accumulator instead of its sub-registers, $hi and $lo.
We need this change to prevent a mflo following a mtlo from reading an
unpredictable/undefined value, as shown in the following example:
mult $6, $7 // result of $6 * $7 is written to $lo and $hi.
mflo $2 // read lower 32-bit result from $lo.
mtlo $4 // write to $lo. the content of $hi becomes unpredictable.
mfhi $3 // read higher 32-bit from $hi, which has an unpredictable value.
I don't have a test case for this change that reliably reproduces the problem.
llvm-svn: 192119
of loops.
Previously, two consecutive calls to function "func" would result in the
following sequence of instructions:
1. load $16, %got(func)($gp) // load address of lazy-binding stub.
2. move $25, $16
3. jalr $25 // jump to lazy-binding stub.
4. nop
5. move $25, $16
6. jalr $25 // jump to lazy-binding stub again.
With this patch, the second call directly jumps to func's address, bypassing
the lazy-binding resolution routine:
1. load $25, %got(func)($gp) // load address of lazy-binding stub.
2. jalr $25 // jump to lazy-binding stub.
3. nop
4. load $25, %got(func)($gp) // load resolved address of func.
5. jalr $25 // directly jump to func.
llvm-svn: 191591
Most constant BUILD_VECTOR's are matched using ComplexPatterns which cover
bitcasted as well as normal vectors. However, it doesn't seem to be possible to
match ldi.[bhwd] in a type-agnostic manner (e.g. to support the widest range of
immediates, it should be possible to use ldi.b to load v2i64) using TableGen so
ldi.[bhwd] is matched using custom code in MipsSEISelDAGToDAG.cpp
This made the majority of the constant splat BUILD_VECTOR lowering redundant.
The only transformation remaining for constant splats is when an (up-to) 32-bit
constant splat is possible but the value does not fit into a 10-bit signed
integer. In this case, the BUILD_VECTOR is transformed into a bitcasted
BUILD_VECTOR so that fill.[bhw] can be used to splat the vector from a GPR32
register (which is initialized using the usual lui/addui sequence).
There are no additional tests since this is a re-implementation of previous
functionality. The change is intended to make it easier to implement some of
the upcoming instruction selection patches since they can rely on existing
support for BUILD_VECTOR's in the DAGCombiner.
compare_float.ll changed slightly because a BITCAST is no longer
introduced during legalization.
llvm-svn: 191299
Changes to MIPS SelectionDAG:
* Added nodes VEXTRACT_[SZ]EXT_ELT to represent extract and extend in a single
operation and implemented the DAG combines necessary to fold sign/zero
extends into the extract.
llvm-svn: 191199
Note: There's a later patch on my branch that re-implements this to select
build_vector without the custom SelectionDAG nodes. The future patch avoids
the constant-folding problems stemming from the custom node (i.e. it doesn't
need to re-implement all the DAG combines related to BUILD_VECTOR).
Changes to MIPS specific SelectionDAG nodes:
* Added VSPLAT
This is a special case of BUILD_VECTOR that covers the case the
BUILD_VECTOR is a splat operation.
* Added VSPLATD
This is a special case of VSPLAT that handles the cases when v2i64 is legal
llvm-svn: 191191
precision loads and stores as well as reg+imm double precision loads and stores.
Previously, expansion of loads and stores was done after register allocation,
but now it takes place during legalization. As a result, users will see double
precision stores and loads being emitted to spill and restore 64-bit FP registers.
llvm-svn: 190235
These intrinsics are legalized to V(ALL|ANY)_(NON)?ZERO nodes,
are matched as SN?Z_[BHWDV]_PSEUDO pseudo's, and emitted as
a branch/mov sequence to evaluate to 0 or 1.
Note: The resulting code is sub-optimal since it doesnt seem to be possible
to feed the result of an intrinsic directly into a brcond. At the moment
it uses (SETCC (VALL_ZERO $ws), 0, SETEQ) and similar which unnecessarily
evaluates the boolean twice.
llvm-svn: 189478
Previously, three instructions were needed:
trunc.w.s $f0, $f2
mfc1 $4, $f0
sw $4, 0($2)
Now we need only two:
trunc.w.s $f0, $f2
swc1 $f0, 0($2)
llvm-svn: 182053
mips16/mips32 floating point interoperability.
This patch fixes returns from mips16 functions so that if the function
was in fact called by a mips32 hard float routine, then values
that would have been returned in floating point registers are so returned.
