X86 Supports Indirect Branch Tracking (IBT) as part of Control-Flow Enforcement Technology (CET).
IBT instruments ENDBR instructions used to specify valid targets of indirect call / jmp.
The `nocf_check` attribute has two roles in the context of X86 IBT technology:
1. Appertains to a function - do not add ENDBR instruction at the beginning of the function.
2. Appertains to a function pointer - do not track the target function of this pointer by adding nocf_check prefix to the indirect-call instruction.
This patch implements `nocf_check` context for Indirect Branch Tracking.
It also auto generates `nocf_check` prefixes before indirect branchs to jump tables that are guarded by range checks.
Differential Revision: https://reviews.llvm.org/D41879
llvm-svn: 327767
Remove the special casing for MRM_F8 by using HANDLE_OPTIONAL.
This should be NFC as the forms that were missing aren't used by any instructions today. They exist in the enum so that we didn't have to put them in one at a time when instructions are added. But looks like we failed here.
llvm-svn: 327298
With this patch, the tablegen 'SubtargetEmitter' always generates processor
resource names.
The impact of this patch on the code size of other llvm tools is small. I have
observed an average increase of 0.03% in code size when doing a release build of
LLVM (on windows, using MSVC) with all the default backends.
This change is done in preparation for the upcoming llvm-mca patch.
llvm-svn: 326993
The former simply makes more sense: we want to access the data here in
the backend, not information about the type.
More importantly, removing users of RecordRecTy::getRecord() allows us
more freedom to refactor the frontend.
Change-Id: Iee8905fd22cdb9b11c42ca03246c03d8fe4dd77f
llvm-svn: 326699
Summary:
Add a target option AllowRegisterRenaming that is used to opt in to
post-register-allocation renaming of registers. This is set to 0 by
default, which causes the hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq
fields of all opcodes to be set to 1, causing
MachineOperand::isRenamable to always return false.
Set the AllowRegisterRenaming flag to 1 for all in-tree targets that
have lit tests that were effected by enabling COPY forwarding in
MachineCopyPropagation (AArch64, AMDGPU, ARM, Hexagon, Mips, PowerPC,
RISCV, Sparc, SystemZ and X86).
Add some more comments describing the semantics of the
MachineOperand::isRenamable function and how it is set and maintained.
Change isRenamable to check the operand's opcode
hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq bit directly instead of
relying on it being consistently reflected in the IsRenamable bit
setting.
Clear the IsRenamable bit when changing an operand's register value.
Remove target code that was clearing the IsRenamable bit when changing
registers/opcodes now that this is done conservatively by default.
Change setting of hasExtraSrcRegAllocReq in AMDGPU target to be done in
one place covering all opcodes that have constant pipe read limit
restrictions.
Reviewers: qcolombet, MatzeB
Subscribers: aemerson, arsenm, jyknight, mcrosier, sdardis, nhaehnle, javed.absar, tpr, arichardson, kristof.beyls, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, escha, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D43042
llvm-svn: 325931
This patch changes GlobalISelEmitter to rank patterns similar to how the
DAG does it (ie it computes a score for a pattern and adds the added
complexity to it).
This is so that the decision tree for GISelSelector remains compatible
with that of SelectionDAG.
https://reviews.llvm.org/D43270
llvm-svn: 325401
Summary:
This patch makes the decoder understand old AMD 3DNow!
instructions that have never been properly supported in the X86
disassembler, despite being supported in other subsystems. Hopefully
this should make the X86 decoder more complete with respect to binaries
containing legacy code.
Reviewers: craig.topper
Reviewed By: craig.topper
Subscribers: llvm-commits, maksfb, bruno
Differential Revision: https://reviews.llvm.org/D43311
llvm-svn: 325295
Summary:
Right now using a ProcResource automatically counts as usage of all
super ProcResGroups. All this is done during codegen, so there is no
way for schedulers to get this information at runtime.
This adds the information of which individual ProcRes units are
contained in a ProcResGroup in MCProcResourceDesc.
Reviewers: gchatelet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43023
llvm-svn: 324582
Summary:
Right now only the ProcResourceUnits that are directly referenced by
instructions are emitted. This change emits all of them, so that
analysis passes can use the information.
