Commit Graph

831 Commits

Author SHA1 Message Date
Tilmann Scheller 318ccb0e62 make it possible to custom lower TRUNCATE (needed for the CellSPU target)
llvm-svn: 60409
2008-12-02 12:12:25 +00:00
Mon P Wang 6e1c6ad127 Removed some unnecessary code in widening.
llvm-svn: 60406
2008-12-02 07:35:08 +00:00
Duncan Sands 3d960941b1 There are no longer any places that require a
MERGE_VALUES node with only one operand, so get
rid of special code that only existed to handle
that possibility.

llvm-svn: 60349
2008-12-01 11:41:29 +00:00
Duncan Sands 6ed40141f7 Change the interface to the type legalization method
ReplaceNodeResults: rather than returning a node which
must have the same number of results as the original
node (which means mucking around with MERGE_VALUES,
and which is also easy to get wrong since SelectionDAG
folding may mean you don't get the node you expect),
return the results in a vector.

llvm-svn: 60348
2008-12-01 11:39:25 +00:00
Sanjiv Gupta 7ae1a84465 Removing redundant semicolons. No functionality change.
llvm-svn: 60149
2008-11-27 05:58:04 +00:00
Sanjiv Gupta 80810f8c6b Allow custom lowering of ADDE/ADDC/SUBE/SUBC operations.
llvm-svn: 60102
2008-11-26 11:19:00 +00:00
Bill Wendling b4ff5322c1 A simplification for checking whether the signs of the operands and sum differ. Thanks, Duncan.
llvm-svn: 60043
2008-11-25 19:40:17 +00:00
Bill Wendling bf592fccd4 Now with the correct type for the 0.
llvm-svn: 60016
2008-11-25 08:19:22 +00:00
Bill Wendling d06c625b95 Get rid of unused variable.
llvm-svn: 60015
2008-11-25 08:13:20 +00:00
Bill Wendling 4498b47677 Hacker's Delight says, "Signed integer overflow of addition occurs if and only
if the operands have the same sign and the sum has sign opposite to that of the
operands."

llvm-svn: 60014
2008-11-25 08:12:19 +00:00
Bill Wendling 66835479d7 - Make lowering of "add with overflow" customizable by back-ends.
- Mark "add with overflow" as having a custom lowering for X86. Give it a null
  lowering representation for now.

llvm-svn: 59971
2008-11-24 19:21:46 +00:00
Evan Cheng a8fd1f2c8e Eliminate some unused variable compile time warnings.
llvm-svn: 59952
2008-11-24 07:09:49 +00:00
Bill Wendling 2278f8f5e1 Add support for llvm.uadd.with.overflow.
llvm-svn: 59926
2008-11-24 01:38:29 +00:00
Bill Wendling be8e7f851c - Move conversion of [SU]ADDO from DAG combiner into legalizer.
- Add "promote integer type" stuff to the legalizer for these nodes.

llvm-svn: 59847
2008-11-22 00:22:52 +00:00
Mon P Wang f414cbc1fd Add missing widen operations, fixed widening for extracting a subvector,
and when loading/storing a widen vector, make sure that they are loaded
and stored in consecutive order.

llvm-svn: 59357
2008-11-15 06:05:52 +00:00
Mon P Wang 58fb9135e2 Added CONVERT_RNDSAT (conversion with rounding and saturation) SDNode to
support targets that support these conversions. Users should avoid using
this node as the current targets don't generating code for it.

llvm-svn: 59001
2008-11-10 20:54:11 +00:00
Mon P Wang 25f0106fd9 Added support for the following definition of shufflevector
<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> 

llvm-svn: 58964
2008-11-10 04:46:22 +00:00
Dale Johannesen 160be0ffda Make FP tests requiring two compares work on PPC (PR 642).
This is Chris' patch from the PR, modified to realize that
SETUGT/SETULT occur legitimately with integers, plus
two fixes in LegalizeDAG to pass a valid result type into
LegalizeSetCC.  The argument of TLI.getSetCCResultType is
ignored on PPC, but I think I'm following usage elsewhere.

llvm-svn: 58871
2008-11-07 22:54:33 +00:00
Mon P Wang 5ca2ec65bd Fixed scalarizing an extract subvector and prevent an infinite loop
when simplify a vector. 

