Commit Graph

138 Commits

Author SHA1 Message Date
Daniel Sanders bf2c03ee69 [arm+x86] Make GNU variants behave like GNU w.r.t combining sin+cos into sincos.
Summary:
canCombineSinCosLibcall() would previously combine sin+cos into sincos for
GNUX32/GNUEABI/GNUEABIHF regardless of whether UnsafeFPMath were set or not.
However, GNU would only combine them for UnsafeFPMath because sincos does not
set errno like sin and cos do. It seems likely that this is an oversight.

Reviewers: t.p.northover

Subscribers: t.p.northover, aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D21431

llvm-svn: 273259
2016-06-21 12:29:03 +00:00
James Y Knight 148a6469dc Support expanding partial-word cmpxchg to full-word cmpxchg in AtomicExpandPass.
Many CPUs only have the ability to do a 4-byte cmpxchg (or ll/sc), not 1
or 2-byte. For those, you need to mask and shift the 1 or 2 byte values
appropriately to use the 4-byte instruction.

This change adds support for cmpxchg-based instruction sets (only SPARC,
in LLVM). The support can be extended for LL/SC-based PPC and MIPS in
the future, supplanting the ISel expansions those architectures
currently use.

Tests added for the IR transform and SPARCv9.

Differential Revision: http://reviews.llvm.org/D21029

llvm-svn: 273025
2016-06-17 18:11:48 +00:00
Davide Italiano bd4243c519 [CodeGen] Change getSDagStackGuard to get an internal sym.
Fixes a crash in the backend during an LTO build of rtld(1) in
FreeBSD.

llvm-svn: 272262
2016-06-09 14:23:38 +00:00
Etienne Bergeron 22bfa83208 [stack-protection] Add support for MSVC buffer security check
Summary:
This patch is adding support for the MSVC buffer security check implementation

The buffer security check is turned on with the '/GS' compiler switch.
  * https://msdn.microsoft.com/en-us/library/8dbf701c.aspx
  * To be added to clang here: http://reviews.llvm.org/D20347

Some overview of buffer security check feature and implementation:
  * https://msdn.microsoft.com/en-us/library/aa290051(VS.71).aspx
  * http://www.ksyash.com/2011/01/buffer-overflow-protection-3/
  * http://blog.osom.info/2012/02/understanding-vs-c-compilers-buffer.html


For the following example:
```
int example(int offset, int index) {
  char buffer[10];
  memset(buffer, 0xCC, index);
  return buffer[index];
}
```

The MSVC compiler is adding these instructions to perform stack integrity check:
```
        push        ebp  
        mov         ebp,esp  
        sub         esp,50h  
  [1]   mov         eax,dword ptr [__security_cookie (01068024h)]  
  [2]   xor         eax,ebp  
  [3]   mov         dword ptr [ebp-4],eax  
        push        ebx  
        push        esi  
        push        edi  
        mov         eax,dword ptr [index]  
        push        eax  
        push        0CCh  
        lea         ecx,[buffer]  
        push        ecx  
        call        _memset (010610B9h)  
        add         esp,0Ch  
        mov         eax,dword ptr [index]  
        movsx       eax,byte ptr buffer[eax]  
        pop         edi  
        pop         esi  
        pop         ebx  
  [4]   mov         ecx,dword ptr [ebp-4]  
  [5]   xor         ecx,ebp  
  [6]   call        @__security_check_cookie@4 (01061276h)  
        mov         esp,ebp  
        pop         ebp  
        ret  
```

The instrumentation above is:
  * [1] is loading the global security canary,
  * [3] is storing the local computed ([2]) canary to the guard slot,
  * [4] is loading the guard slot and ([5]) re-compute the global canary,
  * [6] is validating the resulting canary with the '__security_check_cookie' and performs error handling.

Overview of the current stack-protection implementation:
  * lib/CodeGen/StackProtector.cpp
    * There is a default stack-protection implementation applied on intermediate representation.
    * The target can overload 'getIRStackGuard' method if it has a standard location for the stack protector cookie.
    * An intrinsic 'Intrinsic::stackprotector' is added to the prologue. It will be expanded by the instruction selection pass (DAG or Fast).
    * Basic Blocks are added to every instrumented function to receive the code for handling stack guard validation and errors handling.
    * Guard manipulation and comparison are added directly to the intermediate representation.

  * lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
  * lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    * There is an implementation that adds instrumentation during instruction selection (for better handling of sibbling calls).
      * see long comment above 'class StackProtectorDescriptor' declaration.
    * The target needs to override 'getSDagStackGuard' to activate SDAG stack protection generation. (note: getIRStackGuard MUST be nullptr).
      * 'getSDagStackGuard' returns the appropriate stack guard (security cookie)
    * The code is generated by 'SelectionDAGBuilder.cpp' and 'SelectionDAGISel.cpp'.

  * include/llvm/Target/TargetLowering.h
    * Contains function to retrieve the default Guard 'Value'; should be overriden by each target to select which implementation is used and provide Guard 'Value'.

  * lib/Target/X86/X86ISelLowering.cpp
    * Contains the x86 specialisation; Guard 'Value' used by the SelectionDAG algorithm.

Function-based Instrumentation:
  * The MSVC doesn't inline the stack guard comparison in every function. Instead, a call to '__security_check_cookie' is added to the epilogue before every return instructions.
  * To support function-based instrumentation, this patch is
    * adding a function to get the function-based check (llvm 'Value', see include/llvm/Target/TargetLowering.h),
      * If provided, the stack protection instrumentation won't be inlined and a call to that function will be added to the prologue.
    * modifying (SelectionDAGISel.cpp) do avoid producing basic blocks used for inline instrumentation,
    * generating the function-based instrumentation during the ISEL pass (SelectionDAGBuilder.cpp),
    * if FastISEL (not SelectionDAG), using the fallback which rely on the same function-based implemented over intermediate representation (StackProtector.cpp).

Modifications
  * adding support for MSVC (lib/Target/X86/X86ISelLowering.cpp)
  * adding support function-based instrumentation (lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp, .h)

Results

  * IR generated instrumentation:
```
clang-cl /GS test.cc /Od /c -mllvm -print-isel-input
```

```
*** Final LLVM Code input to ISel ***

; Function Attrs: nounwind sspstrong
define i32 @"\01?example@@YAHHH@Z"(i32 %offset, i32 %index) #0 {
entry:
  %StackGuardSlot = alloca i8*                                                  <<<-- Allocated guard slot
  %0 = call i8* @llvm.stackguard()                                              <<<-- Loading Stack Guard value
  call void @llvm.stackprotector(i8* %0, i8** %StackGuardSlot)                  <<<-- Prologue intrinsic call (store to Guard slot)
  %index.addr = alloca i32, align 4
  %offset.addr = alloca i32, align 4
  %buffer = alloca [10 x i8], align 1
  store i32 %index, i32* %index.addr, align 4
  store i32 %offset, i32* %offset.addr, align 4
  %arraydecay = getelementptr inbounds [10 x i8], [10 x i8]* %buffer, i32 0, i32 0
  %1 = load i32, i32* %index.addr, align 4
  call void @llvm.memset.p0i8.i32(i8* %arraydecay, i8 -52, i32 %1, i32 1, i1 false)
  %2 = load i32, i32* %index.addr, align 4
  %arrayidx = getelementptr inbounds [10 x i8], [10 x i8]* %buffer, i32 0, i32 %2
  %3 = load i8, i8* %arrayidx, align 1
  %conv = sext i8 %3 to i32
  %4 = load volatile i8*, i8** %StackGuardSlot                                  <<<-- Loading Guard slot
  call void @__security_check_cookie(i8* %4)                                    <<<-- Epilogue function-based check
  ret i32 %conv
}
```

  * SelectionDAG generated instrumentation:

```
clang-cl /GS test.cc /O1 /c /FA
```

```
"?example@@YAHHH@Z":                    # @"\01?example@@YAHHH@Z"
# BB#0:                                 # %entry
        pushl   %esi
        subl    $16, %esp
        movl    ___security_cookie, %eax                                        <<<-- Loading Stack Guard value
        movl    28(%esp), %esi
        movl    %eax, 12(%esp)                                                  <<<-- Store to Guard slot
        leal    2(%esp), %eax
        pushl   %esi
        pushl   $204
        pushl   %eax
        calll   _memset
        addl    $12, %esp
        movsbl  2(%esp,%esi), %esi
        movl    12(%esp), %ecx                                                  <<<-- Loading Guard slot
        calll   @__security_check_cookie@4                                      <<<-- Epilogue function-based check
        movl    %esi, %eax
        addl    $16, %esp
        popl    %esi
        retl
```

Reviewers: kcc, pcc, eugenis, rnk

Subscribers: majnemer, llvm-commits, hans, thakis, rnk

Differential Revision: http://reviews.llvm.org/D20346

llvm-svn: 272053
2016-06-07 20:15:35 +00:00
Ahmed Bougacha e4b3812ec2 [CodeGen] Don't mark FMINNUM/FMAXNUM Expand twice. NFC.
They're already in the all_valuetypes() loop above.

