and the RegisterScavenger not to expect traditional liveness
techniques are applicable to these registers, since we don't fully
modify the effects of push and pop after stackification.
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which are identical to the original patterns.
- Change the multiply with overflow so that we distinguish between signed and
unsigned multiplication. Currently, unsigned multiplication with overflow
isn't working!
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ISD::ADD to emit an implicit EFLAGS. This was horribly broken. Instead, replace
the intrinsic with an ISD::SADDO node. Then custom lower that into an
X86ISD::ADD node with a associated SETCC that checks the correct condition code
(overflow or carry). Then that gets lowered into the correct X86::ADDOvf
instruction.
Similar for SUB and MUL instructions.
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overflow/carry from the "arithmetic with overflow" intrinsics. It searches the
machine basic block from bottom to top to find the SETO/SETC instruction that is
its conditional. If an instruction modifies EFLAGS before it reaches the
SETO/SETC instruction, then it defaults to the normal instruction emission.
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target-independent way of determining overflow on multiplication. It's very
tricky. Patch by Zoltan Varga!
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complete. For instance, it lowers the common case into this less-than-optimal
code:
addl %ecx, %eax
seto %cl
testb %cl, %cl
jne LBB1_2 ## overflow
instead of:
addl %ecx, %eax
jo LBB1_2 ## overflow
That will come in a future commit.
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and use it in x86 address mode folding. Also, make
getRegForValue return 0 for illegal types even if it has a
ValueMap for them, because Argument values are put in the
ValueMap. This fixes PR3181.
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loops when they can be subsumed into addressing modes.
Change X86 addressing mode check to realize that
some PIC references need an extra register.
(I believe this is correct for Linux, if not, I'm sure
someone will tell me.)
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1. GlobalBaseReg may have been spilled.
2. It may not be live at the use.
3. Spiller doesn't know this is happening so it won't prevent GlobalBaseReg from being spilled later (That by itself is a nasty hack. It's needed because we don't insert the reload until later).
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the frame reference. This will help post-RA scheduling determine
that spills to distinct stack slots are independent.
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foldMemoryOperand how to "fold" them, by converting them into constant-pool
loads. When they aren't folded, they use xorps/cmpeqd, but for example when
register pressure is high, they may now be folded as memory operands, which
reduces register pressure.
Also, mark V_SET0 isAsCheapAsAMove so that two-address-elimination will
remat it instead of copying zeros around (V_SETALLONES was already marked).
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delegates to the regular x86-32 convention which handles byval, but only
after it handles a few cases, and it's necessary to handle byval before
handling those cases. This fixes PR3122 (and rdar://6400815), llvm-gcc
miscompiling LLVM.
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- LowerXADDO lowers [SU]ADDO into an ADD with an implicit EFLAGS define. The
EFLAGS are fed into a SETCC node which has the conditional COND_O or COND_C,
depending on the type of ADDO requested.
- LowerBRCOND now recognizes if it's coming from a SETCC node with COND_O or
COND_C set.
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MERGE_VALUES node with only one operand, so get
rid of special code that only existed to handle
that possibility.
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ReplaceNodeResults: rather than returning a node which
must have the same number of results as the original
node (which means mucking around with MERGE_VALUES,
and which is also easy to get wrong since SelectionDAG
folding may mean you don't get the node you expect),
return the results in a vector.
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the conditional for the BRCOND statement. For instance, it will generate:
addl %eax, %ecx
jo LOF
instead of
addl %eax, %ecx
; About 10 instructions to compare the signs of LHS, RHS, and sum.
jl LOF
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- Mark "add with overflow" as having a custom lowering for X86. Give it a null
lowering representation for now.
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well as 2 files that use "Registrator"s. These are to be used by the
MSVC builds, as the Win32 linker does not include libs that are
otherwise unreferenced, even if global constructors in the lib have
side-effects.
Patch by Scott Graham!
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(actually, code already all worked, only the comment
changed). Use this to implement 'A' constraint on x86.
Fixes PR 1779.
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special-purpose hook to a new pass. Also, add check to see if any
x87 virtual registers are used, to avoid doing any work in the
common case that no x87 code is needed.
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to be sign-extended when it is promoted to 64 bits for intermediate
offset calculations. The offset calculations are done as uint64_t so that
overflow conditions are well defined.
This fixes a problem which is currently hidden by the x86 AsmPrinter but
which was exposed by r58917 (which is temporarily reverted). See PR3027
for details.
