Commit Graph

55 Commits

Author SHA1 Message Date
Craig Topper 588ceec0f7 Add debug prints for when optimizeLoadInstr folds a load.
llvm-svn: 170298
2012-12-17 03:56:00 +00:00
Joel Jones 24e440d045 Add comment for load folding
llvm-svn: 169880
2012-12-11 16:10:25 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Rafael Espindola 048405f510 Make sure we iterate over newly created instructions. Fixes pr13625. Testcase to
follow in one sec.

llvm-svn: 165951
2012-10-15 18:21:07 +00:00
Jakob Stoklund Olesen 714f595c98 Use standard pattern for iterate+erase.
Increment the MBB iterator at the top of the loop to properly handle the
current (and previous) instructions getting erased.

This fixes PR13625.

llvm-svn: 162099
2012-08-17 14:38:59 +00:00
Jakob Stoklund Olesen 2382d320b3 Add an MCID::Select flag and TII hooks for optimizing selects.
Select instructions pick one of two virtual registers based on a
condition, like x86 cmov. On targets like ARM that support predication,
selects can sometimes be eliminated by predicating the instruction
defining one of the operands.

Teach PeepholeOptimizer to recognize select instructions, and ask the
target to optimize them.

llvm-svn: 162059
2012-08-16 23:11:47 +00:00
Manman Ren ba8122cc25 X86 Peephole: fold loads to the source register operand if possible.
Add more comments and use early returns to reduce nesting in isLoadFoldable.
Also disable folding for V_SET0 to avoid introducing a const pool entry and
a const pool load.

rdar://10554090 and rdar://11873276

llvm-svn: 161207
2012-08-02 19:37:32 +00:00
Manman Ren 5759d01230 X86 Peephole: fold loads to the source register operand if possible.
Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.

This patch is a rework of r160919 and was tested on clang self-host on my local
machine.

rdar://10554090 and rdar://11873276

llvm-svn: 161152
2012-08-02 00:56:42 +00:00
Manman Ren f87dd7c01b Revert r160920 and r160919 due to dragonegg and clang selfhost failure
llvm-svn: 160927
2012-07-29 02:44:09 +00:00
Manman Ren 0fa3ab88ba X86 Peephole: fold loads to the source register operand if possible.
Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.

rdar://10554090 and rdar://11873276

llvm-svn: 160919
2012-07-28 16:48:01 +00:00
Manman Ren 6fa76dc0e0 Add SrcReg2 to analyzeCompare and optimizeCompareInstr to handle Compare
instructions with two register operands.

llvm-svn: 159465
2012-06-29 21:33:59 +00:00
Jakob Stoklund Olesen 0f855e4263 Implement PPCInstrInfo::isCoalescableExtInstr().
The PPC::EXTSW instruction preserves the low 32 bits of its input, just
like some of the x86 instructions. Use it to reduce register pressure
when the low 32 bits have multiple uses.

This requires a small change to PeepholeOptimizer since EXTSW takes a
64-bit input register.

This is related to PR5997.

llvm-svn: 158743
2012-06-19 21:14:34 +00:00
Jakob Stoklund Olesen 8eb9905a7c Style: Don't reuse variables for multiple purposes.
No functional change.

llvm-svn: 158742
2012-06-19 21:10:18 +00:00
Manman Ren 9c9641812c Revert r157755.
The commit is intended to fix rdar://11540023.
It is implemented as part of peephole optimization. We can actually implement
this in the SelectionDAG lowering phase.

llvm-svn: 158122
2012-06-06 23:53:03 +00:00
Manman Ren 9bccb64e56 X86: replace SUB with CMP if possible
This patch will optimize the following
        movq    %rdi, %rax
        subq    %rsi, %rax
        cmovsq  %rsi, %rdi
        movq    %rdi, %rax
to
        cmpq    %rsi, %rdi
        cmovsq  %rsi, %rdi
        movq    %rdi, %rax

Perform this optimization if the actual result of SUB is not used.

rdar: 11540023
llvm-svn: 157755
2012-05-31 17:20:29 +00:00
Jakob Stoklund Olesen 2f06a6579c Constrain regclasses in PeepholeOptimizer.
It can be necessary to restrict to a sub-class before accessing
sub-registers.

llvm-svn: 157164
2012-05-20 18:42:55 +00:00
Manman Ren dc8ad0058f ARM: peephole optimization to remove cmp instruction
This patch will optimize the following cases:
  sub r1, r3 | sub r1, imm
  cmp r3, r1 or cmp r1, r3 | cmp r1, imm
  bge L1

TO
  subs r1, r3
  bge  L1 or ble L1

If the branch instruction can use flag from "sub", then we can replace
"sub" with "subs" and eliminate the "cmp" instruction.

rdar: 10734411
llvm-svn: 156599
2012-05-11 01:30:47 +00:00
Manman Ren b555b382bd Revert: 156550 "ARM: peephole optimization to remove cmp instruction"
This commit broke an external linux bot and gave a compile-time warning.

