Summary:
UB isn't nice. It's cool and powerful, but not nice.
Having a way to detect it is nice though.
[[ https://wg21.link/p1007r3 | P1007R3: std::assume_aligned ]] / http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1007r2.pdf says:
```
We propose to add this functionality via a library function instead of a core language attribute.
...
If the pointer passed in is not aligned to at least N bytes, calling assume_aligned results in undefined behaviour.
```
This differential teaches clang to sanitize all the various variants of this assume-aligned attribute.
Requires D54588 for LLVM IRBuilder changes.
The compiler-rt part is D54590.
Reviewers: ABataev, craig.topper, vsk, rsmith, rnk, #sanitizers, erichkeane, filcab, rjmccall
Reviewed By: rjmccall
Subscribers: chandlerc, ldionne, EricWF, mclow.lists, cfe-commits, bkramer
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D54589
llvm-svn: 351105
This removes the old grow_memory and mem.grow-style builtins, leaving just
the memory.grow-style builtins.
Differential Revision: https://reviews.llvm.org/D56645
llvm-svn: 351089
__builtin_cpu_supports and __builtin_cpu_is use information in __cpu_model to decide cpu features. Before this change, __cpu_model was not declared as dso local. The generated code looks up the address in GOT when reading __cpu_model. This makes it impossible to use these functions in ifunc, because at that time GOT entries have not been relocated. This change makes it dso local.
Differential Revision: https://reviews.llvm.org/D53850
llvm-svn: 349825
Sibling patch to D55855, this emits UADD_SAT/USUB_SAT generic intrinsics for the SSE saturated math intrinsics instead of expanding to a IR code sequence that could be difficult to reassemble.
Differential Revision: https://reviews.llvm.org/D55879
llvm-svn: 349631
The special lowering for __builtin_mul_overflow introduced in r320902
fixed an ICE seen when passing mixed-sign operands to the builtin.
This patch extends the special lowering to cover mixed-width, mixed-sign
operands. In a few common scenarios, calls to muloti4 will no longer be
emitted.
This should address the latest comments in PR34920 and work around the
link failure seen in:
https://bugzilla.redhat.com/show_bug.cgi?id=1657544
Testing:
- check-clang
- A/B output comparison with: https://gist.github.com/vedantk/3eb9c88f82e5c32f2e590555b4af5081
Differential Revision: https://reviews.llvm.org/D55843
llvm-svn: 349542
Summary:
This patch adds `__builtin_launder`, which is required to implement `std::launder`. Additionally GCC provides `__builtin_launder`, so thing brings Clang in-line with GCC.
I'm not exactly sure what magic `__builtin_launder` requires, but based on previous discussions this patch applies a `@llvm.invariant.group.barrier`. As noted in previous discussions, this may not be enough to correctly handle vtables.
Reviewers: rnk, majnemer, rsmith
Reviewed By: rsmith
Subscribers: kristina, Romain-Geissler-1A, erichkeane, amharc, jroelofs, cfe-commits, Prazek
Differential Revision: https://reviews.llvm.org/D40218
llvm-svn: 349195
intrin.h had forward declarations for these and lzcntintrin.h had implementations that were only available with -mlzcnt or a -march that supported the lzcnt feature.
For MS compatibility we should always have these builtins available regardless of X86 being the target or the CPU support the lzcnt instruction. The backends should be able to gracefully fallback to something support even if its just shifts and bit ops.
Unfortunately, gcc also implements 2 of the 3 function names here on X86 when lzcnt feature is enabled.
This patch adds builtins for these for MSVC compatibility and drops the forward declarations from intrin.h. To keep the gcc compatibility the two intrinsics that collided have been turned into macros that use the X86 specific builtins with the lzcnt feature check. These macros are only defined when _MSC_VER is not defined. Without them being macros we can get a redefinition error because -ms-extensions doesn't seem to set _MSC_VER but does make the MS builtins available.
Should fix PR40014
Differential Revision: https://reviews.llvm.org/D55677
llvm-svn: 349098
__builtin_cpu_supports and __builtin_cpu_is use information in __cpu_model to decide cpu features. Before this change, __cpu_model was not declared as dso local. The generated code looks up the address in GOT when reading __cpu_model. This makes it impossible to use these functions in ifunc, because at that time GOT entries have not been relocated. This change makes it dso local.
Differential Revision: https://reviews.llvm.org/D53850
llvm-svn: 348978
The addcarry and addcarryx builtins do the same thing. The only difference is that addcarryx previously required adx feature.
