are dead, not just the def of this register. I.e., a register could be dead, but
it's subreg isn't.
Testcase to follow with a subsequent patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106878 91177308-0d34-0410-b5e6-96231b3b80d8
and CallInst for getting hold
of the intrinsic's arguments
simplify along the way (at least for me this is much more legible now)
Bill, Baldrick or Anton, please review\!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106838 91177308-0d34-0410-b5e6-96231b3b80d8
is reused as an input. PR 4118. Testcase is too big,
as usual with bugs in this area, but there's one in
the PR.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106816 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes PR7479 and PR7485. The test cases from those PRs are big, so not
included. However, PR7485 comes from self hosting on FreeBSD, so we will surely
hear about any regression.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106811 91177308-0d34-0410-b5e6-96231b3b80d8
original SDNode. This is badness. Also, this function allows one SDNode to point
multiple flags to another SDNode. Badness as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106793 91177308-0d34-0410-b5e6-96231b3b80d8
This method was always a bit too simplistic for the real world. It didn't really
deal with subregisters and such.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106781 91177308-0d34-0410-b5e6-96231b3b80d8
This code path has never really been used, and we are going to be handling
spilling through the Spiller interface in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106777 91177308-0d34-0410-b5e6-96231b3b80d8
which don't have a catch-all associated with them not just clean-ups. This fixes
the SingleSource/Benchmarks/Shootout-C++/except.cpp testcase that broke because
of my change r105902.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106772 91177308-0d34-0410-b5e6-96231b3b80d8
CoalescerPair can determine if a copy can be coalesced, and which register gets
merged away. The old logic in SimpleRegisterCoalescing had evolved into
something a bit too convoluted.
This second attempt fixes some crashes that only occurred Linux.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106769 91177308-0d34-0410-b5e6-96231b3b80d8
[L]oad, [u]se, [d]ef, or [S]tore slots.
This makes it easier to see if two indices refer to the same instruction,
avoiding mental mod 4 calculations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106766 91177308-0d34-0410-b5e6-96231b3b80d8
In this case it is essential that the kill is real because the spiller will
decide to omit a spill if it thinks there is a later kill.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106751 91177308-0d34-0410-b5e6-96231b3b80d8
when the condition is constant. This optimization shouldn't be
necessary, because codegen shouldn't be able to find dead control
paths that the IR-level optimizer can't find. And it's undesirable,
because it encourages bugpoint to leave "br i1 false" branches
in its output. And it wasn't updating the CFG.
I updated all the tests I could, but some tests are too reduced
and I wasn't able to meaningfully preserve them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106748 91177308-0d34-0410-b5e6-96231b3b80d8
CoalescerPair can determine if a copy can be coalesced, and which register gets
merged away. The old logic in SimpleRegisterCoalescing had evolved into
something a bit too convoluted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106701 91177308-0d34-0410-b5e6-96231b3b80d8
into the same node, but with different non-memory operands, we need to replace
the memory operands after it's finished morphing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106643 91177308-0d34-0410-b5e6-96231b3b80d8
atomic intrinsics, either because the use locking instructions for the
atomics, or because they perform the locking directly. Add support in the
DAG combiner to fold away the fences.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106630 91177308-0d34-0410-b5e6-96231b3b80d8
instructions.
This does not affect codegen much because SUBREG_TO_REG is only used by X86 and
X86 does not use the register scavenger, but it prevents verifier errors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106583 91177308-0d34-0410-b5e6-96231b3b80d8
into a utility routine, teach it how to update MachineLoopInfo, and
make use of it in MachineLICM to split critical edges on demand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106555 91177308-0d34-0410-b5e6-96231b3b80d8
Measurements show that it does not speed up coalescing, so there is no reason
the keep the added complexity around.
Also clean out some unused methods and static functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106548 91177308-0d34-0410-b5e6-96231b3b80d8
opportunities. For example, this lets it emit this:
movq (%rax), %rcx
addq %rdx, %rcx
instead of this:
movq %rdx, %rcx
addq (%rax), %rcx
in the case where %rdx has subsequent uses. It's the same number
of instructions, and usually the same encoding size on x86, but
it appears faster, and in general, it may allow better scheduling
for the load.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106493 91177308-0d34-0410-b5e6-96231b3b80d8
Split the code for materializing a value out of
SelectionDAGBuilder::getValue into a helper function, so that it can
be used in other ways. Add a new getNonRegisterValue function which
uses it, for use in code which doesn't want a CopyFromReg even
when FuncMap.ValueMap already has an entry for it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106422 91177308-0d34-0410-b5e6-96231b3b80d8
- This fixed a number of bugs in if-converter, tail merging, and post-allocation
scheduler. If-converter now runs branch folding / tail merging first to
maximize if-conversion opportunities.