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FIXME: it seems, that most of targets don't support
offsets wrt CPI/GlobalAddress', was it intentional?
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This is a temporary fix for the -print-emitted-asm option, where
errs() is used as the stream, in the case where other code is
using stderr without using errs()' buffer. Hopefully soon we'll
fix errs() to be non-buffered instead. Patch by Preston Gurd.
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priority function. Instead, just iterate over the AllNodes list, which is
already in topological order. This eliminates a fair amount of bookkeeping,
and speeds up the isel phase by about 15% on many testcases.
The impact on most targets is that AddToISelQueue calls can be simply removed.
In the x86 target, there are two additional notable changes.
The rule-bending AND+SHIFT optimization in MatchAddress that creates new
pre-isel nodes during isel is now a little more verbose, but more robust.
Instead of either creating an invalid DAG or creating an invalid topological
sort, as it has historically done, it can now just insert the new nodes into
the node list at a position where they will be consistent with the topological
ordering.
Also, the address-matching code has logic that checked to see if a node was
"already selected". However, when a node is selected, it has all its uses
taken away via ReplaceAllUsesWith or equivalent, so it won't recieve any
further visits from MatchAddress. This code is now removed.
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have its node id set. The new and and shift nodes are the nodes that need
the IDs. This fixes PR2982.
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callee-saved restore code. It could skip over conditional jumps
accidentally. Instead, just skip the "return" instructions.
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a memset using 16-byte XMM stores, but where the stack realignment code
didn't work. Until it does (PR2962) disable use of xmm regs in memcpy
and memset formation for linux and other targets with insufficiently
aligned stacks.
This is part of PR2888
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flag. Then in a debugger developers can set breakpoints at these calls
to see waht is about to be selected and what the resulting subgraph
looks like. This really helps when debugging instruction selection.
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target-independent code to target-specific code. This prevents it
from running on targets that aren't using fast-isel.
In addition to saving compile time, this addresses the problem
that not all targets are prepared for it. In order to use this
pass, all instructions must declare all their fixed uses and
defs of physical registers.
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variable is moved to the execution engine. The JIT calls the TargetJITInfo
to allocate thread local storage. Currently, only linux/x86 knows how to
allocate thread local global variables.
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LHS is a foldable load, then LHS and RHS are swapped
and SetCCOpcode is changed to SETUGT. But the later
code is expecting operands to be the wrong way round
for SETUGT, but they are not in this case, resulting
in an inverted compare. The solution is to move the
load normalization before the correction for SETUGT.
This bug was tickled by LegalizeTypes which happened
to legalize the testcase slightly differently to
LegalizeDAG.
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assume that i64 has been turned into a BUILD_PAIR
node (when called from LegalizeTypes this hasn't
happened yet) and don't use a vector shuffle mask
with an illegal element type.
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The same one Apple gcc uses, faster. Also gets the
extreme case in gcc.c-torture/execute/ieee/rbug.c
correct which we weren't before; this is not
sufficient to get the test to pass though, there
is another bug.
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in the 32-bit signed offset field of addresses. Even though this
may be intended, some linkers refuse to relocate code where the
relocated address computation overflows.
Also, fix the sign-extension of constant offsets to use the
actual pointer size, rather than the size of the GlobalAddress
node, which may be different, for example on x86-64 where MVT::i32
is used when the address is being fit into the 32-bit displacement
field.
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Where previously LLVM might emit code like this:
ucomisd %xmm1, %xmm0
setne %al
setp %cl
orb %al, %cl
jne .LBB4_2
it now emits this:
ucomisd %xmm1, %xmm0
jne .LBB4_2
jp .LBB4_2
It has fewer instructions and uses fewer registers, but it does
have more branches. And in the case that this code is followed by
a non-fallthrough edge, it may be followed by a jmp instruction,
resulting in three branch instructions in sequence. Some effort
is made to avoid this situation.
To achieve this, X86ISelLowering.cpp now recognizes FCMP_OEQ and
FCMP_UNE in lowered form, and replace them with code that emits
two branches, except in the case where it would require converting
a fall-through edge to an explicit branch.
Also, X86InstrInfo.cpp's branch analysis and transform code now
knows now to handle blocks with multiple conditional branches. It
uses loops instead of having fixed checks for up to two
instructions. It can now analyze and transform code generated
from FCMP_OEQ and FCMP_UNE.
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the copy instruction from the instruction list before asking the
target to create the new instruction. This gets the old instruction
out of the way so that it doesn't interfere with the target's
rematerialization code. In the case of x86, this helps it find
more cases where EFLAGS is not live.
