is.
- The problem is that formatted_ostream forces its underlying buffer to be
unbuffered, so if some client happens to wrap a formatted_ostream around
something, but still use the underlying stream, then we can end up writing on
a fully unbuffered output (which was never intended to be unbuffered).
- This makes clang (and presumably llvm-gcc) -emit-llvm -S a mere 10x faster.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82434 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
stringref because they may not be nul terminated. For options like -Lfoo
this now avoids a O(n) temporary std::strings where N is the length of
the string after -L.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82345 91177308-0d34-0410-b5e6-96231b3b80d8
a massive number of temporary strings created when parsing a command line.
More still left to eliminate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82318 91177308-0d34-0410-b5e6-96231b3b80d8
to. This can be combined with LCSSA or SSI form to store more information on a
PHINode than can be computed by looking at its incoming values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82317 91177308-0d34-0410-b5e6-96231b3b80d8
this is run after the 'standard function passes', SRoA was
recently run. This saves a domfrontier construction. Thanks
to Eli for noticing this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82291 91177308-0d34-0410-b5e6-96231b3b80d8
In getMallocArraySize(), fix bug in the case that array size is the product of 2 constants.
Extend isArrayMalloc() and getMallocArraySize() to handle case where malloc is used as char array.
Ensure that ArraySize in LowerAllocations::runOnBasicBlock() is correct type.
Extend Instruction::isSafeToSpeculativelyExecute() to handle malloc calls.
Add verification for malloc calls.
Reviewed by Dan Gohman.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82257 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
instead of the PtrTraits provided. Allows PointerIntPair to contain a
PointerUnion safely, as long as the bits add up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82163 91177308-0d34-0410-b5e6-96231b3b80d8
where the induction variable has a non-unit stride, such as {0,+,2}, and
there are expressions such as {1,+,2} inside the loop formed with
or or add nsw operators.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82151 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
instead of cloning and RAUWing it.
- Make AbstractTypeUser a friend of Value so that it can offer
its subclasses a way to update a Value's type in place. This
is better than a universally visible setType method on Value,
and it's sufficient for the immediate need.
- Eliminate the constant "convert" functions. This eliminates a
lot of logic duplication, and fixes a complicated bug where a
constant can't actually be cloned during the type refinement
process because some of the types that its folder needs are
half-destroyed, being in the middle of refinement themselves.
- Move the getValType functions from being static overloaded
functions in Constants.cpp to be members of class template
specializations in ConstantsContext.h. This means that the
code ends up getting instantiated twice, however it also
makes it possible to eliminate all "convert" functions, so
it's not a big net code size increase. And if desired, the
duplicate instantiations could be eliminated with some
reorganization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81861 91177308-0d34-0410-b5e6-96231b3b80d8
argpromote to avoid invalidating an iterator. This fixes PR4977.
All clang tests now pass with expensive checking (on my system
at least).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81843 91177308-0d34-0410-b5e6-96231b3b80d8
GetProcessId was introduced only in XP. As a bonus, this change makes Program
objects copyable, since Program is now basically a PID.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81826 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
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
working. To support this, add an is_displayed() function to raw_ostream,
and generalize Process::StandardOutIsDisplayed and friends in order to
support it.
Also, call RemoveFileOnSignal before creating a file instead of after, so
that the file isn't left behind if the program is interrupted between when
the file is created and RemoveFileOnSignal is called.
While here, add a -S to llvm-extract and port it to IRReader so that it
supports assembly input.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81568 91177308-0d34-0410-b5e6-96231b3b80d8
(uniqued if unnamed) global variable name with the prefix that
it is supposed to get. It doesn't do "mangling" in the sense of
adding quotes and hacking on bad characters.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81505 91177308-0d34-0410-b5e6-96231b3b80d8
within the notional bounds of the static type of the getelementptr (which
is not the same as "inbounds") from GlobalOpt into a utility routine,
and use it in ConstantFold.cpp to check whether there are any mis-behaved
indices.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81478 91177308-0d34-0410-b5e6-96231b3b80d8
that things like .word can be parsed as target specific. Moved parsing .word
out of AsmParser.cpp into X86AsmParser.cpp as it is 2 bytes on X86 and 4 bytes
for other targets that support the .word directive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81461 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
all disassemblers.
Modified the MemoryObject to support 64-bit address
spaces, regardless of the LLVM process's address
width.
Modified the Target class to allow extraction of a
MCDisassembler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81392 91177308-0d34-0410-b5e6-96231b3b80d8