- Also changed the t2IT instruction slightly. It now defines the ITSTATE
register which is read by instructions in the IT block.
- Added Thumb2 specific hazard recognizer to ensure the scheduler doesn't
change the instruction ordering in the IT block (since IT mask has been
finalized). It also ensures no other instructions can be scheduled between
instructions in the IT block.
This is not yet enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106344 91177308-0d34-0410-b5e6-96231b3b80d8
instructions, but it doesn't really understand live ranges, so the first
INSERT_SUBREG uses an implicitly defined register.
Fix it in LiveVariableAnalysis by adding the <undef> flag.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106333 91177308-0d34-0410-b5e6-96231b3b80d8
entries used by llvm-gcc. *_[U]MIN and such can be added later if needed.
This enables the front ends to simplify handling of the atomic intrinsics by
removing the target-specific decision about which targets can handle the
intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106321 91177308-0d34-0410-b5e6-96231b3b80d8
so when IfConverter::CopyAndPredicateBlock checks to see if it should ignore
an instruction because it is a branch, it should not check if the branch is
predicated.
This case (when IgnoreBr is true) is only relevant from IfConvertTriangle,
where new branches are inserted after the block has been copied and predicated.
If the original branch is not removed, we end up with multiple conditional
branches (possibly conflicting) at the end of the block. Aside from any
immediate errors resulting from that, this confuses the AnalyzeBranch functions
so that the branches are not analyzable. That in turn causes the IfConverter to
think that the "Simple" pattern can be applied, and things go downhill fast
because the "Simple" pattern does _not_ apply if the block can fall through.
This is pretty fragile. If there are other degenerate cases where AnalyzeBranch
fails, but where the block may still fall through, the IfConverter should not
perform its "Simple" if-conversion. But, I don't know how to do that with the
current AnalyzeBranch interface, so for now, the best thing seems to be to
avoid creating branches that AnalyzeBranch cannot handle.
Evan, please review!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106291 91177308-0d34-0410-b5e6-96231b3b80d8
switch from this:
if (TimePassesIsEnabled) {
NamedRegionTimer T(Name, GroupName);
do_something();
} else {
do_something(); // duplicate the code, this time without a timer!
}
to this:
{
NamedRegionTimer T(Name, GroupName, TimePassesIsEnabled);
do_something();
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106285 91177308-0d34-0410-b5e6-96231b3b80d8
addresses a longstanding deficiency noted in many FIXMEs scattered
across all the targets.
This effectively moves the problem up one level, replacing eleven
FIXMEs in the targets with eight FIXMEs in CodeGen, plus one path
through FastISel where we actually supply a DebugLoc, fixing Radar
7421831.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106243 91177308-0d34-0410-b5e6-96231b3b80d8
for the moment. The implementation of the libcall will follow.
Currently, the llvm-gcc knows when the intrinsics can be correctly handled by
the back end and only generates them in those cases, issuing libcalls directly
otherwise. That's too much coupling. The intrinsics should always be
generated and the back end decide how to handle them, be it with a libcall,
inline code, or whatever. This patch is a step in that direction.
rdar://8097623
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106227 91177308-0d34-0410-b5e6-96231b3b80d8
LiveVariableAnalysis was a bit picky about a register only being redefined once,
but that really isn't necessary.
Here is an example of chained INSERT_SUBREGs that we can handle now:
68 %reg1040<def> = INSERT_SUBREG %reg1040, %reg1028<kill>, 14
register: %reg1040 +[70,134:0)
76 %reg1040<def> = INSERT_SUBREG %reg1040, %reg1029<kill>, 13
register: %reg1040 replace range with [70,78:1) RESULT: %reg1040,0.000000e+00 = [70,78:1)[78,134:0) 0@78-(134) 1@70-(78)
84 %reg1040<def> = INSERT_SUBREG %reg1040, %reg1030<kill>, 12
register: %reg1040 replace range with [78,86:2) RESULT: %reg1040,0.000000e+00 = [70,78:1)[78,86:2)[86,134:0) 0@86-(134) 1@70-(78) 2@78-(86)
92 %reg1040<def> = INSERT_SUBREG %reg1040, %reg1031<kill>, 11
register: %reg1040 replace range with [86,94:3) RESULT: %reg1040,0.000000e+00 = [70,78:1)[78,86:2)[86,94:3)[94,134:0) 0@94-(134) 1@70-(78) 2@78-(86) 3@86-(94)
rdar://problem/8096390
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106152 91177308-0d34-0410-b5e6-96231b3b80d8
will conflict with another live range. The place which creates this scenerio is
the code in X86 that lowers a select instruction by splitting the MBBs. This
eliminates the need to check from the bottom up in an MBB for live pregs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106066 91177308-0d34-0410-b5e6-96231b3b80d8
SimpleRegisterCoalescing::JoinIntervals() uses CoalescerPair to determine if a
copy is coalescable, and in very rare cases it can return true where LHS is not
live - the coalescable copy can come from an alias of the physreg in LHS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106021 91177308-0d34-0410-b5e6-96231b3b80d8
combined to an insert_subreg, i.e., where the destination register is larger
than the source. We need to check that the subregs can be composed for that
case in a symmetrical way to the case when the destination is smaller.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106004 91177308-0d34-0410-b5e6-96231b3b80d8
Early clobbers defining a virtual register were first alocated to a physreg and
then processed as a physreg EC, spilling the virtreg.
