The transform is somewhat involved, but the basic idea is simple: find
derived pointers that have been offset from the base pointer using gep
and replace the relocate of the derived pointer with a gep to the
relocated base pointer (with the same offset).
llvm-svn: 226060
Summary:
Some pseudo instruction expansions break down a wide register use into
multiple uses of smaller sub registers. If the super register was
partially undefined the broken down sub registers may be completely
undefined now leading to MachineVerifier complaints. Unfortunately
liveness information to add the required dead flags is not easily
(cheaply) available when expanding pseudo instructions.
This commit changes the verifier to be quiet if there is an additional
implicit use of a super register. Pseudo instruction expanders can use
this to mark cases where partially defined values get potentially broken
into completely undefined ones.
Differential Revision: http://reviews.llvm.org/D6973
llvm-svn: 226047
This patch stops the implicit creation of comdats during codegen.
Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.
llvm-svn: 226038
Some benchmarks have shown that this could lead to a potential
performance benefit, and so adding some flags to try to help measure the
difference.
A possible explanation. In diamond-shaped CFGs (A followed by either
B or C both followed by D), putting B and C both in between A and
D leads to the code being less dense than it could be. Always either
B or C have to be skipped increasing the chance of cache misses etc.
Moving either B or C to after D might be beneficial on average.
In the long run, but we should probably do a better job of analyzing the
basic block and branch probabilities to move the correct one of B or
C to after D. But even if we don't use this in the long run, it is
a good baseline for benchmarking.
Original patch authored by Daniel Jasper with test tweaks and a second
flag added by me.
Differential Revision: http://reviews.llvm.org/D6969
llvm-svn: 226034
This fixes lots of generic CodeGen tests that use __gcc_personality_v0.
This suggests that using ExceptionHandling::MSVC was a mistake, and we
should instead classify each function by personality function. This
would, for example, allow us to LTO a binary containing uses of SEH and
Itanium EH.
llvm-svn: 226019
utils/sort_includes.py.
I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.
llvm-svn: 225974
This option takes the name of the basic block you want to visualize
with -view-*-dags
Differential Revision: http://reviews.llvm.org/D6948
llvm-svn: 225953
In case folding a node end up with a NaN as operand for the select,
the folding of the condition of the selectcc node returns "UNDEF".
Differential Revision: http://reviews.llvm.org/D6889
llvm-svn: 225952
When processing an array, every Elt has the same layout, it is
useless to recursively call each ComputeLinearIndex on each element.
Just do it once and multiply by the number of elements.
Differential Revision: http://reviews.llvm.org/D6832
llvm-svn: 225949
Now that the source and destination types can be specified,
allow doing an expansion that doesn't use an EXTLOAD of the
result type. Try to do a legal extload to an intermediate type
and extend that if possible.
This generalizes the special case custom lowering of extloads
R600 has been using to work around this problem.
This also happens to fix a bug that would incorrectly use more
aligned loads than should be used.
llvm-svn: 225925
A pass that adds random noops to X86 binaries to introduce diversity with the goal of increasing security against most return-oriented programming attacks.
Command line options:
-noop-insertion // Enable noop insertion.
-noop-insertion-percentage=X // X% of assembly instructions will have a noop prepended (default: 50%, requires -noop-insertion)
-max-noops-per-instruction=X // Randomly generate X noops per instruction. ie. roll the dice X times with probability set above (default: 1). This doesn't guarantee X noop instructions.
In addition, the following 'quick switch' in clang enables basic diversity using default settings (currently: noop insertion and schedule randomization; it is intended to be extended in the future).
-fdiversify
This is the llvm part of the patch.
clang part: D3393
http://reviews.llvm.org/D3392
Patch by Stephen Crane (@rinon)
llvm-svn: 225908
PATCHPOINT is a strange pseudo-instruction. Depending on how it is used, and
whether or not the AnyReg calling convention is being used, it might or might
not define a value. However, its TableGen definition says that it defines one
value, and so when it doesn't, the code in ScheduleDAGSDNodes::RegDefIter
becomes confused and the code that uses the RegDefIter will try to get the
register class of the MVT::Other type associated with the PATCHPOINT's chain
result (under certain circumstances).
This will be covered by the PPC64 PatchPoint test cases once that support is
re-committed.
llvm-svn: 225907
This adds handling for ExceptionHandling::MSVC, used by the
x86_64-pc-windows-msvc triple. It assumes that filter functions have
already been outlined in either the frontend or the backend. Filter
functions are used in place of the landingpad catch clause type info
operands. In catch clause order, the first filter to return true will
catch the exception.
The C specific handler table expects the landing pad to be split into
one block per handler, but LLVM IR uses a single landing pad for all
possible unwind actions. This patch papers over the mismatch by
synthesizing single instruction BBs for every catch clause to fill in
the EH selector that the landing pad block expects.
Missing functionality:
- Accessing data in the parent frame from outlined filters
- Cleanups (from __finally) are unsupported, as they will require
outlining and parent frame access
- Filter clauses are unsupported, as there's no clear analogue in SEH
In other words, this is the minimal set of changes needed to write IR to
catch arbitrary exceptions and resume normal execution.
