to emit target-specific things at the beginning of the asm output. This
fixes a problem for PPC, where the text sections are not being kept together
as expected. The base class doInitialization code calls DW->BeginModule()
which emits a bunch of DWARF section directives. The PPC doInitialization
code then emits all the TEXT section directives, with the intention that they
will be kept together. But as I understand it, the Darwin assembler treats
the default TEXT section as a special case and moves it to the beginning of
the file, which means that all those DWARF sections are in the middle of
the text. With this change, the EmitStartOfAsmFile hook is called before
the DWARF section directives are emitted, so that all the PPC text section
directives come out right at the beginning of the file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83176 91177308-0d34-0410-b5e6-96231b3b80d8
basic blocks that are so long that their size overflows a short.
Also assert that overflow does not happen in the future, as requested by Evan.
This fixes PR4401.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83159 91177308-0d34-0410-b5e6-96231b3b80d8
information. This allows arbitrary code involving DW_OP_plus_uconst
and DW_OP_deref. The scheme allows for easy extention to include,
any, or all of the DW_OP_ opcodes. I thought about just exposing all
of them, but, wasn't sure if people wanted the dwarf opcodes exposed
in the api. Is that a layering violation?
With this scheme, the entire existing block scheme used by llvm-gcc
can be switched over to the new scheme. I think that would be
cleaner, as then the compiler specific bits are not present in llvm
proper. Before the old code can be yanked however, similar code in
clang would have to be removed.
Next up, more testing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83120 91177308-0d34-0410-b5e6-96231b3b80d8
so a simple "current register" will suffice. Also add some additional
sanity-checking assertions to make sure things are as we expect.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83081 91177308-0d34-0410-b5e6-96231b3b80d8
the instruction we're scavenging for. The scavenger needs to know to avoid
them when analyzing register usage.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83077 91177308-0d34-0410-b5e6-96231b3b80d8
physical registers. This is especially critical for the later two since they
start the live interval of a super-register. e.g.
%DO<def> = INSERT_SUBREG %D0<undef>, %S0<kill>, 1
If this instruction is eliminated, the register scavenger will not be happy as
D0 is not defined previously.
This fixes PR5055.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82968 91177308-0d34-0410-b5e6-96231b3b80d8
allocatable. Even if it doesn't appear to have any defs, it may latter
on after register allocation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82834 91177308-0d34-0410-b5e6-96231b3b80d8
which have no defs anywhere in the function. In particular, this fixes sinking
of instructions that reference RIP on x86-64, which is currently being modeled
as a register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82815 91177308-0d34-0410-b5e6-96231b3b80d8
- Allocate MachineMemOperands and MachineMemOperand lists in MachineFunctions.
This eliminates MachineInstr's std::list member and allows the data to be
created by isel and live for the remainder of codegen, avoiding a lot of
copying and unnecessary translation. This also shrinks MemSDNode.
- Delete MemOperandSDNode. Introduce MachineSDNode which has dedicated
fields for MachineMemOperands.
- Change MemSDNode to have a MachineMemOperand member instead of its own
fields with the same information. This introduces some redundancy, but
it's more consistent with what MachineInstr will eventually want.
- Ignore alignment when searching for redundant loads for CSE, but remember
the greatest alignment.
Target-specific code which previously used MemOperandSDNodes with generic
SDNodes now use MemIntrinsicSDNodes, with opcodes in a designated range
so that the SelectionDAG framework knows that MachineMemOperand information
is available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82794 91177308-0d34-0410-b5e6-96231b3b80d8
naming scheme used in SelectionDAG, where there are multiple kinds
of "target" nodes, but "machine" nodes are nodes which represent
a MachineInstr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82790 91177308-0d34-0410-b5e6-96231b3b80d8
before producing FSIN, FCOS, FSQRT. If they aren't
so marked we have to assume they might set errno.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82781 91177308-0d34-0410-b5e6-96231b3b80d8
allows appropriate backends to generate a sqrt instruction.
On x86, this isn't done at -O0 because we go through
FastISel instead. This is a behavior change from before
this series of sqrt patches started. I think this is OK
considering that compile speed is most important at -O0, but
could be convinced otherwise.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82778 91177308-0d34-0410-b5e6-96231b3b80d8
For the AAPCS ABI, SP must always be 4-byte aligned, and at any "public
interface" it must be 8-byte aligned. For the older ARM APCS ABI, the stack
alignment is just always 4 bytes. For X86, we currently align SP at
entry to a function (e.g., to 16 bytes for Darwin), but no stack alignment
is needed at other times, such as for a leaf function.