This fixes PR7382.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105998 91177308-0d34-0410-b5e6-96231b3b80d8
Given a copy instruction, CoalescerPair can determine which registers to
coalesce in order to eliminate the copy. It deals with all the subreg fun to
determine a tuple (DstReg, SrcReg, SubIdx) such that:
- SrcReg is a virtual register that will disappear after coalescing.
- DstReg is a virtual or physical register whose live range will be extended.
- SubIdx is 0 when DstReg is a physical register.
- SrcReg can be joined with DstReg:SubIdx.
CoalescerPair::isCoalescable() determines if another copy instruction is
compatible with the same tuple. This fixes some NEON miscompilations where
shuffles are getting coalesced as if they were copies.
The CoalescerPair class will replace a lot of the spaghetti logic in JoinCopy
later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105997 91177308-0d34-0410-b5e6-96231b3b80d8
replacing the overly conservative checks that I had introduced recently to
deal with correctness issues. This makes a pretty noticable difference
in our testcases where reg_sequences are used. I've updated one test to
check that we no longer emit the unnecessary subreg moves.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105991 91177308-0d34-0410-b5e6-96231b3b80d8
- Rename ExactHazardRecognizer to PostRAHazardRecognizer and move its header to include to allow targets to extend it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105959 91177308-0d34-0410-b5e6-96231b3b80d8
clean-up to a catch-all after inlining, take into account that there could be
filter IDs as well. The presence of filters don't mean that the selector catches
anything. It's just metadata information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105872 91177308-0d34-0410-b5e6-96231b3b80d8
This is a bit of a hack to make inline asm look more like call instructions.
It would be better to produce correct dead flags during isel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105749 91177308-0d34-0410-b5e6-96231b3b80d8
%reg1025 = <sext> %reg1024
...
%reg1026 = SUBREG_TO_REG 0, %reg1024, 4
into this:
%reg1025 = <sext> %reg1024
...
%reg1027 = EXTRACT_SUBREG %reg1025, 4
%reg1026 = SUBREG_TO_REG 0, %reg1027, 4
The problem here is that SUBREG_TO_REG is there to assert that an implicit zext
occurs. It doesn't insert a zext instruction. If we allow the EXTRACT_SUBREG
here, it will give us the value after the <sext>, not the original value of
%reg1024 before <sext>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105741 91177308-0d34-0410-b5e6-96231b3b80d8
register allocation.
Process all of the clobber lists at the end of the function, marking the
registers as used in MachineRegisterInfo.
This is necessary in case the calls clobber callee-saved registers (sic).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105473 91177308-0d34-0410-b5e6-96231b3b80d8
replace an OpA with a widened OpB, it is possible to get new uses of OpA due to CSE
when recursively updating nodes. Since OpA has been processed, the new uses are
not examined again. The patch checks if this occurred and it it did, updates the
new uses of OpA to use OpB.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105453 91177308-0d34-0410-b5e6-96231b3b80d8
Check that all the instructions are in the same basic block, that the
EXTRACT_SUBREGs write to the same subregs that are being extracted, and that
the source and destination registers are in the same regclass. Some of
these constraints can be relaxed with a bit more work. Jakob suggested
that the loop that checks for subregs when NewSubIdx != 0 should use the
"nodbg" iterator, so I made that change here, too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105437 91177308-0d34-0410-b5e6-96231b3b80d8
registers it defines then interfere with an existing preg live range.
For instance, if we had something like these machine instructions:
BB#0
... = imul ... EFLAGS<imp-def,dead>
test ..., EFLAGS<imp-def>
jcc BB#2 EFLAGS<imp-use>
BB#1
... ; fallthrough to BB#2
BB#2
... ; No code that defines EFLAGS
jcc ... EFLAGS<imp-use>
Machine sink will come along, see that imul implicitly defines EFLAGS, but
because it's "dead", it assumes that it can move imul into BB#2. But when it
does, imul's "dead" imp-def of EFLAGS is raised from the dead (a zombie) and
messes up the condition code for the jump (and pretty much anything else which
relies upon it being correct).
