When a mux instruction is created from a pair of complementary conditional
transfers, it can be placed at the location of either the earlier or the
later of the transfers. Since it will use the operands of the original
transfers, putting it in the earlier location may hoist a kill of a source
register that was originally further down. Make sure the kill flag is
removed if the register is still used afterwards.
llvm-svn: 305300
The initial assumption was that the simplification would converge to a
fixed point relatvely quickly. Turns out that there are legitimate situa-
tions where the complexity of the code causes it to take a large number
of iterations.
Two main changes:
- Instead of aborting upon hitting the limit, simply return nullptr.
- Reduce the limit to 10,000 from 100,000.
llvm-svn: 304441
For multiplications of 64-bit values (giving 64-bit result), detect
cases where the arguments are sign-extended 32-bit values, on a per-
operand basis. This will allow few patterns to match a wider variety
of combinations in which extensions can occur.
llvm-svn: 304223
Rewrite fixupKills() to use the LivePhysRegs class. Simplifies the code
and fixes a bug where the CSR registers in return blocks where missed
leading to invalid kill flags. Also remove the unnecessary rule that we
wouldn't set kill flags on tied operands.
No tests as I have an upcoming commit improving MachineVerifier checks
to catch these cases in multiple existing lit tests.
llvm-svn: 304055
Using arguments with attribute inalloca creates problems for verification
of machine representation. This attribute instructs the backend that the
argument is prepared in stack prior to CALLSEQ_START..CALLSEQ_END
sequence (see http://llvm.org/docs/InAlloca.htm for details). Frame size
stored in CALLSEQ_START in this case does not count the size of this
argument. However CALLSEQ_END still keeps total frame size, as caller can
be responsible for cleanup of entire frame. So CALLSEQ_START and
CALLSEQ_END keep different frame size and the difference is treated by
MachineVerifier as stack error. Currently there is no way to distinguish
this case from actual errors.
This patch adds additional argument to CALLSEQ_START and its
target-specific counterparts to keep size of stack that is set up prior to
the call frame sequence. This argument allows MachineVerifier to calculate
actual frame size associated with frame setup instruction and correctly
process the case of inalloca arguments.
The changes made by the patch are:
- Frame setup instructions get the second mandatory argument. It
affects all targets that use frame pseudo instructions and touched many
files although the changes are uniform.
- Access to frame properties are implemented using special instructions
rather than calls getOperand(N).getImm(). For X86 and ARM such
replacement was made previously.
- Changes that reflect appearance of additional argument of frame setup
instruction. These involve proper instruction initialization and
methods that access instruction arguments.
- MachineVerifier retrieves frame size using method, which reports sum of
frame parts initialized inside frame instruction pair and outside it.
The patch implements approach proposed by Quentin Colombet in
https://bugs.llvm.org/show_bug.cgi?id=27481#c1.
It fixes 9 tests failed with machine verifier enabled and listed
in PR27481.
Differential Revision: https://reviews.llvm.org/D32394
llvm-svn: 302527
Hoisting common code can cause registers that live-in in the successor
blocks to no longer be live-in. The live-in information needs to be
updated to reflect this, or otherwise incorrect code can be generated
later on.
Differential Revision: https://reviews.llvm.org/D32661
llvm-svn: 302228
Allocframe and the following stores on the stack have a latency of 2 cycles
when not in the same packet. This happens because R29 is needed early by the
store instruction. Since one of such stores can be packetized along with
allocframe and use old value of R29, we can assign it 0 cycle latency
while leaving latency of other stores to the default value of 2 cycles.
Patch by Jyotsna Verma.
llvm-svn: 302034
The compiler was generating code that ends up ignoring a multiple
latency dependence between two instructions by scheduling the
intructions in back-to-back packets.
The packetizer needs to end a packet if the latency of the current
current insruction and the source in the previous packet is
greater than 1 cycle. This case occurs when there is still room in
the current packet, but scheduling the instruction causes a stall.
