Commit Graph

289 Commits

Author SHA1 Message Date
Vedant Kumar ee4bfcaa5a [DAGCombiner] Set the right SDLoc on a newly-created zextload (1/N)
Setting the right SDLoc on a newly-created zextload fixes a line table
bug which resulted in non-linear stepping behavior.

Several backend tests contained CHECK lines which relied on the IROrder
inherited from the wrong SDLoc. This patch breaks that dependence where
feasbile and regenerates test cases where not.

In some cases, changing a node's IROrder may alter register allocation
and spill behavior. This can affect performance. I have chosen not to
prevent this by applying a "known good" IROrder to SDLocs, as this may
hide a more general bug in the scheduler, or cause regressions on other
test inputs.

rdar://33755881, Part of: llvm.org/PR37262

Differential Revision: https://reviews.llvm.org/D45995

llvm-svn: 331300
2018-05-01 19:26:15 +00:00
Daniel Cederman 4557178061 Revert "This pass, fixing an erratum in some LEON 2 processors..."
Summary:
Reading Atmel's AT697E errata document this does not seem like a valid
workaround. While the text only mentions SDIV, it says that the ICC flags
can be wrong, and those are only generated by SDIVcc. Verification on
hardware shows that simply replacing SDIV with SDIVcc does not avoid
the bug with negative operands.

This reverts r283727.

Reviewers: lero_chris, jyknight

Reviewed By: jyknight

Subscribers: fedor.sergeev, jrtc27, llvm-commits

Differential Revision: https://reviews.llvm.org/D45813

llvm-svn: 330397
2018-04-20 07:53:27 +00:00
Daniel Cederman c67b3ffba7 [Sparc] Use synthetic instruction clr to zero register instead of sethi
Using `clr reg`/`mov %g0, reg`/`or %g0, %g0, reg` to zero a register
looks much better than `sethi 0, reg`.

Reviewers: jyknight, venkatra

Reviewed By: jyknight

Subscribers: eraman, fedor.sergeev, jrtc27, llvm-commits

Differential Revision: https://reviews.llvm.org/D45810

llvm-svn: 330396
2018-04-20 07:47:12 +00:00
Daniel Cederman 793af3b9f0 [Sparc] Fix addressing mode when using 64-bit values in inline assembly
Summary:
If a 64-bit register is used as an operand in inline assembly together
with a memory reference, the memory addressing will be wrong. The
addressing will be a single reg, instead of reg+reg or reg+imm. This
will generate a bad offset value or an exception in printMemOperand().

For example:

```
long long int val = 5;
long long int mem;
__asm__ volatile ("std %1, %0":"=m"(mem):"r"(val));
```
becomes:

```
std %i0, [%i2+589833]
```

The problem is that SelectInlineAsmMemoryOperand() is never called for
the memory references if one of the operands is a 64-bit register.
By calling SelectInlineAsmMemoryOperands() in tryInlineAsm() the Sparc
version of  SelectInlineAsmMemoryOperand() gets called for each memory
reference.

Reviewers: jyknight, venkatra

Reviewed By: jyknight

Subscribers: eraman, fedor.sergeev, jrtc27, llvm-commits

Differential Revision: https://reviews.llvm.org/D45761

llvm-svn: 330392
2018-04-20 06:57:49 +00:00
Hiroshi Inoue 372ffa15cb [NFC] fix trivial typos in comments
"the the" -> "the", "we we" -> "we", etc

llvm-svn: 330006
2018-04-13 11:37:06 +00:00
Geoff Berry a2b9011290 Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Re-enable commit r323991 now that r325931 has been committed to make
MachineOperand::isRenamable() check more conservative w.r.t. code
changes and opt-in on a per-target basis.

llvm-svn: 326208
2018-02-27 16:59:10 +00:00
Jonas Paulsson 8ff0773b13 [Sparc] Return true in enableMultipleCopyHints().
Enable multiple COPY hints to eliminate more COPYs during register allocation.