llvm-svn: 156556
2012-05-10 18:49:43 +00:00
Manman Ren c860887b2d ARM: peephole optimization to remove cmp instruction
This patch will optimize the following cases:
  sub r1, r3 | sub r1, imm
  cmp r3, r1 or cmp r1, r3 | cmp r1, imm
  bge L1

TO
  subs r1, r3
  bge  L1 or ble L1

If the branch instruction can use flag from "sub", then we can replace
"sub" with "subs" and eliminate the "cmp" instruction.

rdar: 10734411
llvm-svn: 156550
2012-05-10 16:48:21 +00:00
Jim Grosbach edcb868fe3 Tidy up. Naming conventions.
llvm-svn: 155960
2012-05-01 23:21:41 +00:00
Lang Hames d5862ce317 Make the peephole optimizer clear kill flags on a vreg if it's about to add new
uses of the vreg, since the old kills may no longer be valid.  This was causing
-verify-machineinstrs to complain about uses after kills, and could potentially
have been causing subtle register allocation issues, but I haven't come across a
test case yet.

llvm-svn: 151425
2012-02-25 02:01:00 +00:00
Lang Hames 31bb57bc55 Fixed typo.
llvm-svn: 151417
2012-02-25 00:46:38 +00:00
Andrew Trick 1fa5bcbe2a Codegen pass definition cleanup. No functionality.
Moving toward a uniform style of pass definition to allow easier target configuration.
Globally declare Pass ID.
Globally declare pass initializer.
Use INITIALIZE_PASS consistently.
Add a call to the initializer from CodeGen.cpp.
Remove redundant "createPass" functions and "getPassName" methods.

While cleaning up declarations, cleaned up comments (sorry for large diff).

llvm-svn: 150100
2012-02-08 21:23:13 +00:00
Andrew Trick 9e761997d8 whitespace
llvm-svn: 150094
2012-02-08 21:22:43 +00:00
Evan Cheng 7f8e563a69 Add bundle aware API for querying instruction properties and switch the code
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.

For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.

llvm-svn: 146026
2011-12-07 07:15:52 +00:00
Nick Lewycky 594a545821 If MI is deleted then remove it from the set. If a new MI is created, it could
have the same address as the one we deleted, and we don't want that in the set
yet. Noticed by inspection.

llvm-svn: 141849
2011-10-13 02:16:18 +00:00
Duncan Sands 3ac1836540 SrcDef is only written and never read. Remove it.
llvm-svn: 136080
2011-07-26 15:05:06 +00:00
Evan Cheng 6cc775f905 - Rename TargetInstrDesc, TargetOperandInfo to MCInstrDesc and MCOperandInfo and
sink them into MC layer.
- Added MCInstrInfo, which captures the tablegen generated static data. Chang
TargetInstrInfo so it's based off MCInstrInfo.

llvm-svn: 134021
2011-06-28 19:10:37 +00:00
Evan Cheng e4b8ac9fef Add a peephole optimization to optimize pairs of bitcasts. e.g.
v2 = bitcast v1
...
v3 = bitcast v2
...
   = v3
=>
v2 = bitcast v1
...
   = v1
if v1 and v3 are of in the same register class.

bitcast between i32 and fp (and others) are often not nops since they
are in different register classes. These bitcast instructions are often
left because they are in different basic blocks and cannot be
eliminated by dag combine.

rdar://9104514

llvm-svn: 127668
2011-03-15 05:13:13 +00:00
Evan Cheng 98196b4ebb Fix thinko. Cmp can be the first instruction in a MBB.
llvm-svn: 125552
2011-02-15 05:00:24 +00:00
Evan Cheng 9bf3f8e08b Fix PR8854. Track inserted copies to avoid read before write. Sorry, it's hard to reduce a sensible small test case.
llvm-svn: 125523
2011-02-14 21:50:37 +00:00
Jakob Stoklund Olesen 2fb5b31578 Simplify a bunch of isVirtualRegister() and isPhysicalRegister() logic.
These functions not longer assert when passed 0, but simply return false instead.

No functional change intended.

llvm-svn: 123155
2011-01-10 02:58:51 +00:00
Evan Cheng 6eb516dbea Do not model all INLINEASM instructions as having unmodelled side effects.
Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.

This allows memory instructions to be moved around INLINEASM instructions.

llvm-svn: 123044
2011-01-07 23:50:32 +00:00
Evan Cheng 0638c20e7c DBG_VALUE does not have any side effects; it also makes no sense to mark it cheap as a copy.
llvm-svn: 123031
2011-01-07 21:08:26 +00:00
Evan Cheng 7f8ab6ee8b Remove ARM isel hacks that fold large immediates into a pair of add, sub, and,
and xor. The 32-bit move immediates can be hoisted out of loops by machine
LICM but the isel hacks were preventing them.

Instead, let peephole optimization pass recognize registers that are defined by
immediates and the ARM target hook will fold the immediates in.

