Most of our cost model tables have been created assuming cost kind == recip-throughput. But we're starting to see passes wanting to get accurate costs for the other kinds as well. Some of these can be determined procedurally (e.g. codesize by default could just be the split count after type legalization), but others are going to need to be handled in cost tables - this is especially true for x86 which has so many ISA combinations.
I've created a 'CostKindCosts' struct which can hold cost values for the 4 cost kinds, defaulting to -1U for unknown cost, this can be used with the existing CostTblEntryT/CostTableLookup template code. I've also added a [TargetCostKind] accessor to make it much easier to look up individual <Optional> costs.
This just changes the ISD::SELECT costs to check the effect (and also to check that the ISD::SETCC are correctly handled for default/None cost kinds) - the plan would be to slowly extend this and move the CostKindTblEntry type somewhere generic to allow other targets to use it once its matured.
I'm also going to resurrect D103695 so that it can help with latency/codesize/sizelatency coverage testing.
For sizelatency - IIRC the definition was vague to let it be target specific - I've tried to use typical uop counts so they're comparable to MicroOpBufferSize etc.
Differential Revision: https://reviews.llvm.org/D132216
Update three changes:
1.Split the Load/Store resources into two, Ld0St and Ld1,
since only one of them is capable of stores.
2.Integer ADD and SUB instructions have different latencies
and processor resource usage (pipeline) when they have a shift of
zero vs. non-zero, refer to D8043
3.The throughout of scalar DIV instruction.
Reviewed By: dmgreen, bryanpkc
Differential Revision: https://reviews.llvm.org/D132529
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.
Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.
KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.
A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:
```
.c:
int f(void);
int (*p)(void) = f;
p();
.s:
.4byte __kcfi_typeid_f
.global f
f:
...
```
Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.
As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.
Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.
Relands 67504c9549 with a fix for
32-bit builds.
Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay
Differential Revision: https://reviews.llvm.org/D119296
The patch adds support for OpenCL and SPIR-V built-in functions.
Their detection and properties are implemented using TableGen.
Five tests are added to demonstrate the improvement.
Differential Revision: https://reviews.llvm.org/D132024
Co-authored-by: Aleksandr Bezzubikov <zuban32s@gmail.com>
Co-authored-by: Michal Paszkowski <michal.paszkowski@outlook.com>
Co-authored-by: Andrey Tretyakov <andrey1.tretyakov@intel.com>
Co-authored-by: Konrad Trifunovic <konrad.trifunovic@intel.com>
We may be requested to emit an unaligned nop sequence (e.g. 7-bytes or
3-bytes). These should be 0-filled even though that is not a valid
instruction. This matches the behaviour on other architectures like
ARM, X86, and MIPS. When a custom section is emitted, it may be
classified as text even though it may be a data section or we may be
emitting data into a text segment (e.g. a literal pool). In such cases,
we should be resilient to the emission request.
This was originally identified by the Linux kernel build and reported on
D131270 by Nathan Chancellor.
Differential Revision: https://reviews.llvm.org/D132482
Reviewed By: luismarques
Tested By: Nathan Chancellor
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.
Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.
KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.
A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:
```
.c:
int f(void);
int (*p)(void) = f;
p();
.s:
.4byte __kcfi_typeid_f
.global f
f:
...
```
Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.
As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.
Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.
Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay
Differential Revision: https://reviews.llvm.org/D119296
This patch adds a Type operand to the TLI isCheapToSpeculateCttz/isCheapToSpeculateCtlz callbacks, allowing targets to decide whether branches should occur on a type-by-type/legality basis.
For X86, this patch proposes to allow CTTZ speculation for i8/i16 types that will lower to promoted i32 BSF instructions by masking the operand above the msb (we already do something similar for i8/i16 TZCNT). This required a minor tweak to CTTZ lowering - if the src operand is known never zero (i.e. due to the promotion masking) we can remove the CMOV zero src handling.
Although BSF isn't very fast, most CPUs from the last 20 years don't do that bad a job with it, although there are some annoying passthrough EFLAGS dependencies. Additionally, now that we emit 'REP BSF' in most cases, we are tending towards assuming this will most likely be executed as a TZCNT instruction on any semi-modern CPU.
Differential Revision: https://reviews.llvm.org/D132520
Allows things like `(G_PTR_ADD (G_PTR_ADD a, b), c)` to be
simplified into a single ADD3 instruction instead of two adds.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D131254
This commit moves the information on whether a register is constant into
the Tablegen files to allow generating the implementaiton of
isConstantPhysReg(). I've marked isConstantPhysReg() as final in this
generated file to ensure that changes are made to tablegen instead of
overriding this function, but if that turns out to be too restrictive,
we can remove the qualifier.
This should be pretty much NFC, but I did notice that e.g. the AMDGPU
generated file also includes the LO16/HI16 registers now.
The new isConstant flag will also be used by D131958 to ensure that
constant registers are marked as call-preserved.
Differential Revision: https://reviews.llvm.org/D131962
This issue is found by build llvm-testsuite with `-Oz`, linker will complain
`dangerous relocation: %pcrel_lo missing matching %pcrel_hi` and that
turn out cause by we outlined pcrel-lo, but leave pcrel-hi there, that's
not problem in general, but the problem is they put into different section, they
pcrel-hi and pcrel-lo pair (e.g. AUIPC+ADDI) *MUST* put be present in same
section due to the implementation.
Outlined function will put into .text name, but the source functions
will put in .text.<function-name> if function-section is enabled or the
function has `comdat` attribute.