After discussing this with Dan, I decided to go with the approach of adding
a new "TransientStackAlignment" field to TargetFrameInfo. This value
specifies the stack alignment that must be maintained even in between calls.
It defaults to 1 except for ARM, where it is 4. (Some other targets may
also want to set this if they have similar stack requirements. It's not
currently required for PPC because it sets targetHandlesStackFrameRounding
and handles the alignment in target-specific code.) The existing StackAlignment
value specifies the alignment upon entry to a function, which is how we've
been using it anyway.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82767 91177308-0d34-0410-b5e6-96231b3b80d8
interest for this, as it currently reserves a register rather than using
the scavenger for matierializing constants as needed.
Instead of scavenging registers on the fly while eliminating frame indices,
new virtual registers are created, and then a scavenged collectively in a
post-pass over the function. This isolates the bits that need to interact
with the scavenger, and sets the stage for more intelligent use, and reuse,
of scavenged registers.
For the time being, this is disabled by default. Once the bugs are worked out,
the current scavenging calls in replaceFrameIndices() will be removed and
the post-pass scavenging will be the default. Until then,
-enable-frame-index-scavenging enables the new code. Currently, only the
Thumb1 back end is set up to use it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82734 91177308-0d34-0410-b5e6-96231b3b80d8
LocalAreaOffset. (We don't have any of those right now.)
PEI::calculateFrameObjectOffsets includes the absolute value of the
LocalAreaOffset in the cumulative offset value used to calculate the
stack frame size. It then adds the raw value of the LocalAreaOffset
to the stack size. For a StackGrowsDown target, that raw value is negative
and has the effect of cancelling out the absolute value that was added
earlier, but that obviously won't work for a StackGrowsUp target. Change
to subtract the absolute value of the LocalAreaOffset.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82693 91177308-0d34-0410-b5e6-96231b3b80d8
LiveVariables add implicit kills to correctly track partial register kills. This works well enough and is fairly accurate. But coalescer can make it impossible to maintain these markers. e.g.
BL <ga:sss1>, %R0<kill,undef>, %S0<kill>, %R0<imp-def>, %R1<imp-def,dead>, %R2<imp-def,dead>, %R3<imp-def,dead>, %R12<imp-def,dead>, %LR<imp-def,dead>, %D0<imp-def>, ...
...
%reg1031<def> = FLDS <cp#1>, 0, 14, %reg0, Mem:LD4[ConstantPool]
...
%S0<def> = FCPYS %reg1031<kill>, 14, %reg0, %D0<imp-use,kill>
When reg1031 and S0 are coalesced, the copy (FCPYS) will be eliminated the the implicit-kill of D0 is lost. In this case it's possible to move the marker to the FLDS. But in many cases, this is not possible. Suppose
%reg1031<def> = FOO <cp#1>, %D0<imp-def>
...
%S0<def> = FCPYS %reg1031<kill>, 14, %reg0, %D0<imp-use,kill>
When FCPYS goes away, the definition of S0 is the "FOO" instruction. However, transferring the D0 implicit-kill to FOO doesn't work since it is the def of D0 itself. We need to fix this in another time by introducing a "kill" pseudo instruction to track liveness.
Disabling the assertion is not ideal, but machine verifier is doing that job now. It's important to know double-def is not a miscomputation since it means a register should be free but it's not tracked as free. It's a performance issue instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82677 91177308-0d34-0410-b5e6-96231b3b80d8
The machine code verifier did not check for explicit operands correctly. It
used MachineInstr::getNumExplicitOperands, but that method may cheat and use
the declared count in the TargetInstrDesc.
Now we check the explicit operands one at a time in visitMachineOperand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82652 91177308-0d34-0410-b5e6-96231b3b80d8
of the defs are processed.
Also fix a implicit_def propagation bug: a implicit_def of a physical register
should be applied to uses of the sub-registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82616 91177308-0d34-0410-b5e6-96231b3b80d8
two different places for printing MachineMemOperands.
Drop the virtual from Value::dump and instead give Value a
protected virtual hook that can be overridden by subclasses
to implement custom printing. This lets printing be more
consistent, and simplifies printing of PseudoSourceValue
values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82599 91177308-0d34-0410-b5e6-96231b3b80d8
%S0<def> = EXTRACT_SUBREG %Q0<kill>, 1
to
%S0<def> = IMPLICIT_DEF %Q0<imp-use,kill>
Implicit_def does not *read* any register so the operand should be marked "implicit". The missing "implicit" marker on the operand is wrong, but it doesn't actually break anything.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82503 91177308-0d34-0410-b5e6-96231b3b80d8
variable increment / decrement slighter high priority.
