Commit Graph

17214 Commits

Author SHA1 Message Date
Bill Schmidt
e0bc37579b Add -mattr=+altivec and remove XFAIL.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165666 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 22:25:11 +00:00
Bill Schmidt
3a55b64e5e XFAIL for all targets pending investigation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165664 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 21:52:10 +00:00
Nadav Rotem
87255a431b Patch by Shuxin Yang <shuxin.llvm@gmail.com>.
Original message:

The attached is the fix to radar://11663049. The optimization can be outlined by following rules:

   (select (x != c), e, c) -> select (x != c), e, x),
   (select (x == c), c, e) -> select (x == c), x, e)
where the <c> is an integer constant.

 The reason for this change is that : on x86, conditional-move-from-constant needs two instructions;
however, conditional-move-from-register need only one instruction.

  While the LowerSELECT() sounds to be the most convenient place for this optimization, it turns out to be a bad place. The reason is that by replacing the constant <c> with a symbolic value, it obscure some instruction-combining opportunities which would otherwise be very easy to spot. For that reason, I have to postpone the change to last instruction-combining phase.

  The change passes the test of "make check-all -C <build-root/test" and "make -C project/test-suite/SingleSource".



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165661 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 21:31:55 +00:00
Bill Schmidt
26160f4e64 When generating spill and reload code for vector registers on PowerPC,
the compiler makes use of GPR0.  However, there are two flavors of
GPR0 defined by the target:  the 32-bit GPR0 (R0) and the 64-bit GPR0
(X0).  The spill/reload code makes use of R0 regardless of whether we
are generating 32- or 64-bit code.

This patch corrects the problem in the obvious manner, using X0 and
ADDI8 for 64-bit and R0 and ADDI for 32-bit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165658 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 21:25:01 +00:00
Bill Schmidt
a5d0ab5553 The PowerPC VRSAVE register has been somewhat of an odd beast since
the Altivec extensions were introduced.  Its use is optional, and
allows the compiler to communicate to the operating system which
vector registers should be saved and restored during a context switch.
In practice, this information is ignored by the various operating
systems using the SVR4 ABI; the kernel saves and restores the entire
register state.  Setting the VRSAVE register is no longer performed by
the AIX XL compilers, the IBM i compilers, or by GCC on Power Linux
systems.  It seems best to avoid this logic within LLVM as well.

This patch avoids generating code to update and restore VRSAVE for the
PowerPC SVR4 ABIs (32- and 64-bit).  The code remains in place for the
Darwin ABI.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165656 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 20:54:15 +00:00
Duncan Sands
ea46827d6c Add the testcase from pr13254 (the old scalarreply pass handles this wrong;
the new sroa pass handles it right).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165644 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 18:41:19 +00:00
Michael Liao
4e2c56bdcb Specify CPU model to avoid breaking ATOM builds
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165638 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 18:04:52 +00:00
Michael Liao
44c2d61b67 Add support for FP_ROUND from v2f64 to v2f32
- Due to the current matching vector elements constraints in
  ISD::FP_ROUND, rounding from v2f64 to v4f32 (after legalization from
  v2f32) is scalarized. Add a customized v2f32 widening to convert it
  into a target-specific X86ISD::VFPROUND to work around this
  constraints.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165631 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 16:53:28 +00:00
NAKAMURA Takumi
98f01bf34b [CMake] check-all: Don't include check-llvm into check-all without LLVM_BUILD_TOOLS.
FIXME: Would you like to run llvm/unittests w/o LLVM_BUILD_TESTS regardless of LLVM_BUILD_TOOLS?

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165619 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 13:33:00 +00:00
Stepan Dyatkovskiy
2c2cb3c09f Fix for LDRB instruction:
SDNode for LDRB_POST_IMM is invalid: number of registers added to SDNode fewer
that described in .td.

7 ops is needed, but SDNode with only 6 is created.

In more details:
In ARMInstrInfo.td, in multiclass AI2_ldridx, in definition _POST_IMM, offset
operand is defined as am2offset_imm. am2offset_imm is complex parameter type,
and actually it consists from dummy register and imm itself. As I understood
trick with dummy reg was made for AsmParser. In ARMISelLowering.cpp, this dummy
register was not added to SDNode, and it cause crash in Peephole Optimizer pass.

The problem fixed by setting up additional dummy reg when emitting
LDRB_POST_IMM instruction.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165617 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 11:43:40 +00:00
Stepan Dyatkovskiy
661afe75e8 Issue description:
SchedulerDAGInstrs::buildSchedGraph ignores dependencies between FixedStack
objects and byval parameters. So loading byval parameters from stack may be
inserted *before* it will be stored, since these operations are treated as
independent.