llvm-svn: 271316
2016-05-31 18:50:21 +00:00
Craig Topper 33772c5375 [CodeGen] Default CTTZ_ZERO_UNDEF/CTLZ_ZERO_UNDEF to Expand in TargetLoweringBase. This is what the majority of the targets want and removes a bunch of code. Set it to Legal explicitly in the few cases where that's the desired behavior.
llvm-svn: 267853
2016-04-28 03:34:31 +00:00
Sanjay Patel d66607bd8c [CodeGenPrepare] use branch weight metadata to decide if a select should be turned into a branch
This is part of solving PR27344:
https://llvm.org/bugs/show_bug.cgi?id=27344

CGP should undo the SimplifyCFG transform for the same reason that earlier patches have used this
same mechanism: it's possible that passes between SimplifyCFG and CGP may be able to optimize the
IR further with a select in place.

For the TLI hook default, >99% taken or not taken is chosen as the default threshold for a highly
predictable branch. Even the most limited HW branch predictors will be correct on this branch almost
all the time, so even a massive mispredict penalty perf loss would be overcome by the win from all
the times the branch was predicted correctly.

As a follow-up, we could make the default target hook less conservative by using the SchedMachineModel's
MispredictPenalty. Or we could just let targets override the default by implementing the hook with that
and other target-specific options. Note that trying to statically determine mispredict rates for 
close-to-balanced profile weight data is generally impossible if the HW is sufficiently advanced. Ie, 
50/50 taken/not-taken might still be 100% predictable.

Finally, note that this patch as-is will not solve PR27344 because the current __builtin_unpredictable()
branch weight default values are 4 and 64. A proposal to change that is in D19435.

Differential Revision: http://reviews.llvm.org/D19488

llvm-svn: 267572
2016-04-26 17:11:17 +00:00
Matt Arsenault 940d19a09c TLI: Only iterate over integer vector types
Instead of iterating over all vectors and skipping integers.

llvm-svn: 267220
2016-04-22 21:16:17 +00:00
Tim Shen a1d8bc5597 [PPC, SSP] Support PowerPC Linux stack protection.
llvm-svn: 266809
2016-04-19 20:14:52 +00:00
James Y Knight 7873fb9d73 Pre-fill LibcallRoutineNames with nullptr.
And rearrange InitLibcallNames slightly.

llvm-svn: 266142
2016-04-12 22:32:47 +00:00
James Y Knight 19f6cce4e3 Add __atomic_* lowering to AtomicExpandPass.
(Recommit of r266002, with r266011, r266016, and not accidentally
including an extra unused/uninitialized element in LibcallRoutineNames)

AtomicExpandPass can now lower atomic load, atomic store, atomicrmw, and
cmpxchg instructions to __atomic_* library calls, when the target
doesn't support atomics of a given size.

This is the first step towards moving all atomic lowering from clang
into llvm. When all is done, the behavior of __sync_* builtins,
__atomic_* builtins, and C11 atomics will be unified.

Previously LLVM would pass everything through to the ISelLowering
code. There, unsupported atomic instructions would turn into __sync_*
library calls. Because of that behavior, Clang currently avoids emitting
llvm IR atomic instructions when this would happen, and emits __atomic_*
library functions itself, in the frontend.

This change makes LLVM able to emit __atomic_* libcalls, and thus will
eventually allow clang to depend on LLVM to do the right thing.

It is advantageous to do the new lowering to atomic libcalls in
AtomicExpandPass, before ISel time, because it's important that all
atomic operations for a given size either lower to __atomic_*
libcalls (which may use locks), or native instructions which won't. No
mixing and matching.

At the moment, this code is enabled only for SPARC, as a
demonstration. The next commit will expand support to all of the other
targets.

Differential Revision: http://reviews.llvm.org/D18200

llvm-svn: 266115
2016-04-12 20:18:48 +00:00
Rafael Espindola d41b54be11 This reverts commit r266002, r266011 and r266016.
They broke the msan bot.

Original message:

Add __atomic_* lowering to AtomicExpandPass.

AtomicExpandPass can now lower atomic load, atomic store, atomicrmw,and
cmpxchg instructions to __atomic_* library calls, when the target
doesn't support atomics of a given size.

This is the first step towards moving all atomic lowering from clang
into llvm. When all is done, the behavior of __sync_* builtins,
__atomic_* builtins, and C11 atomics will be unified.