There are few solutions for this issue:
1. Always disallow instructions with pcrel-lo flags.
2. Only disallow instructions with pcrel-lo flags that when function-section is
enabled or this function has `comdat` attribute.
3. Check the corresponding instruction with pcrel-high also included in the
outlining candidate sequence or not, and allow that only when pcrel-high is
included in the outlining candidate.
First one is most conservative, that might lose some optimization
opportunities, and second one could save those opportunities, and last
one is hard to implement, and don't have any benefits since pcrel-high
are using different label even accessing same symbol.
Use custom section name might also cause this problem, but that already
filtered by RISCVInstrInfo::isFunctionSafeToOutlineFrom.
Reviewed By: luismarques
Differential Revision: https://reviews.llvm.org/D132528
Add SVE patterns to make use of predicated smin, umin, smax, and umax instructions,
add sve-min-max-pred.ll test file for the new patterns
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D132122
llvm-exegesis uses operand type information provided in tablegen files to initialize
immediate arguments of the instruction. Some of them simply don't have such information.
Thus we should set into relevant immediate operands their specific type.
Also create verification methods for them.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D131771
In order to convert to mulwide.s32, we compute the 2nd operand as MulWide.32 $r, (1 << 31).
(1 << 31) is interpreted as a negative number, and is not equivalent to the original instruction.
The code `int64_t r = (int64_t)a << 31;` incorrectly compiled to `mul.wide.s32 %rd7, %r1, -2147483648;`
Reviewed By: jchlanda
Differential Revision: https://reviews.llvm.org/D132516
Add zihintntl compressed instructions and some files related to zihintntl.
This patch is base on {D121670}.
Reviewed By: kito-cheng
Differential Revision: https://reviews.llvm.org/D121779
Summary: Currently, an error was reported when a thread local symbol has an invalid name. D100956 create a new symbol to prefix the TLS symbol name with a dot. When the symbol name is renamed, the error occurs. This patch uses the original symbol name (name in the symbol table) as the input for the symbol for TOC entry.
Reviewed By: shchenz, lkail
Differential Revision: https://reviews.llvm.org/D132348
In branch relaxation pass, `j`'s with offset over 1MiB will be relaxed
to `jump` pseudo-instructions.
This patch allocates a stack slot for functions with a size greater than
1MiB. If the register scavenger cannot find a scratch register for
`jump`, spill a register to the slot before the jump and restore it
after the jump.
.mbb:
foo
j .dest_bb
bar
bar
bar
.dest_bb:
baz
The above code will be relaxed to the following code.
.mbb:
foo
sd s11, 0(sp)
jump .restore_bb, s11
bar
bar
bar
j .dest_bb
.restore_bb:
ld s11, 0(sp)
.dest_bb:
baz
Depends on D129999.
Reviewed By: StephenFan
Differential Revision: https://reviews.llvm.org/D130560
Enables fixed sized vectors to detect SK_Splice shuffle patterns and provides basic X86 cost support
Differential Revision: https://reviews.llvm.org/D132374
There were two sections of code that had a lot of lambdas and in the patch
D40554 it was suggested that we clean them up as a follow-up NFC patch.
Reviewed By: nemanjai, #powerpc
Differential Revision: https://reviews.llvm.org/D132394
This has the effect of exposing the power-of-two property for use in memory op costing, but no target actually uses it yet. The main point of this change is simple consistency with the recently changes getArithmeticInstrCost, and to remove the last (interface) use of OperandValueKind.
This patch fixes the list of subtarget features enabled for the
Cortex-X1C processor, including the following:
* Fix incorrect version used for FeatureRCPC:
* Use FEAT_LRCPC2 instead of FEAT_LRCPC.
* Add missing v8.4-A features included in the TRM:
* Flag Manipulation Instructions - FeatureFlagM (FEAT_FlagM)
* Large System Extension 2 - FeatureLSE2 (FEAT_LSE2)
Reviewed By: vhscampos
Differential Revision: https://reviews.llvm.org/D132120
This assert always fails. It is unclear to me what it was attempting to
test, but removing it gets our tests passing, so it clearly isn't
checking the right thing.
This change completes the process of replacing OperandValueKind and OperandValueProperties which were previously passed independently in this API with a single container class which contains both.
This is the change which motivated the whole sequence which preceeded it. In an original spike version of this change, I'd noticed a nasty bug: I'd changed the signature without changing names, and as result, we silently passed additional information through a callsite which previously dropped the power-of-two fact. This might be harmless in most cases, but at least a couple clearly dependend for correctness on not passing that property through.
I did my best to split off prior changes which reduced the scope of this one, and which made it possible to use compiler assistance. For instance, every parameter which changes type in this change also changes name. This was intentional to make sure that every call site possible effected must show up in the diff. This let me audit each one closely.
This is part of an ongoing transition to use OperandValueInfo which combines OperandValueKind and OperandValueProperties. This change adds some accessor methods and uses them to simplify backend code. The primary motivation of doing so is removing uses of the parameters so that an upcoming api change is less error prone.
Both are reasonable names; this is solely that an upcoming change can use the OpNInfo name, and the compiler can tell me if I forgot to update something (instead of silently passing along properties that might not hold.)
This interface allows a target to reject a proposed
SMS schedule. For Hexagon/PowerPC, all schedules
are accepted, leaving behavior unchanged. For ARM,
schedules which exceed register pressure limits are
rejected.
Also, two RegisterPressureTracker methods now need to be public so
that register pressure can be computed by more callers.
Reapplication of D128941/(reversion:D132037) with small fix.
Differential Revision: https://reviews.llvm.org/D132170
Simon Pilgrim