Similar to PR/25526, fast-regalloc introduces spills at the end of basic
blocks. When this occurs in between an ll and sc, the stores can cause the
atomic sequence to fail.
This patch fixes the issue by introducing more pseudos to represent atomic
operations and moving their lowering to after the expansion of postRA
pseudos.
This version addresses issues with the initial implementation and covers
all atomic operations.
This resolves PR/32020.
Thanks to James Cowgill for reporting the issue!
Patch By: Simon Dardis
Differential Revision: https://reviews.llvm.org/D31287
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This change fixes the issue that arises when we duplicate condition from
the predecessor block. If the condition's arguments are not considered alive
across the blocks, fast regalloc gets confused and starts generating reloads
from the slots that have never been spilled to. This change also leads to
smaller code given that, unlike on architectures with condition codes, on
Mips we can branch directly on register value, thus we gain nothing by
duplication.
Patch by Dragan Mladjenovic.
Differential Revision: https://reviews.llvm.org/D48642
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These are identical but use microMIPS instructions instead of MIPS instructions.
Also, flatten the 'let AdditionalPredicates = [InMicroMips]' by using the
ISA_MICROMIPS adjective. Add tests for constant materialization.
Reviewers: atanasyan, abeserminji, smaksimovic
Differential Revision: https://reviews.llvm.org/D48275
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Author: milena.vujosevic.janicic
Reviewers: sdardis
The patch extends size reduction pass for MicroMIPS.
It introduces reduction of two instructions into one instruction:
Two SW instructions are transformed into one SWP instrucition.
Two LW instructions are transformed into one LWP instrucition.
Differential Revision: https://reviews.llvm.org/D39115
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Extend LONG_BRANCH_LUi and LONG_BRANCH_ADDiu pseudo instructions with
additional flag, so instead of always lowering to lui %hi(...),
addiu %lo(...) or addiu %hi(...), now they can lower to either %lo, %hi,
%higher or %highest depending on the added flag.
Differential Revision: https://reviews.llvm.org/D47941
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When program is compiled for mips3 with n64 abi, wrong register class
is used for creating an emergency spill slot. This patch fixes the
correct register class to be chosen.
This patch resolves PR35859.
Thanks to John Baldwin for reporting the issue!
Differential Revision: https://reviews.llvm.org/D47938
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MipsLongBranchPass and MipsHazardSchedule passes are joined to one pass
because of mutual conflict. When MipsHazardSchedule inserts 'nop's, it
potentially breaks some jumps, so they have to be expanded to long
branches. When some branch is expanded to long branch, it potentially
creates a hazard situation, which should be fixed by adding nops.
New pass is called MipsBranchExpansion, it combines these two passes,
and runs them alternately until one of them reports no changes were made.
Differential Revision: https://reviews.llvm.org/D46641
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MipsLongBranchPass and MipsHazardSchedule passes are joined to one pass
because of mutual conflict. When MipsHazardSchedule inserts 'nop's, it
potentially breaks some jumps, so they have to be expanded to long
branches. When some branch is expanded to long branch, it potentially
creates a hazard situation, which should be fixed by adding nops.
New pass is called MipsBranchExpansion, it combines these two passes,
and runs them alternately until one of them reports no changes were made.
Differential Revision: https://reviews.llvm.org/D46641
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Add support for this target hook, covering MIPS, microMIPS and MIPSR6, along
with some tests. Also add missing getOppositeBranchOpc() cases exposed by the
tests.
Reviewers: atanasyan, abeserminji, smaksimovic
Differential Revision: https://reviews.llvm.org/D46794
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Summary:
SelectionDAGLegalize::ExpandNode() inserts an ISD::MUL when lowering a
BR_JT opcode. While many backends optimize this multiply into a shift, e.g.
the MIPS backend currently always lowers this into a sequence of
load-immediate+multiply+mflo in MipsSETargetLowering::lowerMulDiv().
I initially changed the multiply to a shift in the MIPS backend but it
turns out that would not have handled the MIPSR6 case and was a lot more
code than doing it in LegalizeDAG.
I believe performing this simple optimization in LegalizeDAG instead of
each individual backend is the better solution since this also fixes other
backeds such as MSP430 which calls the multiply runtime function
__mspabi_mpyi without this patch.
Reviewers: sdardis, atanasyan, pftbest, asl
Reviewed By: sdardis
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45760
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In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is
!DILabel(scope: !1, name: "foo", file: !2, line: 3)
We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is
llvm.dbg.label(metadata !1)
It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.
We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.