llvm-svn: 58820
2008-11-06 22:52:21 +00:00
Mon P Wang 9a8d60a7c0 Widening cleanup
llvm-svn: 58796
2008-11-06 05:31:54 +00:00
Dale Johannesen db6b956585 80 columns
llvm-svn: 58717
2008-11-04 20:52:49 +00:00
Duncan Sands 0207a3f897 Make VAARG work with x86 long double (which is
10 bytes long, but is passed in 12/16 bytes).

llvm-svn: 58608
2008-11-03 11:51:11 +00:00
Mon P Wang 01b8a5a967 Add missing vsetcc expansion for widening
llvm-svn: 58443
2008-10-30 18:21:52 +00:00
Mon P Wang 58c3794c27 Add initial support for vector widening. Logic is set to widen for X86.
One will only see an effect if legalizetype is not active.  Will move
support to LegalizeType soon.

llvm-svn: 58426
2008-10-30 08:01:45 +00:00
Dale Johannesen 28929589e7 Add an SSE2 algorithm for uint64->f64 conversion.
The same one Apple gcc uses, faster.  Also gets the
extreme case in gcc.c-torture/execute/ieee/rbug.c
correct which we weren't before; this is not
sufficient to get the test to pass though, there
is another bug.

llvm-svn: 57926
2008-10-21 20:50:01 +00:00
Dan Gohman 97d3f6cfe3 Make the NaN test come second, heuristically assuming
that NaNs are less common.

llvm-svn: 57871
2008-10-21 03:12:54 +00:00
Evan Cheng 3b0f5e4d61 - Add target lowering hooks that specify which setcc conditions are illegal,
i.e. conditions that cannot be checked with a single instruction. For example,
SETONE and SETUEQ on x86.
- Teach legalizer to implement *illegal* setcc as a and / or of a number of
legal setcc nodes. For now, only implement FP conditions. e.g. SETONE is
implemented as SETO & SETNE, SETUEQ is SETUO | SETEQ.
- Move x86 target over.

llvm-svn: 57542
2008-10-15 02:05:31 +00:00
Evan Cheng 07d53b1d33 Rename LoadX to LoadExt.
llvm-svn: 57526
2008-10-14 21:26:46 +00:00
Evan Cheng da9b752883 FIX PR2794. Make sure SIGN_EXTEND_INREG nodes introduced by LegalizeSetCCOperands are leglized. Patch by Richard Pennington.
llvm-svn: 57460
2008-10-13 18:46:18 +00:00
Chris Lattner 2753955fc0 Change CALLSEQ_BEGIN and CALLSEQ_END to take TargetConstant's as
parameters instead of raw Constants.  This prevents the constants from
being selected by the isel pass, fixing PR2735.

llvm-svn: 57385
2008-10-11 22:08:30 +00:00
Dale Johannesen 54306fe499 Rename APFloat::convertToAPInt to bitcastToAPInt to
make it clearer what the function does.  No functional
change.

llvm-svn: 57325
2008-10-09 18:53:47 +00:00
Andrew Lenharth 21dca9cbb1 Use Dan's supperior check
llvm-svn: 57255
2008-10-07 18:27:23 +00:00
Andrew Lenharth d69bdaef64 No need for |=
llvm-svn: 57249
2008-10-07 17:11:29 +00:00
Andrew Lenharth 6d409f08be Use ADDC if it is valid at any smaller size. Do it right this time
llvm-svn: 57248
2008-10-07 17:09:16 +00:00
Andrew Lenharth 6606f17e50 Use ADDC if it is valid at any smaller size. fixes test/Codegen/Generic/i128-addsub.ll on x86
llvm-svn: 57247
2008-10-07 17:03:15 +00:00
Andrew Lenharth 3a9be150be Expand arith on machines without carry flags
llvm-svn: 57243
2008-10-07 14:15:42 +00:00
Chris Lattner 2416896b3c wrap some long lines and expand i32 mul's to libcalls, inspired by a
patch by Mikael Lepisto!