Also, in the X86InstrInfo.cpp, teach isSafeToClobberEFLAGS to check
to see if it reached the end of the block after scanning each
instruction, instead of just before. This lets it notice when the
end of the block is only two instructions away, without doing any
additional scanning.
These changes allow rematerialization to clobber EFLAGS in more
cases, for example using xor instead of mov to set the return value
to zero in the included testcase.
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LowerOperation if it doesn't know what else to do.
This methods should probably be factorized some,
but this is good enough for the moment. Have
LowerATOMIC_BINARY_64 use EXTRACT_ELEMENT rather
than assuming the operand is a BUILD_PAIR (if it
is then getNode will automagically simplify the
EXTRACT_ELEMENT). This way LowerATOMIC_BINARY_64
usable from LegalizeTypes.
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and add a TargetLowering hook for it to use to determine when this
is legal (i.e. not in PIC mode, etc.)
This allows instruction selection to emit folded constant offsets
in more cases, such as the included testcase, eliminating the need
for explicit arithmetic instructions.
This eliminates the need for the C++ code in X86ISelDAGToDAG.cpp
that attempted to achieve the same effect, but wasn't as effective.
Also, fix handling of offsets in GlobalAddressSDNodes in several
places, including changing GlobalAddressSDNode's offset from
int to int64_t.
The Mips, Alpha, Sparc, and CellSPU targets appear to be
unaware of GlobalAddress offsets currently, so set the hook to
false on those targets.
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in 32-bit mode instead of assigning a register pair. This has nothing to
do with PR2356, but I happened to notice it while working on it.
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use a SUB instruction instead of an ADD, because -128 can be
encoded in an 8-bit signed immediate field, while +128 can't be.
This avoids the need for a 32-bit immediate field in this case.
A similar optimization applies to 64-bit adds with 0x80000000,
with the 32-bit signed immediate field.
To support this, teach tablegen how to handle 64-bit constants.
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shift counts, and patterns that match dynamic shift counts
when the subtract is obscured by a truncate node.
Add DAGCombiner support for recognizing rotate patterns
when the shift counts are defined by truncate nodes.
Fix and simplify the code for commuting shld and shrd
instructions to work even when the given instruction doesn't
have a parent, and when the caller needs a new instruction.
These changes allow LLVM to use the shld, shrd, rol, and ror
instructions on x86 to replace equivalent code using two
shifts and an or in many more cases.
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x86 backend. These will all be answered with "patches welcome", so
a PR doesn't help drive them along.
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the predicates by extending simple predicates to create
more complex predicates instead of duplicating the logic
for the simple predicates.
This doesn't reduce much redundancy in DAGISelEmitter.cpp's
generated source yet; that will require improvements to
DAGISelEmitter.cpp's instruction sorting, to make it more
effectively group nodes with similar predicates together.
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are due to argument passing in calls. This is significant because
it hits all immediate arguments to calls on x86-32.
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1. Compute action in X86SelectSelect based on MVT instead of type.
2. Use TLI.getValueType(..) instead of MVT::getVT(..) because the former
handles pointers and the later doesn't.
3. Don't pass TLI into isTypeLegal, since it already has access to it as
an ivar.
#2 gives fast isel some minor new functionality: handling load/stores of
pointers.
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which makes it easy to share the compare/imm folding logic with 'setcc'.
This shaves a bunch of instructions off the common select case, which
happens a lot in llvm-gcc.
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i.e. conditions that cannot be checked with a single instruction. For example,
SETONE and SETUEQ on x86.
- Teach legalizer to implement *illegal* setcc as a and / or of a number of
legal setcc nodes. For now, only implement FP conditions. e.g. SETONE is
implemented as SETO & SETNE, SETUEQ is SETUO | SETEQ.
- Move x86 target over.
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- Move the EH landing-pad code and adjust it so that it works
with FastISel as well as with SDISel.
- Add FastISel support for @llvm.eh.exception and
@llvm.eh.selector.
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instead of requiring all "short description" strings to begin with
two spaces. This makes these strings less mysterious, and it fixes
some cases where short description strings mistakenly did not
begin with two spaces.
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create a new DAG node to represent the new shift to keep the
DAG consistent, even though it'll almost always be folded into
the address.
If a user of the resulting address has multiple uses, the
nodes may get revisited by a later MatchAddress call, in which
case DAG inconsistencies do matter.
This fixes PR2849.
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parameters instead of raw Constants. This prevents the constants from
being selected by the isel pass, fixing PR2735.