Fix:
Currently ARMTargetLowering::LowerFormalArguments saves byval registers with
FixedStack MachinePointerInfo. To fix the problem we need to store byval
registers with MachinePointerInfo referenced to first the "byval" parameter.

Also commit adds two new fields to the InputArg structure: Function's argument
index and InputArg's part offset in bytes relative to the start position of
Function's argument. E.g.: If function's argument is 128 bit width and it was
splitted onto 32 bit regs, then we got 4 InputArg structs with same arg index,
but different offset values. 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165616 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 11:37:36 +00:00
Craig Topper
ebf3a37c0a Test case for r165480.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165594 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 02:54:23 +00:00
Akira Hatanaka
97d9f081a9 Implement MipsTargetLowering::CanLowerReturn.
Patch by Sasa Stankovic. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165585 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 01:27:09 +00:00
Evan Cheng
e61e516a51 When expanding atomic load arith instructions, do not lose target flags. rdar://12453106
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165568 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 23:48:33 +00:00
Jack Carter
2f68b311a1 Initial assembler implementation of Mips load address macro
This patch provides initial implementation of load address 
macro instruction for Mips. We have implemented two kinds 
of expansions with their variations depending on the size 
of immediate operand:

 1) load address with immediate value directly:
    * la d,j => addiu d,$zero,j   (for -32768 <= j <= 65535)
    * la d,j => lui d,hi16(j)
                ori d,d,lo16(j)   (for any other 32 bit value of j)

 2) load load address with register offset value
    * la d,j(s) => addiu d,s,j     (for -32768 <= j <= 65535)
    * la d,j(s) => lui d,hi16(j)   (for any other 32 bit value of j)
                   ori d,d,lo16(j)
                   addu d,d,s

This patch does not cover the case when the address is loaded 
from the value of the label or function.

Contributer: Vladimir Medic


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165561 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 23:29:45 +00:00
Bill Wendling
28d1c60f89 Inline the checks for mutually exclusive attributes since they're used in only one module.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165539 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 20:11:19 +00:00
Rafael Espindola
b4e971f376 Enable response files in all tools. Patch by Liu, Yaxun (Sam). I have simplified
the test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165535 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 19:52:10 +00:00
Michael Ilseman
440ae6800e New EarlyCSE tests for CSE-ing across commutativity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165510 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 16:58:13 +00:00
Alexey Samsonov
e97a3a4b4f Fix PR14016.
DeadArgumentElimination pass can replace one LLVM function with another,
invalidating a pointer stored in debug info metadata entry for this function.
To fix this, we collect debug info descriptors for functions before
running a DeadArgumentElimination pass and "patch" pointers in metadata nodes
if we replace a function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165490 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 08:13:15 +00:00
NAKAMURA Takumi
7c8998eaba Revert r117093, "test/Makefile: Force lit -j1 on Cygwin."
lit -jN works on cygwin in most cases, but still sometimes I can see stalls with iterative run on the buildbot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165482 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 05:07:18 +00:00
Chandler Carruth
2fdb25b5a9 Fix PR14034, an infloop / heap corruption / crash bug in the new SROA.
Thanks to Benjamin for the raw test case. This one took about 50 times
longer to reduce than to fix. =/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165476 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-09 01:58:35 +00:00
Jakob Stoklund Olesen
6be75ae196 Don't crash on extra evil irreducible control flow.
When the CFG contains a loop with multiple entry blocks, the traces
computed by MachineTraceMetrics don't always have the same nice
properties. Loop back-edges are normally excluded from traces, but
MachineLoopInfo doesn't recognize loops with multiple entry blocks, so
those back-edges may be included.

Avoid asserting when that happens by adding an isEarlierInSameTrace()
function that accurately determines if a dominating block is part of the
same trace AND is above the currrent block in the trace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165434 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 22:06:44 +00:00
Adhemerval Zanella
1c7d69bbe2 PR12716: PPC crashes on vector compare
Vector compare using altivec 'vcmpxxx' instructions have as third argument
a vector register instead of CR one, different from integer and float-point
compares. This leads to a failure in code generation, where 'SelectSETCC'
expects a DAG with a CR register and gets vector register instead.

This patch changes the behavior by just returning a DAG with the 
vector compare instruction based on the type. The patch also adds a testcase
for all vector types llvm defines.