Note that this is something all targets should do, see
https://reviews.llvm.org/D38128.

Review: James Y Knight
llvm-svn: 326028
2018-02-24 08:24:31 +00:00
Jonas Devlieghere e0af7c390d [Sparc] Include __tls_get_addr in symbol table for TLS calls to it
Global Dynamic and Local Dynamic call relocations only implicitly
reference __tls_get_addr; there is no connection in the ELF file between
the relocations and the symbol other than the specification for the
relocations' semantics. However, it still needs to be in the symbol
table despite the lack of explicit references to the symbol table entry,
since it needs to be bound at link time for these relocations, otherwise
any objects will fail to link.

For details, see https://sourceware.org/bugzilla/show_bug.cgi?id=22832.

Path by: James Clarke (jrtc27)

Differential revision: https://reviews.llvm.org/D43271

llvm-svn: 325688
2018-02-21 15:25:26 +00:00
Quentin Colombet 48abac82b8 Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
This reverts commit r323991.

This commit breaks target that don't model all the register constraints
in TableGen. So far the workaround was to set the
hasExtraXXXRegAllocReq, but it proves that it doesn't cover all the
cases.
For instance, when mutating an instruction (like in the lowering of
COPYs) the isRenamable flag is not properly updated. The same problem
will happen when attaching machine operand from one instruction to
another.

Geoff Berry is working on a fix in https://reviews.llvm.org/D43042.

llvm-svn: 325421
2018-02-17 03:05:33 +00:00
Geoff Berry 94503c7bc3 [MachineCopyPropagation] Extend pass to do COPY source forwarding
Summary:
This change extends MachineCopyPropagation to do COPY source forwarding
and adds an additional run of the pass to the default pass pipeline just
after register allocation.

This version of this patch uses the newly added
MachineOperand::isRenamable bit to avoid forwarding registers is such a
way as to violate constraints that aren't captured in the
Machine IR (e.g. ABI or ISA constraints).

This change is a continuation of the work started in D30751.

Reviewers: qcolombet, javed.absar, MatzeB, jonpa, tstellar

Subscribers: tpr, mgorny, mcrosier, nhaehnle, nemanjai, jyknight, hfinkel, arsenm, inouehrs, eraman, sdardis, guyblank, fedor.sergeev, aheejin, dschuff, jfb, myatsina, llvm-commits

Differential Revision: https://reviews.llvm.org/D41835

llvm-svn: 323991
2018-02-01 18:54:01 +00:00
Jonas Devlieghere 865de57bde [Sparc] Account for bias in stack readjustment
Summary: This was broken long ago in D12208, which failed to account for
the fact that 64-bit SPARC uses a stack bias of 2047, and it is the
*unbiased* value which should be aligned, not the biased one. This was
seen to be an issue with Rust.

Patch by: jrtc27 (James Clarke)

Reviewers: jyknight, venkatra

Reviewed By: jyknight

Subscribers: jacob_hansen, JDevlieghere, fhahn, fedor.sergeev, llvm-commits

Differential Revision: https://reviews.llvm.org/D39425

llvm-svn: 323643
2018-01-29 12:10:32 +00:00
Richard Trieu efef032f02 Revert r318704 - [Sparc] efficient pattern for UINT_TO_FP conversion
See bug https://bugs.llvm.org/show_bug.cgi?id=35631
r318704 is giving a fatal error on some code with unsigned to floating point
conversions.

llvm-svn: 320429
2017-12-11 22:25:04 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Francis Visoiu Mistrih c71cced0aa [CodeGen] Always use `printReg` to print registers in both MIR and debug
output

As part of the unification of the debug format and the MIR format,
always use `printReg` to print all kinds of registers.

Updated the tests using '_' instead of '%noreg' until we decide which
one we want to be the default one.

