Commit Graph

590 Commits

Author SHA1 Message Date
Teresa Johnson 08d5b4ef0d [ThinLTO] Print module summary index to assembly
Summary:
Implements AsmWriter support for printing the module summary index to
assembly with the format discussed in the RFC "LLVM Assembly format for
ThinLTO Summary".

Implements just enough of the parsing support to recognize and ignore
the summary entries. As agreed in the RFC thread, this will be the
behavior when assembling the IR. A follow on change will implement
parsing/assembling of the summary entries for use by tools that
currently build the summary index from bitcode.

Reviewers: dexonsmith, pcc

Subscribers: inglorion, eraman, steven_wu, dblaikie, llvm-commits

Differential Revision: https://reviews.llvm.org/D46699

llvm-svn: 333335
2018-05-26 02:34:13 +00:00
Hans Wennborg 2cfcc01b22 LangRef.rst: the "\01" prefix applies not just to variables
llvm-svn: 332967
2018-05-22 10:14:07 +00:00
Piotr Padlewski ce358262eb Dissallow non-empty metadata for invariant.group
Summary:
This feature is not needed, but it might be usefull in the future
to use metadata to mark what which function should support it
(and strip it when not).

Reviewers: rsmith, sanjoy, amharc, kuhar

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45419

llvm-svn: 332787
2018-05-18 23:53:46 +00:00
Piotr Padlewski 5dde809404 Rename invariant.group.barrier to launder.invariant.group
Summary:
This is one of the initial commit of "RFC: Devirtualization v2" proposal:
https://docs.google.com/document/d/16GVtCpzK8sIHNc2qZz6RN8amICNBtvjWUod2SujZVEo/edit?usp=sharing

Reviewers: rsmith, amharc, kuhar, sanjoy

Subscribers: arsenm, nhaehnle, javed.absar, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45111

llvm-svn: 331448
2018-05-03 11:03:01 +00:00
Piotr Padlewski 74b155fdf6 Mark invariant.group as experimental
Differential Revision: https://reviews.llvm.org/D33235

llvm-svn: 329531
2018-04-08 13:53:04 +00:00
Vlad Tsyrklevich d17f61ea3b Add the ShadowCallStack attribute
Summary:
Introduce the ShadowCallStack function attribute. It's added to
functions compiled with -fsanitize=shadow-call-stack in order to mark
functions to be instrumented by a ShadowCallStack pass to be submitted
in a separate change.

Reviewers: pcc, kcc, kubamracek

Reviewed By: pcc, kcc

Subscribers: cryptoad, mehdi_amini, javed.absar, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D44800

llvm-svn: 329108
2018-04-03 20:10:40 +00:00
Sanjay Patel d96a363855 [LangRef] fix description and examples of fptrunc
As noted in PR36966:
https://bugs.llvm.org/show_bug.cgi?id=36966

The old description doesn't match what we do in code, 
so this just fixes the documentation to avoid confusion.

Differential Revision: https://reviews.llvm.org/D45190

llvm-svn: 329065
2018-04-03 13:05:20 +00:00
Matt Morehouse 3181941bcf Document optforfuzzing attribute created in r328214.
llvm-svn: 328236
2018-03-22 19:50:10 +00:00
Sanjay Patel bab6ce018f [LangRef] add note about format of FP types
llvm-svn: 328105
2018-03-21 15:22:09 +00:00
Sanjay Patel 85fa9ef626 [LangRef] more hyphens: always write "floating-point"
We were inconsistent, sometimes even within a single sentence.
The consensus seems clear that the FP we're looking for is
spelled "floating-point". Without the hyphen, it's a 
"surprisingly fine" jazz album.

llvm-svn: 328098
2018-03-21 14:15:33 +00:00
Sanjay Patel ec95e0eed9 [LangRef] fix link formatting
llvm-svn: 328001
2018-03-20 17:05:19 +00:00
Sanjay Patel 54b161e47f [LangRef] describe the default FP environment
Follow-up for D44216: add a section and examples to describe the FP env.
Also, add pointers from the FP instructions to this new section to reduce
bloat.

Differential Revision: https://reviews.llvm.org/D44318

llvm-svn: 327998
2018-03-20 16:38:22 +00:00
Oren Ben Simhon fdd72fd522 [X86] Added support for nocf_check attribute for indirect Branch Tracking
X86 Supports Indirect Branch Tracking (IBT) as part of Control-Flow Enforcement Technology (CET).
IBT instruments ENDBR instructions used to specify valid targets of indirect call / jmp.
The `nocf_check` attribute has two roles in the context of X86 IBT technology:
	1. Appertains to a function - do not add ENDBR instruction at the beginning of the function.
	2. Appertains to a function pointer - do not track the target function of this pointer by adding nocf_check prefix to the indirect-call instruction.

This patch implements `nocf_check` context for Indirect Branch Tracking.
It also auto generates `nocf_check` prefixes before indirect branchs to jump tables that are guarded by range checks.

Differential Revision: https://reviews.llvm.org/D41879

llvm-svn: 327767
2018-03-17 13:29:46 +00:00
Reid Kleckner f8b51c5f90 [IR] Avoid the need to prefix MS C++ symbols with '\01'
Now the Windows mangling modes ('w' and 'x') do not do any mangling for
symbols starting with '?'. This means that clang can stop adding the
hideous '\01' leading escape. This means LLVM debug logs are less likely
to contain ASCII escape characters and it will be easier to copy and
paste MS symbol names from IR.

Finally.

For non-Windows platforms, names starting with '?' still get IR
mangling, so once clang stops escaping MS C++ names, we will get extra
'_' prefixing on MachO. That's fine, since it is currently impossible to
construct a triple that uses the MS C++ ABI in clang and emits macho
object files.

Differential Revision: https://reviews.llvm.org/D7775

llvm-svn: 327734
2018-03-16 20:13:32 +00:00
Sanjay Patel 3aaf6a02ee [LangRef] make it clear that FP instructions do not have side effects
Also, fix the undef vs. UB example to use 'sdiv' because that can trigger div-by-zero UB.

The existing text for the constrained intrinsics says:
"By default, LLVM optimization passes assume that the rounding mode is round-to-nearest 
and that floating point exceptions will not be monitored. Constrained FP intrinsics are 
used to support non-default rounding modes and accurately preserve exception behavior 
without compromising LLVM’s ability to optimize FP code when the default behavior is 
used."
...so the additional text with the normal FP opcodes should make the different modes
clear.