It also included a fix on signed 5-bits predicates printing, where
signed values were not handled correctly as signed (char are unsigned by
default for PowerPC). This generates 'vspltisw' (vector splat)
instruction with SIM out of range.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165419 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 18:59:53 +00:00
Adhemerval Zanella
51aaadb7bd Add floating-point to and from integer conversion
This patch add altivec support for v4i32 to v4f32 and for v4f32 to
v4i32 vector rounding conversion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165409 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 17:27:24 +00:00
Micah Villmow
791cfc211a Move TargetData to DataLayout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165403 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 16:39:34 +00:00
James Molloy
c1054710ca Some regression tests which are testing the old jit and are exercising functionality which is both known to be broken and not expected to be fixed in the old jit. To remove these from the regression test output, I've marked them XFAIL (for lit tests) and ifdef'd them out (unit tests). These modifications remove the last long-standing regression test failures from the buildbots (though updating the triple to reflect new ubuntu configuration has temporarily caused some new failures). Tested on x86-64 and ARM Linux.
Patch by David Tweed!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165390 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 13:06:30 +00:00
Benjamin Kramer
dcf2420b07 X86: fcmov doesn't handle all possible EFLAGS, fall back to a branch for the others.
Otherwise it will try to use SSE patterns and fail horribly if sse is disabled.
Fixes PR14035.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165377 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-07 15:34:27 +00:00
Jack Carter
de33227462 Adding support for instructions mfc0, mfc2, mtc0, mtc2
move from and to coprocessors 0 and 2.

Contributer: Vladimir Medic


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165351 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-06 01:17:37 +00:00
Reed Kotler
dfb8dbb4fd Patch for integer multiply, signed/unsigned, long/long long.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165322 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-05 18:27:54 +00:00
NAKAMURA Takumi
b894f96de4 Enable llvm/test/ExecutionEngine/MCJIT also for cygwin.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165313 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-05 14:10:29 +00:00
Rafael Espindola
7c0278e14e Convert to unix line endings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165308 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-05 13:32:38 +00:00
Eli Friedman
ce3da6f1d5 Make sure to generate the right kind of MDNode for enum forward declarations.
PR14029, LLVM part.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165288 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-05 01:49:14 +00:00
Evan Cheng
2a2947885a Follow up to r165072. Try a different approach: only move the load when it's going to be folded into the call. rdar://12437604
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165287 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-05 01:48:22 +00:00
Chandler Carruth
fca3f4021a Teach the new SROA a new trick. Now we zap any memcpy or memmoves which
are in fact identity operations. We detect these and kill their
partitions so that even splitting is unaffected by them. This is
particularly important because Clang relies on emitting identity memcpy
operations for struct copies, and these fold away to constants very
often after inlining.

Fixes the last big performance FIXME I have on my plate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165285 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-05 01:29:09 +00:00
Nadav Rotem
ea2c50c041 When merging connsecutive stores, use vectors to store the constant zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165267 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 22:35:15 +00:00
Jim Grosbach
837c28a840 ARM: locate user-defined text sections next to default text.
Make sure functions located in user specified text sections (via the
section attribute) are located together with the default text sections.
Otherwise, for large object files, the relocations for call instructions
are more likely to be out of range. This becomes even more likely in the
presence of LTO.

rdar://12402636

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165254 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 21:33:24 +00:00
Eric Christopher
0313ced016 Update this a bit more to represent how the prologue should work:
a) frame setup instructions define the prologue
b) we shouldn't change our location mid-stream

Add a test to make sure that the stack adjustment stays within
the prologue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165250 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 20:46:14 +00:00
Benjamin Kramer
1e21db6e83 SimplifyCFG: Enhance the "remove CFG edge that leads to null pointer dereference" optimization to also handle instructions with multiple uses.
We conservatively only check the first use to avoid walking long use chains.
This catches the common case of having both a load and a store to a pointer
supplied by a PHI node.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165232 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 16:11:49 +00:00
Duncan Sands
7508f946bc In my recent change to avoid use of underaligned memory I didn't notice that
cpyDest can be mutated in some cases, which would then cause a crash later if
indeed the memory was underaligned.  This brought down several buildbots, so
I guess the underaligned case is much more common than I thought!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165228 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 13:53:21 +00:00
Duncan Sands
ffcf6dffee The alignment of an sret parameter is known: it must be at least the
alignment of the return type.  Teach the optimizers this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165226 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 13:36:31 +00:00
Chandler Carruth
b2d98c2917 Fix PR13969, a mini-phase-ordering issue with the new SROA pass.
Currently, we re-visit allocas when something changes about the way they
might be *split* to allow better scalarization to take place. However,
we weren't handling the case when the *promotion* is what would change
the behavior of SROA. When an address derived from an alloca is stored
into another alloca, we consider the first to have escaped. If the
second is ever promoted to an SSA value, we will suddenly be able to run
the SROA pass on the first alloca.

This patch adds explicit support for this form if iteration. When we
detect a store of a pointer derived from an alloca, we flag the
underlying alloca for reprocessing after promotion. The logic works hard
to only do this when there is definitely going to be promotion and it
might remove impediments to the analysis of the alloca.