This has major impact on some micro-benchmarks. On MultiSource/Applications
and spec tests, it's a minor win. It also reduce 256.bzip instruction count
by 8%, 55 on 164.gzip on i386 / Darwin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82485 91177308-0d34-0410-b5e6-96231b3b80d8
the base pointer, without the offset. This matches MemSDNode's
new alignment behavior, and holds more interesting information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82473 91177308-0d34-0410-b5e6-96231b3b80d8
The machine code verifier no longer tolerates phi instructions with noop
operands. All MBBs on a phi instruction must be in the CFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82448 91177308-0d34-0410-b5e6-96231b3b80d8
feature, either build the JIT in debug mode to enable it by default or pass
-jit-emit-debug to lli.
Right now, the only debug information that this communicates to GDB is call
frame information, since it's already being generated to support exceptions in
the JIT. Eventually, when DWARF generation isn't tied so tightly to AsmPrinter,
it will be easy to push that information to GDB through this interface.
Here's a step-by-step breakdown of how the feature works:
- The JIT generates the machine code and DWARF call frame info
(.eh_frame/.debug_frame) for a function into memory.
- The JIT copies that info into an in-memory ELF file with a symbol for the
function.
- The JIT creates a code entry pointing to the ELF buffer and adds it to a
linked list hanging off of a global descriptor at a special symbol that GDB
knows about.
- The JIT calls a function marked noinline that GDB knows about and has put an
internal breakpoint in.
- GDB catches the breakpoint and reads the global descriptor to look for new
code.
- When sees there is new code, it reads the ELF from the inferior's memory and
adds it to itself as an object file.
- The JIT continues, and the next time we stop the program, we are able to
produce a proper backtrace.
Consider running the following program through the JIT:
#include <stdio.h>
void baz(short z) {
long w = z + 1;
printf("%d, %x\n", w, *((int*)NULL)); // SEGFAULT here
}
void bar(short y) {
int z = y + 1;
baz(z);
}
void foo(char x) {
short y = x + 1;
bar(y);
}
int main(int argc, char** argv) {
char x = 1;
foo(x);
}
Here is a backtrace before this patch:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x2aaaabdfbd10 (LWP 25476)]
0x00002aaaabe7d1a8 in ?? ()
(gdb) bt
#0 0x00002aaaabe7d1a8 in ?? ()
#1 0x0000000000000003 in ?? ()
#2 0x0000000000000004 in ?? ()
#3 0x00032aaaabe7cfd0 in ?? ()
#4 0x00002aaaabe7d12c in ?? ()
#5 0x00022aaa00000003 in ?? ()
#6 0x00002aaaabe7d0aa in ?? ()
#7 0x01000002abe7cff0 in ?? ()
#8 0x00002aaaabe7d02c in ?? ()
#9 0x0100000000000001 in ?? ()
#10 0x00000000014388e0 in ?? ()
#11 0x00007fff00000001 in ?? ()
#12 0x0000000000b870a2 in llvm::JIT::runFunction (this=0x1405b70,
F=0x14024e0, ArgValues=@0x7fffffffe050)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/JIT/JIT.cpp:395
#13 0x0000000000baa4c5 in llvm::ExecutionEngine::runFunctionAsMain
(this=0x1405b70, Fn=0x14024e0, argv=@0x13f06f8, envp=0x7fffffffe3b0)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/ExecutionEngine.cpp:377
#14 0x00000000007ebd52 in main (argc=2, argv=0x7fffffffe398,
envp=0x7fffffffe3b0) at /home/rnk/llvm-gdb/tools/lli/lli.cpp:208
And a backtrace after this patch:
Program received signal SIGSEGV, Segmentation fault.