This has no functional impact. It typically adds a few entries (e.g. 4
for X86/haswell) to the generated ProcRes table.
Reviewers: gchatelet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42903
llvm-svn: 324228
Summary:
This is a bit of a reimplementation the work done in
https://reviews.llvm.org/D41446, since that patch only really works for
tied operands of instructions, not aliases.
Instead of checking the constraints based on the matched instruction's opcode,
this patch uses the match-info's convert function to check the operand
constraints for that specific instruction/alias.
This is based on the matched operands for the instruction, not the
resulting opcode of the MCInst.
This patch adds the following enum/table to the *GenAsmMatcher.inc file:
enum {
Tie0_1_1,
Tie0_1_2,
Tie0_1_5,
...
};
const char TiedAsmOperandTable[][3] = {
/* Tie0_1_1 */ { 0, 1, 1 },
/* Tie0_1_2 */ { 0, 1, 2 },
/* Tie0_1_5 */ { 0, 1, 5 },
...
};
And it is referenced directly in the ConversionTable, like this:
static const uint8_t ConversionTable[CVT_NUM_SIGNATURES][13] = {
...
{ CVT_95_addRegOperands, 1,
CVT_95_addRegOperands, 2,
CVT_Tied, Tie0_1_5,
CVT_95_addRegOperands, 6, CVT_Done },
...
The Tie0_1_5 (and corresponding table) encodes that:
* Result operand 0 is the operand to copy (which is e.g. done when
building up the operands to the MCInst in convertToMCInst())
* Asm operands 1 and 5 should be the same operands (which is checked
in checkAsmTiedOperandConstraints()).
Reviewers: olista01, rengolin, fhahn, craig.topper, echristo, apazos, dsanders
Reviewed By: olista01
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42293
llvm-svn: 324196
Summary:
Apparently, we missed on constraining register classes of VReg-operands of all the instructions
built from a destination pattern but the root (top-level) one. The issue exposed itself
while selecting G_FPTOSI for armv7: the corresponding pattern generates VTOSIZS wrapped
into COPY_TO_REGCLASS, so top-level COPY_TO_REGCLASS gets properly constrained,
while nested VTOSIZS (or rather its destination virtual register to be exact) does not.
Fixing this by issuing GIR_ConstrainSelectedInstOperands for every nested GIR_BuildMI.
https://bugs.llvm.org/show_bug.cgi?id=35965
rdar://problem/36886530
Patch by Roman Tereshin
Reviewers: dsanders, qcolombet, rovka, bogner, aditya_nandakumar, volkan
Reviewed By: dsanders, qcolombet, rovka
Subscribers: aemerson, javed.absar, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D42565
llvm-svn: 323692
Collected statistics for the number of patterns emitted can be
incorrect because rules can be grouped if OptimizeMatchTable
is enabled. Increase the counter in RuleMatcher::emit(...)
to avoid that.
llvm-svn: 323391
This is a bit of a hack, but removes a cycle that broke modular builds
of LLVM. Of course the cycle is still there in form of a dependency
on the .def file.
llvm-svn: 323383
llvm::Regex is still the slowest regex engine on earth, running it over
all instructions on X86 takes a while. Extract a prefix and use a binary
search to reduce the search space before we resort to regex matching.
There are a couple of caveats here:
- The generic opcodes are outside of the sorted enum. They're handled in an extra loop.
- If there's a top-level bar we can't use the prefix trick.
- We bail on top-level ?. This could be handled, but it's rare.
This brings the time to generate X86GenInstrInfo.inc from 21s to 4.7s on
my machine.
llvm-svn: 323277
It appears that we haven't been prioritizing rules that contain nested
instructions properly. InstructionOperandMatcher didn't override
isHigherPriorityThan so it never compared the instructions/operands/predicates
inside nested instructions.
Fixes PR35926. Thanks to Diana Picus for the bug report.
llvm-svn: 322754
Summary:
This patch adds CustomRenderer which renders the matched
operands to the specified instruction.