llvm-svn: 57077
2008-10-04 21:27:46 +00:00
Dale Johannesen 5d60c1ebb1 Pass MemOperand through for 64-bit atomics on 32-bit,
incidentally making the case where the memop is a
pointer deref work.  Fix cmp-and-swap regression.

llvm-svn: 57027
2008-10-03 19:41:08 +00:00
Dale Johannesen 867d549fce Handle some 64-bit atomics on x86-32, some of the time.
llvm-svn: 56963
2008-10-02 18:53:47 +00:00
Dan Gohman 3a293e7404 Fix typos in comments.
llvm-svn: 56919
2008-10-01 15:07:49 +00:00
Dan Gohman 86aa16a69a Optimize SelectionDAG's AssignTopologicalOrder even further.
Completely eliminate the TopOrder std::vector. Instead, sort
the AllNodes list in place. This also eliminates the need to
call AllNodes.size(), a linear-time operation, before
performing the sort.

Also, eliminate the Sources temporary std::vector, since it
essentially duplicates the sorted result as it is being
built.

This also changes the direction of the topological sort
from bottom-up to top-down. The AllNodes list starts out in
roughly top-down order, so this reduces the amount of
reordering needed. Top-down is also more convenient for
Legalize, and ISel needed only minor adjustments.

llvm-svn: 56867
2008-09-30 18:30:35 +00:00
Dale Johannesen f61a84ec43 Remove misuse of ReplaceNodeResults for atomics with
valid types.  No functional change.

llvm-svn: 56808
2008-09-29 22:25:26 +00:00
Dale Johannesen 0e32a2c935 Add "inreg" field to CallSDNode (doesn't increase
its size).  Adjust various lowering functions to
pass this info through from CallInst.  Use it to
implement sseregparm returns on X86.  Remove
X86_ssecall calling convention.

llvm-svn: 56677
2008-09-26 19:31:26 +00:00
Richard Pennington 4b35e64504 bug 2812: Segmentation fault on a big emdiam processor.
llvm-svn: 56609
2008-09-25 16:15:10 +00:00
Dan Gohman e2947e1e07 Fix the alignment of loads from constant pool entries when the
load address has an offset from the base of the constant pool
entry.

llvm-svn: 56479
2008-09-22 22:40:08 +00:00
Dan Gohman 64d6c6fe30 Change SelectionDAG::getConstantPool to always set the alignment of the
ConstantPoolSDNode, using the target's preferred alignment for the
constant type.

In LegalizeDAG, when performing loads from the constant pool, the
ConstantPoolSDNode's alignment is used in the calls to getLoad and
getExtLoad.

This change prevents SelectionDAG::getLoad/getExtLoad from incorrectly
choosing the ABI alignment for constant pool loads when Alignment == 0.
The incorrect alignment is only a performance issue when ABI alignment
does not equal preferred alignment (i.e., on x86 it was generating
MOVUPS instead of MOVAPS for v4f32 constant loads when the default ABI
alignment for 128bit vectors is forced to 1 byte.)

Patch by Paul Redmond!

llvm-svn: 56253
2008-09-16 22:05:41 +00:00
Bill Wendling 24c79f28b1 Reverting r56249. On further investigation, this functionality isn't needed.
Apologies for the thrashing.

llvm-svn: 56251
2008-09-16 21:48:12 +00:00
Bill Wendling 8bc392fb1d - Change "ExternalSymbolSDNode" to "SymbolSDNode".
- Add linkage to SymbolSDNode (default to external).
- Change ISD::ExternalSymbol to ISD::Symbol.
- Change ISD::TargetExternalSymbol to ISD::TargetSymbol

These changes pave the way to allowing SymbolSDNodes with non-external linkage.

llvm-svn: 56249
2008-09-16 21:12:30 +00:00
Dan Gohman ec270fb640 Change ConstantSDNode and ConstantFPSDNode to use ConstantInt* and
ConstantFP* instead of APInt and APFloat directly.

This reduces the amount of time to create ConstantSDNode
and ConstantFPSDNode nodes when ConstantInt* and ConstantFP*
respectively are already available, as is the case in
SelectionDAGBuild.cpp. Also, it reduces the amount of time
to legalize constants into constant pools, and the amount of
time to add ConstantFP operands to MachineInstrs, due to
eliminating ConstantInt::get and ConstantFP::get calls.