Differential Revision: https://reviews.llvm.org/D40421

llvm-svn: 319445
2017-11-30 16:12:24 +00:00
Fedor Sergeev a476117e3a [Sparc] efficient pattern for UINT_TO_FP conversion
Summary:
        while investigating performance degradation of imagick benchmark
        there were found inefficient pattern for UINT_TO_FP conversion.
        That pattern causes RAW hazard in assembly code. Specifically,
        uitofp IR operator results in poor assembler :

        st          %i0, [%fp - 952]
        ldd         [%fp - 952], %f0

        it stores 32-bit integer register into memory location and then
        loads 64-bit floating point data from that location.
        That is exactly RAW hazard case. To optimize that case it is
        possible to use SPISD::ITOF and SPISD::XTOF for conversion from
        integer to floating point data type and to use ISD::BITCAST to
        copy from integer register into floating point register.
        The fix is to write custom UINT_TO_FP pattern using SPISD::ITOF,
        SPISD::XTOF, ISD::BITCAST.

Patch by Alexey Lapshin

Reviewers: fedor.sergeev, jyknight, dcederman, lero_chris

Reviewed By: jyknight

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D36875

llvm-svn: 318704
2017-11-20 22:33:58 +00:00
Geoff Berry fabedbad11 Revert "Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding""
This reverts commit r314729.

Another bug has been encountered in an out-of-tree target reported by Quentin.

llvm-svn: 314814
2017-10-03 16:59:13 +00:00
Geoff Berry bfc5fb4571 Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Issues addressed since original review:
- Avoid bug in regalloc greedy/machine verifier when forwarding to use
  in an instruction that re-defines the same virtual register.
- Fixed bug when forwarding to use in EarlyClobber instruction slot.
- Fixed incorrect forwarding to register definitions that showed up in
  explicit_uses() iterator (e.g. in INLINEASM).
- Moved removal of dead instructions found by
  LiveIntervals::shrinkToUses() outside of loop iterating over
  instructions to avoid instructions being deleted while pointed to by
  iterator.
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
  doing so can break code that implicitly relies on the physical
  register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
  can break the machine verifier by creating LiveRanges that don't
  end on a use (since the undef operand is not considered a use).

  [MachineCopyPropagation] Extend pass to do COPY source forwarding

  This change extends MachineCopyPropagation to do COPY source forwarding.

  This change also extends the MachineCopyPropagation pass to be able to
  be run during register allocation, after physical registers have been
  assigned, but before the virtual registers have been re-written, which
  allows it to remove virtual register COPY LiveIntervals that become dead
  through the forwarding of all of their uses.

llvm-svn: 314729
2017-10-02 22:01:37 +00:00
Walter Lee 35b09cbd42 Add support for Myriad ma2x8x series of CPUs
Summary: Also add support for some older Myriad CPUs that were missing.

Reviewers: jyknight

Subscribers: fedor.sergeev

Differential Revision: https://reviews.llvm.org/D37552

llvm-svn: 314705
2017-10-02 18:50:48 +00:00
Sam McCall f71bb198ed Revert "Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding""
This crashes on boringSSL on PPC (will send reduced testcase)

This reverts commit r312328.

llvm-svn: 312490
2017-09-04 15:47:00 +00:00
Geoff Berry 65528f2991 Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Issues addressed since original review:
- Moved removal of dead instructions found by
  LiveIntervals::shrinkToUses() outside of loop iterating over
  instructions to avoid instructions being deleted while pointed to by
  iterator.
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
  doing so can break code that implicitly relies on the physical
  register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
  can break the machine verifier by creating LiveRanges that don't
  end on a use (since the undef operand is not considered a use).

  [MachineCopyPropagation] Extend pass to do COPY source forwarding

  This change extends MachineCopyPropagation to do COPY source forwarding.