Previously LLVM would pass everything through to the ISelLowering
code. There, unsupported atomic instructions would turn into __sync_*
library calls. Because of that behavior, Clang currently avoids emitting
llvm IR atomic instructions when this would happen, and emits __atomic_*
library functions itself, in the frontend.

This change makes LLVM able to emit __atomic_* libcalls, and thus will
eventually allow clang to depend on LLVM to do the right thing.

It is advantageous to do the new lowering to atomic libcalls in
AtomicExpandPass, before ISel time, because it's important that all
atomic operations for a given size either lower to __atomic_*
libcalls (which may use locks), or native instructions which won't. No
mixing and matching.

At the moment, this code is enabled only for SPARC, as a
demonstration. The next commit will expand support to all of the other
targets.

Differential Revision: http://reviews.llvm.org/D18200

llvm-svn: 266062
2016-04-12 12:30:25 +00:00
James Y Knight b91d38c5fe Add __atomic_* lowering to AtomicExpandPass.
AtomicExpandPass can now lower atomic load, atomic store, atomicrmw, and
cmpxchg instructions to __atomic_* library calls, when the target
doesn't support atomics of a given size.

This is the first step towards moving all atomic lowering from clang
into llvm. When all is done, the behavior of __sync_* builtins,
__atomic_* builtins, and C11 atomics will be unified.

Previously LLVM would pass everything through to the ISelLowering
code. There, unsupported atomic instructions would turn into __sync_*
library calls. Because of that behavior, Clang currently avoids emitting
llvm IR atomic instructions when this would happen, and emits __atomic_*
library functions itself, in the frontend.

This change makes LLVM able to emit __atomic_* libcalls, and thus will
eventually allow clang to depend on LLVM to do the right thing.

It is advantageous to do the new lowering to atomic libcalls in
AtomicExpandPass, before ISel time, because it's important that all
atomic operations for a given size either lower to __atomic_*
libcalls (which may use locks), or native instructions which won't. No
mixing and matching.

At the moment, this code is enabled only for SPARC, as a
demonstration. The next commit will expand support to all of the other
targets.

Differential Revision: http://reviews.llvm.org/D18200

llvm-svn: 266002
2016-04-11 22:22:33 +00:00
Tim Shen 0012756489 [SSP] Remove llvm.stackprotectorcheck.
This is a cleanup patch for SSP support in LLVM. There is no functional change.
llvm.stackprotectorcheck is not needed, because SelectionDAG isn't
actually lowering it in SelectBasicBlock; rather, it adds check code in
FinishBasicBlock, ignoring the position where the intrinsic is inserted
(See FindSplitPointForStackProtector()).

llvm-svn: 265851
2016-04-08 21:26:31 +00:00
Craig Topper 00230805f2 Use std::fill to simplify some code. NFC
llvm-svn: 265771
2016-04-08 07:10:46 +00:00
Sanjoy Das df9ae70f49 Add lowering support for llvm.experimental.deoptimize
Summary:
Only adds support for "naked" calls to llvm.experimental.deoptimize.
Support for round-tripping through RewriteStatepointsForGC will come
as a separate patch (should be simpler than this one).

Reviewers: reames

Subscribers: sanjoy, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D18429

llvm-svn: 264329
2016-03-24 20:23:29 +00:00
James Y Knight f44fc5219f Tweak some atomics functions in preparation for larger changes; NFC.
- Rename getATOMIC to getSYNC, as llvm will soon be able to emit both
  '__sync' libcalls and '__atomic' libcalls, and this function is for
  the '__sync' ones.

- getInsertFencesForAtomic() has been replaced with
  shouldInsertFencesForAtomic(Instruction), so that the decision can be
  made per-instruction. This functionality will be used soon.

- emitLeadingFence/emitTrailingFence are no longer called if
  shouldInsertFencesForAtomic returns false, and thus don't need to
  check the condition themselves.

llvm-svn: 263665
2016-03-16 22:12:04 +00:00
Petar Jovanovic 23e44f5e39 [Power PC] softening long double type
This patch implements softening of long double type (ppcf128) on ppc32
architecture and enables operations for this type for soft float.

Patch by Strahinja Petrovic.