Differential Revision: https://reviews.llvm.org/D44216

llvm-svn: 327138
2018-03-09 15:27:48 +00:00
Sanjay Patel 7b7224051c [LangRef] fix formatting in FP descriptions; NFC
This is a clean-up step to reduce diffs ahead of real
changes to the FP semantics as discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2018-February/121444.html

llvm-svn: 326913
2018-03-07 17:18:22 +00:00
Hans Wennborg 89c35fc44d Support for the mno-stack-arg-probe flag
Adds support for this flag. There is also another piece for clang
(separate review). More info:
https://bugs.llvm.org/show_bug.cgi?id=36221

By Ruslan Nikolaev!

Differential Revision: https://reviews.llvm.org/D43107

llvm-svn: 325900
2018-02-23 13:46:25 +00:00
Dylan McKay ced2fe68f3 Add default address space for functions to the data layout (1/3)
Summary:
This adds initial support for letting targets specify which address
spaces their functions should reside in by default.

If a function is created by a frontend, it will get the default address space specified in the DataLayout, unless the frontend explicitly uses a more general `llvm::Function` constructor. Function address spaces will become a part of the bitcode and textual IR forms, as we do not have access to a data layout whilst parsing LL.

It will be possible to write IR that explicitly has `addrspace(n)` on a function. In this case, the function will reside in the specified space, ignoring the default in the DL.

This is the first step towards placing functions into the correct
address space for Harvard architectures.

Full patchset
* Add program address space to data layout D37052
* Require address space to be specified when creating functions D37054
* [clang] Require address space to be specified when creating functions D37057

Reviewers: pcc, arsenm, kparzysz, hfinkel, theraven

Reviewed By: theraven

Subscribers: arichardson, simoncook, rengolin, wdng, uabelho, bjope, asb, llvm-commits

Differential Revision: https://reviews.llvm.org/D37052

llvm-svn: 325479
2018-02-19 09:56:22 +00:00
Pablo Barrio e28cb8399a [ARM] Allow 64- and 128-bit types with 't' inline asm constraint
Summary:
In LLVM, 't' selects a floating-point/SIMD register and only supports
32-bit values. This is appropriately documented in the LLVM Language
Reference Manual. However, this behaviour diverges from that of GCC, where
't' selects the s0-s31 registers and its qX and dX variants depending on
additional operand modifiers (q/P).

For example, the following C code:

#include <arm_neon.h>
float32x4_t a, b, x;
asm("vadd.f32 %0, %1, %2" : "=t" (x) : "t" (a), "t" (b))

results in the following assembly if compiled with GCC:

vadd.f32 s0, s0, s1

whereas LLVM will show "error: couldn't allocate output register for
constraint 't'", since a, b, x are 128-bit variables, not 32-bit.

This patch extends the use of 't' to mean that of GCC, thus allowing
selection of the lower Q vector regs and their D/S variants. For example,
the earlier code will now compile as:

vadd.f32 q0, q0, q1

This behaviour still differs from that of GCC but I think it is actually
more correct, since LLVM picks up the right register type based on the
datatype of x, while GCC would need an extra operand modifier to achieve
the same result, as follows:

asm("vadd.f32 %q0, %q1, %q2" : "=t" (x) : "t" (a), "t" (b))

Since this is only an extension of functionality, existing code should not
be affected by this change. Note that operand modifiers q/P are already
supported by LLVM, so this patch should suffice to support inline
assembly with constraint 't' originally built for GCC.

Reviewers: grosbach, rengolin

Reviewed By: rengolin

Subscribers: rogfer01, efriedma, olista01, aemerson, javed.absar, eraman, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D42962

llvm-svn: 325244
2018-02-15 14:44:22 +00:00
Elena Demikhovsky 945b7e5aa6 Adding a width of the GEP index to the Data Layout.
Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:memory_size:alignment:pref_alignment:index_size_in_bits.
The index size parameter is optional, if not specified, it is equal to the pointer size.

Till now, the InstCombiner normalized GEPs and extended the Index operand to the pointer width.
It works fine if you can convert pointer to integer for address calculation and all registered targets do this.
But some ISAs have very restricted instruction set for the pointer calculation. During discussions were desided to retrieve information for GEP index from the Data Layout.
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120416.html

I added an interface to the Data Layout and I changed the InstCombiner and some other passes to take the Index width into account.
This change does not affect any in-tree target. I added tests to cover data layouts with explicitly specified index size.

Differential Revision: https://reviews.llvm.org/D42123

llvm-svn: 325102
2018-02-14 06:58:08 +00:00
Vedant Kumar 51ce668d12 [LangRef] Update out-of-date instrprof names
llvm-svn: 323575
2018-01-26 23:54:25 +00:00
Sander de Smalen 1cb9431e69 Fixes Sphinx issue ('undefined label') introduced in r323313.
(and also slightly reformatted the related lines to look better in
the rendered HTML)

llvm-svn: 323317
2018-01-24 10:30:23 +00:00
Sander de Smalen fdf40917d9 [Metadata] Extend 'count' field of DISubrange to take a metadata node
Summary:
This patch extends the DISubrange 'count' field to take either a
(signed) constant integer value or a reference to a DILocalVariable
or DIGlobalVariable.

This is patch [1/3] in a series to extend LLVM's DISubrange Metadata
node to support debugging of C99 variable length arrays and vectors with
runtime length like the Scalable Vector Extension for AArch64. It is
also a first step towards representing more complex cases like arrays
in Fortran.

Reviewers: echristo, pcc, aprantl, dexonsmith, clayborg, kristof.beyls, dblaikie

Reviewed By: aprantl

Subscribers: rnk, probinson, fhahn, aemerson, rengolin, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D41695

llvm-svn: 323313
2018-01-24 09:56:07 +00:00
Daniel Neilson aac0f8f399 Additional fixes for docs in addition to r322968.
llvm-svn: 322969
2018-01-19 17:32:33 +00:00
Daniel Neilson 39eb6a50ad Fix docs build break caused by r322965
llvm-svn: 322968
2018-01-19 17:24:21 +00:00
Daniel Neilson 1e68724d24 Remove alignment argument from memcpy/memmove/memset in favour of alignment attributes (Step 1)
Summary:
 This is a resurrection of work first proposed and discussed in Aug 2015:
   http://lists.llvm.org/pipermail/llvm-dev/2015-August/089384.html
and initially landed (but then backed out) in Nov 2015:
   http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

 The @llvm.memcpy/memmove/memset intrinsics currently have an explicit argument
which is required to be a constant integer. It represents the alignment of the
dest (and source), and so must be the minimum of the actual alignment of the
two.