This commit removes the adx feature check from addcarryx and removes the addcarry builtin. This matches the builtins that gcc has. We don't guarantee compatibility in builtins, but we generally try to be consistent if its not a burden.
llvm-svn: 348738
It seems the two failing tests can be simply fixed after r348037
Fix 3 cases in Analysis/builtin-functions.cpp
Delete the bad CodeGen/builtin-constant-p.c for now
llvm-svn: 348053
Kept the "indirect_builtin_constant_p" test case in test/SemaCXX/constant-expression-cxx1y.cpp
while we are investigating why the following snippet fails:
extern char extern_var;
struct { int a; } a = {__builtin_constant_p(extern_var)};
llvm-svn: 348039
This was reverted in r347656 due to me thinking it caused a miscompile of
Chromium. Turns out it was the Chromium code that was broken.
llvm-svn: 347756
This caused a miscompile in Chrome (see crbug.com/908372) that's
illustrated by this small reduction:
static bool f(int *a, int *b) {
return !__builtin_constant_p(b - a) || (!(b - a));
}
int arr[] = {1,2,3};
bool g() {
return f(arr, arr + 3);
}
$ clang -O2 -S -emit-llvm a.cc -o -
g() should return true, but after r347417 it became false for some reason.
This also reverts the follow-up commits.
r347417:
> Re-Reinstate 347294 with a fix for the failures.
>
> Don't try to emit a scalar expression for a non-scalar argument to
> __builtin_constant_p().
>
> Third time's a charm!
r347446:
> The result of is.constant() is unsigned.
r347480:
> A __builtin_constant_p() returns 0 with a function type.
r347512:
> isEvaluatable() implies a constant context.
>
> Assume that we're in a constant context if we're asking if the expression can
> be compiled into a constant initializer. This fixes the issue where a
> __builtin_constant_p() in a compound literal was diagnosed as not being
> constant, even though it's always possible to convert the builtin into a
> constant.
r347531:
> A "constexpr" is evaluated in a constant context. Make sure this is reflected
> if a __builtin_constant_p() is a part of a constexpr.
llvm-svn: 347656
This was originally part of:
D50924
and should resolve PR37387:
https://bugs.llvm.org/show_bug.cgi?id=37387
...but it was reverted because some bots using a gcc host compiler
would crash for unknown reasons with this included in the patch.
Trying again now to see if that's still a problem.
llvm-svn: 347527
Summary:
A __builtin_constant_p may end up with a constant after inlining. Use
the is.constant intrinsic if it's a variable that's in a context where
it may resolve to a constant, e.g., an argument to a function after
inlining.
Reviewers: rsmith, shafik
Subscribers: jfb, kristina, cfe-commits, nickdesaulniers, jyknight
Differential Revision: https://reviews.llvm.org/D54355
llvm-svn: 347294
As suggested by Richard Smith, and initially put up for review here:
https://reviews.llvm.org/D53341, this patch removes a hack that was used
to ensure that proper target-feature lists were used when emitting
cpu-dispatch (and eventually, target-clones) implementations. As a part
of this, the GlobalDecl object is proliferated to a bunch more
locations.
Originally, this was put up for review (see above) to get acceptance on
the approach, though discussion with Richard in San Diego showed he
approved of the approach taken here. Thus, I believe this is acceptable
for Review-After-commit
Differential Revision: https://reviews.llvm.org/D53341
Change-Id: I0a0bd673340d334d93feac789d653e03d9f6b1d5
llvm-svn: 346757
Fix places where the return type of a FunctionDecl was being used in
place of the function type
FunctionDecl::Create() takes as its T parameter the type of function
that should be created, not the return type. Passing in the return type
looks to have been copypasta'd around a bit, but the number of correct
usages outweighs the incorrect ones so I've opted for keeping what T is
the same and fixing up the call sites instead.
This fixes a crash in Clang when attempting to compile the following
snippet of code with -fblocks -fsanitize=function -x objective-c++ (my
original repro case):
void g(void(^)());
void f()
{
__block int a = 0;
g(^(){ a++; });
}
as well as the following which only requires -fsanitize=function -x c++:
void f(char * buf)
{
__builtin_os_log_format(buf, "");
}
Patch by: Ben (bobsayshilol)
Differential revision: https://reviews.llvm.org/D53263
llvm-svn: 346601
A mask type is a 1 to 8-byte string that follows the "mask." annotation
in the format string. This enables obfuscating data in the event the
provided privacy level isn't enabled.
rdar://problem/36756282
llvm-svn: 346211
This is fifth in a series of patches to move intrinsic definitions out of intrin.h.