Differential Revision: https://reviews.llvm.org/D45024
Patch by Hsiangkai Wang.
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Introduced a new pattern for matching splat.d explicitly.
Both splat.d and splati.d can now be generated from the @llvm.mips.splat.d
intrinsic depending on whether an immediate value has been passed.
Differential Revision: https://reviews.llvm.org/D45683
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As Roman Tereshin pointed out in https://reviews.llvm.org/D45541, the
-global-isel option is redundant when -run-pass is given. -global-isel sets up
the GlobalISel passes in the pass manager but -run-pass skips that entirely and
configures it's own pipeline.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331603 91177308-0d34-0410-b5e6-96231b3b80d8
The previous version of this patch restricted the 'jal' instruction to MIPS and
microMIPSr3. microMIPS32r6 does not have this instruction and instead uses jal
as an alias for balc.
Original commit message:
> Reviewers: smaksimovic, atanasyan, abeserminji
>
> Differential Revision: https://reviews.llvm.org/D46114
>
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Debug var, expr and loc were only supported for non-fixed stack objects.
This patch adds the following fields to the "fixedStack:" entries, and
renames the ones from "stack:" to:
* debug-info-variable
* debug-info-expression
* debug-info-location
Differential Revision: https://reviews.llvm.org/D46032
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ISel is currently picking 'JAL' over 'JAL_MM' for calling a function when
targeting microMIPS. A later patch will correct this behaviour.
This patch extends the mechanism for transforming instructions into their short
delay to recognise 'JAL_MM' for transforming into 'JALS_MM'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@330825 91177308-0d34-0410-b5e6-96231b3b80d8
Guard the MIPS64 variant correctly for i64, mark the MIPS32 version as not
in microMIPS and provide the microMIPS version.
Additionally, remove a related stale XFAIL'd test as bswap has its own test
case providing coverage.
Reviewers: smaksimovic, abeserminji, atanasyan
Differential Revision: https://reviews.llvm.org/D45816
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These instructions lacked the correct predicates, were not marked
as loads and stores and lacked the proper instruction mapping information.
In the case of microMIPS sw(l|r)e (EVA) these instructions were using the load
EVA description.
Reviewers: abeserminji, smaksimovic, atanasyan
Differential Revision: https://reviews.llvm.org/D45626
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Previously, the MIPS backend would alwyas break down constant multiplications
into a series of shifts, adds, and subs. This patch changes that so the cost of
doing so is estimated.
The cost is estimated against worst case constant materialization and retrieving
the results from the HI/LO registers.
For cases where the value type of the multiplication is not legal, the cost of
legalization is estimated and is accounted for before performing the
optimization of breaking down the constant
This resolves PR36884.
Thanks to npl for reporting the issue!
Reviewers: abeserminji, smaksimovic
Differential Revision: https://reviews.llvm.org/D45316
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This is causing compilation timeouts on code with long sequences of
local values and calls (i.e. foo(1); foo(2); foo(3); ...). It turns out
that code coverage instrumentation is a great way to create sequences
like this, which how our users ran into the issue in practice.
Intel has a tool that detects these kinds of non-linear compile time
issues, and Andy Kaylor reported it as PR37010.
The current sinking code scans the whole basic block once per local
value sink, which happens before emitting each call. In theory, local
values should only be introduced to be used by instructions between the
current flush point and the last flush point, so we should only need to
scan those instructions.
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Add the minimal support necessary to lower a function that returns the
sum of two i32 values.
Support argument/return lowering of i32 values through registers only.
Add tablegen for regbankselect and instructionselect.
Patch by Petar Avramovic.
Differential Revision: https://reviews.llvm.org/D44304
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Summary:
RegisterCoalescer::removePartialRedundancy tries to hoist B = A from
BB0/BB2 to BB1:
BB1:
...
BB0/BB2: ----
B = A; |
... |
A = B; |
|-------
|
It does so if a number of conditions are fulfilled. However, it failed
to check if B was used by any of the terminators in BB1. Since we must
insert B = A before the terminators (since it's not a terminator itself),
this means that we could erroneously insert a new definition of B before a
use of it.
Reviewers: wmi, qcolombet
Reviewed By: wmi
Subscribers: MatzeB, llvm-commits, sdardis
Differential Revision: https://reviews.llvm.org/D44918
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Summary:
Local values are constants, global addresses, and stack addresses that
can't be folded into the instruction that uses them. For example, when
storing the address of a global variable into memory, we need to
materialize that address into a register.
FastISel doesn't want to materialize any given local value more than
once, so it generates all local value materialization code at
EmitStartPt, which always dominates the current insertion point. This
allows it to maintain a map of local value registers, and it knows that
the local value area will always dominate the current insertion point.