 This change is the first in a series that allows source and dest to each
have their own alignments by using the alignment attribute on their arguments.

 In this change we:
1) Remove the alignment argument.
2) Add alignment attributes to the source & dest arguments. We, temporarily,
   require that the alignments for source & dest be equal.

 For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 100, i32 4, i1 false)
will now read
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %dest, i8* align 4 %src, i32 100, i1 false)

 Downstream users may have to update their lit tests that check for
@llvm.memcpy/memmove/memset call/declaration patterns. The following extended sed script
may help with updating the majority of your tests, but it does not catch all possible
patterns so some manual checking and updating will be required.

s~declare void @llvm\.mem(set|cpy|move)\.p([^(]*)\((.*), i32, i1\)~declare void @llvm.mem\1.p\2(\3, i1)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* \3, i8 \4, i8 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* \3, i8 \4, i16 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* \3, i8 \4, i32 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* \3, i8 \4, i64 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* \3, i8 \4, i128 \5, i1 \6)~g
s~call void @llvm\.memset\.p([^(]*)i8\(i8([^*]*)\* (.*), i8 (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i8(i8\2* align \6 \3, i8 \4, i8 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i16\(i8([^*]*)\* (.*), i8 (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i16(i8\2* align \6 \3, i8 \4, i16 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i32\(i8([^*]*)\* (.*), i8 (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i32(i8\2* align \6 \3, i8 \4, i32 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i64\(i8([^*]*)\* (.*), i8 (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i64(i8\2* align \6 \3, i8 \4, i64 \5, i1 \7)~g
s~call void @llvm\.memset\.p([^(]*)i128\(i8([^*]*)\* (.*), i8 (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.memset.p\1i128(i8\2* align \6 \3, i8 \4, i128 \5, i1 \7)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* \4, i8\5* \6, i8 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* \4, i8\5* \6, i16 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* \4, i8\5* \6, i32 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* \4, i8\5* \6, i64 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 [01], i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* \4, i8\5* \6, i128 \7, i1 \8)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i8\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i8 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i8(i8\3* align \8 \4, i8\5* align \8 \6, i8 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i16\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i16 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i16(i8\3* align \8 \4, i8\5* align \8 \6, i16 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i32\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i32 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i32(i8\3* align \8 \4, i8\5* align \8 \6, i32 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i64\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i64 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i64(i8\3* align \8 \4, i8\5* align \8 \6, i64 \7, i1 \9)~g
s~call void @llvm\.mem(cpy|move)\.p([^(]*)i128\(i8([^*]*)\* (.*), i8([^*]*)\* (.*), i128 (.*), i32 ([0-9]*), i1 ([^)]*)\)~call void @llvm.mem\1.p\2i128(i8\3* align \8 \4, i8\5* align \8 \6, i128 \7, i1 \9)~g

 The remaining changes in the series will:
Step 2) Expand the IRBuilder API to allow creation of memcpy/memmove with differing
   source and dest alignments.
Step 3) Update Clang to use the new IRBuilder API.
Step 4) Update Polly to use the new IRBuilder API.
Step 5) Update LLVM passes that create memcpy/memmove calls to use the new IRBuilder API,
        and those that use use MemIntrinsicInst::[get|set]Alignment() to use
        getDestAlignment() and getSourceAlignment() instead.
Step 6) Remove the single-alignment IRBuilder API for memcpy/memmove, and the
        MemIntrinsicInst::[get|set]Alignment() methods.

Reviewers: pete, hfinkel, lhames, reames, bollu

Reviewed By: reames

Subscribers: niosHD, reames, jholewinski, qcolombet, jfb, sanjoy, arsenm, dschuff, dylanmckay, mehdi_amini, sdardis, nemanjai, david2050, nhaehnle, javed.absar, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, llvm-commits

Differential Revision: https://reviews.llvm.org/D41675

llvm-svn: 322965
2018-01-19 17:13:12 +00:00
Florian Hahn edae5a6e11 [LangRef] Clarify Varargs forwarding for musttail calls.
This clarification was suggested by @efriedma in D41335, which uses this
behavior to inline musttail calls with varargs.

Reviewers: hfinkel, efriedma, rnk

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D41861

llvm-svn: 322786
2018-01-17 23:29:25 +00:00
Hiroshi Inoue 760c0c9ed3 [NFC] fix trivial typos in documents
"the the" -> "the"

llvm-svn: 322552
2018-01-16 13:19:48 +00:00
Sam Clegg ea7caceedc [WebAssembly] Add COMDAT support
This adds COMDAT support to the Wasm object-file format.
Spec: https://github.com/WebAssembly/tool-conventions/pull/31

Corresponding LLD change:
https://bugs.llvm.org/show_bug.cgi?id=35533, and D40845

Patch by Nicholas Wilson

Differential Revision: https://reviews.llvm.org/D40844

llvm-svn: 322135
2018-01-09 23:43:14 +00:00
Evgeniy Stepanov c667c1f47a Hardware-assisted AddressSanitizer (llvm part).
Summary:
This is LLVM instrumentation for the new HWASan tool. It is basically
a stripped down copy of ASan at this point, w/o stack or global
support. Instrumenation adds a global constructor + runtime callbacks
for every load and store.

HWASan comes with its own IR attribute.

A brief design document can be found in
clang/docs/HardwareAssistedAddressSanitizerDesign.rst (submitted earlier).

Reviewers: kcc, pcc, alekseyshl

Subscribers: srhines, mehdi_amini, mgorny, javed.absar, eraman, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D40932

llvm-svn: 320217
2017-12-09 00:21:41 +00:00
Sanjay Patel 7fb231202c [LangRef] clarify semantics of the frem instruction
As noted in D40594, the frem instruction corresponds to fmod() except that it can't set errno.
I modified the text that we currently use for intrinsics that map to libm functions and applied
it to frem.

Differential Revision: https://reviews.llvm.org/D40629

llvm-svn: 319437
2017-11-30 14:59:03 +00:00
Yaxun Liu 407ca36b27 Let llvm.invariant.group.barrier accepts pointer to any address space
llvm.invariant.group.barrier may accept pointers to arbitrary address space.

This patch let it accept pointers to i8 in any address space and returns
pointer to i8 in the same address space.