Differential Revision: http://reviews.llvm.org/D15811

llvm-svn: 259791
2016-02-04 14:43:50 +00:00
Philip Reames cb0f947a2a [Statepoints] Use Indirect operands for spill slots
Teach the statepoint lowering code to emit Indirect stackmap entries for spill inserted by StatepointLowering (i.e. SelectionDAG), but Direct stackmap entries for in-IR allocas which represent manual stack slots. This is what the docs call for (http://llvm.org/docs/StackMaps.html#stack-map-format), but we've been emitting both as Direct. This was pointed out recently on the mailing list as a bug. It also blocks http://reviews.llvm.org/D15632 which extends the lowering to handle vector-of-pointers since only Indirect references can encode a variable sized slot.

To implement this, I introduced a new flag on the StackObject class used to maintian information about stack slots. I original considered (and prototyped in http://reviews.llvm.org/D15632), the idea of using the existing isSpillSlot flag, but end up deciding that was a bit too risky and that the cost of adding a new flag was low. Having the new flag will also allow us - in the future - to emit better comments in verbose assembly which indicate where a particular stack spill around a call comes from. (deopt, gc, regalloc).

Differential Revision: http://reviews.llvm.org/D15759

llvm-svn: 256352
2015-12-23 23:44:28 +00:00
Michael Kuperstein 801ee74167 Do not try to use i8 and i16 versions of FP_TO_U/SINT soft float library calls
It appears that neither compiler-rt nor the gnu soft-float libraries actually
implement these conversions. Instead of emitting calls to library functions
that don't exist, handle it similarly to the way we handle i8 -> float and
i16 -> float conversions: call the i32 library function, and adjust the type.

Differential Revision: http://reviews.llvm.org/D15151

llvm-svn: 255643
2015-12-15 12:55:50 +00:00
David Majnemer bbfc7219ef [IR] Remove terminatepad
It turns out that terminatepad gives little benefit over a cleanuppad
which calls the termination function.  This is not sufficient to
implement fully generic filters but MSVC doesn't support them which
makes terminatepad a little over-designed.

Depends on D15478.

Differential Revision: http://reviews.llvm.org/D15479

llvm-svn: 255522
2015-12-14 18:34:23 +00:00
David Majnemer 8a1c45d6e8 [IR] Reformulate LLVM's EH funclet IR
While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
  but they are difficult to explain to others, even to seasoned LLVM
  experts.
- catchendpad and cleanupendpad are optimization barriers.  They cannot
  be split and force all potentially throwing call-sites to be invokes.
  This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
  It is unsplittable, starts a funclet, and has control flow to other
  funclets.
- The nesting relationship between funclets is currently a property of
  control flow edges.  Because of this, we are forced to carefully
  analyze the flow graph to see if there might potentially exist illegal
  nesting among funclets.  While we have logic to clone funclets when
  they are illegally nested, it would be nicer if we had a
  representation which forbade them upfront.

Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
  flow, just a bunch of simple operands;  catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
  the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
  the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad.  Their presence can be inferred
  implicitly using coloring information.

N.B.  The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for.  An expert should take a
look to make sure the results are reasonable.

Reviewers: rnk, JosephTremoulet, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D15139

llvm-svn: 255422
2015-12-12 05:38:55 +00:00
Hal Finkel cd8664c3c2 Revert r248483, r242546, r242545, and r242409 - absdiff intrinsics
After much discussion, ending here:

  http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151123/315620.html

it has been decided that, instead of having the vectorizer directly generate
special absdiff and horizontal-add intrinsics, we'll recognize the relevant
reduction patterns during CodeGen. Accordingly, these intrinsics are not needed
(the operations they represent can be pattern matched, as is already done in
some backends). Thus, we're backing these out in favor of the current
development work.

r248483 - Codegen: Fix llvm.*absdiff semantic.
r242546 - [ARM] Use [SU]ABSDIFF nodes instead of intrinsics for VABD/VABA
r242545 - [AArch64] Use [SU]ABSDIFF nodes instead of intrinsics for ABD/ABA
r242409 - [Codegen] Add intrinsics 'absdiff' and corresponding SDNodes for absolute difference operation

llvm-svn: 255387
2015-12-11 23:11:52 +00:00
Chih-Hung Hsieh ed7d81e5d4 [X86] Part 1 to fix x86-64 fp128 calling convention.
Almost all these changes are conditioned and only apply to the new
x86-64 f128 type configuration, which will be enabled in a follow up
patch. They are required together to make new f128 work. If there is
any error, we should fix or revert them as a whole.
These changes should have no impact to current configurations.