  This change also extends the MachineCopyPropagation pass to be able to
  be run during register allocation, after physical registers have been
  assigned, but before the virtual registers have been re-written, which
  allows it to remove virtual register COPY LiveIntervals that become dead
  through the forwarding of all of their uses.

llvm-svn: 312328
2017-09-01 14:27:20 +00:00
Hans Wennborg 24775a0a6c Revert r312154 "Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding""
It caused PR34387: Assertion failed: (RegNo < NumRegs && "Attempting to access record for invalid register number!")

> Issues identified by buildbots addressed since original review:
> - Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
> - The pass no longer forwards COPYs to physical register uses, since
>   doing so can break code that implicitly relies on the physical
>   register number of the use.
> - The pass no longer forwards COPYs to undef uses, since doing so
>   can break the machine verifier by creating LiveRanges that don't
>   end on a use (since the undef operand is not considered a use).
>
>   [MachineCopyPropagation] Extend pass to do COPY source forwarding
>
>   This change extends MachineCopyPropagation to do COPY source forwarding.
>
>   This change also extends the MachineCopyPropagation pass to be able to
>   be run during register allocation, after physical registers have been
>   assigned, but before the virtual registers have been re-written, which
>   allows it to remove virtual register COPY LiveIntervals that become dead
>   through the forwarding of all of their uses.

llvm-svn: 312178
2017-08-30 22:11:37 +00:00
Geoff Berry feffb0c8af Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Issues identified by buildbots addressed since original review:
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
  doing so can break code that implicitly relies on the physical
  register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
  can break the machine verifier by creating LiveRanges that don't
  end on a use (since the undef operand is not considered a use).

  [MachineCopyPropagation] Extend pass to do COPY source forwarding

  This change extends MachineCopyPropagation to do COPY source forwarding.

  This change also extends the MachineCopyPropagation pass to be able to
  be run during register allocation, after physical registers have been
  assigned, but before the virtual registers have been re-written, which
  allows it to remove virtual register COPY LiveIntervals that become dead
  through the forwarding of all of their uses.

llvm-svn: 312154
2017-08-30 18:41:07 +00:00
Geoff Berry bd47e8a4f7 Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding" round 2
This reverts commit r311135.

sanitizer-x86_64-linux-android buildbot is timing out with just this
patch applied.

llvm-svn: 311142
2017-08-18 01:43:11 +00:00
Geoff Berry 51f52c4fca Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Two issues identified by buildbots were addressed:
    - The pass no longer forwards COPYs to physical register uses, since
      doing so can break code that implicitly relies on the physical
      register number of the use.
    - The pass no longer forwards COPYs to undef uses, since doing so
      can break the machine verifier by creating LiveRanges that don't
      end on a use (since the undef operand is not considered a use).

    [MachineCopyPropagation] Extend pass to do COPY source forwarding

    This change extends MachineCopyPropagation to do COPY source forwarding.

    This change also extends the MachineCopyPropagation pass to be able to
    be run during register allocation, after physical registers have been
    assigned, but before the virtual registers have been re-written, which
    allows it to remove virtual register COPY LiveIntervals that become dead
    through the forwarding of all of their uses.

    Reviewers: qcolombet, javed.absar, MatzeB, jonpa

    Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny

    Differential Revision: https://reviews.llvm.org/D30751

llvm-svn: 311135
2017-08-17 23:06:55 +00:00
Geoff Berry 4e38e02e6f Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
This reverts commit r311038.

Several buildbots are breaking, and at least one appears to be due to
the forwarding of physical regs enabled by this change.  Reverting while
I investigate further.

llvm-svn: 311062
2017-08-17 04:04:11 +00:00
Geoff Berry 87f8d25150 [MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.

This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.

Reviewers: qcolombet, javed.absar, MatzeB, jonpa

Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny

Differential Revision: https://reviews.llvm.org/D30751

llvm-svn: 311038
2017-08-16 20:50:01 +00:00
James Y Knight bb76d48d59 [SPARC] Clean up the support for disabling fsmuld and fmuls instructions.
Summary:
Also enable no-fsmuld for sparcv7 (which doesn't have the
instruction).