Instead, the packetizer should start a new packet. Also, if the
current packet already contains a stall, then it is okay to add
another instruction to the packet that also causes a stall. This
occurs when there are no instructions that can be scheduled in
between the producer and consumer instructions.
This patch changes the latency for loads to 2 cycles from 3 cycles.
This change refects that a load only needs to be separated by
one extra packet to eliminate the stall.
Patch by Ikhlas Ajbar.
llvm-svn: 301954
When a PHI operand has a subregister, create a COPY instead of simply
replacing the PHI output with the input it.
Differential Revision: https://reviews.llvm.org/D32650
llvm-svn: 301699
Also, make a few changes to allow using the pass in .mir testcases.
Among other things, change the abbreviation from opt-amode to amode-opt,
because otherwise lit would expand the "opt" part to the full path to
the opt binary.
llvm-svn: 300707
- Avoid explosive growth of the simplification queue by not queuing
expressions that are alredy in it.
- Add an iteration counter and abort after a sufficiently large number
of iterations (assuming that it's a symptom of an infinite loop).
llvm-svn: 298655
[Hexagon] Recognize polynomial-modulo loop idiom again
Regain the ability to recognize loops calculating polynomial modulo
operation. This ability has been lost due to some changes in the
preceding optimizations. Add code to preprocess the IR to a form
that the pattern matching code can recognize.
llvm-svn: 298400
Regain the ability to recognize loops calculating polynomial modulo
operation. This ability has been lost due to some changes in the
preceding optimizations. Add code to preprocess the IR to a form
that the pattern matching code can recognize.
llvm-svn: 298282
- Fix the insertion point, which occasionally could have been incorrect.
- Avoid creating multiple bitsplits with the same operands, if an old one
could be reused.
llvm-svn: 297414
When extracting a bitfield from the high register in a register pair,
the final offset should be relative to the high register (for 32-bit
extracts).
llvm-svn: 297288
If a block has non-analyzable branches, the listed successors don't need
to add up to one. For example, if a block has a conditional tail call,
that tail call will not have a corresponding successor in the successor
list, but will still be a possible branch.
Differential Revision: https://reviews.llvm.org/D30556
llvm-svn: 297054
Merge the tail block into the loop in cases where the main loop body
exits early, subject to profitability constraints. This will coalesce
the loop body into fewer blocks.
For example:
loop: loop:
// loop body // loop body
if (...) jump exit --> // more body
more: if (...) jump exit
// more body jump loop
jump loop
llvm-svn: 297033
The code in updateDeadFlags removed unnecessary <dead> flags, but there
can be cases where such a flag is not set, and yet a register has become
dead. For example, if a mux with identical inputs is replaced with a COPY,
the predicate register may no longer be used after that.
llvm-svn: 297032
On Hexagon, values of type i1 are passed in registers of type i32,
even though i1 is not a legal value for these registers. This is a
special case and needs special handling to maintain consistency of
the lowering information.
This fixes PR32089.
llvm-svn: 296645
The motivation for filling out these select-of-constants cases goes back to D24480,
where we discussed removing an IR fold from add(zext) --> select. And that goes back to:
https://reviews.llvm.org/rL75531https://reviews.llvm.org/rL159230
The idea is that we should always canonicalize patterns like this to a select-of-constants
in IR because that's the smallest IR and the best for value tracking. Note that we currently
do the opposite in some cases (like the cases in *this* patch). Ie, the proposed folds in
this patch already exist in InstCombine today:
https://github.com/llvm-mirror/llvm/blob/master/lib/Transforms/InstCombine/InstCombineSelect.cpp#L1151
As this patch shows, most targets generate better machine code for simple ext/add/not ops
rather than a select of constants. So the follow-up steps to make this less of a patchwork
of special-case folds and missing IR canonicalization:
1. Have DAGCombiner convert any select of constants into ext/add/not ops.
2 Have InstCombine canonicalize in the other direction (create more selects).
Differential Revision: https://reviews.llvm.org/D30180
llvm-svn: 296137
When the pipeliner is renaming phi values, it may need to iterate through
the phi operands to check for other phis. However, the pipeliner should
stop once it reaches a phi that is outside the pipelined loop.