Targets can enable the matching of SDNodeXForm by adding
a definition that inherits from GICustomOperandRenderer and
GISDNodeXFormEquiv as follows.
def gi_imm8 : GICustomOperandRenderer<"renderImm8”>,
GISDNodeXFormEquiv<imm8_xform>;
Custom renderer functions should be of the form:
void render(MachineInstrBuilder &MIB, const MachineInstr &I);
Reviewers: dsanders, ab, rovka
Reviewed By: dsanders
Subscribers: kristof.beyls, javed.absar, llvm-commits, mgrang, qcolombet
Differential Revision: https://reviews.llvm.org/D42012
llvm-svn: 322582
Prior to this we had a separate instruction and register class that excluded eax to prevent matching the instruction that would encode with 0x90.
This patch changes this to just use an InstAlias to force xchgl %eax, %eax to use XCHG32rr instruction in 64-bit mode. This gets rid of the separate instruction and register class.
llvm-svn: 322532
Summary:
This extends TableGen's AsmMatcherEmitter with code that generates
a table with tied-operand constraints. The constraints are checked
when parsing the instruction. If an operand is not equal to its tied operand,
the assembler will give an error.
Patch [2/3] in a series to add operand constraint checks for SVE's predicated ADD/SUB.
Reviewers: olista01, rengolin, mcrosier, fhahn, craig.topper, evandro, echristo
Reviewed By: fhahn
Subscribers: javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D41446
llvm-svn: 322166
This patch improves diagnostic for case when mapped instruction
does not contain a field listed under RowFields.
Differential Revision: https://reviews.llvm.org/D41778
llvm-svn: 322004
This change deals with intrinsics with multiple outputs, for example load
instrinsic with address updated.
DAG selection for Instrinsics could be done either through source code or
tablegen. Handling all intrinsics in source code would introduce a huge chunk
of repetitive code if we have a large number of intrinsic that return multiple
values (see NVPTX as an example). While intrinsic class in tablegen supports
multiple outputs, tablegen only supports Intrinsics with zero or one output on
TreePattern. This appears to be a simple bug in tablegen that is fixed by this
change.
For Intrinsics defined as:
def int_xxx_load_addr_updated: Intrinsic<[llvm_i32_ty, llvm_ptr_ty], [llvm_ptr_ty, llvm_i32_ty], []>;
Instruction will be defined as:
def L32_X: Inst<(outs reg:$d1, reg:$d2), (ins reg:$s1, reg:$s2), "ld32_x $d1, $d2, $s2", [(set i32:$d1, i32:$d2, (int_xxx_load_addr_updated i32:$s1, i32:$s2))]>;
Patch by Wenbo Sun, thanks!
Differential Revision: https://reviews.llvm.org/D32888
llvm-svn: 321704
Allows preserving MachineMemOperands on intrinsics
through selection. For reasons I don't understand, this
is a static property of the pattern and the selector
deliberately goes out of its way to drop if not present.
Intrinsics already inherit from SDPatternOperator allowing
them to be used directly in instruction patterns. SDPatternOperator
has a list of SDNodeProperty, but you currently can't set them on
the intrinsic. Without SDNPMemOperand, when the node is selected
any memory operands are always dropped. Allowing setting this
on the intrinsics avoids needing to introduce another equivalent
target node just to have SDNPMemOperand set.
llvm-svn: 321212
NFC for currently supported targets. This resolves a problem encountered by
targets such as RISCV that reference `Subtarget` in ImmLeaf predicates.
llvm-svn: 321176
This patch resubmits the SVE ZIP1/ZIP2 patch series consisting of
of r320992, r320986, r320973, and r320970 by reverting
https://reviews.llvm.org/rL321024.
The issue that caused r321024 has been addressed in https://reviews.llvm.org/rL321158,
so this patch-series should be safe to resubmit.
llvm-svn: 321163
Between the creation of the last InstructionMatcher and the first
emission of the related Rule, we need to clear the internal map of IDs.
We used to do that right after the creation of the main
InstructionMatcher when building the rule and although that worked, this
is fragile because if for some reason some later code decides to create
more InstructionMatcher before the final call to emit, then the IDs
would be completely messed up.
Move that to the beginning of "emit" so that the IDs are guarantee to be
consistent.