The previous code which used a post-processing pass to do this was
unnecessary; disabling the instruction is entirely sufficient.

Reviewers: jacob_hansen, ekedaigle

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35576

llvm-svn: 308661
2017-07-20 20:09:11 +00:00
James Y Knight dda87cab7d [Sparc] Added software multiplication/division feature
Added a feature to the Sparc back-end that replaces the integer multiply and
divide instructions with calls to .mul/.sdiv/.udiv. This is a step towards
having full v7 support.

Patch by: Eric Kedaigle
Differential Revision: https://reviews.llvm.org/D35500

llvm-svn: 308343
2017-07-18 19:08:38 +00:00
Davide Italiano 9b8e3d308f [Solaris] emit .init_array instead of .ctors on Solaris (Sparc/x86)
Patch by Fedor Sergeev.

Differential Revision:  https://reviews.llvm.org/D33868

llvm-svn: 305948
2017-06-21 20:36:32 +00:00
Hans Wennborg b00ffd8cb7 Revert r302938 "Add LiveRangeShrink pass to shrink live range within BB."
This also reverts follow-ups r303292 and r303298.

It broke some Chromium tests under MSan, and apparently also internal
tests at Google.

llvm-svn: 303369
2017-05-18 18:50:05 +00:00
Dehao Chen 02828a93e8 Only enable LiveRangeShrink for x86.
Summary: Moving LiveRangeShrink to x86 as this pass is mostly useful for archtectures with great register pressure.

Reviewers: MatzeB, qcolombet

Reviewed By: qcolombet

Subscribers: jholewinski, jyknight, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33294

llvm-svn: 303292
2017-05-17 20:18:13 +00:00
Daniel Cederman 4af795b499 [Sparc] Remove execute permissions from non-executable text files
Reviewers: jyknight, lero_chris, venkatra

Reviewed By: jyknight

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D27127

llvm-svn: 303245
2017-05-17 11:05:20 +00:00
Nirav Dave da8f221273 Elide stores which are overwritten without being observed.
Summary:
In SelectionDAG, when a store is immediately chained to another store
to the same address, elide the first store as it has no observable
effects. This is causes small improvements dealing with intrinsics
lowered to stores.

Test notes:

* Many testcases overwrite store addresses multiple times and needed
  minor changes, mainly making stores volatile to prevent the
  optimization from optimizing the test away.

* Many X86 test cases optimized out instructions associated with
  associated with va_start.

* Note that test_splat in CodeGen/AArch64/misched-stp.ll no longer has
  dependencies to check and can probably be removed and potentially
  replaced with another test.

Reviewers: rnk, john.brawn

Subscribers: aemerson, rengolin, qcolombet, jyknight, nemanjai, nhaehnle, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D33206

llvm-svn: 303198
2017-05-16 19:43:56 +00:00
Dehao Chen 65dd23e273 Add LiveRangeShrink pass to shrink live range within BB.
Summary: LiveRangeShrink pass moves instruction right after the definition with the same BB if the instruction and its operands all have more than one use. This pass is inexpensive and guarantees optimal live-range within BB.

Reviewers: davidxl, wmi, hfinkel, MatzeB, andreadb

Reviewed By: MatzeB, andreadb

Subscribers: hiraditya, jyknight, sanjoy, skatkov, gberry, jholewinski, qcolombet, javed.absar, krytarowski, atrick, spatel, RKSimon, andreadb, MatzeB, mehdi_amini, mgorny, efriedma, davide, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32563

llvm-svn: 302938
2017-05-12 19:29:27 +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
Adrian Prantl 083e6a5b5c Don't emit CFI instructions at the end of a function
When functions are terminated by unreachable instructions, the last
instruction might trigger a CFI instruction to be generated. However,
emitting it would be be illegal since the function (and thus the FDE
the CFI is in) has already ended with the previous instruction.