Also, when the generateExistingPhis code is unable to reuse an existing
phi, the default code that computes the PhiOp2 is only to be used when
the pipeliner is generating the kernel. Otherwise, the phi may be a value
computed earlier in the same epilog.
Patch by Brendon Cahoon.
llvm-svn: 290355
test/CodeGen/MIR should contain tests that intent to test the MIR
printing or parsing. Tests that test something else should be in
test/CodeGen/TargetName even when they are written in .mir.
As a rule of thumb, only tests using "llc -run-pass none" should be in
test/CodeGen/MIR.
llvm-svn: 289254
The Stack slot coloring pass removes a store that is followed by a load
that deal with the same stack slot. The function isLoadFromStackSlot
is supposed to consider the loads that have no side-effects. This
patch fixed the issue by removing the unsafe loads from this function
Eg:
%vreg0<def> = L2_loadruh_io <fi#15>, 0
S2_storeri_io <fi#15>, 0, %vreg0
In this case, we load an unsigned extended half word and store this in to
the same stack slot. The Stack slot coloring pass considers safe to remove
the store. This patch marked all the non-vector byte and half word loads as
unsafe.
llvm-svn: 286843
For pairs of 32-bit registers: isub_lo, isub_hi.
For pairs of vector registers: vsub_lo, vsub_hi.
Add generic subreg indices: ps_sub_lo, ps_sub_hi, and a function
HexagonRegisterInfo::getHexagonSubRegIndex(RegClass, GenericSubreg)
that returns the appropriate subreg index for RegClass.
llvm-svn: 286377
When LivePhysRegs adds live-in registers, it recognizes ~0 as a special
lane mask indicating the entire register. If the lane mask is not ~0,
it will only add the subregisters that overlap the specified lane mask.
The problem is that if a live-in register does not have subregisters,
and the lane mask is not ~0, it will not be added to the live set.
(The given lane mask may simply be the lane mask of its register class.)
If a register does not have subregisters, add it to the live set if
the lane mask is non-zero.
Differential Revision: https://reviews.llvm.org/D26094
llvm-svn: 285440
Do not use LiveIntervals to recalculate kills, because that cannot be
done accurately without implicit uses on predicated instructions.
llvm-svn: 285409
After register allocation it is possible to have a spill of a register
that is only partially defined. That in itself it fine, but creates a
problem for double vector registers. Stores of such registers are pseudo
instructions that are expanded into pairs of individual vector stores,
and in case of a partially defined source, one of the stores may use
an entirely undefined register. To avoid this, track the defined parts
and only generate actual stores for those.
llvm-svn: 284841
This required reengineering of some of the part of liveness calculation,
including fixing some issues caused by the limitations of the previous
approach. The current code is not necessarily the fastest, but it should
be functionally correct (at least more so than before). The compile-time
performance will be addressed in the future.
llvm-svn: 284609
Branch folder removes implicit defs if they are the only non-branching
instructions in a block, and the branches do not use the defined registers.
The problem is that in some cases these implicit defs are required for
the liveness information to be correct.
Differential Revision: https://reviews.llvm.org/D25478
llvm-svn: 284036
This avoids llc using the hosts OS/vendor as defaults and triggering
unwanted behaviour in the tests. This should deal with the buildbot
breakages on windows after r283140.
llvm-svn: 283149
Each shadow only represents data flow that is restricted to its reaching
def. Propagating more than that could lead to spurious register liveness,
resulting in extra (incorrectly) block live-ins.
llvm-svn: 283143
Normally, if conversion would add implicit uses for redefined registers,
e.g. R0<def> = add_if ..., R0<imp-use>. However, if only subregisters of
R0 are known to be live but not R0 itself, such implicit uses will not be
added, causing prior definitions of such subregisters and R0 itself to
become dead.
llvm-svn: 282626
descriptions now tag add instructions, and the Hexagon backend is using this to
identify loop induction statements.
