recalculation needs to
be handled as it was before, by inserting a pseudo instruction that gets
expanded late.
Most of the support for the old approach is still here, but it no longer
has any connection to the eh_sjlj_dispatchsetup intrinsic. Clean up the
parts related to the intrinsic and just generate the pseudo instruction
directly.
llvm-svn: 144781
Add support for trimming constants to GetDemandedBits. This fixes some funky
constant generation that occurs when stores are expanded for targets that don't
support unaligned stores natively.
llvm-svn: 144102
When this field is true it means that the load is from constant (runt-time or compile-time) and so can be hoisted from loops or moved around other memory accesses
llvm-svn: 144100
fixes: Use a separate register, instead of SP, as the
calling-convention resource, to avoid spurious conflicts with
actual uses of SP. Also, fix unscheduling of calling sequences,
which can be triggered by pseudo-two-address dependencies.
llvm-svn: 143206
it fixes the dragonegg self-host (it looks like gcc is miscompiled).
Original commit messages:
Eliminate LegalizeOps' LegalizedNodes map and have it just call RAUW
on every node as it legalizes them. This makes it easier to use
hasOneUse() heuristics, since unneeded nodes can be removed from the
DAG earlier.
Make LegalizeOps visit the DAG in an operands-last order. It previously
used operands-first, because LegalizeTypes has to go operands-first, and
LegalizeTypes used to be part of LegalizeOps, but they're now split.
The operands-last order is more natural for several legalization tasks.
For example, it allows lowering code for nodes with floating-point or
vector constants to see those constants directly instead of seeing the
lowered form (often constant-pool loads). This makes some things
somewhat more complicated today, though it ought to allow things to be
simpler in the future. It also fixes some bugs exposed by Legalizing
using RAUW aggressively.
Remove the part of LegalizeOps that attempted to patch up invalid chain
operands on libcalls generated by LegalizeTypes, since it doesn't work
with the new LegalizeOps traversal order. Instead, define what
LegalizeTypes is doing to be correct, and transfer the responsibility
of keeping calls from having overlapping calling sequences into the
scheduler.
Teach the scheduler to model callseq_begin/end pairs as having a
physical register definition/use to prevent calls from having
overlapping calling sequences. This is also somewhat complicated, though
there are ways it might be simplified in the future.
This addresses rdar://9816668, rdar://10043614, rdar://8434668, and others.
Please direct high-level questions about this patch to management.
Delete #if 0 code accidentally left in.
llvm-svn: 143188
on every node as it legalizes them. This makes it easier to use
hasOneUse() heuristics, since unneeded nodes can be removed from the
DAG earlier.
Make LegalizeOps visit the DAG in an operands-last order. It previously
used operands-first, because LegalizeTypes has to go operands-first, and
LegalizeTypes used to be part of LegalizeOps, but they're now split.
The operands-last order is more natural for several legalization tasks.
For example, it allows lowering code for nodes with floating-point or
vector constants to see those constants directly instead of seeing the
lowered form (often constant-pool loads). This makes some things
somewhat more complicated today, though it ought to allow things to be
simpler in the future. It also fixes some bugs exposed by Legalizing
using RAUW aggressively.
Remove the part of LegalizeOps that attempted to patch up invalid chain
operands on libcalls generated by LegalizeTypes, since it doesn't work
with the new LegalizeOps traversal order. Instead, define what
LegalizeTypes is doing to be correct, and transfer the responsibility
of keeping calls from having overlapping calling sequences into the
scheduler.
Teach the scheduler to model callseq_begin/end pairs as having a
physical register definition/use to prevent calls from having
overlapping calling sequences. This is also somewhat complicated, though
there are ways it might be simplified in the future.
This addresses rdar://9816668, rdar://10043614, rdar://8434668, and others.
Please direct high-level questions about this patch to management.
llvm-svn: 143177
that the set of callee-saved registers is correct for the specific platform.
<rdar://problem/10313708> & ctor_dtor_count & ctor_dtor_count-2
llvm-svn: 142706
On spec/gcc, this caused a codesize improvement of ~1.9% for ARM mode and ~4.9% for Thumb(2) mode. This is
codesize including literal pools.
The pools themselves doubled in size for ARM mode and quintupled for Thumb mode, leaving suggestion that there
is still perhaps redundancy in LLVM's use of constant pools that could be decreased by sharing entries.
Fixes PR11087.
llvm-svn: 142530
register and then compare against that" method when it's too large. We have to
move the value into the register in the "movw, movt" pair of instructions.
llvm-svn: 142440
register and then compare against that" method when it's too large. We have to
move the value into the register in the "movw, movt" pair of instructions.
llvm-svn: 142437
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.
llvm-svn: 142397
predecessor to remove the jump to it as well. Delay clearing the 'landing pad'
flag until after the jumps have been removed. (There is an implicit assumption
in several modules that an MBB which jumps to a landing pad has only two
successors.)
<rdar://problem/10304224>
llvm-svn: 142390
Once the intrinsics are marked as having a custom inserter, it will call this
method to emit the dispatch table into the machine function.
llvm-svn: 142245
Evan Cheng