Reviewers: majnemer
Differential Revision: http://reviews.llvm.org/D6300
llvm-svn: 225904
This reverts commit r225852, it was a bad idea.
MachineReg should always be a physical register. If it isn't this DebugLoc
shouldn't have been created in the first place.
llvm-svn: 225857
emitDebugLocValue() into DwarfExpression.
Ought to be NFC, but it actually uncovered a bug in the debug-loc-asan.ll
testcase. The testcase checks that the address of variable "y" is stored
at [RSP+16], which also lines up with the comment.
It also check(ed) that the *value* of "y" is stored in RDI before that,
but that is actually incorrect, since RDI is the very value that is
stored in [RSP+16]. Here's the assembler output:
movb 2147450880(%rcx), %r8b
#DEBUG_VALUE: bar:y <- RDI
cmpb $0, %r8b
movq %rax, 32(%rsp) # 8-byte Spill
movq %rsi, 24(%rsp) # 8-byte Spill
movq %rdi, 16(%rsp) # 8-byte Spill
.Ltmp3:
#DEBUG_VALUE: bar:y <- [RSP+16]
Fixed the comment to spell out the correct register and the check to
expect an address rather than a value.
Note that the range that is emitted for the RDI location was and is still
wrong, it claims to begin at the function prologue, but really it should
start where RDI is first assigned.
llvm-svn: 225851
This requires a new hook to prevent expanding sqrt in terms
of rsqrt and reciprocal. v_rcp_f32, v_rsq_f32, and v_sqrt_f32 are
all the same rate, so this expansion would just double the number
of instructions and cycles.
llvm-svn: 225828
When computing the call-site offset, use AP.CurrentFnSymForSize instead of
AP.CurrentFnSym. There should be no change for other targets, but this is
necessary for generating valid expressions for PPC64/ELF.
llvm-svn: 225807
While, generally speaking, the process of lowering arguments for a patchpoint
is the same as lowering a regular indirect call, on some targets it may not be
exactly the same. Targets may not, for example, want to add additional register
dependencies that apply only to making cross-DSO calls through linker stubs,
may not want to load additional registers out of function descriptors, and may
not want to add additional side-effect-causing instructions that cannot be
removed later with the call itself being generated.
The PowerPC target will use this in a future commit (for all of the reasons
stated above).
llvm-svn: 225806
Some targets, PowerPC for example, have pseudo-registers (such as that used to
represent the rounding mode), that don't have DWARF register numbers or a
register class. These are used only for internal dependency tracking, and
should not appear in the recorded live-outs. This adds a callback allowing the
target to pre-process the live-out mask in order to remove these kinds of
registers so that the StackMaps code does not complain about them and/or
attempt to include them in the output.
This will be used by the PowerPC target in a future commit.
llvm-svn: 225805
Peephole optimizer is scanning a basic block forward. At some point it
needs to answer the question "given a pointer to an MI in the current
BB, is it located before or after the current instruction".
To perform this, it keeps a set of the MIs already seen during the scan,
if a MI is not in the set, it is assumed to be after.
It means that newly created MIs have to be inserted in the set as well.
This commit passes the set as an argument to the target-dependent
optimizeSelect() so that it can properly update the set with the
(potentially) newly created MIs.
llvm-svn: 225772
This name is less descriptive, but it sort of puts things in the
'llvm.frame...' namespace, relating it to frameallocate and
frameaddress. It also avoids using "allocate" and "allocation" together.
llvm-svn: 225752
These intrinsics allow multiple functions to share a single stack
allocation from one function's call frame. The function with the
allocation may only perform one allocation, and it must be in the entry
block.
Functions accessing the allocation call llvm.recoverframeallocation with
the function whose frame they are accessing and a frame pointer from an
active call frame of that function.
These intrinsics are very difficult to inline correctly, so the
intention is that they be introduced rarely, or at least very late
during EH preparation.
Reviewers: echristo, andrew.w.kaylor
Differential Revision: http://reviews.llvm.org/D6493
llvm-svn: 225746
Move the declaration of DebugLocDwarfExpression into DwarfExpression.h
because it needs to be accessed from AsmPrinterDwarf.cpp and DwarfDebug.cpp
NFC.
llvm-svn: 225734
Otherwise we'll attempt to forward ECX, EDX, and EAX for cdecl and
stdcall thunks, leaving us with no scratch registers for indirect call
targets.
Fixes PR22052.
llvm-svn: 225729
into a new class DwarfExpression that can be shared between AsmPrinter
and DwarfUnit.
This is the first step towards unifying the two entirely redundant
implementations of dwarf expression emission in DwarfUnit and AsmPrinter.
Almost no functional change — Testcases were updated because asm comments
that used to be on two lines now appear on the same line, which is
actually preferable.
llvm-svn: 225706
This is a fixed version of reverted r225500. It fixes the too early
if() continue; of the last patch and adds a comment to the unorthodox
loop.
llvm-svn: 225652
Ramkumar Ramachandra