* Relax type legalization checks to accept new f128 type configuration,
  whose TypeAction is TypeSoftenFloat, not TypeLegal, but also has
  TLI.isTypeLegal true.
* Relax GetSoftenedFloat to return in some cases f128 type SDValue,
  which is TLI.isTypeLegal but not "softened" to i128 node.
* Allow customized FABS, FNEG, FCOPYSIGN on new f128 type configuration,
  to generate optimized bitwise operators for libm functions.
* Enhance related Lower* functions to handle f128 type.
* Enhance DAGTypeLegalizer::run, SoftenFloatResult, and related functions
  to keep new f128 type in register, and convert f128 operators to library calls.
* Fix Combiner, Emitter, Legalizer routines that did not handle f128 type.
* Add ExpandConstant to handle i128 constants, ExpandNode
  to handle ISD::Constant node.
* Add one more parameter to getCommonSubClass and firstCommonClass,
  to guarantee that returned common sub class will contain the specified
  simple value type.
  This extra parameter is used by EmitCopyFromReg in InstrEmitter.cpp.
* Fix infinite loop in getTypeLegalizationCost when f128 is the value type.
* Fix printOperand to handle null operand.
* Enhance ISD::BITCAST node to handle f128 constant.
* Expand new f128 type for BR_CC, SELECT_CC, SELECT, SETCC nodes.
* Enhance X86AsmPrinter to emit f128 values in comments.

Differential Revision: http://reviews.llvm.org/D15134

llvm-svn: 254653
2015-12-03 22:02:40 +00:00
Yury Gribov d7dbb66eb8 Introduce new @llvm.get.dynamic.area.offset.i{32, 64} intrinsics.
The @llvm.get.dynamic.area.offset.* intrinsic family is used to get the offset
from native stack pointer to the address of the most recent dynamic alloca on
the caller's stack. These intrinsics are intendend for use in combination with
@llvm.stacksave and @llvm.restore to get a pointer to the most recent dynamic
alloca. This is useful, for example, for AddressSanitizer's stack unpoisoning
routines.

Patch by Max Ostapenko.

Differential Revision: http://reviews.llvm.org/D14983

llvm-svn: 254404
2015-12-01 11:40:55 +00:00
James Molloy 90111f79f9 [SDAG] Introduce a new BITREVERSE node along with a corresponding LLVM intrinsic
Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target.

This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support.

The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently).

llvm-svn: 252878
2015-11-12 12:29:09 +00:00
Matt Arsenault d8fed1b793 Add target preference for GatherAllAliases max depth
llvm-svn: 252775
2015-11-11 18:44:33 +00:00
Oliver Stannard 563585789c [CodeGen] Always promote f16 if not legal
We don't currently have any runtime library functions for operations on
f16 values (other than conversions to and from f32 and f64), so we
should always promote it to f32, even if that is not a legal type. In
that case, the f32 values would be softened to f32 library calls.

SoftenFloatRes_FP_EXTEND now needs to check the promoted operand's type,
as it may ne a no-op or require a different library call.

getCopyFromParts and getCopyToParts now need to cope with a
floating-point value stored in a larger integer part, as is the case for
any target that needs to store an f16 value in a 32-bit integer
register.

Differential Revision: http://reviews.llvm.org/D12856

llvm-svn: 252459
2015-11-09 11:03:18 +00:00
Joseph Tremoulet f748c8937e [WinEH] Update exception pointer registers
Summary:
The CLR's personality routine passes these in rdx/edx, not rax/eax.

Make getExceptionPointerRegister a virtual method parameterized by
personality function to allow making this distinction.

Similarly make getExceptionSelectorRegister a virtual method parameterized
by personality function, for symmetry.


Reviewers: pgavlin, majnemer, rnk

Subscribers: jyknight, dsanders, llvm-commits

Differential Revision: http://reviews.llvm.org/D14344

llvm-svn: 252383
2015-11-07 01:11:31 +00:00
Evgeniy Stepanov d1aad26589 [safestack] Fast access to the unsafe stack pointer on AArch64/Android.
Android libc provides a fixed TLS slot for the unsafe stack pointer,
and this change implements direct access to that slot on AArch64 via
__builtin_thread_pointer() + offset.

This change also moves more code into TargetLowering and its
target-specific subclasses to get rid of target-specific codegen
in SafeStackPass.

This change does not touch the ARM backend because ARM lowers
builting_thread_pointer as aeabi_read_tp, which is not available
on Android.