Differential Revision: https://reviews.llvm.org/D39973

llvm-svn: 318413
2017-11-16 16:32:16 +00:00
Dan Gohman 2c74fe977d Add an @llvm.sideeffect intrinsic
This patch implements Chandler's idea [0] for supporting languages that
require support for infinite loops with side effects, such as Rust, providing
part of a solution to bug 965 [1].

Specifically, it adds an `llvm.sideeffect()` intrinsic, which has no actual
effect, but which appears to optimization passes to have obscure side effects,
such that they don't optimize away loops containing it. It also teaches
several optimization passes to ignore this intrinsic, so that it doesn't
significantly impact optimization in most cases.

As discussed on llvm-dev [2], this patch is the first of two major parts.
The second part, to change LLVM's semantics to have defined behavior
on infinite loops by default, with a function attribute for opting into
potential-undefined-behavior, will be implemented and posted for review in
a separate patch.

[0] http://lists.llvm.org/pipermail/llvm-dev/2015-July/088103.html
[1] https://bugs.llvm.org/show_bug.cgi?id=965
[2] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118632.html

Differential Revision: https://reviews.llvm.org/D38336

llvm-svn: 317729
2017-11-08 21:59:51 +00:00
Sanjay Patel 629c411538 [IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' fast-math-flag
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html
and again more recently:
http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html

...this is a step in cleaning up our fast-math-flags implementation in IR to better match
the capabilities of both clang's user-visible flags and the backend's flags for SDNode.

As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 
'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic 
reassociation - 'AllowReassoc'.

We're also adding a bit to allow approximations for library functions called 'ApproxFunc' 
(this was initially proposed as 'libm' or similar).

...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did 
look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), 
but that's apparently already used for other purposes. Also, I don't think we can just 
add a field to FPMathOperator because Operator is not intended to be instantiated. 
We'll defer movement of FMF to another day.

We keep the 'fast' keyword. I thought about removing that, but seeing IR like this:
%f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2
...made me think we want to keep the shortcut synonym.

Finally, this change is binary incompatible with existing IR as seen in the 
compatibility tests. This statement:
"Newer releases can ignore features from older releases, but they cannot miscompile 
them. For example, if nsw is ever replaced with something else, dropping it would be 
a valid way to upgrade the IR." 
( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility )
...provides the flexibility we want to make this change without requiring a new IR 
version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will 
fail to optimize some previously 'fast' code because it's no longer recognized as 
'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'.

Note: an inter-dependent clang commit to use the new API name should closely follow 
commit.

Differential Revision: https://reviews.llvm.org/D39304

llvm-svn: 317488
2017-11-06 16:27:15 +00:00
Jonas Devlieghere aaecdc44ae [docs] Update code block for compatibility with Sphinx 1.5.1
It is currently not possible to build the documentation with cmake and
the same version of Sphinx (1.5.1) used to generate the public facing
documentation on llvm.org. When code blocks cannot be parsed by
Pygments, it generates a warning which is treated as an error.

In addition to being annoying and confusing for developers, this
needlessly increases the bar for newcomers that want to get involved.

This patch removes the language specifier from the affected block. The
result is the same as when parsing fails: the block are not highlighted.

llvm-svn: 317472
2017-11-06 11:47:24 +00:00
Hiroshi Yamauchi dce9def3dd Irreducible loop metadata for more accurate block frequency under PGO.
Summary:
Currently the block frequency analysis is an approximation for irreducible
loops.

The new irreducible loop metadata is used to annotate the irreducible loop
headers with their header weights based on the PGO profile (currently this is
approximated to be evenly weighted) and to help improve the accuracy of the
block frequency analysis for irreducible loops.

This patch is a basic support for this.

Reviewers: davidxl

Reviewed By: davidxl

Subscribers: mehdi_amini, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D39028

llvm-svn: 317278
2017-11-02 22:26:51 +00:00
Sean Fertile c70d28bff5 Represent runtime preemption in the IR.
Currently we do not represent runtime preemption in the IR, which has several
drawbacks:

  1) The semantics of GlobalValues differ depending on the object file format
     you are targeting (as well as the relocation-model and -fPIE value).
  2) We have no way of disabling inlining of run time interposable functions,
     since in the IR we only know if a function is link-time interposable.
     Because of this llvm cannot support elf-interposition semantics.
  3) In LTO builds of executables we will have extra knowledge that a symbol
     resolved to a local definition and can't be preemptable, but have no way to
     propagate that knowledge through the compiler.

This patch adds preemptability specifiers to the IR with the following meaning:

dso_local --> means the compiler may assume the symbol will resolve to a
 definition within the current linkage unit and the symbol may be accessed
 directly even if the definition is not within this compilation unit.

dso_preemptable --> means that the compiler must assume the GlobalValue may be
replaced with a definition from outside the current linkage unit at runtime.

To ease transitioning dso_preemptable is treated as a 'default' in that
low-level codegen will still do the same checks it did previously to see if a
symbol should be accessed indirectly. Eventually when IR producers emit the
specifiers on all Globalvalues we can change dso_preemptable to mean 'always
access indirectly', and remove the current logic.

Differential Revision: https://reviews.llvm.org/D20217

llvm-svn: 316668
2017-10-26 15:00:26 +00:00
Bjorn Pettersson e1285e3cdf [LangRef] Update description of Constant Expressions
Summary:
When describing trunc/zext/sext/ptrtoint/inttoptr in the chapter
about Constant Expressions we now simply refer to the Instruction
Reference. As far as I know there are no difference when it comes
to the semantics and the argument constraints. The only difference
is that the syntax is slighly different for the constant expressions,
regarding the use of parenthesis in constant expressions.
Referring to the Instruction Reference is the same solution as
already used for several other operations, such as bitcast.

The main goal was to add information that vector types are allowed
also in trunc/zext/sext/ptrtoint/inttoptr constant expressions.
That was not explicitly mentioned earlier, and resulted in some
questions in the review of https://reviews.llvm.org/D38546

Reviewers: efriedma, majnemer

Reviewed By: efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39165

llvm-svn: 316429
2017-10-24 11:59:20 +00:00
Matthew Simpson 36bbc8ce98 Add !callees metadata
This patch adds a new kind of metadata that indicates the possible callees of
indirect calls.