Patch by Sam Parker and Sjoerd Meijer.
Differential Revision: https://reviews.llvm.org/D23601
llvm-svn: 281304
Shadow uses need to be analyzed together, since each individual shadow
will only have a partial reaching def. All shadows together may cover
a given register ref, while each individual shadow may not.
llvm-svn: 280855
This reverts commit r280268, it causes all MSVC 2013 to ICE. This
appears to have been fixed in a later MSVC 2013 update, because I cannot
reproduce it locally. That said, all upstream LLVM bots are broken right
now, so I am reverting.
Also reverts dependent change r280275, "[Hexagon] Deal with undefs when
extending live intervals".
llvm-svn: 280301
This bug shows up with diamonds that share unpredicable, unanalyzable branches.
There's an included test case from Hexagon. What was happening was that we were
attempting to predicate the branch instruction despite the fact that it was
checked to be the same. Now for unanalyzable branches we skip over the branch
instructions when predicating the block.
Differential Revision: https://reviews.llvm.org/D23939
llvm-svn: 279985
Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.
Differential Revision: http://reviews.llvm.org/D23850
llvm-svn: 279698
The register allocator can split a live interval of a register into a set
of smaller intervals. After the allocation of registers is complete, the
rewriter will modify the IR to replace virtual registers with the corres-
ponding physical registers. At this stage, if a register corresponding
to a subregister of a virtual register is used, the rewriter will check
if that subregister is undefined, and if so, it will add the <undef> flag
to the machine operand. The function verifying liveness of the subregis-
ter would assume that it is undefined, unless any of the subranges of the
live interval proves otherwise.
The problem is that the live intervals created during splitting do not
have any subranges, even if the original parent interval did. This could
result in the <undef> flag placed on a register that is actually defined.
Differential Revision: http://reviews.llvm.org/D21189
llvm-svn: 279625
Improved handling of fma, floating point min/max, additional load/store
instructions for floating point types.
Patch by Jyotsna Verma.
llvm-svn: 279239
The pipeliner was generating an invalid Phi name for an operand
in the epilog block, which caused an assert in the live variable
analysis pass. The fix is to the code that generates new Phis
in the epilog block. In this case, there is an existing Phi that
needs to be reused rather than creating a new Phi instruction.
Differential Revision: https://reviews.llvm.org/D23513
llvm-svn: 278805
If a loop is not rotated (for example when optimizing for size), the latch is not the backedge. If we promote an expression to post-inc form, we not only increase register pressure and add a COPY for that IV expression but for all IVs!
Motivating testcase:
void f(float *a, float *b, float *c, int n) {
while (n-- > 0)
*c++ = *a++ + *b++;
}
It's imperative that the pointer increments be located in the latch block and not the header block; if not, we cannot use post-increment loads and stores and we have to keep both the post-inc and pre-inc values around until the end of the latch which bloats register usage.
llvm-svn: 278658
LowerTargetConstantPool is not properly setting the TargetFlag to indicate
desired relocation. Coding error, the offset parameter was omitted, so the
TargetFlag was used as the offset, and the TargetFlag defaulted to zero.
This only affects -fpic compilation, and only those items created in a
Constant Pool, for example a vector of constants. Halide ran into this issue.
llvm-svn: 278614
From the point of view of register assignment, byval parameters are
ignored: a byval parameter is not going to be assigned to a register,
and it will not affect the assignments of subsequent parameters.
When matching registers with parameters in the bit tracker, make sure
to skip byval parameters before advancing the registers.
llvm-svn: 278375
This change makes it possible for tail-duplication and tail-merging to
be disjoint. By being less aggressive when merging during layout, there are no
overlapping cases between tail-duplication and tail-merging, provided the
thresholds are disjoint.
There is a remaining TODO to benchmark the succ_size() test for non-layout tail
merging.
llvm-svn: 278265
Floating point instructions use general purpose registers, so the few
instructions that can put floating point immediates into registers are,
in fact, integer instruction. Use them explicitly instead of having
pseudo-instructions specifically for dealing with floating point values.