Note: This was reviewed and approved in D54065 but somehow that diff was messed
up. Committing this again with the proper diff.
llvm-svn: 346205
Summary: This is fifth in a series of patches to move intrinsic definitions out of intrin.h.
Reviewers: rnk, efriedma, mstorsjo, TomTan
Reviewed By: efriedma
Subscribers: javed.absar, kristof.beyls, chrib, jfb, kristina, cfe-commits
Differential Revision: https://reviews.llvm.org/D54065
llvm-svn: 346191
Summary: This is third in a series of patches to move intrinsic definitions out of intrin.h.
Reviewers: rnk, efriedma, mstorsjo, TomTan
Reviewed By: efriedma
Subscribers: javed.absar, kristof.beyls, chrib, jfb, kristina, cfe-commits
Differential Revision: https://reviews.llvm.org/D54062
llvm-svn: 346189
Summary: Windows SDK needs these intrinsics to be proper builtins. This is second in a series of patches to move intrinsic defintions out of intrin.h.
Reviewers: rnk, mstorsjo, efriedma, TomTan
Reviewed By: rnk, efriedma
Subscribers: javed.absar, kristof.beyls, chrib, jfb, kristina, cfe-commits
Differential Revision: https://reviews.llvm.org/D54046
llvm-svn: 346044
The size of an os_log buffer is known at any stage of compilation, so making it
a constant expression means that the common idiom of declaring a buffer for it
won't result in a VLA. That allows the compiler to skip saving and restoring
the stack pointer around such buffers.
This also moves the OSLog and other FormatString helpers from
libclangAnalysis to libclangAST to avoid a circular dependency.
llvm-svn: 345971
This patch should not introduce any behavior changes. It consists of
mostly one of two changes:
1. Replacing fall through comments with the LLVM_FALLTHROUGH macro
2. Inserting 'break' before falling through into a case block consisting
of only 'break'.
We were already using this warning with GCC, but its warning behaves
slightly differently. In this patch, the following differences are
relevant:
1. GCC recognizes comments that say "fall through" as annotations, clang
doesn't
2. GCC doesn't warn on "case N: foo(); default: break;", clang does
3. GCC doesn't warn when the case contains a switch, but falls through
the outer case.
I will enable the warning separately in a follow-up patch so that it can
be cleanly reverted if necessary.
Reviewers: alexfh, rsmith, lattner, rtrieu, EricWF, bollu
Differential Revision: https://reviews.llvm.org/D53950
llvm-svn: 345882
The size of an os_log buffer is known at any stage of compilation, so making it
a constant expression means that the common idiom of declaring a buffer for it
won't result in a VLA. That allows the compiler to skip saving and restoring
the stack pointer around such buffers.
This also moves the OSLog helpers from libclangAnalysis to libclangAST
to avoid a circular dependency.
llvm-svn: 345866
This also reverts a couple of follow-up commits trying to fix the
dependency issues. Latest revision added a cyclic dependency that can't
just be patched up in 5 minutes.
llvm-svn: 345846
The size of an os_log buffer is known at any stage of compilation, so making it
a constant expression means that the common idiom of declaring a buffer for it
won't result in a VLA. That allows the compiler to skip saving and restoring
the stack pointer around such buffers.
llvm-svn: 345828
Summary: Use the same convention as all the other WebAssembly builtin names.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, sunfish, kristina, cfe-commits
Differential Revision: https://reviews.llvm.org/D53724
llvm-svn: 345804
Generate the FP16FML intrinsics into arm_neon.h (AArch64 only for now).
Add two new type modifiers to NeonEmitter to handle the new prototypes.
Define __ARM_FEATURE_FP16FML when +fp16fml is enabled and guard the
intrinsics with the macro in arm_neon.h.
Based on a patch by Gao Yiling.
Differential Revision: https://reviews.llvm.org/D53633
llvm-svn: 345344
libgcc supports more than 32 features by adding a new 32-bit variable __cpu_features2.
This adds the clang support for checking these feature bits.
Patches for compiler-rt and llvm to support this are coming as well.
Probably still need an additional patch for target multiversioning in clang.