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the same pattern as roundpd/roundps, the Intel compiler
builtins do not: rounds* has an extra operand. Fixes
gcc.target/i386/sse4_1-rounds[sd]-[1234].c
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SDISel typically adds them in. This makes it a little easier
to compare FastISel output with SDISel output.
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X86::CL that was used, emit an EXTRACT_SUBREG from the CL
super-register to CL. This more precisely describes how the
CL register is being used.
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Instead, just create one, and make sure everything that needs
it can access it. Previously most of the SelectionDAGISel
subclasses all had their own TargetLowering object, which was
redundant with the TargetLowering object in the TargetMachine
subclasses, except on Sparc, where SparcTargetMachine
didn't have a TargetLowering object. Change Sparc to work
more like the other targets here.
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local register allocator's physreg liveness doesn't recognize subregs,
so it doesn't know that defs of %ecx that are immediately followed by
uses of %cl aren't dead. This comes up due to the way fast-isel emits
shift instructions.
This is a temporary workaround. Arguably, local regalloc should
handle subreg references correctly. On the other hand, perhaps
fast-isel should use INSERT_SUBREG instead of just assigning to the
most convenient super-register of %cl when lowering shifts.
This fixes MultiSource/Benchmarks/MallocBench/espresso,
MultiSource/Applications/hexxagon, and others, under -fast.
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a constant vector ("{0x123, 0x456}" syntax). The fix is to simplify the
_mm_srli_si128 macro, and move the "* 8" from the macro into the compiler
back-end. I can't change the existing __builtins because so many people are
using them :-(."
Patch by Stuart Hastings!
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This allows the 64-bit forms to use+def RSP instead of ESP. This
doesn't fix any real bugs today, but it is more precise and it
makes the debug dumps on x86-64 look more consistent.
Also, add some comments describing the CALL instructions' physreg
operand uses and defs.
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`-fno-builtin' flag. Currently, it's used to replace "memset" with "_bzero"
instead of "__bzero" on Darwin10+. This arguably violates the meaning of this
flag, but is currently sufficient. The meaning of this flag should become more
specific over time.
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Completely eliminate the TopOrder std::vector. Instead, sort
the AllNodes list in place. This also eliminates the need to
call AllNodes.size(), a linear-time operation, before
performing the sort.
Also, eliminate the Sources temporary std::vector, since it
essentially duplicates the sorted result as it is being
built.
This also changes the direction of the topological sort
from bottom-up to top-down. The AllNodes list starts out in
roughly top-down order, so this reduces the amount of
reordering needed. Top-down is also more convenient for
Legalize, and ISel needed only minor adjustments.
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and X86FastISel.cpp into X86MachineFunction.h, so that it
can be shared, instead of having each selector keep track
of its own.
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its size). Adjust various lowering functions to
pass this info through from CallInst. Use it to
implement sseregparm returns on X86. Remove
X86_ssecall calling convention.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56677 91177308-0d34-0410-b5e6-96231b3b80d8
require RIP-relative addressing and use it to fix a bug
in X86FastISel in x86-64 PIC mode, where it was trying to
use base/index registers with RIP-relative addresses. This
fixes a bunch of x86-64 testsuite failures.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56676 91177308-0d34-0410-b5e6-96231b3b80d8
information is in an unreachable block, then it's possible that the high/low pc
values won't be set for the dwarf information. E.g., this function:
void abort(void) __attribute__((__noreturn__));
void dead_beef(void) __attribute__ ((noreturn));
int *b;
void dead_beef(void) {
*b=0xdeadbeef;
abort();
}
has a call to "@llvm.dbg.region.end" only in the unreachable block:
define void @dead_beef() noreturn nounwind {
entry:
call void @llvm.dbg.func.start(...)
call void @llvm.dbg.stoppoint(...)
...
call void @abort( ) noreturn nounwind
unreachable
return: ; No predecessors!
call void @llvm.dbg.stoppoint(...)
call void @llvm.dbg.region.end(...)
ret void
}
The dwarf information emitted is something like:
0x00000084: TAG_subprogram [5]
AT_name( "dead_beef" )
AT_external( 0x01 )
AT_prototyped( 0x01 )
AT_decl_file( 0x01 )
AT_decl_line( 0x08 )
Note that this is *not* the best fix for this problem, but a band-aid for an
gaping wound. This code needs to be changed when we revamp our debugging
information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56628 91177308-0d34-0410-b5e6-96231b3b80d8