Darwin's dwarfdump --verify --eh-frame complains about this and the
specification supports this.
Relevant bits from the DWARF 5 standard (6.4 Call Frame Information):

"[The] address_range [field in an FDE]: The number of bytes of
 program instructions described by this entry."

"Row creation instructions: [...]
 The new location value is always greater than the current one."
The first quotation implies that a CFI cannot describe a target
address outside of the enclosing FDE's range.

rdar://problem/26244988

Differential Revision: https://reviews.llvm.org/D32246

llvm-svn: 301219
2017-04-24 18:45:59 +00:00
Daniel Cederman 9db582a656 [Sparc] Check register use with isPhysRegUsed() instead of reg_nodbg_empty()
Summary: By using reg_nodbg_empty() to determine if a function can be
treated as a leaf function or not, we miss the case when the register
pair L0_L1 is used but not L0 by itself. This has the effect that
use_all_i32_regs(), a test in reserved-regs.ll which tries to use all
registers, gets treated as a leaf function.

Reviewers: jyknight, venkatra

Reviewed By: jyknight

Subscribers: davide, RKSimon, sepavloff, llvm-commits

Differential Revision: https://reviews.llvm.org/D27089

llvm-svn: 297285
2017-03-08 15:23:10 +00:00
Kyle Butt 7fbec9bdf1 Codegen: Make chains from trellis-shaped CFGs
Lay out trellis-shaped CFGs optimally.
A trellis of the shape below:

  A     B
  |\   /|
  | \ / |
  |  X  |
  | / \ |
  |/   \|
  C     D

would be laid out A; B->C ; D by the current layout algorithm. Now we identify
trellises and lay them out either A->C; B->D or A->D; B->C. This scales with an
increasing number of predecessors. A trellis is a a group of 2 or more
predecessor blocks that all have the same successors.

because of this we can tail duplicate to extend existing trellises.

As an example consider the following CFG:

    B   D   F   H
   / \ / \ / \ / \
  A---C---E---G---Ret

Where A,C,E,G are all small (Currently 2 instructions).

The CFG preserving layout is then A,B,C,D,E,F,G,H,Ret.

The current code will copy C into B, E into D and G into F and yield the layout
A,C,B(C),E,D(E),F(G),G,H,ret

define void @straight_test(i32 %tag) {
entry:
  br label %test1
test1: ; A
  %tagbit1 = and i32 %tag, 1
  %tagbit1eq0 = icmp eq i32 %tagbit1, 0
  br i1 %tagbit1eq0, label %test2, label %optional1
optional1: ; B
  call void @a()
  br label %test2
test2: ; C
  %tagbit2 = and i32 %tag, 2
  %tagbit2eq0 = icmp eq i32 %tagbit2, 0
  br i1 %tagbit2eq0, label %test3, label %optional2
optional2: ; D
  call void @b()
  br label %test3
test3: ; E
  %tagbit3 = and i32 %tag, 4
  %tagbit3eq0 = icmp eq i32 %tagbit3, 0
  br i1 %tagbit3eq0, label %test4, label %optional3
optional3: ; F
  call void @c()
  br label %test4
test4: ; G
  %tagbit4 = and i32 %tag, 8
  %tagbit4eq0 = icmp eq i32 %tagbit4, 0
  br i1 %tagbit4eq0, label %exit, label %optional4
optional4: ; H
  call void @d()
  br label %exit
exit:
  ret void
}