Differential Revision: https://reviews.llvm.org/D37354

llvm-svn: 315944
2017-10-16 22:22:11 +00:00
Hans Wennborg 6519562bc6 Docs: fix link to Debugger intrinsic functions
llvm-svn: 314420
2017-09-28 15:16:37 +00:00
Sanjoy Das 6d489490e6 Fix a misleading phrase in the LangRef
Reviewers: hfinkel, dberlin

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D37432

llvm-svn: 313170
2017-09-13 18:49:22 +00:00
Reid Kleckner d4523689a6 Fix RST syntax in LangRef for llvm.codeview.annotation intrinsic
llvm-svn: 312571
2017-09-05 20:26:25 +00:00
Reid Kleckner e33c94f1b0 Add llvm.codeview.annotation to implement MSVC __annotation
Summary:
This intrinsic represents a label with a list of associated metadata
strings. It is modelled as reading and writing inaccessible memory so
that it won't be removed as dead code. I think the intention is that the
annotation strings should appear at most once in the debug info, so I
marked it noduplicate. We are allowed to inline code with annotations as
long as we strip the annotation, but that can be done later.

Reviewers: majnemer

Subscribers: eraman, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D36904

llvm-svn: 312569
2017-09-05 20:14:58 +00:00
Wei Ding a131d3fb29 Add ‘llvm.experimental.constrained.fma‘ Intrinsic.
Differential Revision: http://reviews.llvm.org/D36335

llvm-svn: 311629
2017-08-24 04:18:24 +00:00
Pete Couperus ed9569dac8 Test commit.
Fix instrinsic -> intrinsic typo.

llvm-svn: 311598
2017-08-23 20:58:22 +00:00
Erich Keane 0343ef8672 Emit section information for extern variables
Update IR generated to retain section information for external declarations. 
This is related to https://reviews.llvm.org/D36487

Patch By: eandrews
Differential Revision: https://reviews.llvm.org/D36712

llvm-svn: 311459
2017-08-22 15:30:43 +00:00
Steven Wu 86a511e836 [Doc] Update LangRef for new Module Flag Behavior
Summary:
Add the documentation for the new module flag behavior. The new
ModFlagBehavior is added in r303590.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36557

llvm-svn: 310926
2017-08-15 16:16:33 +00:00
Andrew Kaylor 53a5fbb45f Add strictfp attribute to prevent unwanted optimizations of libm calls
Differential Revision: https://reviews.llvm.org/D34163

llvm-svn: 310885
2017-08-14 21:15:13 +00:00
Matthias Braun 93f2b4bdde LangRef: Fix/improve cmpxchg wording
llvm-svn: 310533
2017-08-09 22:22:04 +00:00
Sumanth Gundapaneni 6af104e418 Add documentation for the attribute "no-jump-tables"
llvm-svn: 309445
2017-07-28 22:26:22 +00:00
Adrian Prantl 1b842dad3e Reword sentence in LangRef
llvm-svn: 309431
2017-07-28 20:44:29 +00:00
Adrian Prantl abe04759a6 Remove the obsolete offset parameter from @llvm.dbg.value
There is no situation where this rarely-used argument cannot be
substituted with a DIExpression and removing it allows us to simplify
the DWARF backend. Note that this patch does not yet remove any of
the newly dead code.

rdar://problem/33580047
Differential Revision: https://reviews.llvm.org/D35951

llvm-svn: 309426
2017-07-28 20:21:02 +00:00
Daniel Neilson 965613ef1b Add element atomic memset intrinsic
Summary: Continuing the work from https://reviews.llvm.org/D33240, this change introduces an element unordered-atomic memset intrinsic. This intrinsic is essentially memset with the implementation requirement that all stores used for the assignment are done with unordered-atomic stores of a given element size.

Reviewers: eli.friedman, reames, mkazantsev, skatkov

Reviewed By: reames

Subscribers: jfb, dschuff, sbc100, jgravelle-google, aheejin, efriedma, llvm-commits

Differential Revision: https://reviews.llvm.org/D34885

llvm-svn: 307854
2017-07-12 21:57:23 +00:00
Daniel Neilson 57226ef33c Add element atomic memmove intrinsic
Summary: Continuing the work from https://reviews.llvm.org/D33240, this change introduces an element unordered-atomic memmove intrinsic. This intrinsic is essentially memmove with the implementation requirement that all loads/stores used for the copy are done with unordered-atomic loads/stores of a given element size.

Reviewers: eli.friedman, reames, mkazantsev, skatkov

Reviewed By: reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34884

llvm-svn: 307796
2017-07-12 15:25:26 +00:00
Konstantin Zhuravlyov bb80d3e1d3 Enhance synchscope representation
OpenCL 2.0 introduces the notion of memory scopes in atomic operations to
  global and local memory. These scopes restrict how synchronization is
  achieved, which can result in improved performance.

  This change extends existing notion of synchronization scopes in LLVM to
  support arbitrary scopes expressed as target-specific strings, in addition to
  the already defined scopes (single thread, system).

  The LLVM IR and MIR syntax for expressing synchronization scopes has changed
  to use *syncscope("<scope>")*, where <scope> can be "singlethread" (this
  replaces *singlethread* keyword), or a target-specific name. As before, if
  the scope is not specified, it defaults to CrossThread/System scope.

  Implementation details:
    - Mapping from synchronization scope name/string to synchronization scope id
      is stored in LLVM context;
    - CrossThread/System and SingleThread scopes are pre-defined to efficiently
      check for known scopes without comparing strings;
    - Synchronization scope names are stored in SYNC_SCOPE_NAMES_BLOCK in
      the bitcode.

Differential Revision: https://reviews.llvm.org/D21723

llvm-svn: 307722
2017-07-11 22:23:00 +00:00
Hiroshi Inoue b93daec909 fix trivial typos in documents; NFC
llvm-svn: 306975
2017-07-02 12:44:27 +00:00
whitequark 08b20356c3 Define behavior of "stack-probe-size" attribute when inlining.
Also document the attribute, since "probe-stack" already is.

Reviewed By: majnemer

Differential Revision: https://reviews.llvm.org/D34528

llvm-svn: 306069
2017-06-22 23:22:36 +00:00
whitequark ed54b4a798 Add a "probe-stack" attribute
This attribute is used to ensure the guard page is triggered on stack
overflow. Stack frames larger than the guard page size will generate
a call to __probestack to touch each page so the guard page won't
be skipped.

Reviewed By: majnemer

Differential Revision: https://reviews.llvm.org/D34386

llvm-svn: 305939
2017-06-21 18:46:50 +00:00
David Blaikie f91b030a95 [Doc] Fix getelementptr description about arguments
Section "Arguments" of `getelementptr` [1] says the first argument is a
type, the second argument is a pointer or a vector of pointers, and is
the base address to start from. Update `getelementptr` FAQ [2]
accordingly, based on discussion with David on the mailing list [3].