The solution is to know which pregs are live going into a basic block. However,
that information isn't calculated at this point. Nor does the LiveVariables pass
take into account non-allocatable physical registers. In lieu of this, we do a
*very* conservative pass through the basic block to determine if a preg is live
coming out of it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105387 91177308-0d34-0410-b5e6-96231b3b80d8
expansion is the same as that used by LegalizeDAG.
The resulting code sucks in terms of performance/codesize on x86-32 for a
64-bit operation; I haven't looked into whether different expansions might be
better in general.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105378 91177308-0d34-0410-b5e6-96231b3b80d8
spills and reloads.
This means that a partial define of a register causes a reload so the other
parts of the register are preserved.
The reload can be prevented by adding an <imp-def> operand for the full
register. This is already done by the coalescer and live interval analysis where
relevant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105369 91177308-0d34-0410-b5e6-96231b3b80d8
register updates.
These operands tell the spiller that the other parts of the partially defined
register are don't-care, and a reload is not necessary.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105361 91177308-0d34-0410-b5e6-96231b3b80d8
instruction defines subregisters.
Any existing subreg indices on the original instruction are preserved or
composed with the new subreg index.
Also substitute multiple operands mentioning the original register by using the
new MachineInstr::substituteRegister() function. This is necessary because there
will soon be <imp-def> operands added to non read-modify-write partial
definitions. This instruction:
%reg1234:foo = FLAP %reg1234<imp-def>
will reMaterialize(%reg3333, bar) like this:
%reg3333:bar-foo = FLAP %reg333:bar<imp-def>
Finally, replace the TargetRegisterInfo pointer argument with a reference to
indicate that it cannot be NULL.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105358 91177308-0d34-0410-b5e6-96231b3b80d8
backends and removes the virtual declaration. With that out of the way
I should be able to cleanup one backend at a time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105321 91177308-0d34-0410-b5e6-96231b3b80d8
The comment about ordering of subreg indices is no longer true.
This exposed a bug in the new substVirtReg method that is also fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105294 91177308-0d34-0410-b5e6-96231b3b80d8
handle structs passed by value via an extract/insert pair, as a bitcast
won't work on a struct. rdar://7742824
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105280 91177308-0d34-0410-b5e6-96231b3b80d8
that are too large. This causes the freebsd bootloader to be too
large apparently.
It's unclear if this should be an -Os or -Oz thing. Thoughts welcome.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105228 91177308-0d34-0410-b5e6-96231b3b80d8
shouldn't have a TargetLoweringInfo member. And FunctionLoweringInfo::set
doesn't needs its EnableFastISel argument.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105101 91177308-0d34-0410-b5e6-96231b3b80d8
implementation that is correct for most targets. Tablegen will override where
needed.
Add MachineOperand::subst{Virt,Phys}Reg methods that correctly handle existing
subreg indices when sustituting registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104985 91177308-0d34-0410-b5e6-96231b3b80d8
optimization level.
This only really affects llc for now because both the llvm-gcc and clang front
ends override the default register allocator. I intend to remove that code later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104904 91177308-0d34-0410-b5e6-96231b3b80d8
implementing pop with a linear search for a "best" element. The priority
queue was a neat idea, but in practice the comparison functions depend
on dynamic information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104718 91177308-0d34-0410-b5e6-96231b3b80d8
If you have a setjmp/longjmp situation, it's possible for stack slot coloring to
reuse a stack slot before it's really dead. For instance, if we have something
like this:
1: y = g;
x = sigsetjmp(env, 0);
switch (x) {
case 1:
/* ... */
goto run;
case 0:
run:
do_run(); /* marked as "no return" */
break;
case 3:
if (...) {
/* ... */
goto run;
}
/* ... */
break;
}
2: g = y;
"y" may be put onto the stack, so the expression "g = y" is relying upon the
fact that the stack slot containing "y" isn't modified between (1) and (2). But
it can be, because of the "no return" calls in there. A longjmp might come back
with 3, modify the stack slot, and then go to case 0. And it's perfectly
acceptable to reuse the stack slot there because there's no CFG flow from case 3
to (2).
The fix is to disable certain optimizations in these situations. Ideally, we'd
disable them for all "returns twice" functions. But we don't support that
attribute. Check for "setjmp" and "sigsetjmp" instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104640 91177308-0d34-0410-b5e6-96231b3b80d8
Mon Ping provided; unfortunately bugpoint failed to
reduce it, but I think it's important to have a test for
this in the suite. 8023512.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104624 91177308-0d34-0410-b5e6-96231b3b80d8