Simplify the constant loading instructions (from sdata) to have only two:
one for 32-bit values and one for 64-bit values: CONST32 and CONST64.
llvm-svn: 278244
When the same base address is used to load two different data types, LSR
would assume a memory type of "void". This type is not sized and has no
alignment information. Checking for it causes a crash.
llvm-svn: 277601
Identify patterns where the address is aligned to an 8-byte boundary,
but both the base address and the constant offset are both proper
multiples of 4. In such cases, extract Base+4 into a separate instruc-
tion, and use S2_storerd_io, instead of using S4_storerd_rr.
llvm-svn: 277497
Scavenging slots were only reserved when pseudo-instruction expansion in
frame lowering created new virtual registers. It is possible to still
need a scavenging slot even if no virtual registers were created, in cases
where the stack is large enough to overflow instruction offsets.
llvm-svn: 277355
The DAG combiner will try to merge consecutive stores into a bigger
store, unless the resulting store is not fast. Misaligned vector stores
are allowed on Hexagon, but are not fast. Add a testcase to make sure
this type of merging does not occur.
Patch by Pranav Bhandarkar.
llvm-svn: 277182
The DAG combiner tries to merge stores to adjacent vector wide memory
locations by creating stores which are integral multiples of the vector
width. Discourage this by informing it that this is slow. This should
not affect legalization passes, because all of them ignore the "Fast"
argument.
Patch by Pranav Bhandarkar.
llvm-svn: 277178
Software pipelining is an optimization for improving ILP by
overlapping loop iterations. Swing Modulo Scheduling (SMS) is
an implementation of software pipelining that attempts to
reduce register pressure and generate efficient pipelines with
a low compile-time cost.
This implementaion of SMS is a target-independent back-end pass.
When enabled, the pass should run just prior to the register
allocation pass, while the machine IR is in SSA form. If the pass
is successful, then the original loop is replaced by the optimized
loop. The optimized loop contains one or more prolog blocks, the
pipelined kernel, and one or more epilog blocks.
This pass is enabled for Hexagon only. To enable for other targets,
a couple of target specific hooks must be implemented, and the
pass needs to be called from the target's TargetMachine
implementation.
Differential Review: http://reviews.llvm.org/D16829
llvm-svn: 277169
If the mask of a vector shuffle has alternating odd or even numbers
starting with 1 or 0 respectively up to the largest possible index
for the given type in the given HVX mode (single of double) we can
generate vpacko or vpacke instruction respectively.
E.g.
%42 = shufflevector <32 x i16> %37, <32 x i16> %41,
<32 x i32> <i32 1, i32 3, ..., i32 63>
is %42.h = vpacko(%41.w, %37.w)
Patch by Pranav Bhandarkar.
llvm-svn: 277168
Rebalances address calculation trees and applies Hexagon-specific
optimizations to the trees to improve instruction selection.
Patch by Tobias Edler von Koch.
llvm-svn: 277151
Normally, CFI instructions should be inserted after allocframe, but
if allocframe is in the same packet with a call, the CFI instructions
should be inserted before that packet.
llvm-svn: 277020
Before adding a new preheader block, check if there is a candidate block
where the loop setup could be placed speculatively. This will be off by
default.
llvm-svn: 276919
Consider this case:
vreg1 = A2_zxth vreg0 (1)
...
vreg2 = A2_zxth vreg1 (2)
Redundant instruction elimination could delete the instruction (1)
because the user (2) only cares about the low 16 bits. Then it could
delete (2) because the input is already zero-extended. The problem
is that the properties allowing each individual instruction to be
deleted depend on the existence of the other instruction, so either
one can be deleted, but not both.
The existing check for this situation in RIE was insufficient. The
fix is to update all dependent cells when an instruction is removed
(replaced via COPY) in RIE.
llvm-svn: 276792
Schedule a load and its use in the same packet in MISched. Previously,
isResourceAvailable was returning false for dependences in the same
packet, which prevented MISched from packetizing a load and its use in
the same packet for v60.