[1] http://llvm.org/docs/LangRef.html#getelementptr-instruction
[2] http://llvm.org/docs/GetElementPtr.html
[3] http://lists.llvm.org/pipermail/llvm-dev/2017-June/114294.html

Patch by Wei-Ren Chen!

Differential Revision: https://reviews.llvm.org/D34325

llvm-svn: 305662
2017-06-19 05:34:21 +00:00
Daniel Neilson 3faabbbe85 [Atomics] Rename and change prototype for atomic memcpy intrinsic
Summary:

Background: http://lists.llvm.org/pipermail/llvm-dev/2017-May/112779.html

This change is to alter the prototype for the atomic memcpy intrinsic. The prototype itself is being changed to more closely resemble the semantics and parameters of the llvm.memcpy intrinsic -- to ease later combination of the llvm.memcpy and atomic memcpy intrinsics. Furthermore, the name of the atomic memcpy intrinsic is being changed to make it clear that it is not a generic atomic memcpy, but specifically a memcpy is unordered atomic.

Reviewers: reames, sanjoy, efriedma

Reviewed By: reames

Subscribers: mzolotukhin, anna, llvm-commits, skatkov

Differential Revision: https://reviews.llvm.org/D33240

llvm-svn: 305558
2017-06-16 14:43:59 +00:00
Teresa Johnson d72f51c113 [Doc] Document prof metadata in LangRef
Summary:
Points to existing documentation for branch_weights and
function_entry_count, and adds an example for VP value profile metadata.

Reviewers: davidxl, reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34218

llvm-svn: 305475
2017-06-15 15:57:12 +00:00
Florian Hahn ffc498dfcc Align definition of DW_OP_plus with DWARF spec [3/3]
Summary:
This patch is part of 3 patches that together form a single patch, but must be introduced in stages in order not to break things.
 
The way that LLVM interprets DW_OP_plus in DIExpression nodes is basically that of the DW_OP_plus_uconst operator since LLVM expects an unsigned constant operand. This unnecessarily restricts the DW_OP_plus operator, preventing it from being used to describe the evaluation of runtime values on the expression stack. These patches try to align the semantics of DW_OP_plus and DW_OP_minus with that of the DWARF definition, which pops two elements off the expression stack, performs the operation and pushes the result back on the stack.
 
This is done in three stages:
• The first patch (LLVM) adds support for DW_OP_plus_uconst.
• The second patch (Clang) contains changes all its uses from DW_OP_plus to DW_OP_plus_uconst.
• The third patch (LLVM) changes the semantics of DW_OP_plus and DW_OP_minus to be in line with its DWARF meaning. This patch includes the bitcode upgrade from legacy DIExpressions.

Patch by Sander de Smalen.

Reviewers: echristo, pcc, aprantl

Reviewed By: aprantl

Subscribers: fhahn, javed.absar, aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D33894

llvm-svn: 305386
2017-06-14 13:14:38 +00:00
Florian Hahn c9c403c0d4 Align definition of DW_OP_plus with DWARF spec [1/3]
Summary:
This patch is part of 3 patches that together form a single patch, but must be introduced in stages in order not to break things.
 
The way that LLVM interprets DW_OP_plus in DIExpression nodes is basically that of the DW_OP_plus_uconst operator since LLVM expects an unsigned constant operand. This unnecessarily restricts the DW_OP_plus operator, preventing it from being used to describe the evaluation of runtime values on the expression stack. These patches try to align the semantics of DW_OP_plus and DW_OP_minus with that of the DWARF definition, which pops two elements off the expression stack, performs the operation and pushes the result back on the stack.
 
This is done in three stages:
• The first patch (LLVM) adds support for DW_OP_plus_uconst.
• The second patch (Clang) contains changes all its uses from DW_OP_plus to DW_OP_plus_uconst.
• The third patch (LLVM) changes the semantics of DW_OP_plus and DW_OP_minus to be in line with its DWARF meaning. This patch includes the bitcode upgrade from legacy DIExpressions.

Patch by Sander de Smalen.

Reviewers: pcc, echristo, aprantl

Reviewed By: aprantl

Subscribers: fhahn, aprantl, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33892

llvm-svn: 305304
2017-06-13 16:54:44 +00:00
Adrian Prantl 6c2497fd51 Update LangRef for PR27284.
And reverse the ownership between DICompileUnit and DISubprogram.

llvm-svn: 305254
2017-06-12 23:59:43 +00:00
Peter Collingbourne 89061b2224 IR: Replace the "Linker Options" module flag with "llvm.linker.options" named metadata.
The new metadata is easier to manipulate than module flags.

Differential Revision: https://reviews.llvm.org/D31349

llvm-svn: 305227
2017-06-12 20:10:48 +00:00
Nuno Lopes b2781fb186 [docs] Make it clear shifts yield poison when shift amount >= bitwidth
Some InstCombine optimizations already rely on the result being poison
rather than undef.

For example, the following rewrite is wrong if undef is used:
; (1 << Y) * X  ->  X << Y
%Op0 = shl 1, %Y
%r = mul %Op0, %Op1
  =>
%r = shl %Op1, %Y

ERROR: Mismatch in values for i4 %r

Example:
i4 %Y = 0x8 (8, -8)
i4 %Op0 = 0x0 (0)
i4 %Op1 = 0x0 (0)
source: 0x0 (0)
target: 0x1 (1)

The optimization is correct if poison is returned instead:
http://rise4fun.com/Alive/ygX


Differential Revision: https://reviews.llvm.org/D33654

llvm-svn: 304780
2017-06-06 08:28:17 +00:00
Andrew Kaylor f466001eef Add constrained intrinsics for some libm-equivalent operations
Differential revision: https://reviews.llvm.org/D32319

llvm-svn: 303922
2017-05-25 21:31:00 +00:00
Adrian Prantl 14bd244398 Delete an obsolete paragraph in LangRef.
llvm-svn: 303896
2017-05-25 18:54:06 +00:00
George Burgess IV fbc3498f58 [docs] Small style nits.
llvm-svn: 303486
2017-05-20 04:52:29 +00:00
James Y Knight d4e1b00e7c [SPARC] Support 'f' and 'e' inline asm constraints.
Based on patch by Patrick Boettcher and Chris Dewhurst.