Differential Revision: https://reviews.llvm.org/D53458
llvm-svn: 344832
Summary:
The multiversioning code repurposed the code from __builtin_cpu_supports for checking if a single feature is enabled. That code essentially performed (_cpu_features & (1 << C)) != 0. But with the multiversioning path, the mask is no longer guaranteed to be a power of 2. So we return true anytime any one of the bits in the mask is set not just all of the bits.
The correct check is (_cpu_features & mask) == mask
Reviewers: erichkeane, echristo
Reviewed By: echristo
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D53460
llvm-svn: 344824
Emit llvm.amdgcn.update.dpp for both __builtin_amdgcn_mov_dpp and
__builtin_amdgcn_update_dpp. The first argument to
llvm.amdgcn.update.dpp will be undef for __builtin_amdgcn_mov_dpp.
Differential Revision: https://reviews.llvm.org/D52320
llvm-svn: 344665
Previously we used a select and the zero_undef=true intrinsic. In -O2 this pattern will get optimized to zero_undef=false. But in -O0 this optimization won't happen. This results in a compare and cmov being wrapped around a tzcnt/lzcnt instruction.
By using the zero_undef=false intrinsic directly without the select, we can improve the -O0 codegen to just an lzcnt/tzcnt instruction.
Differential Revision: https://reviews.llvm.org/D52392
llvm-svn: 343126
unsigned long long builtin_unpack_vector_int128 (vector int128_t, int);
vector int128_t builtin_pack_vector_int128 (unsigned long long, unsigned long long);
Builtins should behave the same way as in GCC.
Patch By: wuzish (Zixuan Wu)
Differential Revision: https://reviews.llvm.org/D52074
llvm-svn: 342614
This is the clang side of D51803. The llvm intrinsic now returns two results. So we need to emit an explicit store in IR for the out parameter. This is similar to addcarry/subborrow/rdrand/rdseed.
Differential Revision: https://reviews.llvm.org/D51805
llvm-svn: 341699
This is the clang side of D51769. The llvm intrinsics now return two results instead of using an out parameter.
Differential Revision: https://reviews.llvm.org/D51771
llvm-svn: 341678
These aren't documented in the Intel Intrinsics Guide, but are supported by gcc and icc.
Includes these intrinsics:
_ktestc_mask8_u8, _ktestz_mask8_u8, _ktest_mask8_u8
_ktestc_mask16_u8, _ktestz_mask16_u8, _ktest_mask16_u8
_ktestc_mask32_u8, _ktestz_mask32_u8, _ktest_mask32_u8
_ktestc_mask64_u8, _ktestz_mask64_u8, _ktest_mask64_u8
llvm-svn: 341265
This adds:
_cvtmask8_u32, _cvtmask16_u32, _cvtmask32_u32, _cvtmask64_u64
_cvtu32_mask8, _cvtu32_mask16, _cvtu32_mask32, _cvtu64_mask64
_load_mask8, _load_mask16, _load_mask32, _load_mask64
_store_mask8, _store_mask16, _store_mask32, _store_mask64
These are currently missing from the Intel Intrinsics Guide webpage.
llvm-svn: 341251
This adds the following intrinsics:
_kshiftli_mask8
_kshiftli_mask16
_kshiftli_mask32
_kshiftli_mask64
_kshiftri_mask8
_kshiftri_mask16
_kshiftri_mask32
_kshiftri_mask64
llvm-svn: 341234
This adds the following intrinsics:
_kadd_mask64
_kadd_mask32
_kadd_mask16
_kadd_mask8
These are missing from the Intel Intrinsics Guide, but are implemented by both gcc and icc.
llvm-svn: 340879
This also adds a second intrinsic name for the 16-bit mask versions.
These intrinsics match gcc and icc. They just aren't published in the Intel Intrinsics Guide so I only recently found they existed.
llvm-svn: 340719
EmitX86BuiltinExpr() emits all args into Ops at the beginning, so don't do that
work again.
This changes behavior: If e.g. ++a was passed as an arg, we incremented a twice
previously. This change fixes that bug.
https://reviews.llvm.org/D50979
llvm-svn: 340348
This is a partial retry of rL340137 (reverted at rL340138 because of gcc host compiler crashing)
with 1 change:
Remove the changes to make microsoft builtins also use the LLVM intrinsics.
This exposes the LLVM funnel shift intrinsics as more familiar bit rotation functions in clang
(when both halves of a funnel shift are the same value, it's a rotate).
We're free to name these as we want because we're not copying gcc, but if there's some other
existing art (eg, the microsoft ops) that we want to replicate, we can change the names.