It increases the amount of work needed to create new constants
in cases where the client doesn't already have a ConstantInt*
or ConstantFP*, such as legalize expanding 64-bit integer constants
to 32-bit constants. And it adds a layer of indirection for the
accessor methods. But these appear to be outweight by the benefits
in most cases.

It will also make it easier to make ConstantSDNode and
ConstantFPNode more consistent with ConstantInt and ConstantFP.

llvm-svn: 56162
2008-09-12 18:08:03 +00:00
Dan Gohman effb894453 Rename ConstantSDNode::getValue to getZExtValue, for consistency
with ConstantInt. This led to fixing a bug in TargetLowering.cpp
using getValue instead of getAPIntValue.

llvm-svn: 56159
2008-09-12 16:56:44 +00:00
Dale Johannesen baf6762e26 The sequence for ppcf128 compares was not IEEE
safe in the presence of NaNs.

llvm-svn: 56136
2008-09-12 00:30:56 +00:00
Evan Cheng 0fff397a13 A few more places where FPOW is being ignored.
llvm-svn: 56032
2008-09-09 23:35:53 +00:00
Evan Cheng f4e5de4583 Legalizer was missing code that expand fpow to a libcall.
llvm-svn: 56028
2008-09-09 23:02:14 +00:00
Dale Johannesen da2d80688b Add intrinsics for log, log2, log10, exp, exp2.
No functional change (and no FE change to generate them).

llvm-svn: 55753
2008-09-04 00:47:13 +00:00
Gabor Greif f304a7aa4d erect abstraction boundaries for accessing SDValue members, rename Val -> Node to reflect semantics
llvm-svn: 55504
2008-08-28 21:40:38 +00:00
Dale Johannesen 41be0d4445 Split the ATOMIC NodeType's to include the size, e.g.
ATOMIC_LOAD_ADD_{8,16,32,64} instead of ATOMIC_LOAD_ADD.
Increased the Hardcoded Constant OpActionsCapacity to match.
Large but boring; no functional change.

This is to support partial-word atomics on ppc; i8 is
not a valid type there, so by the time we get to lowering, the
ATOMIC_LOAD nodes looks the same whether the type was i8 or i32.
The information can be added to the AtomicSDNode, but that is the
largest SDNode; I don't fully understand the SDNode allocation,
but it is sensitive to the largest node size, so increasing
that must be bad.  This is the alternative.

llvm-svn: 55457
2008-08-28 02:44:49 +00:00
Gabor Greif abfdf928d8 disallow direct access to SDValue::ResNo, provide a getter instead
llvm-svn: 55394
2008-08-26 22:36:50 +00:00
Dan Gohman d56f73f2f2 Optimize SelectionDAG's topological sort to use one pass instead
of two, and to not need a scratch std::vector. Also, use the
SelectionDAG's topological sort in LegalizeDAG instead of having
a separate implementation.

llvm-svn: 55389
2008-08-26 21:42:18 +00:00
Dan Gohman 2af34bd309 Add libcalls for the new rounding opcodes.
llvm-svn: 55133
2008-08-21 18:38:14 +00:00
Dan Gohman c6337ac069 Add libm-oriented ISD opcodes for rounding operations.
llvm-svn: 55130
2008-08-21 17:55:02 +00:00
Dan Gohman 550c9af91f Improve support for vector casts in LLVM IR and CodeGen.
llvm-svn: 54784
2008-08-14 20:04:46 +00:00
Nate Begeman 82f1925708 Fix broken CellSPU lowering, re-instate braces in Legalize
llvm-svn: 54168
2008-07-29 19:07:27 +00:00
Nate Begeman d63495ff25 Disable a fix in the previous patch, since it breaks CellSPU.
The CellSPU codegen is broken, but needs to be fixed before we can
put this back in.

llvm-svn: 54164
2008-07-29 18:28:31 +00:00
Nate Begeman fecbc8cff1 Add vector shifts to the IR, patch by Eli Friedman.
CodeGen & Clang work coming next.