Patch by Ikhlas Ajbar.
llvm-svn: 275804
The machine scheduler needs to account for available resources
more accurately in order to avoid scheduling an instruction that
forces a new packet to be created.
This occurs in two ways: First, an instruction without an available
resource may have a large priority due to other metrics and be
scheduled when there are other instructions with available resources.
Second, an instruction with a non-zero latency may become available
prematurely. In both these cases, we attempt change the priority
in order to allow a better instruction to be scheduled.
Patch by Brendon Cahoon.
llvm-svn: 275793
An instruction may have multiple predecessors that are candidates
for using .cur. However, only one of them can use .cur in the
packet. When this case occurs, we need to make sure that only
one of the dependences gets a 0 latency value.
Patch by Brendon Cahoon.
llvm-svn: 275790
- Treat bitwise OR with a frame index as an ADD wherever possible, fold it
into addressing mode.
- Extend patterns for memops to allow memops with frame indexes as address
operands.
llvm-svn: 275569
On Hexagon is it legal to packetize the instructions setting up call
arguments with the call instruction itself. This was already done,
except for tail calls. Make sure tail calls are handled as well.
llvm-svn: 275458
Transform: (store ch addr (add x (add (shl y c) e)))
to: (store ch addr (add x (shl (add y d) c))),
where e = (shl d c) for some integer d.
The purpose of this is to enable generation of loads/stores with
shifted addressing mode, i.e. mem(x+y<<#c). For that, the shift
value c must be 0, 1 or 2.
llvm-svn: 273466
The aggressive anti-dependency breaker can rename the restored callee-
saved registers. To prevent this, mark these registers are live on all
paths to the return/tail-call instructions, and add implicit use operands
for them to these instructions.
llvm-svn: 270898
When looking for an available spill slot, the register scavenger would stop
after finding the first one with no register assigned to it. That slot may
have size and alignment that do not meet the requirements of the register
that is to be spilled. Instead, find an available slot that is the closest
in size and alignment to one that is needed to spill a register from RC.
Differential Revision: http://reviews.llvm.org/D20295
llvm-svn: 269969
Recent changes to the instruction selection code exposed a problem where
a dead node was not removed on time. This node had both input and output
chains, which lead to an apparent cycle.
llvm-svn: 269458
When generating .cfi_offset instructions, make sure that the offset is
calculated with respect to the register used to define the CFA (which is
currently always FP+8).
llvm-svn: 269191
An example from Hexagon where things went wrong:
%R0<def> = L2_loadrigp <ga:@fp04> ; load function address
J2_callr %R0<kill>, ..., %R0<imp-def> ; call *R0, return value in R0
ScheduleDAGInstrs::buildSchedGraph would visit all instructions going
backwards, and in each instruction it would visit all operands in their
order on the operand list. In the case of this call, it visited the use
of R0 first, then removed it from the set Uses after it visited the def.
This caused the DAG to be missing the data dependence edge on R0 between
the load and the call.
Differential Revision: http://reviews.llvm.org/D20102
llvm-svn: 269076
ScheduleDAGMI::initQueues changes the RegionBegin to the first non-debug
instruction. Since it does not track register pressure, it does not affect
any RP trackers. ScheduleDAGMILive inherits initQueues from ScheduleDAGMI,
and it does reset the TopTPTracker in its schedule method. Any derived,
target-specific scheduler will need to do it as well, but the TopRPTracker
is only exposed as a "const" object to derived classes. Without the ability
to modify the tracker directly, this leaves a derived scheduler with a
potential of having the TopRPTracker out-of-sync with the CurrentTop.
The symptom of the problem:
void llvm::ScheduleDAGMILive::scheduleMI(llvm::SUnit *, bool):
Assertion `TopRPTracker.getPos() == CurrentTop && "out of sync"' failed.