here is the layout after D27742:
straight_test:                          # @straight_test
; ... Prologue elided
; BB#0:                                 # %entry ; A (merged with test1)
; ... More prologue elided
	mr 30, 3
	andi. 3, 30, 1
	bc 12, 1, .LBB0_2
; BB#1:                                 # %test2 ; C
	rlwinm. 3, 30, 0, 30, 30
	beq	 0, .LBB0_3
	b .LBB0_4
.LBB0_2:                                # %optional1 ; B (copy of C)
	bl a
	nop
	rlwinm. 3, 30, 0, 30, 30
	bne	 0, .LBB0_4
.LBB0_3:                                # %test3 ; E
	rlwinm. 3, 30, 0, 29, 29
	beq	 0, .LBB0_5
	b .LBB0_6
.LBB0_4:                                # %optional2 ; D (copy of E)
	bl b
	nop
	rlwinm. 3, 30, 0, 29, 29
	bne	 0, .LBB0_6
.LBB0_5:                                # %test4 ; G
	rlwinm. 3, 30, 0, 28, 28
	beq	 0, .LBB0_8
	b .LBB0_7
.LBB0_6:                                # %optional3 ; F (copy of G)
	bl c
	nop
	rlwinm. 3, 30, 0, 28, 28
	beq	 0, .LBB0_8
.LBB0_7:                                # %optional4 ; H
	bl d
	nop
.LBB0_8:                                # %exit ; Ret
	ld 30, 96(1)                    # 8-byte Folded Reload
	addi 1, 1, 112
	ld 0, 16(1)
	mtlr 0
	blr

The tail-duplication has produced some benefit, but it has also produced a
trellis which is not laid out optimally. With this patch, we improve the layouts
of such trellises, and decrease the cost calculation for tail-duplication
accordingly.

This patch produces the layout A,C,E,G,B,D,F,H,Ret. This layout does have
back edges, which is a negative, but it has a bigger compensating
positive, which is that it handles the case where there are long strings
of skipped blocks much better than the original layout. Both layouts
handle runs of executed blocks equally well. Branch prediction also
improves if there is any correlation between subsequent optional blocks.

Here is the resulting concrete layout:

straight_test:                          # @straight_test
; BB#0:                                 # %entry ; A (merged with test1)
	mr 30, 3
	andi. 3, 30, 1
	bc 12, 1, .LBB0_4
; BB#1:                                 # %test2 ; C
	rlwinm. 3, 30, 0, 30, 30
	bne	 0, .LBB0_5
.LBB0_2:                                # %test3 ; E
	rlwinm. 3, 30, 0, 29, 29
	bne	 0, .LBB0_6
.LBB0_3:                                # %test4 ; G
	rlwinm. 3, 30, 0, 28, 28
	bne	 0, .LBB0_7
	b .LBB0_8
.LBB0_4:                                # %optional1 ; B (Copy of C)
	bl a
	nop
	rlwinm. 3, 30, 0, 30, 30
	beq	 0, .LBB0_2
.LBB0_5:                                # %optional2 ; D (Copy of E)
	bl b
	nop
	rlwinm. 3, 30, 0, 29, 29
	beq	 0, .LBB0_3
.LBB0_6:                                # %optional3 ; F (Copy of G)
	bl c
	nop
	rlwinm. 3, 30, 0, 28, 28
	beq	 0, .LBB0_8
.LBB0_7:                                # %optional4 ; H
	bl d
	nop
.LBB0_8:                                # %exit

Differential Revision: https://reviews.llvm.org/D28522

llvm-svn: 295223
2017-02-15 19:49:14 +00:00
Sanne Wouda 57b63d6ade [LLC] Add an inline assembly diagnostics handler.
Summary:
llc would hit a fatal error for errors in inline assembly. The
diagnostics message is now printed.

Reviewers: rengolin, MatzeB, javed.absar, anemet

Reviewed By: anemet

Subscribers: jyknight, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D29408

llvm-svn: 293999
2017-02-03 11:14:39 +00:00
Kyle Butt b15c06677c CodeGen: Allow small copyable blocks to "break" the CFG.
When choosing the best successor for a block, ordinarily we would have preferred
a block that preserves the CFG unless there is a strong probability the other
direction. For small blocks that can be duplicated we now skip that requirement
as well, subject to some simple frequency calculations.

Differential Revision: https://reviews.llvm.org/D28583

llvm-svn: 293716
2017-01-31 23:48:32 +00:00
James Y Knight 99a2ce2af2 Check for register clobbers when merging a vreg live range with a
reserved physreg in RegisterCoalescer.