llvm-svn: 54161
2008-07-29 15:49:41 +00:00
Dan Gohman 2ce6f2ad5e Rename SDOperand to SDValue.
llvm-svn: 54128
2008-07-27 21:46:04 +00:00
Dan Gohman 91e5dcb680 Tidy SDNode::use_iterator, and complete the transition to have it
parallel its analogue, Value::value_use_iterator. The operator* method
now returns the user, rather than the use.

llvm-svn: 54127
2008-07-27 20:43:25 +00:00
Mon P Wang 7334350d31 When splitting a vector shuffle, fixed which type we used for the hi part
llvm-svn: 54007
2008-07-25 01:30:26 +00:00
Dan Gohman 581cc87f57 Add titles to the various SelectionDAG viewGraph calls
that include useful information like the name of the
block being viewed and the current phase of compilation.

llvm-svn: 53872
2008-07-21 20:00:07 +00:00
Duncan Sands b0e3938651 Add VerifyNode, a place to put sanity checks on
generic SDNode's (nodes with their own constructors
should do sanity checking in the constructor).  Add
sanity checks for BUILD_VECTOR and fix all the places
that were producing bogus BUILD_VECTORs, as found by
"make check".  My favorite is the BUILD_VECTOR with
only two operands that was being used to build a
vector with four elements!

llvm-svn: 53850
2008-07-21 10:20:31 +00:00
Duncan Sands 77a3d05f1e Factorize some code for determining which libcall to use.
llvm-svn: 53713
2008-07-17 02:36:29 +00:00
Mon P Wang 97432f4f1b Fixed potential bug if the source and target of a bit convert have different alignment
llvm-svn: 53590
2008-07-15 05:28:34 +00:00
Dan Gohman 02c7c6cb33 Include a frame index in the "fixed stack" pseudo source value
instead of using the frame index for the SVOffset, which was
inconsistent.

llvm-svn: 53486
2008-07-11 22:44:52 +00:00
Chris Lattner 87909d0629 Fix a bug in the soft-float handling of FCOPYSIGN that Duncan noticed
when working on legalizetypes.  Both legalizetypes and legalizeops now
produce hte same code for CodeGen/ARM/fcopysign.ll.

llvm-svn: 53435
2008-07-10 23:46:13 +00:00
Duncan Sands 5e6d1402c2 Add a mysteriously missing libcall, FPTOSINT_F80_I32.
Be nice to 16 bit machines by supporting FP_TO_XINT
expansion for these.

llvm-svn: 53407
2008-07-10 15:33:02 +00:00
Evan Cheng 34ef1db87c Do not CSE DEBUG_LOC, DBG_LABEL, DBG_STOPPOINT, DECLARE, and EH_LABEL SDNode's. This improves compile time slightly at -O0 -g.
llvm-svn: 53246
2008-07-08 20:06:39 +00:00
Dan Gohman 56e3f63ec5 Add explicit keywords.
llvm-svn: 53179
2008-07-07 18:00:37 +00:00
Dan Gohman 38740a98b2 Make DenseMap's insert return a pair, to more closely resemble std::map.
llvm-svn: 53177
2008-07-07 17:46:23 +00:00
Evan Cheng d8b83e1292 LegalizeSetCCOperands should legalize the result of ExpandLibCall. Patch by Richard Osborne.
llvm-svn: 53169
2008-07-07 07:18:09 +00:00
Mon P Wang 5c755ff51b Fixed generating incorrect aligned stores that I backout of r53031
that fixed problems in EmitStackConvert where the source and target type
have different alignment by creating a stack slot with the max
alignment of source and target type.

llvm-svn: 53150
2008-07-05 20:40:31 +00:00
Duncan Sands 93e180342a Rather than having a different custom legalization
hook for each way in which a result type can be
legalized (promotion, expansion, softening etc),
just use one: ReplaceNodeResults, which returns
a node with exactly the same result types as the
node passed to it, but presumably with a bunch of
custom code behind the scenes.  No change if the
new LegalizeTypes infrastructure is not turned on.

llvm-svn: 53137
2008-07-04 11:47:58 +00:00
Evan Cheng fad8be450d Backed out 53031.
llvm-svn: 53110
2008-07-03 18:20:14 +00:00
Duncan Sands 739a0548c4 Add a new getMergeValues method that does not need
to be passed the list of value types, and use this
where appropriate.  Inappropriate places are where
the value type list is already known and may be
long, in which case the existing method is more
efficient.