Thanks to Nick for the great test case and Benjamin for some sanity
check review.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165223 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 12:33:50 +00:00
Duncan Sands
f58747517c The memcpy optimizer was happily doing call slot forwarding when the new memory
was less aligned than the old.  In the testcase this results in an overaligned
memset: the memset alignment was correct for the original memory but is too much
for the new memory.  Fix this by either increasing the alignment of the new
memory or bailing out if that isn't possible.  Should fix the gcc-4.7 self-host
buildbot failure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165220 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:54:40 +00:00
Chandler Carruth
aa3cb334af Teach the integer-promotion rewrite strategy to be endianness aware.
Sorry for this being broken so long. =/

As part of this, switch all of the existing tests to be Little Endian,
which is the behavior I was asserting in them anyways! Add in a new
big-endian test that checks the interesting behavior there.

Another part of this is to tighten the rules abotu when we perform the
full-integer promotion. This logic now rejects cases where there fully
promoted integer is a non-multiple-of-8 bitwidth or cases where the
loads or stores touch bits which are in the allocated space of the
alloca but are not loaded or stored when accessing the integer. Sadly,
these aren't really observable today as the rest of the pass will
already ensure the invariants hold. However, the latter situation is
likely to become a potential concern in the future.

Thanks to Benjamin and Duncan for early review of this patch. I'm still
looking into whether there are further endianness issues, please let me
know if anyone sees BE failures persisting past this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165219 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 10:39:28 +00:00
Jack Carter
9d577c8614 Implement methods that enable expansion of load immediate
macro instruction (li) in the assembler.

We have identified three possible expansions depending on 
the size of immediate operand:
  1) for 0 ≤ j ≤ 65535.
     li d,j =>
     ori d,$zero,j

  2) for −32768 ≤ j < 0.
     li d,j =>
     addiu d,$zero,j

  3) for any other value of j that is representable as a 32-bit integer.
     li d,j =>
     lui d,hi16(j)
     ori d,d,lo16(j)

All of the above have been implemented in ths patch.

Contributer: Vladimir Medic


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165199 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 04:03:53 +00:00
Jack Carter
30116cd2e2 This patch is a partial implementation of mips .set assembler directive. Directive is defined as follows:
.set option
The patch implements following options

    at - lets the assembler use the $at register for macros,
         but generates warnings if the source program uses $at

    noat - let source programs use $at without issuingwarnings.

    noreorder - prevents the assembler from reordering machine 
                language instructions.
    nomacro - causes the assembler to print a warning whenever 
              an assembler operation generates more than one 
              machine language instruction.
    macro - lets the assembler generate multiple machine instructions 
            from a single assembler instruction
    reorder - lets the assembler reorder machine language 
               instructions to improve performance

The above variants are parsed and their boolean values set or unset.
The code to actually use them will come later.

Following options are not implemented yet:

nomips16
nomicromips
move
nomove

Contributer: Vladimir Medic


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165194 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04 02:29:46 +00:00
Jakub Staszak
395c1502a7 Fix PR13967.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165187 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-03 23:59:47 +00:00
Chad Rosier
34448ae393 [ms-inline asm] Add support in the X86AsmPrinter for printing memory references
in the Intel syntax.

The MC layer supports emitting in the Intel syntax, but this would require the
inline assembly MachineInstr to be lowered to an MCInst before emission.  This
is potential future work, but for now emitting directly from the MachineInstr
suffices.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165173 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-03 22:06:44 +00:00
Nadav Rotem
2e7d38192d Fix a cycle in the DAG. In this code we replace multiple loads with a single load and
multiple stores with a single load. We create the wide loads and stores (and their chains)
before we remove the scalar loads and stores and fix the DAG chain. We attempted to merge
loads with a different chain. When that happened, the assumption that it is safe to RAUW
broke and a cycle was introduced.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165148 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-03 19:30:31 +00:00
Tim Northover
565ebde5fe Implement .rel relocation for R_ARM_ABS32 in MCJIT.
Patch by Amara Emerson.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165128 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-03 16:29:42 +00:00
Nadav Rotem
c653de6c0f A DAGCombine optimization for mergeing consecutive stores to memory. The optimization
is not profitable in many cases because modern processors perform multiple stores
in parallel and merging stores prior to merging requires extra work. We handle two main cases:

1. Store of multiple consecutive constants:
  q->a = 3;
  q->4 = 5;
In this case we store a single legal wide integer.

2. Store of multiple consecutive loads:
  int a = p->a;
  int b = p->b;
  q->a = a;
  q->b = b;
In this case we load/store either ilegal vector registers or legal wide integer registers.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165125 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-03 16:11:15 +00:00