Differential Revision: http://reviews.llvm.org/D19438
llvm-svn: 267918
When a block is tail-duplicated, the PHI nodes from that block are
replaced with appropriate COPY instructions. When those PHI nodes
contained use operands with subregisters, the subregisters were
dropped from the COPY instructions, resulting in incorrect code.
Keep track of the subregister information and use this information
when remapping instructions from the duplicated block.
Differential Revision: http://reviews.llvm.org/D19337
llvm-svn: 267583
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.
Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.
Motivation
----------
Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.
We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.
Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.
http://reviews.llvm.org/D19034
<rdar://problem/25256815>
llvm-svn: 266446
In PIC mode, the registers R14, R15 and R28 are reserved for use by
the PLT handling code. This causes all functions to clobber these
registers. While this is not new for regular function calls, it does
also apply to save/restore functions, which do not follow the standard
ABI conventions with respect to the volatile/non-volatile registers.
Patch by Jyotsna Verma.
llvm-svn: 264324
Replace spills to memory with spills to registers, if possible. This
applies mostly to predicate registers (both scalar and vector), since
they are very limited in number. A spill of a predicate register may
happen even if there is a general-purpose register available. In cases
like this the stack spill/reload may be eliminated completely.
This optimization will consider all stack objects, regardless of where
they came from and try to match the live range of the stack slot with
a dead range of a register from an appropriate register class.
llvm-svn: 260758
Rewrite the code to handle all pseudo-instructions in a single pass.
This temporarily reverts spill slot optimization that used general-
purpose registers to hold values of spilled predicate registers.
llvm-svn: 260696
We can generate the actual instructions from the intrinsics without the
need for pseudo-instructions. Also, since the intrinsics have a side-
effect in a form of a store, attempt to optimize away loads from the
store location.
llvm-svn: 260690
The DataLayout can calculate alignment of vectors based on the alignment
of the element type and the number of elements. In fact, it is the product
of these two values. The problem is that for vectors of N x i1, this will
return the alignment of N bytes, since the alignment of i1 is 8 bits. The
vector types of vNi1 should be aligned to N bits instead. Provide explicit
alignment for HVX vectors to avoid such complications.
llvm-svn: 260678
Fix the lit bug that enabled this "feature" (empty triple is substring
of all possible target triples) and change the two outliers to use the
documented * syntax.
llvm-svn: 259799
If converter was somewhat careless about "diamond" cases, where there
was no join block, or in other words, where the true/false blocks did
not have analyzable branches. In such cases, it was possible for it to
remove (needed) branches, resulting in a loss of entire basic blocks.
Differential Revision: http://reviews.llvm.org/D16156
llvm-svn: 258310
This removes an unpleasant hack involving a global variable for special
lowering of certain memcpy calls. These are now lowered as intended in
EmitTargetCodeForMemcpy in the same way that other targets do it.
llvm-svn: 255785
(This is the second attempt to submit this patch. The first caused two assertion
failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687)
The patch in http://reviews.llvm.org/D13745 is broken into four parts:
1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.
This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.
All uses of weight-based interfaces are now updated to use probability-based
ones.
Differential revision: http://reviews.llvm.org/D14973
llvm-svn: 254377
and the follow-up r254356: "Fix a bug in MachineBlockPlacement that may cause assertion failure during BranchProbability construction."
Asserts were firing in Chromium builds. See PR25687.
llvm-svn: 254366
The patch in http://reviews.llvm.org/D13745 is broken into four parts:
1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.
This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.
All uses of weight-based interfaces are now updated to use probability-based
ones.
Differential revision: http://reviews.llvm.org/D14973
llvm-svn: 254348
The patch in http://reviews.llvm.org/D13745 is broken into four parts:
1. New interfaces without functional changes.
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights.
3. Use new interfaces in all other passes.
4. Remove old interfaces.
This the second patch above. In this patch SelectionDAG starts to use
probability-based interfaces in MBB to add successors but other MC passes are
still using weight-based interfaces. Therefore, we need to maintain correct
weight list in MBB even when probability-based interfaces are used. This is
done by updating weight list in probability-based interfaces by treating the
numerator of probabilities as weights. This change affects many test cases
that check successor weight values. I will update those test cases once this
patch looks good to you.