llvm-svn: 53035
2008-07-02 17:40:58 +00:00
Mon P Wang 4b7c1acf26 Fixed problem in EmitStackConvert where the source and target type
have different alignment by creating a stack slot with the max
alignment of source and target type.

llvm-svn: 53031
2008-07-02 17:07:12 +00:00
Evan Cheng 4c609abd90 Eliminate a compile time warning.
llvm-svn: 52982
2008-07-01 21:35:46 +00:00
Dan Gohman fb19f9402b Split ISD::LABEL into ISD::DBG_LABEL and ISD::EH_LABEL, eliminating
the need for a flavor operand, and add a new SDNode subclass,
LabelSDNode, for use with them to eliminate the need for a label id
operand.

Change instruction selection to let these label nodes through
unmodified instead of creating copies of them. Teach the MachineInstr
emitter how to emit a MachineInstr directly from an ISD label node.

This avoids the need for allocating SDNodes for the label id and
flavor value, as well as SDNodes for each of the post-isel label,
label id, and label flavor.

llvm-svn: 52943
2008-07-01 00:05:16 +00:00
Dan Gohman 5c73a886b4 Rename ISD::LOCATION to ISD::DBG_STOPPOINT to better reflect its
purpose, and give it a custom SDNode subclass so that it doesn't
need to have line number, column number, filename string, and
directory string, all existing as individual SDNodes to be the
operands.

This was the only user of ISD::STRING, StringSDNode, etc., so
remove those and some associated code.

This makes stop-points considerably easier to read in
-view-legalize-dags output, and reduces overhead (creating new
nodes and copying std::strings into them) on code containing
debugging information.

llvm-svn: 52924
2008-06-30 20:59:49 +00:00
Duncan Sands 1ae6ef83ee Revert the SelectionDAG optimization that makes
it impossible to create a MERGE_VALUES node with
only one result: sometimes it is useful to be able
to create a node with only one result out of one of
the results of a node with more than one result, for
example because the new node will eventually be used
to replace a one-result node using ReplaceAllUsesWith,
cf X86TargetLowering::ExpandFP_TO_SINT.  On the other
hand, most users of MERGE_VALUES don't need this and
for them the optimization was valuable.  So add a new
utility method getMergeValues for creating MERGE_VALUES
nodes which by default performs the optimization.
Change almost everywhere to use getMergeValues (and
tidy some stuff up at the same time).

llvm-svn: 52893
2008-06-30 10:19:09 +00:00
Chris Lattner 9d3740ed1c Implement split and scalarize for SELECT_CC, fixing PR2504
llvm-svn: 52887
2008-06-30 02:43:01 +00:00
Dan Gohman aa01afd47c Remove the OrigVT member from AtomicSDNode, as it is redundant with
the base SDNode's VTList.

llvm-svn: 52722
2008-06-25 16:07:49 +00:00
Mon P Wang 6a490371c9 Added MemOperands to Atomic operations since Atomics touches memory.
Added abstract class MemSDNode for any Node that have an associated MemOperand
Changed atomic.lcs => atomic.cmp.swap, atomic.las => atomic.load.add, and
atomic.lss => atomic.load.sub

llvm-svn: 52706
2008-06-25 08:15:39 +00:00
Duncan Sands 5fb92e58de Make custom lowering of ADD work correctly. This
fixes PR2476; patch by Richard Osborne.  The same
problem exists for a bunch of other operators, but
I'm ignoring this because they will be automagically
fixed when the new LegalizeTypes infrastructure lands,
since it already solves this problem centrally.