The downside is that local value instructions are always emitted without
a source location. This is done to prevent jumpy line tables, but it
means that the local value area will be considered part of the previous
statement. Consider this C code:
call1(); // line 1
++global; // line 2
++global; // line 3
call2(&global, &local); // line 4
Today we end up with assembly and line tables like this:
.loc 1 1
callq call1
leaq global(%rip), %rdi
leaq local(%rsp), %rsi
.loc 1 2
addq $1, global(%rip)
.loc 1 3
addq $1, global(%rip)
.loc 1 4
callq call2
The LEA instructions in the local value area have no source location and
are treated as being on line 1. Stepping through the code in a debugger
and correlating it with the assembly won't make much sense, because
these materializations are only required for line 4.
This is actually problematic for the VS debugger "set next statement"
feature, which effectively assumes that there are no registers live
across statement boundaries. By sinking the local value code into the
statement and fixing up the source location, we can make that feature
work. This was filed as https://bugs.llvm.org/show_bug.cgi?id=35975 and
https://crbug.com/793819.
This change is obviously not enough to make this feature work reliably
in all cases, but I felt that it was worth doing anyway because it
usually generates smaller, more comprehensible -O0 code. I measured a
0.12% regression in code generation time with LLC on the sqlite3
amalgamation, so I think this is worth doing.
There are some special cases worth calling out in the commit message:
1. local values materialized for phis
2. local values used by no-op casts
3. dead local value code
Local values can be materialized for phis, and this does not show up as
a vreg use in MachineRegisterInfo. In this case, if there are no other
uses, this patch sinks the value to the first terminator, EH label, or
the end of the BB if nothing else exists.
Local values may also be used by no-op casts, which adds the register to
the RegFixups table. Without reversing the RegFixups map direction, we
don't have enough information to sink these instructions.
Lastly, if the local value register has no other uses, we can delete it.
This comes up when fastisel tries two instruction selection approaches
and the first materializes the value but fails and the second succeeds
without using the local value.
Reviewers: aprantl, dblaikie, qcolombet, MatzeB, vsk, echristo
Subscribers: dotdash, chandlerc, hans, sdardis, amccarth, javed.absar, zturner, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D43093
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For the MIPS O32 ABI, the current call lowering logic naively lowers each
call, creating the reserved argument area to hold the argument spill areas for
$a0..$a3 and the outgoing parameter area if one is required at each call site.
In the case of a sufficently large byval argument, a call to memcpy is used
to write the start+16..end of the argument into the outgoing parameter area.
This is done within the CALLSEQ_START..CALLSEQ_END of the callee. The CALLSEQ
nodes are responsible for performing the necessary stack adjustments.
Since the O32/N32/N64 MIPS ABIs do not have a red-zone and writing below the
stack pointer and reading the values back is unpredictable, the call to memcpy
cannot be hoisted out of the callee's CALLSEQ nodes.
However, for the O32 ABI requires the reserved argument area for functions
which have parameters. The naive lowering of calls will then create nested
CALLSEQ sequences. For N32 and N64 these nodes are also created, but with
zero stack adjustments as those ABIs do not have a reserved argument area.
This patch addresses the correctness issue by recognizing the special case
of lowering a byval argument that uses memcpy. By recognizing that the
incoming chain already has a CALLSEQ_START node on it when calling memcpy,
the CALLSEQ nodes are not created. For the N32 and N64 ABIs, this is not an
issue, as no stack adjustment has to be performed.
For the O32 ABI, the correctness reasoning is different. In the case of a
sufficently large byval argument, registers a0..a3 are going to be used for
the callee's arguments, mandating the creation of the reserved argument area.
The call to memcpy in the naive case will also create its own reserved
argument area. However, since the reserved argument area consists of undefined
values, both calls can use the same reserved argument area.
Reviewers: abeserminji, atanasyan
Differential Revision: https://reviews.llvm.org/D44296
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Emulated TLS is enabled by llc flag -emulated-tls,
which is passed by clang driver.
When llc is called explicitly or from other drivers like LTO,
missing -emulated-tls flag would generate wrong TLS code for targets
that supports only this mode.
Now use useEmulatedTLS() instead of Options.EmulatedTLS to decide whether
emulated TLS code should be generated.
Unit tests are modified to run with and without the -emulated-tls flag.
Differential Revision: https://reviews.llvm.org/D42999
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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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326208 91177308-0d34-0410-b5e6-96231b3b80d8
Aleksandar Beserminji