Differential revision: http://reviews.llvm.org/D14361
llvm-svn: 253965
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html
These intrinsics currently have an explicit alignment argument which is
required to be a constant integer. It represents the alignment of the
source and dest, and so must be the minimum of those.
This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments. The alignment
argument itself is removed.
There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe. For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.
For example, code which used to read:
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)
For out of tree owners, I was able to strip alignment from calls using sed by replacing:
(call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
$1i1 false)
and similarly for memmove and memcpy.
I then added back in alignment to test cases which needed it.
A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.
In IRBuilder itself, a new argument was added. Instead of calling:
CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)
There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool. This is to prevent isVolatile here from passing its default
parameter to the source alignment.
Note, changes in future can now be made to codegen. I didn't change anything here, but this
change should enable better memcpy code sequences.
Reviewed by Hal Finkel.
llvm-svn: 253511
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.
For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.
This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.
Since this is an IR change, a bitcode upgrade has been provided.
Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.
Differential Revision: http://reviews.llvm.org/D14265
llvm-svn: 252219
Do not tail duplicate blocks where the successor has a phi node,
and the corresponding value in that phi node uses a subregister.
http://reviews.llvm.org/D13922
llvm-svn: 250877
Emit the CFI instructions after all code transformation have been done.
This will avoid any interference between CFI instructions and packetization.
llvm-svn: 250714
In if-conversion, there is a utility function MergeBlocks() that is used to merge blocks. However, when new edges are built in this function the edge weight is either not provided or not updated properly, leading to a modified CFG with incorrect edge weights. This patch corrects this issue.
Differential Revision: http://reviews.llvm.org/D12513
llvm-svn: 248030
As a follow-up to r246098, require `DISubprogram` definitions
(`isDefinition: true`) to be 'distinct'. Specifically, add an assembler
check, a verifier check, and bitcode upgrading logic to combat testcase
bitrot after the `DIBuilder` change.
While working on the testcases, I realized that
test/Linker/subprogram-linkonce-weak-odr.ll isn't relevant anymore. Its
purpose was to check for a corner case in PR22792 where two subprogram
definitions match exactly and share the same metadata node. The new
verifier check, requiring that subprogram definitions are 'distinct',
precludes that possibility.
I updated almost all the IR with the following script:
git grep -l -E -e '= !DISubprogram\(.* isDefinition: true' |
grep -v test/Bitcode |
xargs sed -i '' -e 's/= \(!DISubprogram(.*, isDefinition: true\)/= distinct \1/'
Likely some variant of would work for out-of-tree testcases.
llvm-svn: 246327
Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode. This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.
Almost all the testcases were updated with this script:
git grep -e '= !DICompileUnit' -l -- test |
grep -v test/Bitcode |
xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'
I imagine something similar should work for out-of-tree testcases.
llvm-svn: 243885
Remove the fake `DW_TAG_auto_variable` and `DW_TAG_arg_variable` tags,
using `DW_TAG_variable` in their place Stop exposing the `tag:` field at
all in the assembly format for `DILocalVariable`.
Most of the testcase updates were generated by the following sed script:
find test/ -name "*.ll" -o -name "*.mir" |
xargs grep -l 'DILocalVariable' |
xargs sed -i '' \
-e 's/tag: DW_TAG_arg_variable, //' \
-e 's/tag: DW_TAG_auto_variable, //'
There were only a handful of tests in `test/Assembly` that I needed to
update by hand.
(Note: a follow-up could change `DILocalVariable::DILocalVariable()` to
set the tag to `DW_TAG_formal_parameter` instead of `DW_TAG_variable`
(as appropriate), instead of having that logic magically in the backend
in `DbgVariable`. I've added a FIXME to that effect.)
llvm-svn: 243774
Krzysztof Parzyszek