Differential Revision: https://reviews.llvm.org/D29116

llvm-svn: 302911
2017-05-12 15:59:10 +00:00
Javed Absar f3d7904d20 [IR] Allow attributes with global variables
This patch extends llvm-ir to allow attributes to be set on global variables.
An RFC was sent out earlier by my colleague James Molloy: http://lists.llvm.org/pipermail/cfe-dev/2017-March/053100.html
A key part of that proposal was to extend LLVM-IR to carry attributes on global variables.
This generic feature could be useful for multiple purposes.
In our present context, it would be useful to carry user specified sections for bss/rodata/data.

Reviewed by: Jonathan Roelofs, Reid Kleckner
Differential Revision: https://reviews.llvm.org/D32009

llvm-svn: 302794
2017-05-11 12:28:08 +00:00
Amara Emerson cf9daa33a7 Introduce experimental generic intrinsics for horizontal vector reductions.
- This change allows targets to opt-in to using them instead of the log2
  shufflevector algorithm.
- The SLP and Loop vectorizers have the common code to do shuffle reductions
  factored out into LoopUtils, and now have a unified interface for generating
  reductions regardless of the preference of the target. LoopUtils now uses TTI
  to determine what kind of reductions the target wants to handle.
- For CodeGen, basic legalization support is added.

Differential Revision: https://reviews.llvm.org/D30086

llvm-svn: 302514
2017-05-09 10:43:25 +00:00
Elad Cohen ef5798acf5 Support arbitrary address space pointers in masked gather/scatter intrinsics.
Fixes PR31789 - When loop-vectorize tries to use these intrinsics for a
non-default address space pointer we fail with a "Calling a function with a
bad singature!" assertion. This patch solves this by adding the 'vector of
pointers' argument as an overloaded type which will determine the address
space.

Differential revision: https://reviews.llvm.org/D31490

llvm-svn: 302018
2017-05-03 12:28:54 +00:00
Xin Tong c7180204ca Typo in LangRef.rst. NFC
llvm-svn: 301985
2017-05-02 23:24:12 +00:00
Matt Arsenault b19b57ea60 Add speculatable function attribute
This attribute tells the optimizer that the function may be speculated.

Patch by Tom Stellard

llvm-svn: 301680
2017-04-28 20:25:27 +00:00
Andrew Kaylor 73b4a9a4a4 Fix formatting of constrained FP intrinsic documentation
llvm-svn: 300865
2017-04-20 18:18:36 +00:00
Adrian Prantl 6825fb64e9 PR32382: Fix emitting complex DWARF expressions.
The DWARF specification knows 3 kinds of non-empty simple location
descriptions:
1. Register location descriptions
  - describe a variable in a register
  - consist of only a DW_OP_reg
2. Memory location descriptions
  - describe the address of a variable
3. Implicit location descriptions
  - describe the value of a variable
  - end with DW_OP_stack_value & friends

The existing DwarfExpression code is pretty much ignorant of these
restrictions. This used to not matter because we only emitted very
short expressions that we happened to get right by accident.  This
patch makes DwarfExpression aware of the rules defined by the DWARF
standard and now chooses the right kind of location description for
each expression being emitted.

This would have been an NFC commit (for the existing testsuite) if not
for the way that clang describes captured block variables. Based on
how the previous code in LLVM emitted locations, DW_OP_deref
operations that should have come at the end of the expression are put
at its beginning. Fixing this means changing the semantics of
DIExpression, so this patch bumps the version number of DIExpression
and implements a bitcode upgrade.

There are two major changes in this patch:

I had to fix the semantics of dbg.declare for describing function
arguments. After this patch a dbg.declare always takes the *address*
of a variable as the first argument, even if the argument is not an
alloca.

When lowering a DBG_VALUE, the decision of whether to emit a register
location description or a memory location description depends on the
MachineLocation — register machine locations may get promoted to
memory locations based on their DIExpression. (Future) optimization
passes that want to salvage implicit debug location for variables may
do so by appending a DW_OP_stack_value. For example:
  DBG_VALUE, [RBP-8]                        --> DW_OP_fbreg -8
  DBG_VALUE, RAX                            --> DW_OP_reg0 +0
  DBG_VALUE, RAX, DIExpression(DW_OP_deref) --> DW_OP_reg0 +0

All testcases that were modified were regenerated from clang. I also
added source-based testcases for each of these to the debuginfo-tests
repository over the last week to make sure that no synchronized bugs
slip in. The debuginfo-tests compile from source and run the debugger.

https://bugs.llvm.org/show_bug.cgi?id=32382
<rdar://problem/31205000>

Differential Revision: https://reviews.llvm.org/D31439

llvm-svn: 300522
2017-04-18 01:21:53 +00:00
George Burgess IV 8a464a7592 Remove more lies from the LangRef.
Same change as in r300168, but for invoke instead of call.

llvm-svn: 300172
2017-04-13 05:00:31 +00:00
George Burgess IV 39c9105e25 Update the LangRef to reflect reality.
At the very least, we have CallInst::setIsNoInline() for adding the
noinline attribute to callsites, and I'm told alwaysinline seems to
work.

Thought of adding "not all attributes are guaranteed to work here". If
someone thinks that would be better (or has a better way of phrasing
that, etc.), happy to add it.

llvm-svn: 300168
2017-04-13 04:01:55 +00:00
Sanjay Patel 6e41018942 [InstCombine] fix wrong undef handling when converting select to shuffle
As discussed in:
https://bugs.llvm.org/show_bug.cgi?id=32486
...the canonicalization of vector select to shufflevector does not hold up
when undef elements are present in the condition vector. 

Try to make the undef handling clear in the code and the LangRef.

Differential Revision: https://reviews.llvm.org/D31980

llvm-svn: 300092
2017-04-12 18:39:53 +00:00
Piotr Padlewski aa1b24124e [LangRef] fix documentation
llvm-svn: 300050
2017-04-12 11:18:19 +00:00
Piotr Padlewski f8486e31ca Invariant.group and mustalias docs fixes
Summary:
Alias analysis would like to know that
invariant.group.barrier returns pointer that mustalias,
but this can't imply that we can replace one pointer with another

Reviewers: dberlin, sanjoy

Subscribers: llvm-commits, chandlerc, hfinkel, nlewycky, amharc

Differential Revision: https://reviews.llvm.org/D31758

llvm-svn: 300033
2017-04-12 07:59:35 +00:00
Andrew Kaylor caf24d2b6c Minor updates to floating point intrinsic documentation
llvm-svn: 299991
2017-04-11 21:52:40 +00:00
Matt Arsenault 3c1fc768ed Allow DataLayout to specify addrspace for allocas.
LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

llvm-svn: 299888
2017-04-10 22:27:50 +00:00
Matt Arsenault c749bdc346 LangRef: Don't refer to a 'generic' address space.
Consistently call this the default address space.

llvm-svn: 299131
2017-03-30 23:36:47 +00:00
Adam Nemet cd847a8f30 [IR] Add AllowContract to FastMathFlags
-ffp-contract=fast does not currently work with LTO because it's passed as a
TargetOption to the backend rather than in the IR. This adds it to
FastMathFlags.

