Summary:
This patch implements a new UBSan check, which verifies
that function arguments declared to be nonnull with __attribute__((nonnull))
are actually nonnull in runtime.
To implement this check, we pass FunctionDecl to CodeGenFunction::EmitCallArgs
(where applicable) and if function declaration has nonnull attribute specified
for a certain formal parameter, we compare the corresponding RValue to null as
soon as it's calculated.
Test Plan: regression test suite
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits, rnk
Differential Revision: http://reviews.llvm.org/D5082
llvm-svn: 217389
This makes use of the recently-added @llvm.assume intrinsic to implement a
__builtin_assume(bool) intrinsic (to provide additional information to the
optimizer). This hooks up __assume in MS-compatibility mode to mirror
__builtin_assume (the semantics have been intentionally kept compatible), and
implements GCC's __builtin_assume_aligned as assume((p - o) & mask == 0). LLVM
now contains special logic to deal with assumptions of this form.
llvm-svn: 217349
made the 8-bit masks actually 8-bit arguments to these intrinsics.
These builtins are a mess. Many were missing the I qualifier which
I added where obviously correct. Most aren't tested, but I've updated
the relevant tests. I've tried to catch all the things that should
become 'c' in this round.
It's also frustrating because the set of these is really ad-hoc and
doesn't really map that cleanly to the set supported by either GCC or
LLVM. Oh well...
llvm-svn: 217311
This patch adds support for the 32bit numeric max/min and directed round-to-integral NEON intrinsics that were added as part of v8, along with unit tests.
Patch by Graham Hunter!
llvm-svn: 217242
For naked functions with parameters, Clang would still emit stores in the prologue
that would clobber the stack, because LLVM doesn't set up a stack frame. (This
shows up in -O0 compiles, because the stores are optimized away otherwise.)
For example:
__attribute__((naked)) int f(int x) {
asm("movl $42, %eax");
asm("retl");
}
Would result in:
_Z1fi:
movl 12(%esp), %eax
movl %eax, (%esp) <--- Oops.
movl $42, %eax
retl
Differential Revision: http://reviews.llvm.org/D5183
llvm-svn: 217198
If control falls off the end of a function after an __asm block, MSVC
assumes that the inline assembly filled the EAX and possibly EDX
registers with an appropriate return value. This functionality is used
in inline functions returning 64-bit integers in system headers, so we
need some amount of compatibility.
This is implemented in Clang by adding extra output constraints to every
inline asm block, and storing the resulting output registers into the
return value slot. If we see an asm block somewhere in the function
body, we emit a normal epilogue instead of marking the end of the
function with a return type unreachable.
Normal returns in functions not using this functionality will overwrite
the return value slot, and in most cases LLVM should be able to
eliminate the dead stores.
Fixes PR17201.
Reviewed By: majnemer
Differential Revision: http://reviews.llvm.org/D5177
llvm-svn: 217187
Summary:
This allows us to easily find them in the backend after the aggregates have
been lowered to other types. This is important on big-endian targets using
the N32/N64 ABI's since these ABI's must shift small structures into the
upper bits of the register.
Reviewers: atanasyan
Reviewed By: atanasyan
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5005
llvm-svn: 217160
Summary:
They are returned indirectly which causes the other arguments to move to
the next argument slot.
With this, utils/ABITest does not discover any failing cases in the first
500 attempts on big/little endian for O32. Previously some of these failed.
Also tested N32/N64 little endian (big endian has other known issues) with
no issues.
Reviewers: atanasyan
Reviewed By: atanasyan
Subscribers: atanasyan, cfe-commits
Differential Revision: http://reviews.llvm.org/D4811
llvm-svn: 217147
Using the intrinsic allows the SelectionDAGBuilder to turn this call
into the FABS Node and also the intrinsic is something the vectorizer knows
how to vectorize.
