Displaying 20 results from an estimated 1100 matches similar to: "x86 instruction format which takes a single 64-bit immediate"
2018 Mar 28
0
x86 instruction format which takes a single 64-bit immediate
Copy Ii32 in X86InstrFormats.td rename to Ii64 and change Imm32 to Imm64.
Instantiate your instruction inheriting from Ii64. Pass RawFrm to the form
parameter.
Initial documentation for the encoding system is attached.
~Craig
On Wed, Mar 28, 2018 at 4:50 PM, Gus Smith via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> I am attempting to create an instruction which takes a single
2016 Nov 23
4
RFC: code size reduction in X86 by replacing EVEX with VEX encoding
Hi All.
This is an RFC for a proposed target specific X86 optimization for reducing code size in the encoding of AVX-512 instructions when possible.
When the AVX512F instruction set was introduced in X86 it included additional 32 registers of 512bit size each ZMM0 - ZMM31, as well as additional 16 XMM registers XMM16-XMM31 and 16 YMM registers YMM16-YMM31.
In order to encode the new registers of
2016 Nov 24
3
RFC: code size reduction in X86 by replacing EVEX with VEX encoding
> I would like a command line option to disable this optimization. That way tests can still verify that EVEX instructions came out of isel by using -show-mc-encoding.
I think that keeping tests compatibility is not a reason for an additional “llc” flag. We check encoding in test/MC/X86 dir.
Is there any option to report-out from llc in non-debug mode? It should be an option to control
2016 Nov 23
2
RFC: code size reduction in X86 by replacing EVEX with VEX encoding
I would like a command line option to disable this optimization. That way
tests can still verify that EVEX instructions came out of isel by using
-show-mc-encoding.
On Wed, Nov 23, 2016 at 5:01 AM Hal Finkel via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
>
> ------------------------------
>
> *From: *"Gadi via llvm-dev Haber" <llvm-dev at lists.llvm.org>
>
2016 Nov 28
2
RFC: code size reduction in X86 by replacing EVEX with VEX encoding
Hal, that’s a good point. There are more manually-maintained tables in the X86 backend that should probably be tablegened: the memory-folding tables and ReplaceableInstrs, to name a couple.
If you have ideas on how to get these auto-generated, please let us know.
From: llvm-dev [mailto:llvm-dev-bounces at lists.llvm.org] On Behalf Of Hal Finkel via llvm-dev
Sent: Wednesday, November 23, 2016
2013 Aug 28
3
[PATCH] x86: AVX instruction emulation fixes
- we used the C4/C5 (first prefix) byte instead of the apparent ModR/M
one as the second prefix byte
- early decoding normalized vex.reg, thus corrupting it for the main
consumer (copy_REX_VEX()), resulting in #UD on the two-operand
instructions we emulate
Also add respective test cases to the testing utility plus
- fix get_fpu() (the fall-through order was inverted)
- add cpu_has_avx2,
2017 Sep 05
2
Issues in Vector Add Instruction Machine Code Emission
I was getting same error when i keep both EVEX/EVEX_4V and TA. So, i
restored my original instructions and for that i have to include
bool HasTA = TSFlags & X86II::TA; in x86MCCodeEmitter.cpp
then used this condition;
if(HasTA)
++SrcRegNum;
in order to emit binary correctly.
Is it right?
On Tue, Sep 5, 2017 at 5:45 AM, Craig Topper <craig.topper at gmail.com> wrote:
>
2017 Sep 05
2
Issues in Vector Add Instruction Machine Code Emission
Thank You,
I changed TA to EVEX or EVEX_4V. But now i am getting following error:
Invalid prefix!
UNREACHABLE executed at
/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp:647!
On Tue, Sep 5, 2017 at 4:36 AM, Craig Topper <craig.topper at gmail.com> wrote:
> Not all instructions can use EVEX_4V. Move instructions in particular
> cannot because they don't have 2 sources.
>
2017 Jul 08
5
Error in v64i32 type in x86 backend
Thank You.
I have seen the opcode is 8 bits and all the combinations are already used
in llvm x86.
Now what to do?
On Sat, Jul 8, 2017 at 10:57 AM, Craig Topper <craig.topper at gmail.com>
wrote:
> Yes its an opcode conflict. You'll have to look through Intel documents
> and find an unused opcode. I've only added instructions based on a real
> spec so I don't know
2012 Nov 08
2
[LLVMdev] X86 Tablegen Description and VEX.W
Hi,
A question from r162999 changes:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrFMA.td?r1=162999&r2=162998&pathrev=162999
For the multiclass "fma4s", why is "mr" not inherited from "VEX_W" and
"MemOp4" like those of "rm" or "rr" ?
multiclass fma4s< >
...
def mr : FMA4<opc, MRMSrcMem, (outs
2012 Nov 08
2
[LLVMdev] X86 Tablegen Description and VEX.W
On 8 November 2012 11:12, Cameron McInally <cameron.mcinally at nyu.edu> wrote:
> On Wed, Nov 7, 2012 at 10:52 PM, Anitha Boyapati <anitha.boyapati at gmail.com>
> wrote:
> ...