Mips16 mode has no floating point instructions so there is no way to
load values into floating point registers.
This is needed when returning float, double, single complex, double complex
in the Mips ABI.
Helper functions in libc for mips16 are available to do this.
For efficiency purposes, these helper functions have a different calling
convention from normal Mips calls.
Registers v0,v1,a0,a1 are used to pass parameters instead of
a0,a1,a2,a3.
This is because v0,v1,a0,a1 are the natural registers used to return
floating point values in soft float. These values can then be moved
to the appropriate floating point registers with no extra cost.
The only register that is modified is ra in this call.
The helper functions make sure that the return values are in the floating
point registers that they would be in if soft float was not in effect
(which it is for mips16, though the soft float is implemented using a mips32
library that uses hard float).
llvm-svn: 181641
- ISD::SHL/SRL/SRA must have either both scalar or both vector operands
but TLI.getShiftAmountTy() so far only return scalar type. As a
result, backend logic assuming that breaks.
- Rename the original TLI.getShiftAmountTy() to
TLI.getScalarShiftAmountTy() and re-define TLI.getShiftAmountTy() to
return target-specificed scalar type or the same vector type as the
1st operand.
- Fix most TICG logic assuming TLI.getShiftAmountTy() a simple scalar
type.
llvm-svn: 176364
Allow Mips16 routines to call Mips32 routines that have abi requirements
that either arguments or return values are passed in floating point
registers. This handles only the pic case. We have not done non pic
for Mips16 yet in any form.
The libm functions are Mips32, so with this addition we have a complete
Mips16 hard float implementation.
We still are not able to complete mix Mip16 and Mips32 with hard float.
That will be the next phase which will have several steps. For Mips32
to freely call Mips16 some stub functions must be created.
llvm-svn: 173320
In this case, essentially it is soft float with different library routines.
The next step will be to make this fully interoperational with mips32 floating
point and that requires creating stubs for functions with signatures that
contain floating point types.
I have a more sophisticated design for mips16 hardfloat which I hope to
implement at a later time that directly does floating point without the need
for function calls.
The mips16 encoding has no floating point instructions so one needs to
switch to mips32 mode to execute floating point instructions.
llvm-svn: 170259
mention the inline memcpy / memset expansion code is a mess?
This patch split the ZeroOrLdSrc argument into two: IsMemset and ZeroMemset.
The first indicates whether it is expanding a memset or a memcpy / memmove.
The later is whether the memset is a memset of zero. It's totally possible
(likely even) that targets may want to do different things for memcpy and
memset of zero.
llvm-svn: 169959
Also added more comments to explain why it is generally ok to return true.
- Rename getOptimalMemOpType argument IsZeroVal to ZeroOrLdSrc. It's meant to
be true for loaded source (memcpy) or zero constants (memset). The poor name
choice is probably some kind of legacy issue.
llvm-svn: 169954
1. Teach it to use overlapping unaligned load / store to copy / set the trailing
bytes. e.g. On 86, use two pairs of movups / movaps for 17 - 31 byte copies.
2. Use f64 for memcpy / memset on targets where i64 is not legal but f64 is. e.g.
x86 and ARM.
3. When memcpy from a constant string, do *not* replace the load with a constant
if it's not possible to materialize an integer immediate with a single
instruction (required a new target hook: TLI.isIntImmLegal()).
4. Use unaligned load / stores more aggressively if target hooks indicates they
are "fast".
5. Update ARM target hooks to use unaligned load / stores. e.g. vld1.8 / vst1.8.
Also increase the threshold to something reasonable (8 for memset, 4 pairs
for memcpy).
This significantly improves Dhrystone, up to 50% on ARM iOS devices.
rdar://12760078
llvm-svn: 169791
This method emits nodes for passing byval arguments in registers and stack.
This has the same functionality as existing functions PassByValArg64 and
WriteByValArg which will be deleted later.
llvm-svn: 166843
This method copies byval arguments passed in registers onto the stack and has
the same functionality as existing functions CopyMips64ByValRegs and
ReadByValArg which will be deleted later.
llvm-svn: 166841
The frame object which points to the dynamically allocated area will not be
needed after changes are made to cease reserving call frames.
llvm-svn: 161076
to pass around a struct instead of a large set of individual values. This
cleans up the interface and allows more information to be added to the struct
for future targets without requiring changes to each and every target.