0x00002aaaabe7d1a8 in baz ()
(gdb) bt
#0 0x00002aaaabe7d1a8 in baz ()
#1 0x00002aaaabe7d12c in bar ()
#2 0x00002aaaabe7d0aa in foo ()
#3 0x00002aaaabe7d02c in main ()
#4 0x0000000000b870a2 in llvm::JIT::runFunction (this=0x1405b70,
F=0x14024e0, ArgValues=...)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/JIT/JIT.cpp:395
#5 0x0000000000baa4c5 in llvm::ExecutionEngine::runFunctionAsMain
(this=0x1405b70, Fn=0x14024e0, argv=..., envp=0x7fffffffe3c0)
at /home/rnk/llvm-gdb/lib/ExecutionEngine/ExecutionEngine.cpp:377
#6 0x00000000007ebd52 in main (argc=2, argv=0x7fffffffe3a8,
envp=0x7fffffffe3c0) at /home/rnk/llvm-gdb/tools/lli/lli.cpp:208
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82418 91177308-0d34-0410-b5e6-96231b3b80d8
U lib/CodeGen/AsmPrinter/DwarfException.cpp
U lib/CodeGen/AsmPrinter/DwarfException.h
--- Reverse-merging r82274 into '.':
U lib/Target/TargetLoweringObjectFile.cpp
G lib/CodeGen/AsmPrinter/DwarfException.cpp
These revisions were breaking everything.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82396 91177308-0d34-0410-b5e6-96231b3b80d8
internal, they shouldn't use the indirect pointer stuff. In the case of
throw_rethrow_test, it was marked as 'internal' and calculated its own offset to
its contents.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82354 91177308-0d34-0410-b5e6-96231b3b80d8
we pushed the beginning of the interval back 1, so the
interval would overlap with inputs that die. We were
also pushing the end of the interval back 1, though,
which means the earlyclobber didn't overlap with other
output operands. Don't do this. PR 4964.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82342 91177308-0d34-0410-b5e6-96231b3b80d8
into the __DATA section. At launch time, dyld has to update most of the section
to fix up the type info pointers. It's better to place it into the __TEXT
section and use pc-rel indirect pointer encodings. Similar to the personality
routine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82274 91177308-0d34-0410-b5e6-96231b3b80d8
This can be seen on CodeGen/Generic/2006-09-06-SwitchLowering.ll. But it's not known to cause any real regression (but I have added an assertion for it now).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82214 91177308-0d34-0410-b5e6-96231b3b80d8
constants out of loops. These aren't covered by the regular LICM
pass, because in LLVM IR constants don't require separate
instructions. They're not always covered by the MachineLICM pass
either, because it doesn't know how to unfold folded constant-pool
loads. This is somewhat experimental at this point, and off by
default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82076 91177308-0d34-0410-b5e6-96231b3b80d8
Eliminate the PersonalityPrefix/Suffix & NeedsIndirectEncoding
fields from MAI: they aren't part of the asm syntax, they are
related to the structure of the object file.
To replace their functionality, add a new
TLOF::getSymbolForDwarfGlobalReference method which asks targets
to decide how to reference a global from EH in a pc-relative way.
The default implementation just returns the symbol. The default
darwin implementation references the symbol through an indirect
$non_lazy_ptr stub. The bizarro x86-64 darwin specialization
handles the weird "foo@GOTPCREL+4" hack.
DwarfException.cpp now uses this to emit the reference to the
symbol in the right way, and this also eliminates another
horrible hack from DwarfException.cpp:
- if (strcmp(MAI->getPersonalitySuffix(), "+4@GOTPCREL"))
- O << "-" << MAI->getPCSymbol();
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81991 91177308-0d34-0410-b5e6-96231b3b80d8
one implementation into its one caller. This eliminates a totally
awesome and gratuitous hack where we casted a Function* to
GlobalVariable*.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81967 91177308-0d34-0410-b5e6-96231b3b80d8
1. Switch from an std::set to a SmallPtrSet for visited chain nodes.
2. Do not force the recursive flattening of token factor nodes, regardless of
use count.
3. Immediately process newly created TokenFactor nodes.
Also, improve combiner-aa by teaching it that loads to non-overlapping offsets
of relatively aligned objects cannot alias.
These changes result in a >5x speedup for combiner-aa on most testcases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81816 91177308-0d34-0410-b5e6-96231b3b80d8
DAG Combiner to disambiguate chains for loads and stores of types which are
broken up by the Legalizer into smaller pieces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81813 91177308-0d34-0410-b5e6-96231b3b80d8
The gist of this is if source of some of the copies that feed into a phi join is defined by the phi join, we'd like to eliminate them. However, if any of the non-identity source overlaps the live interval of the phi join then the coalescer won't be able to coalesce them. The early coalescer's job is to eliminate the identity copies by partially-coalescing the two live intervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81796 91177308-0d34-0410-b5e6-96231b3b80d8
created once, so shouldn't be stuck in the middle of the loop. Also early exit
if there are no uses of UnwindInst in the function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81785 91177308-0d34-0410-b5e6-96231b3b80d8
full AsmPrinter, and change TargetRegistry to keep track
of registered MCInstPrinters.