This is toward fixing PR25721

Differential Revision: https://reviews.llvm.org/D31164

llvm-svn: 298939
2017-03-28 20:11:52 +00:00
Adrian Prantl b44c77667a Document the status quo of DIExpression semantics in LangRef.rst
llvm-svn: 298528
2017-03-22 18:01:01 +00:00
George Burgess IV 56c7e88c2c Let llvm.objectsize be conservative with null pointers
This adds a parameter to @llvm.objectsize that makes it return
conservative values if it's given null.

This fixes PR23277.

Differential Revision: https://reviews.llvm.org/D28494

llvm-svn: 298430
2017-03-21 20:08:59 +00:00
Evgeniy Stepanov 4d490de232 Fix docs-llvm-html build.
llvm-svn: 298163
2017-03-17 22:31:13 +00:00
Evgeniy Stepanov 51c962f72e Add !associated metadata.
This is an ELF-specific thing that adds SHF_LINK_ORDER to the global's section
pointing to the metadata argument's section. The effect of that is a reverse dependency
between sections for the linker GC.

!associated does not change the behavior of global-dce. The global
may also need to be added to llvm.compiler.used.

Since SHF_LINK_ORDER is per-section, !associated effectively enables
fdata-sections for the affected globals, the same as comdats do.

Differential Revision: https://reviews.llvm.org/D29104

llvm-svn: 298157
2017-03-17 22:17:24 +00:00
Sanjay Patel 2b1f6f4b92 [InstSimplify] vector div/rem with any zero element in divisor is undef
This was suggested as a DAG simplification in the review for rL297026 :
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20170306/435253.html
...but let's start with IR since we have actual docs for IR (LangRef).

Differential Revision:
https://reviews.llvm.org/D30665

llvm-svn: 297390
2017-03-09 16:20:52 +00:00
Konstantin Zhuravlyov f9b41cd3d8 [DebugInfo] Make legal and emit DW_OP_swap and DW_OP_xderef
Differential Revision: https://reviews.llvm.org/D29672

llvm-svn: 297247
2017-03-08 00:28:57 +00:00
Sylvestre Ledru 0604c5ceb7 Fix a typo. Patch by fcrick on github https://github.com/llvm-mirror/llvm/pull/23
llvm-svn: 296969
2017-03-04 14:01:38 +00:00
Eli Friedman 13f2e35311 Explicitly state the behavior of inbounds with a null pointer.
See https://llvm.org/bugs/show_bug.cgi?id=31439; this reflects LLVM's
behavior in practice, and should be compatible with C/C++ rules.

Differential Revision: https://reviews.llvm.org/D28026

llvm-svn: 295916
2017-02-23 00:48:18 +00:00
Sanjoy Das 5be2e8415c [LangRef] Explicitly allow readnone and reaodnly functions to unwind
Summary:
This change edits the language reference to explicitly allow the
existence of readnone and readonly functions that can throw.  Full
discussion at
http://lists.llvm.org/pipermail/llvm-dev/2017-January/108637.html

Reviewers: dberlin, chandlerc, hfinkel, majnemer

Reviewed By: majnemer

Subscribers: majnemer, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D28740

llvm-svn: 295000
2017-02-13 23:19:07 +00:00
Sanjoy Das a3ff994268 [LangRef] Update the TBAA section
Summary:
Update the TBAA section to mention the struct path TBAA that LLVM
implements today.  This is not a proposal or change in semantics -- it
is intended only to **document** what LLVM already does today.

This is related to https://reviews.llvm.org/D26438 where I've tried to
implement some of the constraints as verifier checks.

Reviewers: anna, reames, rsmith, chandlerc, hfinkel, rjmccall, mehdi_amini, dexonsmith, manmanren

Reviewed By: manmanren

Subscribers: dberlin, dberris, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D26831

llvm-svn: 294999
2017-02-13 23:14:03 +00:00
Dehao Chen fb02f7140a Encode duplication factor from loop vectorization and loop unrolling to discriminator.
Summary:
This patch starts the implementation as discuss in the following RFC: http://lists.llvm.org/pipermail/llvm-dev/2016-October/106532.html

When optimization duplicates code that will scale down the execution count of a basic block, we will record the duplication factor as part of discriminator so that the offline process tool can find the duplication factor and collect the accurate execution frequency of the corresponding source code. Two important optimization that fall into this category is loop vectorization and loop unroll. This patch records the duplication factor for these 2 optimizations.

The recording will be guarded by a flag encode-duplication-in-discriminators, which is off by default.

Reviewers: probinson, aprantl, davidxl, hfinkel, echristo

Reviewed By: hfinkel

Subscribers: mehdi_amini, anemet, mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D26420

llvm-svn: 294782
2017-02-10 21:09:07 +00:00
Daniel Berlin 2c438a3075 This patch adds a ssa_copy intrinsic, as part of splitting up D29316.
Summary:
The intrinsic, marked as returning it's first argument, has no code
generation effect (though currently not every optimization pass knows
that intrinsics with the returned attribute can be looked through).

It is about to be used to by the PredicateInfo pass to attach
predicate information to existing operands, and be able to tell what
the predicate information affects.

We deliberately do not attach any info through a second operand so
that the intrinsics do not need to dominate the comparisons/etc (since
in the case of assume, we may want to push them up the post-dominator
tree).

Reviewers: davide, sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29517

llvm-svn: 294341
2017-02-07 19:29:25 +00:00
Reid Kleckner 71cb164a56 [LangRef] Document some LLVM inline asm special escapes
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2017-February/109862.html

llvm-svn: 294204
2017-02-06 18:08:45 +00:00
Alexey Bader adec283513 [LanRef] Fix typo in getelementptr example.
Summary: Change B type from double to pointer to double.

Reviewers: delena, sanjoy

Reviewed By: sanjoy

Subscribers: sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D29009

llvm-svn: 293467
2017-01-30 07:38:58 +00:00