NV_CONTRIB
llvm-svn: 157479
the processor keeps a return addresses stack (RAS) which stores the address
and the instruction execution state of the instruction after a function-call
type branch instruction.
Calling a "noreturn" function with normal call instructions (e.g. bl) can
corrupt RAS and causes 100% return misprediction so LLVM should use a
unconditional branch instead. i.e.
mov lr, pc
b _foo
The "mov lr, pc" is issued in order to get proper backtrace.
rdar://8979299
llvm-svn: 151623
needed to emit a 64-bit gp-relative relocation entry. Make changes necessary
for emitting jump tables which have entries with directive .gpdword. This patch
does not implement the parts needed for direct object emission or JIT.
llvm-svn: 149668
- Modify lowering of global TLS address nodes.
- Modify isel of ThreadPointer.
- Wrap target global TLS address nodes that are operands of loads with WrapperPIC.
- Remove Mips-specific DAG nodes TlsGd, TprelHi and TprelLo, which can be
substituted with other existing nodes.
llvm-svn: 146175
with a vector condition); such selects become VSELECT codegen nodes.
This patch also removes VSETCC codegen nodes, unifying them with SETCC
nodes (codegen was actually often using SETCC for vector SETCC already).
This ensures that various DAG combiner optimizations kick in for vector
comparisons. Passes dragonegg bootstrap with no testsuite regressions
(nightly testsuite as well as "make check-all"). Patch mostly by
Nadav Rotem.
llvm-svn: 139159
nand), atomic.swap and atomic.cmp.swap, all in i8, i16 and i32 versions.
The intrinsics are implemented by creating pseudo-instructions, which are
then expanded in the method MipsTargetLowering::EmitInstrWithCustomInserter.
Patch by Sasa Stankovic.
llvm-svn: 132323
const_casts, and it reinforces the design of the Target classes being
immutable.
SelectionDAGISel::IsLegalToFold is now a static member function, because
PIC16 uses it in an unconventional way. There is more room for API
cleanup here.
And PIC16's AsmPrinter no longer uses TargetLowering.
llvm-svn: 101635
Target independent isel should always pass along the "tail call" property. Change
target hook LowerCall's parameter "isTailCall" into a refernce. If the target
decides it's impossible to honor the tail call request, it should set isTailCall
to false to make target independent isel happy.
llvm-svn: 94626
Instead of awkwardly encoding calling-convention information with ISD::CALL,
ISD::FORMAL_ARGUMENTS, ISD::RET, and ISD::ARG_FLAGS nodes, TargetLowering
provides three virtual functions for targets to override:
LowerFormalArguments, LowerCall, and LowerRet, which replace the custom
lowering done on the special nodes. They provide the same information, but
in a more immediately usable format.
This also reworks much of the target-independent tail call logic. The
decision of whether or not to perform a tail call is now cleanly split
between target-independent portions, and the target dependent portion
in IsEligibleForTailCallOptimization.
This also synchronizes all in-tree targets, to help enable future
refactoring and feature work.
llvm-svn: 78142
Small refactoring in LowerFORMAL_ARGUMENTS().
Correct minor formatting issues.
Remove size argument of CreateCopyOfByValArgument().
Remove dead argument from CalculateStackSlotSize().
Remove unused variable ReturnAddrIndex from various targets.
llvm-svn: 74763
have the alignment be calculated up front, and have the back-ends obey whatever
alignment is decided upon.
This allows for future work that would allow for precise no-op placement and the
like.
llvm-svn: 74564
promote from i1 all the way up to the canonical SetCC type.
In order to discover an appropriate type to use, pass
MVT::Other to getSetCCResultType. In order to be able to
do this, change getSetCCResultType to take a type as an
argument, not a value (this is also more logical).
llvm-svn: 61542
and add a TargetLowering hook for it to use to determine when this
is legal (i.e. not in PIC mode, etc.)
This allows instruction selection to emit folded constant offsets
in more cases, such as the included testcase, eliminating the need
for explicit arithmetic instructions.
This eliminates the need for the C++ code in X86ISelDAGToDAG.cpp
that attempted to achieve the same effect, but wasn't as effective.
Also, fix handling of offsets in GlobalAddressSDNodes in several
places, including changing GlobalAddressSDNode's offset from
int to int64_t.
The Mips, Alpha, Sparc, and CellSPU targets appear to be
unaware of GlobalAddress offsets currently, so set the hook to
false on those targets.
llvm-svn: 57748
Akira Hatanaka