>>
>> For the multiclass "fma4s", why is "mr" not inherited from "VEX_W" and
>> "MemOp4" like those of "rm" or "rr" ?
>
2017 Sep 04
2
Issues in Vector Add Instruction Machine Code Emission
Thank You.
I used EVEX_4V with all the instructions. I replaced TA and EVEX both with
EVEX_4V. Now, I am getting following error:
llvm-tblgen: /utils/TableGen/X86RecognizableInstr.cpp:687: void
llvm::X86Disassembler::RecognizableInstr::emitInstructionSpecifier():
Assertion `numPhysicalOperands >= 2 + additionalOperands &&
numPhysicalOperands <= 4 + additionalOperands &&
2017 Jul 28
3
Purpose of various register classes in X86 target
Hello Matthias,
On 28 July 2017 at 04:13, Matthias Braun <mbraun at apple.com> wrote:
> It's not that hard in principle:
> - A register class is a set of registers.
> - Virtual Registers have a register class assigned.
> - If you have register constraints (like x86 8bit operations only work on
> al,ah,etc.) then you have to create a new register class to express that.
2009 Jun 15
0
[LLVMdev] Regular Expressions
On Jun 15, 2009, at 11:33 AM, David Greene wrote:
> To reduce redundancy, developers must be able to write generic
> patterns
> like this:
>
> [(set DSTREGCLASS:$dst, // rr, rrr
> (xor (INTSRCTYPE (bitconvert (SRCTYPE SRCREGCLASS:$src1))),
> (INTSRCTYPE (bitconvert (SRCTYPE SRCREGCLASS:$src2)))))],
>
> The substitution then fills in the appropriate types,
2009 Jun 15
2
[LLVMdev] Regular Expressions
Chris Lattner wrote:
> However, I don't see any reason to base this off of strings. Instead
> of passing down "f32" as a string, why not do something like this
> pseudo code:
>
> class X86ValueType {
> RegisterClass RegClass;
> ...
> }
>
> def X86_f32 : X86ValueType {
> let RegClass = FR32;
> ... };
> def X86_i32 :
2020 Jul 02
2
flags to reproduce clang -O3 with opt -O3
Hello,
I've been trying to figure out how to reproduce the results of a single
clang -O3 compilation to a binary with a multi-step process using opt.
Specifically I have:
clang -O3 foo.c -o foo.exe
which I want to replicate with:
clang -O0 -c -emit-llvm foo.c
opt -O3 foo.bc -o foo_o.bc
clang foo_o.bc -o foo.exe
Any hints / suggestions on what additional flags I need to produce the same
2020 Jul 03
2
flags to reproduce clang -O3 with opt -O3
Awesome, thanks!
I'd like to have the last step (llc in your example) not perform
additional optimization passes, such as O3, and simply use the O3 pass from
opt in the previous line.
Do you happen to know if I should use 'llc -O0 foo_o.bc -o foo.exe' instead
to achieve this?
On Thu, Jul 2, 2020 at 6:35 PM Mehdi AMINI <joker.eph at gmail.com> wrote:
>
>
> On Thu,
2012 Nov 08
0
[LLVMdev] X86 Tablegen Description and VEX.W
On Thu, Nov 8, 2012 at 1:34 AM, Anitha Boyapati
<anitha.boyapati at gmail.com>wrote:
...
>
> I actually have confusion in mapping the role of vex_w during
> instruction selection. For the moment, lets just consider vex_w and
> not memop.
>
> [1]. What does " def rr : FMA4<>, VEX_W" mean? As per tablegen
> description, "rr" now inherits FMA4 and
2012 Nov 08
0
[LLVMdev] X86 Tablegen Description and VEX.W
On Wed, Nov 7, 2012 at 10:52 PM, Anitha Boyapati
<anitha.boyapati at gmail.com>wrote:
...
> For the multiclass "fma4s", why is "mr" not inherited from "VEX_W" and
> "MemOp4" like those of "rm" or "rr" ?
>
Hey Anitha,
The VEX.W bit is used to denote operand order. In other words, this bit
allows for a memop to be used as
2017 Sep 04
2
Issues in Vector Add Instruction Machine Code Emission
Sorry to ask but what does it mean to put both?
On Tue, Sep 5, 2017 at 4:01 AM, Craig Topper <craig.topper at gmail.com> wrote:
> Leave TA. Put both.
>
> ~Craig
>
> On Mon, Sep 4, 2017 at 4:00 PM, hameeza ahmed <hahmed2305 at gmail.com>
> wrote:
>
>> You are right. But when i defined my instruction as follows:
>> def P_256B_VADD : I<0xE1,