The previous iteration of this change was reverted in r250461. This
version leaves the generic, compiler-rt based implementation in
SafeStack.cpp instead of moving it to TargetLoweringBase in order to
allow testing without a TargetMachine.

llvm-svn: 251324
2015-10-26 18:28:25 +00:00
Evgeniy Stepanov 9addbc9fc1 Revert "[safestack] Fast access to the unsafe stack pointer on AArch64/Android."
Breaks the hexagon buildbot.

llvm-svn: 250461
2015-10-15 21:26:49 +00:00
Evgeniy Stepanov 142947e9f0 [safestack] Fast access to the unsafe stack pointer on AArch64/Android.
Android libc provides a fixed TLS slot for the unsafe stack pointer,
and this change implements direct access to that slot on AArch64 via
__builtin_thread_pointer() + offset.

This change also moves more code into TargetLowering and its
target-specific subclasses to get rid of target-specific codegen
in SafeStackPass.

This change does not touch the ARM backend because ARM lowers
builting_thread_pointer as aeabi_read_tp, which is not available
on Android.

llvm-svn: 250456
2015-10-15 20:50:16 +00:00
Joseph Tremoulet 9ce71f76b9 [WinEH] Add cleanupendpad instruction
Summary:
Add a `cleanupendpad` instruction, used to mark exceptional exits out of
cleanups (for languages/targets that can abort a cleanup with another
exception).  The `cleanupendpad` instruction is similar to the `catchendpad`
instruction in that it is an EH pad which is the target of unwind edges in
the handler and which itself has an unwind edge to the next EH action.
The `cleanupendpad` instruction, similar to `cleanupret` has a `cleanuppad`
argument indicating which cleanup it exits.  The unwind successors of a
`cleanuppad`'s `cleanupendpad`s must agree with each other and with its
`cleanupret`s.

Update WinEHPrepare (and docs/tests) to accomodate `cleanupendpad`.

Reviewers: rnk, andrew.w.kaylor, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12433

llvm-svn: 246751
2015-09-03 09:09:43 +00:00
Ahmed Bougacha f9c19da03a [CodeGen] Support (and default to) expanding READCYCLECOUNTER to 0.
For targets that didn't support this, this will let us respect the
langref instead of failing to select.

Note that we don't need to change the 32-bit x86/PPC lowerings (to
account for the result type/# difference) because they're both
custom and bypass type legalization.

llvm-svn: 246258
2015-08-28 01:49:59 +00:00
Michael Kuperstein dcdab4cd3a [TLI] Refactor "is integer division cheap" queries.
This removes the isPow2SDivCheap() query, as it is not currently used in
any meaningful way. isIntDivCheap() no longer relies on a state variable
(as all in-tree target set it to false), but the interface allows querying
based on the type optimization level.

NFC.

Differential Revision: http://reviews.llvm.org/D12082

llvm-svn: 245430
2015-08-19 11:17:59 +00:00
Alex Lorenz e40c8a2b26 PseudoSourceValue: Replace global manager with a manager in a machine function.
This commit removes the global manager variable which is responsible for
storing and allocating pseudo source values and instead it introduces a new
manager class named 'PseudoSourceValueManager'. Machine functions now own an
instance of the pseudo source value manager class.

This commit also modifies the 'get...' methods in the 'MachinePointerInfo'
class to construct pseudo source values using the instance of the pseudo
source value manager object from the machine function.

This commit updates calls to the 'get...' methods from the 'MachinePointerInfo'
class in a lot of different files because those calls now need to pass in a
reference to a machine function to those methods.

This change will make it easier to serialize pseudo source values as it will
enable me to transform the mips specific MipsCallEntry PseudoSourceValue
subclass into two target independent subclasses.

Reviewers: Akira Hatanaka
llvm-svn: 244693
2015-08-11 23:09:45 +00:00
James Molloy 01cdeccdc7 Add new ISD nodes: ISD::FMINNAN and ISD::FMAXNAN
The intention of these is to be a corollary to ISD::FMINNUM/FMAXNUM,
differing only on how NaNs are treated. FMINNUM returns the non-NaN
input (when given one NaN and one non-NaN), FMINNAN returns the NaN
input instead.

This patch includes support for scalarizing, widening and splitting
vectors, but not expansion or softening. The reason is that these
should never be needed - FMINNAN nodes are only going to be created
in one place (SDAGBuilder::visitSelect) and there we'll check if the
node is legal or custom. I could preemptively add expand and soften
code, but I'm fairly opposed to adding code I can't test. It's bad
enough I can't create tests with this patch, but at least this code
will be exercised by the ARM and AArch64 backends fairly shortly.

llvm-svn: 244581
2015-08-11 09:13:05 +00:00
Chandler Carruth 93205eb966 [TTI] Make the cost APIs in TargetTransformInfo consistently use 'int'
rather than 'unsigned' for their costs.