llvm-svn: 52610
2008-06-22 09:42:16 +00:00
Dan Gohman 3792c470d5 Clean up some uses of std::distance, now that we have allnodes_size.
llvm-svn: 52545
2008-06-20 17:15:19 +00:00
Evan Cheng be0429c558 ISD::UNDEF should be expanded recursively / iteratively.
llvm-svn: 52508
2008-06-19 22:01:11 +00:00
Andrew Lenharth f88d50bfcc add missing atomic intrinsic from gcc
llvm-svn: 52270
2008-06-14 05:48:15 +00:00
Duncan Sands 8651e9c584 Disable some DAG combiner optimizations that may be
wrong for volatile loads and stores.  In fact this
is almost all of them!  There are three types of
problems: (1) it is wrong to change the width of
a volatile memory access.  These may be used to
do memory mapped i/o, in which case a load can have
an effect even if the result is not used.  Consider
loading an i32 but only using the lower 8 bits.  It
is wrong to change this into a load of an i8, because
you are no longer tickling the other three bytes.  It
is also unwise to make a load/store wider.  For
example, changing an i16 load into an i32 load is
wrong no matter how aligned things are, since the
fact of loading an additional 2 bytes can have
i/o side-effects.  (2) it is wrong to change the
number of volatile load/stores: they may be counted
by the hardware.  (3) it is wrong to change a volatile
load/store that requires one memory access into one
that requires several.  For example on x86-32, you
can store a double in one processor operation, but to
store an i64 requires two (two i32 stores).  In a
multi-threaded program you may want to bitcast an i64
to a double and store as a double because that will
occur atomically, and be indivisible to other threads.
So it would be wrong to convert the store-of-double
into a store of an i64, because this will become two
i32 stores - no longer atomic.  My policy here is
to say that the number of processor operations for
an illegal operation is undefined.  So it is alright
to change a store of an i64 (requires at least two
stores; but could be validly lowered to memcpy for
example) into a store of double (one processor op).
In short, if the new store is legal and has the same
size then I say that the transform is ok.  It would
also be possible to say that transforms are always
ok if before they were illegal, whether after they
are illegal or not, but that's more awkward to do
and I doubt it buys us anything much.
However this exposed an interesting thing - on x86-32
a store of i64 is considered legal!  That is because
operations are marked legal by default, regardless of
whether the type is legal or not.  In some ways this
is clever: before type legalization this means that
operations on illegal types are considered legal;
after type legalization there are no illegal types
so now operations are only legal if they really are.
But I consider this to be too cunning for mere mortals.
Better to do things explicitly by testing AfterLegalize.
So I have changed things so that operations with illegal
types are considered illegal - indeed they can never
map to a machine operation.  However this means that
the DAG combiner is more conservative because before
it was "accidentally" performing transforms where the
type was illegal because the operation was nonetheless
marked legal.  So in a few such places I added a check
on AfterLegalize, which I suppose was actually just
forgotten before.  This causes the DAG combiner to do
slightly more than it used to, which resulted in the X86
backend blowing up because it got a slightly surprising
node it wasn't expecting, so I tweaked it.

llvm-svn: 52254
2008-06-13 19:07:40 +00:00
Duncan Sands 11dd424539 Remove comparison methods for MVT. The main cause
of apint codegen failure is the DAG combiner doing
the wrong thing because it was comparing MVT's using
< rather than comparing the number of bits.  Removing
the < method makes this mistake impossible to commit.
Instead, add helper methods for comparing bits and use
them.

llvm-svn: 52098
2008-06-08 20:54:56 +00:00
Duncan Sands 13237ac3b9 Wrap MVT::ValueType in a struct to get type safety
and better control the abstraction.  Rename the type
to MVT.  To update out-of-tree patches, the main
thing to do is to rename MVT::ValueType to MVT, and
rewrite expressions like MVT::getSizeInBits(VT) in
the form VT.getSizeInBits().  Use VT.getSimpleVT()
to extract a MVT::SimpleValueType for use in switch
statements (you will get an assert failure if VT is
an extended value type - these shouldn't exist after
type legalization).
This results in a small speedup of codegen and no
new testsuite failures (x86-64 linux).

llvm-svn: 52044
2008-06-06 12:08:01 +00:00
Scott Michel a7d8649f78 Fix spellnig error
llvm-svn: 51917
2008-06-03 19:13:20 +00:00
Scott Michel d831cc49e5 Add necessary 64-bit support so that gcc frontend compiles (mostly). Current
issue is operand promotion for setcc/select... but looks like the fundamental
stuff is implemented for CellSPU.

llvm-svn: 51884
2008-06-02 22:18:03 +00:00
Dan Gohman 8807147ada Remove an unused variable.
llvm-svn: 51721
2008-05-30 00:56:36 +00:00