This patch also sets the readnone attribute on this call, which should
enable additional optmizations.
llvm-svn: 217042
Previously, EnterStructPointerForCoercedAccess used Alloc size when determining how to convert. This was problematic, because there were situations were the alloc size was larger than the store size. For example, if the first element of a structure were i24 and the destination type were i32, the old code would generate a GEP and a load i24. The code should compare store sizes to ensure the whole object is loaded. I have attached a test case.
This patch modifies the output of arm64-be-bitfield.c test case, but the new IR seems to be equivalent, and after -O3, the compiler generates identical ARM assembly. (asr x0, x0, #54)
Patch by Thomas Jablin!
llvm-svn: 216722
Summary:
We did a great job getting this wrong:
- We messed up which LLVM IR types to use for arguments and return values.
The optimized libcalls use integer types for values.
Clang attempted to use the IR type which corresponds to the value
passed in instead of using an appropriately sized integer type. This
would result in violations of the ABI for, as an example, floating
point types.
- We didn't bother recording the result of the atomic libcall in the
destination memory.
Instead, call the functions with arguments matching the type of the
libcall prototype's parameters.
This fixes PR20780.
Differential Revision: http://reviews.llvm.org/D5098
llvm-svn: 216714
Summary:
The current implementation of asan cookie is incorrect:
we add nosanitize metadata to the cookie load, but the metadata may be lost
and we will instrument the load from poisoned memory.
This change replaces the load with a call to __asan_load_cxx_array_cookie (r216692)
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D5111
llvm-svn: 216702
For the following code:
__declspec(dllimport) int f(int x);
int user(int x) {
return f(x);
}
int f(int x) { return 1; }
Clang will drop the dllimport attribute in the AST, but CodeGen would have
already put it on the LLVM::Function, and that would never get updated.
(The same thing happens for global variables.)
This makes Clang check dropped DLL attribute case each time the LLVM object
is referenced.
This isn't perfect, because we will still get it wrong if the function is
never referenced by codegen after the attribute is dropped, but this handles
the common cases and makes us not fail in the verifier.
llvm-svn: 216699
Summary:
ACLE 2.0 section 9.2 defines the following "miscellaneous data processing intrinsics": `__clz`, `__cls`, `__ror`, `__rev`, `__rev16`, `__revsh` and `__rbit`.
`__clz` has already been implemented in the arm_acle.h header file. The rest are not supported yet. This patch completes ACLE data processing intrinsics.
Reviewers: t.p.northover, rengolin
Reviewed By: rengolin
Subscribers: aemerson, mroth, llvm-commits
Differential Revision: http://reviews.llvm.org/D4983
llvm-svn: 216658
ACLE 2.0 allows __fp16 to be used as a function argument or return
type. This enables this for AArch64.
This also fixes an existing bug that causes clang to not allow
homogeneous floating-point aggregates with a base type of __fp16. This
is valid for AAPCS64, but not for AAPCS-VFP.
llvm-svn: 216558
This tidies up some ARM-specific code added by r208417 to move it out
of the target-independent parts of clang into TargetInfo.cpp. This
also has the advantage that we can now flatten struct arguments to
variadic AAPCS functions.
llvm-svn: 216535
This time though, preserve the extension for bool types since that's compatible
with what MSVC expects.
See http://reviews.llvm.org/D4380
llvm-svn: 216507
Summary:
MSVC doesn't extend integer types smaller than 64bit, so to preserve
binary compatibility, clang shouldn't either.
For example, the following C code built with MSVC:
unsigned test(unsigned v);
unsigned foobar(unsigned short);
int main() { return test(0xffffffff) + foobar(28); }
Produces the following:
0000000000000004: B9 FF FF FF FF mov ecx,0FFFFFFFFh
0000000000000009: E8 00 00 00 00 call test
000000000000000E: 89 44 24 20 mov dword ptr [rsp+20h],eax
0000000000000012: 66 B9 1C 00 mov cx,1Ch
0000000000000016: E8 00 00 00 00 call foobar
And as you can see, when setting up the call to foobar, only cx is overwritten.
If foobar is compiled with clang, then the zero extension added by clang means
the rest of the register, which contains garbage, could be used.