NFC.
llvm-svn: 321053
Move InsnVarID and OpIdx at the beginning of the list of arguments
for all the constructors of the OperandMatcher subclasses.
This matches what we do for the InstructionMatcher.
NFC.
llvm-svn: 321031
In theory, reapplying optimizeRules on each group matchers should give
us a second nesting level on the matching table. In practice, we need
more work to make that happen because all the predicates are actually
not directly available through the predicate matchers list.
NFC.
llvm-svn: 321025
This reverts changes r320992, r320986, r320973, and r320970.
r320970 by itself breaks the test case, and the rest depend on it.
Test case will land soon.
llvm-svn: 321024
*** Context ***
Prior to this patchw, the table generated for matching instruction was
straight forward but highly inefficient.
Basically, each pattern generates its own set of self contained checks
and actions.
E.g., TableGen generated:
// First pattern
CheckNumOperand 3
CheckOpcode G_ADD
...
Build ADDrr
// Second pattern
CheckNumOperand 3
CheckOpcode G_ADD
...
Build ADDri
// Third pattern
CheckNumOperand 3
CheckOpcode G_SUB
...
Build SUBrr
*** Problem ***
Because of that generation, a *lot* of check were redundant between each
pattern and were checked every single time until we reach the pattern
that matches.
E.g., Taking the previous table, let say we are matching a G_SUB, that
means we were going to check all the rules for G_ADD before looking at
the G_SUB rule. In particular we are going to do:
check 3 operands; PASS
check G_ADD; FAIL
; Next rule
check 3 operands; PASS (but we already knew that!)
check G_ADD; FAIL (well it is still not true)
; Next rule
check 3 operands; PASS (really!!)
check G_SUB; PASS (at last :P)
*** Proposed Solution ***
This patch introduces a concept of group of rules (GroupMatcher) that
share some predicates and only get checked once for the whole group.
This patch only creates groups with one nesting level. Conceptually
there is nothing preventing us for having deeper nest level. However,
the current implementation is not smart enough to share the recording
(aka capturing) of values. That limits its ability to do more sharing.
For the given example the current patch will generate:
// First group
CheckOpcode G_ADD
// First pattern
CheckNumOperand 3
...
Build ADDrr
// Second pattern
CheckNumOperand 3
...
Build ADDri
// Second group
CheckOpcode G_SUB
// Third pattern
CheckNumOperand 3
...
Build SUBrr
But if we allowed several nesting level, it could create a sub group
for the checknumoperand 3.
(We would need to call optimizeRules on the rules within a group.)
*** Result ***
With only one level of nesting, the instruction selection pass is up
to 4x faster. For instance, one instruction now takes 500 checks,
instead of 24k! With more nesting we could get in the tens I believe.
Differential Revision: https://reviews.llvm.org/D39034
rdar://problem/34670699
llvm-svn: 321017
Summary: Patch [4/4] in a series to add parsing of predicates and properly parse SVE ZIP1/ZIP2 instructions. This patch further improves diagnostic messages for when the SVE feature is not specified.
Reviewers: rengolin, fhahn, olista01, echristo, efriedma
Reviewed By: fhahn
Subscribers: sdardis, aemerson, javed.absar, tschuett, llvm-commits, kristof.beyls
Differential Revision: https://reviews.llvm.org/D40363
llvm-svn: 320992
Summary:
When emitting a diagnostic for an invalid operand, a specific diagnostic
should only be reported when the instruction being matched is actually
enabled by the feature flags.
Patch [3/4] in a series to add parsing of predicates and properly parse SVE
ZIP1/ZIP2 instructions. This patch fixes bogus diagnostic messages for when
the SVE feature is not specified.
Reviewers: rengolin, craig.topper, olista01, sdardis, stoklund
Reviewed By: olista01, sdardis
Subscribers: fhahn, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D40362
llvm-svn: 320986
Prior to this patch, a predicate wouldn't make sense outside of its
rule. Indeed, it was only during emitting a rule that a predicate would
be made aware of the IDs of the data it is checking. Because of that,
predicates could not be moved around or compared between each other.
NFC.
llvm-svn: 320887