llvm-mc is still linking in the entire
target foo to get the code emitter stuff, but this is an
important step in the right direction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81754 91177308-0d34-0410-b5e6-96231b3b80d8
now that printBasicBlockLabel is only used for starting
a MBB. This allows elimination of a bunch of arguments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81684 91177308-0d34-0410-b5e6-96231b3b80d8
Move GetMBBSymbol up to AsmPrinter and make printBasicBlockLabel use it so that
we only have one place that decides what to name bb labels. Hopefully various
clients of printBasicBlockLabel can start using GetMBBSymbol instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81652 91177308-0d34-0410-b5e6-96231b3b80d8
object, the timer it creates was not being deleted. Since the
timer belonged to a static timer group, the timer group would
be destroyed on shutdown, and would notice and complain that
not all timers it contained were destroyed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81533 91177308-0d34-0410-b5e6-96231b3b80d8
from the exception tables. However, Duncan explained why it's a can of worms to
do it the GCC way. I went back to doing it the LLVM way and added Duncan's
explanation so that I don't do this again in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81434 91177308-0d34-0410-b5e6-96231b3b80d8
like what GCC outputs. The mysterious code to insert padding wasn't in GCC at
all. I modified the TType base offset code to calculate the offset like GCC
does, though.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81424 91177308-0d34-0410-b5e6-96231b3b80d8
code within it was the same inside and out. There's still a problem of the
TypeInfoSize should be the size of the TType format encoding (at least that's
what GCC thinks it should be).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81417 91177308-0d34-0410-b5e6-96231b3b80d8
Basically, this patch is working towards removing the hard-coded values that are
output for the CIE. In particular, the CIE augmentation and the CIE augmentation
size. Both of these should be calculated. In the process, I was able to make a
bunch of code simpler.
The encodings for the personality, LSDA, and FDE in the CIE are still not
correct. They should be generated either from target-specific callbacks (blech!)
or grokked from first-principles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81404 91177308-0d34-0410-b5e6-96231b3b80d8
the MCInst path of the asmprinter. Instead, pull comment printing
out of the autogenerated asmprinter into each target that uses the
autogenerated asmprinter. This causes code duplication into each
target, but in a way that will be easier to clean up later when more
asmprinter stuff is commonized into the base AsmPrinter class.
This also fixes an xcore strangeness where it inserted two tabs
before every instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81396 91177308-0d34-0410-b5e6-96231b3b80d8
to instructions instead of zero extended ones. This makes the asmprinter
print signed values more consistently. This apparently only really affects
the X86 backend.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81265 91177308-0d34-0410-b5e6-96231b3b80d8
instruction to insert before can be end(). getDebugLoc on
end() returns an invalid value, therefore use the debug
loc of the call instruction, and give it to InsertLabel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81207 91177308-0d34-0410-b5e6-96231b3b80d8
from floating-point to integer first, and bitcast the result
back to floating-point. Previously, this test was passing by
falling back to SelectionDAG lowering. The resulting code isn't
as nice, but it's correct and CodeGen now stays on the fast path.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81171 91177308-0d34-0410-b5e6-96231b3b80d8
Do not use DenseMap operator[] because it inserts new entry if lookup fails. Use find() to check an entry in a DenseMap first.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81058 91177308-0d34-0410-b5e6-96231b3b80d8
a new class, MachineInstrIndex, which hides arithmetic details from
most clients. This is a step towards allowing the register allocator
to update/insert code during allocation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81040 91177308-0d34-0410-b5e6-96231b3b80d8
for the complicated case where one register is tied to multiple destinations.
This avoids the extra scan of instruction operands that was introduced by
my recent change. I also pulled some code out into a separate
TryInstructionTransform method, added more comments, and renamed some
variables.
Besides all those changes, this takes care of a FIXME in the code regarding
an assumption about there being a single tied use of a register when
converting to a 3-address form. I'm not aware of cases where that assumption
is violated, but the code now only attempts to transform an instruction,
either by commuting its operands or by converting to a 3-address form,
for the simple case where there is a single pair of tied operands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80945 91177308-0d34-0410-b5e6-96231b3b80d8
avoid reloads by reusing clobbered registers.
This was causing issues in 256.bzip2 when compiled with PIC for
a while (starting at r78217), though the problem has since been masked.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80872 91177308-0d34-0410-b5e6-96231b3b80d8
tied to different source registers, the TwoAddressInstructionPass needs to
be smarter. Change it to check before replacing a source register whether
that source register is tied to a different destination register, and if so,
defer handling it until a subsequent iteration.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80654 91177308-0d34-0410-b5e6-96231b3b80d8
makes an eggregious hack somewhat more palatable. Bringing the LSDA forward
and making it a GV available for reference would be even better, but is
beyond the scope of what I'm looking to solve at this point.
Objective C++ code could generate function names that broke the previous
scheme. This fixes that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80649 91177308-0d34-0410-b5e6-96231b3b80d8
modify the type and location debug information for these variables to match the
programmer's expectations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80625 91177308-0d34-0410-b5e6-96231b3b80d8