For example if foobar is:
unsigned foobar(unsigned short v) {
return v;
}
Compiled with clang -fomit-frame-pointer -O3 gives the following assembly:
foobar:
0000000000000000: 89 C8 mov eax,ecx
0000000000000002: C3 ret
And that function would return garbage because the 16 most significant bits of
ecx still contain garbage from the first call.
With this change, the code for that function is now:
foobar:
0000000000000000: 0F B7 C1 movzx eax,cx
0000000000000003: C3 ret
Reviewers: chapuni, rnk
Reviewed By: rnk
Subscribers: majnemer, cfe-commits
Differential Revision: http://reviews.llvm.org/D4380
llvm-svn: 216491
lowering of the intrinsics.
Prior to this commit, most of the copy-related intrinsics could be optimized
away. The situation is still not ideal as there are several possibilities to
lower a given intrinsic. Currently, we match LLVM behavior.
llvm-svn: 216474
feature is c11 about nested struct declarations must have
struct-declarator-list. Without this change, code
which was meant for c99 breaks. rdar://18125536
llvm-svn: 216469
Summary:
PR19838
When operator new[] is called and an array cookie is created
we want asan to detect buffer overflow bugs that touch the cookie.
For that we need to
a) poison the shadow for the array cookie (call __asan_poison_cxx_array_cookie).
b) ignore the legal accesses to the cookie generated by clang (add 'nosanitize' metadata)
Reviewers: timurrrr, samsonov, rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4774
llvm-svn: 216434
PowerPC uses the special PPC_FP128 type for long double on Linux, which is
composed of two 64-bit doubles. The higher-order double (which contains the
overall sign) comes first, and so the __builtin_signbitl implementation
requires special handling to extract the sign bit.
Fixes PR20691.
llvm-svn: 216341
Moreover, rework some patterns to actually check the emitted instructions
instead of matching unrelated string!
E.g.,
some of the "// CHECK: vmov" were matching stuff like ".globl
funcname_with_vmov" instead of actual instructions.
llvm-svn: 216275
It fits better with LLVM's memory model to try to do this in the
backend. Specifically, narrowing wide loads in the backends should be
relatively straightforward and is generally valuable, whereas widening
loads tends to be very constrained.
Discussion here:
http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20140811/112581.html
This reverts commit r215614.
llvm-svn: 215648
Currently when laying out bitfields that don't need any padding, we
represent them as a wide enough int to contain all of the bits. This
can be hard on the backend since we'll do things like represent stores
to a few bits as loading an i144, masking it with a large constant,
and storing it back.
This turns up in less pathological cases where we load and mask 64 bit
word on a 32 bit platform when we actually only need to access 32 bits.
This leads to bad code being generated in most of our 32 bit backends.
In practice, there are often natural breaks in bitfields, and it's a
fairly simple and effective heuristic to split these fields into legal
integer sized chunks when it will be equivalent (ie, it won't force us
to add any extra padding).
llvm-svn: 215614
Similar approach to the set1 intrinsics is used: implement in terms of vector
initializers and then ensure with an LLVM test that a broadcast is generated
at the end.
Part of <rdar://problem/17688758>
llvm-svn: 215486
Summary:
This patch adds a runtime check verifying that functions
annotated with "returns_nonnull" attribute do in fact return nonnull pointers.
It is based on suggestion by Jakub Jelinek:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140623/223693.html.
Test Plan: regression test suite
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4849
llvm-svn: 215485
Due to the possible presence of return-by-out parameters, using the LLVM
argument number count when numbering debug info arguments can end up
off-by-one. This could produce two arguments with the same number, which
would in turn cause LLVM to emit only one of those arguments (whichever
it found last) or assert (r215157).
llvm-svn: 215227
Note that similar to palingr, we could further optimize these to emit
shufflevector when the shift count is <=64. This however does not
change the overall design that unlike palignr we would still need the LLVM
intrinsic corresponding to this intruction to handle the >64 cases. (palignr
uses the psrldq intrinsic in this case.)
llvm-svn: 214891