Previously, we only checked for clobbers when merging into a READ of
the physreg, but not when merging from a WRITE to the physreg.

Differential Revision: https://reviews.llvm.org/D28527

llvm-svn: 291942
2017-01-13 19:08:36 +00:00
Kyle Butt efe56fed12 Revert "CodeGen: Allow small copyable blocks to "break" the CFG."
This reverts commit ada6595a526d71df04988eb0a4b4fe84df398ded.

This needs a simple probability check because there are some cases where it is
not profitable.

llvm-svn: 291695
2017-01-11 19:55:19 +00:00
Kyle Butt df27aa8c89 CodeGen: Allow small copyable blocks to "break" the CFG.
When choosing the best successor for a block, ordinarily we would have preferred
a block that preserves the CFG unless there is a strong probability the other
direction. For small blocks that can be duplicated we now skip that requirement
as well.

Differential revision: https://reviews.llvm.org/D27742

llvm-svn: 291609
2017-01-10 23:04:30 +00:00
Davide Italiano db00939403 [SPARC] Fix test so that it checks the correct label.
Before it wasn't checking anything.

llvm-svn: 290963
2017-01-04 14:01:58 +00:00
Matthias Braun 325cd2c98a ScheduleDAGInstrs: Add condjump deps to addSchedBarrierDeps()
addSchedBarrierDeps() is supposed to add use operands to the ExitSU
node. The current implementation adds uses for calls/barrier instruction
and the MBB live-outs in all other cases. The use
operands of conditional jump instructions were missed.

Also added code to macrofusion to set the latencies between nodes to
zero to avoid problems with the fusing nodes lingering around in the
pending list now.

Differential Revision: https://reviews.llvm.org/D25140

llvm-svn: 286544
2016-11-11 01:34:21 +00:00
Chris Dewhurst 30de1de144 [Sparc][LEON] Test for FixFDIVSQRT erratum fix.
Note: Test is per differential review, but the other changed code in the review was for an optimisation that din't quite work. Nevertheless, the test is valid for the unoptimised version of the fix.

Differential Review: https://reviews.llvm.org/D24658

llvm-svn: 285692
2016-11-01 14:23:37 +00:00
James Y Knight 2e64b8b79e [Sparc] Don't overlap variable-sized allocas with other stack variables.
On SparcV8, it was previously the case that a variable-sized alloca
might overlap by 4-bytes the last fixed stack variable, effectively
because 92 (the number of bytes reserved for the register spill area) !=
96 (the offset added to SP for where to start a DYNAMIC_STACKALLOC).

It's not as simple as changing 96 to 92, because variables that should
be 8-byte aligned would then be misaligned.

For now, simply increase the allocation size by 8 bytes for each dynamic
allocation -- wastes space, but at least doesn't overlap. As the large
comment says, doing this more efficiently will require larger changes in
llvm.

Also adds some test cases showing that we continue to not support
dynamic stack allocation and over-alignment in the same function.

llvm-svn: 285131
2016-10-25 22:13:28 +00:00
Tim Northover 34c83da4c3 Sparc: fix test.
llvm-svn: 284605
2016-10-19 15:55:11 +00:00
Chris Dewhurst 2c3cdd66d2 [Sparc][LEON] Detects an erratum on UT699 LEON 3 processors involving rounding mode changes and issues an appropriate user error message.
Differential Revision: https://reviews.llvm.org/D24665

llvm-svn: 284591
2016-10-19 14:01:06 +00:00
Chris Dewhurst 850131213f This pass, fixing an erratum in some LEON 2 processors ensures that the SDIV instruction is not issued, but replaced by SDIVcc instead, which does not exhibit the error. Unit test included.
Differential Review: https://reviews.llvm.org/D24660

llvm-svn: 283727
2016-10-10 08:53:06 +00:00