For something like costs in particular there is a natural "negative"
value, that of savings or saved cost. As a consequence, there is a lot
of code that subtracts or creates negative values based on cost, all of
which is prone to awkwardness or bugs when dealing with an unsigned
type. Similarly, we *never* want these values to wrap, as that would
cause Very Bad code generation (likely percieved as an infinite loop as
we try to emit over 2^32 instructions or some such insanity).

All around 'int' seems a much better fit for these basic metrics. I've
added asserts to ensure that at least the TTI interface never returns
negative numbers here. If we ever have a use case for negative numbers,
we can remove this, but this way a bug where someone used '-1' to
produce a 'very large' cost will be caught by the assert.

This passes all tests, and is also UBSan clean.

No functional change intended.

Differential Revision: http://reviews.llvm.org/D11741

llvm-svn: 244080
2015-08-05 18:08:10 +00:00
David Majnemer 654e130b6e New EH representation for MSVC compatibility
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Differential Revision: http://reviews.llvm.org/D11097

llvm-svn: 243766
2015-07-31 17:58:14 +00:00
Sanjay Patel 0f9dcf8b90 move DAGCombiner's allowableAlignment() helper function into the TLI
Making allowableAlignment() more accessible was suggested as a predecessor patch
for D10662, so I've pulled it into TargetLowering. This let's us remove 4 instances
of duplicate logic in LegalizeDAG.

There's a subtle functional change in the implementation: the existing 
allowableAlignment() code was using getPrefTypeAlignment() when checking 
alignment with the DataLayout and assumed that was fast. In this implementation,
we use getABITypeAlignment() and assume that is fast. See the TODO comment or the
discussion in the Phab review for future improvements in this implementation
(don't use the data layout at all).

There are no regression test changes from this difference, and I'm not sure how to
expose it via a test. I think we actually do want to provide the 'Fast' param when
checking this from DAGCombiner::MergeConsecutiveStores(). Ie, we shouldn't merge 
stores if the new stores are not going to be fast. But that change will require 
fixing allowsMisalignedMemoryAccess() overrides as noted in D10662.

Differential Revision: http://reviews.llvm.org/D10905

llvm-svn: 243549
2015-07-29 18:24:18 +00:00
James Molloy 7395a8182c [Codegen] Add intrinsics 'absdiff' and corresponding SDNodes for absolute difference operation
This adds new intrinsics "*absdiff" for absolute difference ops to facilitate efficient code generation for "sum of absolute differences" operation.
The patch also contains the introduction of corresponding SDNodes and basic legalization support.Sanity of the generated code is tested on X86.

This is 1st of the three patches.

Patch by Shahid Asghar-ahmad!

llvm-svn: 242409
2015-07-16 15:22:46 +00:00
Mehdi Amini bd7287ebe5 Move most user of TargetMachine::getDataLayout to the Module one
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11090

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 242386
2015-07-16 06:11:10 +00:00
David Majnemer db82d2f338 Revert the new EH instructions
This reverts commits r241888-r241891, I didn't mean to commit them.

llvm-svn: 241893
2015-07-10 07:15:17 +00:00
David Majnemer ae2ffc8a8c New EH representation for MSVC compatibility
Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support.  Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11041

llvm-svn: 241888
2015-07-10 07:00:44 +00:00
Mehdi Amini eaabc51e78 Re-instate the EVT parameter to getScalarShiftAmountTy() for OOT user
A documentation for this function would be nice by the way.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241807
2015-07-09 15:12:23 +00:00
Mehdi Amini 0cdec1e2ab Make isLegalAddressingMode() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11040

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241778
2015-07-09 02:09:40 +00:00
Mehdi Amini 5c183d5239 Make getByValTypeAlignment() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11038

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241777
2015-07-09 02:09:28 +00:00
Mehdi Amini 9639d650bb Make TargetLowering::getShiftAmountTy() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11037

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241776
2015-07-09 02:09:20 +00:00
Mehdi Amini 44ede33a69 Make TargetLowering::getPointerTy() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, ted, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11028

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241775
2015-07-09 02:09:04 +00:00
Mehdi Amini 56228dabfa Redirect DataLayout from TargetMachine to Module in ComputeValueVTs()
Summary:
Avoid using the TargetMachine owned DataLayout and use the Module owned
one instead. This requires passing the DataLayout up the stack to
ComputeValueVTs().

This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11019

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241773
2015-07-09 01:57:34 +00:00