Other changes include 1) do not fold and / xor into cmp to isel TST / TEQ
instructions if there are multiple uses. This happens when the 'and' is live
out, machine sink would have sinked the computation and that ends up pessimizing
code. The peephole pass would recognize situations where the 'and' can be
toggled to define CPSR and eliminate the comparison anyway.

2) Move peephole pass to after machine LICM, sink, and CSE to avoid blocking
important optimizations.

rdar://8663787, rdar://8241368

llvm-svn: 119548
2010-11-17 20:13:28 +00:00
Evan Cheng 2ce016c7f8 Code clean up. The peephole pass should be the one updating the instruction
iterator, not TII->OptimizeCompareInstr.

llvm-svn: 119186
2010-11-15 21:20:45 +00:00
Bill Wendling c6627eec13 When we look at instructions to convert to setting the 's' flag, we need to look
at more than those which define CPSR. You can have this situation:

(1)  subs  ...
(2)  sub   r6, r5, r4
(3)  movge ...
(4)  cmp   r6, 0
(5)  movge ...

We cannot convert (2) to "subs" because (3) is using the CPSR set by
(1). There's an analogous situation here:

(1)  sub   r1, r2, r3
(2)  sub   r4, r5, r6
(3)  cmp   r4, ...
(5)  movge ...
(6)  cmp   r1, ...
(7)  movge ...

We cannot convert (1) to "subs" because of the intervening use of CPSR.

llvm-svn: 117950
2010-11-01 20:41:43 +00:00
Bill Wendling 7a23c1fb7d The testcase is now XFAILed. Sorry about the breakage.
llvm-svn: 117904
2010-11-01 05:50:55 +00:00
Eric Christopher ef5a1c3ec3 Revert r117876 for now, it's causing more testsuite failures.
llvm-svn: 117879
2010-10-31 22:42:55 +00:00
Bill Wendling 0392f1b437 Disable the peephole optimizer until 186.crafty on armv6 is fixed. This is what
looks like is happening:

Without the peephole optimizer:
  (1)   sub     r6, r6, #32
        orr     r12, r12, lr, lsl r9
        orr     r2, r2, r3, lsl r10
  (x)   cmp     r6, #0
        ldr     r9, LCPI2_10
        ldr     r10, LCPI2_11
  (2)   sub     r8, r8, #32
  (a)   movge   r12, lr, lsr r6
  (y)   cmp     r8, #0
LPC2_10:
        ldr     lr, [pc, r10]
  (b)   movge   r2, r3, lsr r8

With the peephole optimizer:
        ldr     r9, LCPI2_10
        ldr     r10, LCPI2_11
  (1*)  subs    r6, r6, #32
  (2*)  subs    r8, r8, #32
  (a*)  movge   r12, lr, lsr r6
  (b*)  movge   r2, r3, lsr r8

(1) is used by (x) for the conditional move at (a). (2) is used by (y) for the
conditional move at (b). After the peephole optimizer, these the flags resulting
from (1*) are ignored and only the flags from (2*) are considered for both
conditional moves.

llvm-svn: 117876
2010-10-31 22:07:12 +00:00
Owen Anderson 6c18d1aac0 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.

llvm-svn: 116820
2010-10-19 17:21:58 +00:00
Bill Wendling 337a31133b Don't recompute MachineRegisterInfo in the Optimize* method.
llvm-svn: 116750
2010-10-18 21:22:31 +00:00
Owen Anderson 8ac477ffb5 Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.

llvm-svn: 116334
2010-10-12 19:48:12 +00:00
Owen Anderson df7a4f2515 Now with fewer extraneous semicolons!
llvm-svn: 115996
2010-10-07 22:25:06 +00:00
Gabor Greif adbbb93d3d Move the search for the appropriate AND instruction
into OptimizeCompareInstr.
This necessitates the passing of CmpValue around,
so widen the virtual functions to accomodate.

No functionality changes.

llvm-svn: 114428
2010-09-21 12:01:15 +00:00
Gabor Greif f08b36d386 must not peephole away side effects
llvm-svn: 113848
2010-09-14 20:46:08 +00:00
Bill Wendling 27dddd1fd1 Rename ConvertToSetZeroFlag to something more general.
llvm-svn: 113670
2010-09-11 00:13:50 +00:00
Bill Wendling d0a5f4e238 No need to recompute the SrcReg and CmpValue.
llvm-svn: 113666
2010-09-10 23:46:12 +00:00
Bill Wendling 041230014c Move some of the decision logic for converting an instruction into one that sets
the 'zero' bit down into the back-end. There are other cases where this logic
isn't sufficient, so they should be handled separately.

llvm-svn: 113665
2010-09-10 23:34:19 +00:00
Bill Wendling aee679bf35 Modify the comparison optimizations in the peephole optimizer to update the
iterator when an optimization took place. This allows us to do more insane
things with the code than just remove an instruction or two.

llvm-svn: 113640
2010-09-10 21:55:43 +00:00