The funnel shift intrinsics were added here:
https://reviews.llvm.org/D49242
With improved codegen in:
https://reviews.llvm.org/rL337966https://reviews.llvm.org/rL339359
And basic IR optimization added in:
https://reviews.llvm.org/rL338218https://reviews.llvm.org/rL340022
...so these are expected to produce asm output that's equal or better to the multi-instruction
alternatives using primitive C/IR ops.
In the motivating loop example from PR37387:
https://bugs.llvm.org/show_bug.cgi?id=37387#c7
...we get the expected 'rolq' x86 instructions if we substitute the rotate builtin into the source.
Differential Revision: https://reviews.llvm.org/D50924
llvm-svn: 340141
This is a retry of rL340135 (reverted at rL340136 because of gcc host compiler crashing)
with 2 changes:
1. Move the code into a helper to reduce code duplication (and hopefully work-around the crash).
2. The original commit had a formatting bug in the docs (missing an underscore).
Original commit message:
This exposes the LLVM funnel shift intrinsics as more familiar bit rotation functions in clang
(when both halves of a funnel shift are the same value, it's a rotate).
We're free to name these as we want because we're not copying gcc, but if there's some other
existing art (eg, the microsoft ops that are modified in this patch) that we want to replicate,
we can change the names.
The funnel shift intrinsics were added here:
https://reviews.llvm.org/D49242
With improved codegen in:
https://reviews.llvm.org/rL337966https://reviews.llvm.org/rL339359
And basic IR optimization added in:
https://reviews.llvm.org/rL338218https://reviews.llvm.org/rL340022
...so these are expected to produce asm output that's equal or better to the multi-instruction
alternatives using primitive C/IR ops.
In the motivating loop example from PR37387:
https://bugs.llvm.org/show_bug.cgi?id=37387#c7
...we get the expected 'rolq' x86 instructions if we substitute the rotate builtin into the source.
Differential Revision: https://reviews.llvm.org/D50924
llvm-svn: 340137
This exposes the LLVM funnel shift intrinsics as more familiar bit rotation functions in clang
(when both halves of a funnel shift are the same value, it's a rotate).
We're free to name these as we want because we're not copying gcc, but if there's some other
existing art (eg, the microsoft ops that are modified in this patch) that we want to replicate,
we can change the names.
The funnel shift intrinsics were added here:
D49242
With improved codegen in:
rL337966
rL339359
And basic IR optimization added in:
rL338218
rL340022
...so these are expected to produce asm output that's equal or better to the multi-instruction
alternatives using primitive C/IR ops.
In the motivating loop example from PR37387:
https://bugs.llvm.org/show_bug.cgi?id=37387#c7
...we get the expected 'rolq' x86 instructions if we substitute the rotate builtin into the source.
Differential Revision: https://reviews.llvm.org/D50924
llvm-svn: 340135
r337619 added __shiftleft128 / __shiftright128 as functions in intrin.h.
Microsoft's STL plans on using these functions, and they're using intrin0.h
which just has declarations of built-ins to not pull in the huge intrin.h
header in the standard library headers. That requires that these functions are
real built-ins.
https://reviews.llvm.org/D50907
llvm-svn: 340048
Summary: This is the patch that lowers x86 intrinsics to native IR in order to enable optimizations.
Reviewers: craig.topper, spatel, RKSimon
Reviewed By: craig.topper
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D46892
llvm-svn: 339651
gcc defines an intrinsic called __builtin_clrsb which counts the number of extra sign bits on a number. This is equivalent to counting the number of leading zeros on a positive number or the number of leading ones on a negative number and subtracting one from the result. Since we can't count leading ones we need to invert negative numbers to count zeros.
This patch will cause the builtin to be expanded inline while gcc uses a call to a function like clrsbdi2 that is implemented in libgcc. But this is similar to what we already do for popcnt. And I don't think compiler-rt supports clrsbdi2.
Differential Revision: https://reviews.llvm.org/D50168
llvm-svn: 339282
Always emit alloca in entry block for enqueue_kernel builtin.
Ensures the statically sized alloca is not converted to DYNAMIC_STACKALLOC
later because it is not in the entry block.
llvm-svn: 339150
Ensures the statically sized alloca is not converted to DYNAMIC_STACKALLOC
later because it is not in the entry block.
Differential Revision: https://reviews.llvm.org/D50104
llvm-svn: 338899
Vlad Tsyrklevich